ConcoursMustang Forums

Restoring - General discussions that span across many different groups of years and models => Suspension => Topic started by: rockhouse66 on March 20, 2013, 08:41:52 AM

Title: 67-70 Manual Steering Idler Arm Mounting Arm -Re: Original Take Off Idler Arms
Post by: rockhouse66 on March 20, 2013, 08:41:52 AM
The slot in the '67 and later idler arm bracket is characteristic of a manual steering idler.
Title: Re: 67-70 Manual Steering Idler Arm Mounting Arm -Re: Original Take Off Idler Arms
Post by: J_Speegle on March 22, 2013, 07:50:28 PM
Mark Posted the following picture in the for Sale section and the following discussion took place so I moved it over to a more appropriate area ;)

(http://i44.photobucket.com/albums/f49/firetrainer/ConcoursMustang/1967IdlerArm-S_zpsba72fc60.jpg)
Title: Re: 67-70 Manual Steering Idler Arm Mounting Arm -Re: Original Take Off Idler Arms
Post by: J_Speegle on March 22, 2013, 07:59:35 PM
The slot in the '67 and later idler arm bracket is characteristic of a manual steering idler.

Hmm not what I've be seeing - started this thread to continue the discussion away from Marks ad
Title: Re: 67-70 Manual Steering Idler Arm Mounting Arm -Re: Original Take Off Idler Arms
Post by: rockhouse66 on March 22, 2013, 08:01:23 PM
Jeff - I don't know how to respond.  The "no slot" is PS and the "slot" is MS.  Are you suggesting it is the opposite?

Here is an original MS one;



Title: Re: 67-70 Manual Steering Idler Arm Mounting Arm -Re: Original Take Off Idler Arms
Post by: J_Speegle on March 22, 2013, 08:42:21 PM
Jeff - I don't know how to respond.  The "no slot" is PS and the "slot" is MS.  Are you suggesting it is the opposite?

Guess I feel the same way ;)  but hoping we can get to the bottom of it through a discussion

But yes that is why Tim and I posted the way we did. Checked my pictures (have not gone through them all year but here are a few examples I found

What do you believe is the difference in the mounting bracket (angle, length....)  between the two arms?

Did find two like your picture but both were on 70 restored cars

(http://i44.photobucket.com/albums/f49/firetrainer/69-70%20Mustang%20Pics/Boss%20302/idlerarmboss43005007_zps00f1fa62.jpg)


(http://i44.photobucket.com/albums/f49/firetrainer/69-70%20Mustang%20Pics/Boss%20302/idler9F02G222700psengcomp_zps0e5fcb8b.jpg)


Title: Re: 67-70 Manual Steering Idler Arm Mounting Arm -Re: Original Take Off Idler Arms
Post by: rockhouse66 on March 22, 2013, 09:23:53 PM
The bracket is quite a bit different (as you probably know).  The MS and PS arm starts as the same C7 casting but is machined differently to accept different bushing styles and diameters.  I studied this a while back and will have to look at my old notes (will be a few days).  The paint codes on the arms match up with the bracket style.  Pink is MS.

In the meantime, here are the brackets to illustrate the difference.

Title: Re: 67-70 Manual Steering Idler Arm Mounting Arm -Re: Original Take Off Idler Arms
Post by: Anghelrestorations on March 23, 2013, 10:07:46 PM
Not sure if I follow the thread exactly here (for sale section?) but if you are looking at the differences between the manual and power steering idler arms they are indeed in the bracket that bolts to the body of the car as Jim suggests.  Here is a picture comparing two NOS pieces.  All the originals I have seen have the same.

(http://i191.photobucket.com/albums/z213/azscj/DSCN5954_zps71350425.jpg)
Title: Re: 67-70 Manual Steering Idler Arm Mounting Arm -Re: Original Take Off Idler Arms
Post by: 69bossnut on March 24, 2013, 12:19:20 AM
Nice comparison Marcus. Actually the mounting arms are the same as far as the shaft that goes through the bushing. The manual arms & p/s arms use the same bushings that the mount arms go in. Only the bushing that the center drag link goes through is different. The arm itself is the same for either, just the mount arm & lower bush are different between the 2. I will take a pic of the 2 side by side tomorrow. Only have separate pics for now.
Title: Re: 67-70 Manual Steering Idler Arm Mounting Arm -Re: Original Take Off Idler Arms
Post by: specialed on April 10, 2013, 12:58:33 AM
The manual steering idler arm has center slotted hole & pink code on arm & eng # on arm is different c7za # FOMOCO casting on assembly line  but some of the later service replacement arms don't have ford #s.
Title: Re: 67-70 Manual Steering Idler Arm Mounting Arm -Re: Original Take Off Idler Arms
Post by: Murf on September 06, 2013, 09:46:06 PM
This discussion seemed to run out of gas.  Is there a definite answer to the slot/no slot question?  So what does an original idler arm for a 68 with power steering look like - the images in this discussion have me confused.  Help!  My arm is a replacement and will be replaced with the proper idler arm and after reading this I really have no idea which to look for - slotted or solid mounting bracket. Bushings are available and am confident the arm will be lurking somewhere if I knew what to hunt for.  Looks as if the solid mount is for PS - is that correct?
Title: Re: 67-70 Manual Steering Idler Arm Mounting Arm -Re: Original Take Off Idler Arms
Post by: rockhouse66 on September 06, 2013, 10:07:21 PM
John - I believe no slot is correct for PS and it will have the C7Z number cast in.
Title: Re: 67-70 Manual Steering Idler Arm Mounting Arm -Re: Original Take Off Idler Arms
Post by: Murf on September 06, 2013, 10:39:00 PM
Today I drove 80 miles one way, nabbed a slotted type and spent the afternoon cleaning it up and pressing out the bushings.  It appears it is NOT the correct one for my 68 PS car. Grumble!  The arm has raised engineering number C7ZA-3355-B.  The bushing that goes on the stationary end is the same for either manual or PS.  One of the posts suggests the arm is machined differently for PS but the engineering number is the same for both - is that the consensus?  If the "arm" is in fact machined differently then not one darn part of the assembly interchanges except for the support end bushing.  Will go out and hunt a solid stationary end next week and the proper arm will probably still be hooked to it.  At least the correct bushings were ordered.  I feel pretty stupid spending so much time  on something that was not  correct, so off to the salvage yard again to share a morning with the insects and snakes and peer at rusted suspension parts hidden in weeds taller than me.  Thanks, Jim, for getting me back on track!
Title: Re: 67-70 Manual Steering Idler Arm Mounting Arm -Re: Original Take Off Idler Arms
Post by: J_Speegle on September 06, 2013, 11:25:07 PM
This discussion seemed to run out of gas.  Is there a definite answer to the slot/no slot question?  So what does an original idler arm for a 68 with power steering look like - the images in this discussion have me confused. .................  Looks as if the solid mount is for PS - is that correct?


Same as the last one in 69bossnuts post above


(http://i44.photobucket.com/albums/f49/firetrainer/67%20Mustang/7R01A153347-idler_zps7e8defde.jpg) (http://s44.photobucket.com/user/firetrainer/media/67%20Mustang/7R01A153347-idler_zps7e8defde.jpg.html)
Title: Re: 67-70 Manual Steering Idler Arm Mounting Arm -Re: Original Take Off Idler Arms
Post by: Murf on September 09, 2013, 09:16:58 PM
Got it!  Located an original, pressed in the new bushings which were available from NAPA, and am happy.  The arm on the original was not debossed with an engineering number, just a faint debossed "188 " near the center link end of the arm.  The pinched end was still intact on the stationary end threads so I am sure the arm had never been changed.  The cost of the bushings was $26.00 if anyone is interested.  Thanks to all for the help, that had been an elusive part.  Jeff is correct, the idler arm is one of the first items to be replaced and even a trashed original is somewhat difficult to find.  Looked over a pile of at least fifty at Mustang Corrall in Edwardsville, Il before finding a candidate for a rebuild.  $20.00 for the core and an hour of sorting out arms to find the correct one. 
Title: Re: 67-70 Manual Steering Idler Arm Mounting Arm -Re: Original Take Off Idler Arms
Post by: 67gta289 on September 10, 2013, 12:47:49 PM
John,

Are you saying that the core you found has "188" and not "C7Z..."?
Title: Re: 67-70 Manual Steering Idler Arm Mounting Arm -Re: Original Take Off Idler Arms
Post by: Murf on September 10, 2013, 02:33:12 PM
Yes, the core had only a "188" stamped on the arm.  When compared to the C7ZZ arm, the PS arm is a different length so the engineering number would not be on this PS arm.  I am sure it is an actual Ford arm due to the "squeezed" threads on the stationary end and the fact that replacement bushings fit perfectly. In addition after cleaning the arm it had been plainly marked at removal "67 P" in yellow Markal paint which I was sure signified 67 with power steering.  As far as I can tell the only parts in common between the PS arm and the manual arm are as follows:  The self locking nut on the stationary end, the washer and accompanies this nut, and the stationary end bushings are the same on both arms.  Of course the mounting hardware where the stationary arm bolt to the vehicle is also common to both types of idler arms.  The supply of the original arms, both the manual and PS type seems to be limited.  Seems most have been replaced by an aftermarket arm assembly, which certainly would have been far easier and more profitable for shops doing the repair
Title: Re: 67-70 Manual Steering Idler Arm Mounting Arm -Re: Original Take Off Idler Arms
Post by: 67gta289 on September 10, 2013, 06:15:25 PM
The reason why I asked is that I have in my hands what is either a factory original or a Ford service part with the engineering part number.

Pulled from a junkyard from 7F02S209xxx, a power steering car, a couple years back.  The car looks like it was parked there between 1971 and 1975 if I put on my sherlock holmes hat.

Unfortunately the piece is rusted pretty darn badly, not a candidate for a rebuild.  Still looking for something equivalent.  As such the pictures are difficult to decipher.  Heck, the part in my hands is difficult. 

When mounted in a car, looking down from the top is the part number C7ZA-3355-B, followed by a quarter inch space, and a few more characters.  It is these supplimental characters that are the most difficult to read.  They could be a "3" and a "9".

On the same arm, opposite side facing the ground is a "FoMoCo" stamp with a box around it.

I've looked through lots of pictures and see the C7ZA-3355-A (manual) and -B (power steering) associated with the idler arm, but don't recall ever seeing the part number such as the ones posted.
Title: Re: 67-70 Manual Steering Idler Arm Mounting Arm -Re: Original Take Off Idler Arms
Post by: Murf on September 10, 2013, 07:55:46 PM
Checked the engineering number on the manual steering arm and it is in fact a  "-B".  The supplemental numbers you referenced are also unreadable on this arm but I can't imagine they are anything to do with the engineering number but probably something to identify the maker, time or date or some other numbers unrelated to the engineering number.  The "-B" arm looks exactly like the "188"  arm I have except that it appears to be a little longer between centers - 1/8 to 3/16 inch at most but difficult to tell exactly.  The "-B" arm has a hole in the center link end with an ID larger than the "188" arm but this is simply how they could have been machined.  The power steering specific center link end bushing will simply drop through the hole in the "-B" arm.  Given the inside diameter of this "-B" arm there is no way it was ever used with the power steering bushing, but again the same forging could have been used with simply a different bore on the center link end thus becoming a power steering part.  The support bracket on this "-B" arm had the slot, indicating manual steering, and it is different in many respects from the un-slotted power steering arm.  The length of the center link bushing in your image indicates that it was in fact used with a power steering car - that bushing is 2.13 inches tall while the manual steering bushing is only 1.75 inches.  There is an obvious difference in how much of the bushing sticks out of the forging between the manual and PS part.  The support end bushing is the same for either manual or PS.  So I just don't know what to say.  I wish the arm I have did in fact have the engineering number debossed on it but it does not.  Ed Meyer noted that some Ford replacements have no engineering number so maybe?.  One more mystery to contend with - perhaps others will check what they have on their car or have stashed and post here and we can get to the bottom.  I am too stupid to post images but will try to provide them to someone who is interested enough to post them.
Title: Re: 67-70 Manual Steering Idler Arm Mounting Arm -Re: Original Take Off Idler Arms
Post by: 67gta289 on September 10, 2013, 09:25:00 PM
In regards to the "A" vs. "B" and manual vs. power steering, I very well could have been mistaken.  I did admittedly assume that the part in the previous picture, which has the "B" rev, was a power steering version.  There were two reasons for that: (1) I pulled the complete setup from the power steering optioned vehicle, and (2) the vertical arm does not have the center third hole, and all the posts (that I remember) and cars that I've seen have me thinking that the two hole variety was power and three hole variety was manual.  I suppose someone could have mated a power vertical arm to a manual horizontal arm. 

The primary purpose of my previous post was to show that the Ford part number was part of the casting on the horizontal arm.

I like the idea of putting some dimensions in place, especially since I looked at the Moog replacement from 1980 that I have.  There are some distinct differences.  I'll put a CAD drawing together and post it.

As far as being too stupid to post pictures, how about a tutorial to post pictures?  Naturally, the tutorial is in the pictures below.

One final note about attachments - I've noticed recently that if I create a brand new topic with pictures, it does not get created.  I've been posting without the pictures, and then modifying and adding pictures as a second step. 
Title: Re: 67-70 Manual Steering Idler Arm Mounting Arm -Re: Original Take Off Idler Arms
Post by: Murf on September 10, 2013, 11:30:35 PM
John, the last in the series of images that you posted clearly shows the "squeezed" or terribly distorted end of the threaded stationary part of the idler arm.  I am sure that the assembly you picture has never had the arm changed because you cannot remove the nut to change the arm without making the threaded part round again.  All of the threads will peel out of the nut and the squeezed part will be virtually threadless by the time the nut is removed.  That is also the way the arm assembly I have was before I filed off the distorted portion and removed the nut.  I have always looked at those distorted threads on the end of the stationary mount as a sure sign of a virgin idler arm.  I hope that others chime in with some thoughts on this mystery.  Maybe someone has some NOS Ford stuff or pristine original parts for a "show and tell" post. 
Title: Re: 67-70 Manual Steering Idler Arm Mounting Arm -Re: Original Take Off Idler Arms
Post by: Murf on September 11, 2013, 11:11:26 AM
manual vs. power
Title: Re: 67-70 Manual Steering Idler Arm Mounting Arm -Re: Original Take Off Idler Arms
Post by: Murf on September 11, 2013, 11:14:01 AM
More - pink is manual, yellow is power steering
Title: Re: 67-70 Manual Steering Idler Arm Mounting Arm -Re: Original Take Off Idler Arms
Post by: Murf on September 11, 2013, 11:20:51 AM
more  pink = manual, yellow =power steering
Title: Re: 67-70 Manual Steering Idler Arm Mounting Arm -Re: Original Take Off Idler Arms
Post by: specialed on October 05, 2013, 11:06:42 AM
their is a late 1970 p/s version also says ford in circle replaced by square fomoco like many parts from that era.  by 71 fomoco markings are phased out to ford markings. also ihave some idlers with collar type nut at bottom of shaft unlike the domed nut but I think I got them from western trip so from SJ plant cars I think.
Title: Re: 67-70 Manual Steering Idler Arm Mounting Arm -Re: Original Take Off Idler Arms
Post by: chockostang on October 29, 2013, 07:35:38 PM
John,

Are you saying that the core you found has "188" and not "C7Z..."?

All 67-70 Mustang Idlers will have a C7ZA 3355 Casting.

I have actually seen a A,  But most all are B castings.

Difference is the Manual steering idlers will have a Different mounting bracket with a oblonged hole, have a shorter stub.  Reason for the shorter stub,  the Bushing in idler is shorter for Manual STeering.

Now to account for--Why can a C7ZA 3355 B Idler be used in both applications--The Manual Steering Idlers were machined out to accept the larger Diameter (But Shorter) Manual steering Idler.

If a 188 casting,  it is  a OEM--Same company that was contracted to build the originals,  but not for the Production line.  LOOK EXACTLY the same.


Dan
Title: Re: 67-70 Manual Steering Idler Arm Mounting Arm -Re: Original Take Off Idler Arms
Post by: J_Speegle on November 02, 2013, 12:14:42 AM
All 67-70 Mustang Idlers will have a C7ZA 3355 Casting.

Guess this gives us all something to look for and discuss more. There seems to be allot of examples out there without the Ford engineering numbers. IMHO just have to collect more info ;)
Title: Re: 67-70 Manual Steering Idler Arm Mounting Arm -Re: Original Take Off Idler Arms
Post by: 67gtasanjose on January 20, 2015, 12:46:44 PM
I am working on what I believe to be an original Power Steering Idler arm that I just came across. Everything else from this parts donor vehicle are miraculously untouched so if it is not original it could only be an OE Ford service replacement. It does NOT have the Ford engineering number(s).
It does have 3 characters on it and the first one is definitely a "1" but the other two do not look to be "8's" (some minor pitting on it). If I am seeing it correctly, the other two characters look more like "zeros" I might post a picture or two after the evaporust process.

Since I DID NOT round up the "flattened" shaft enough before trying to separate the two halves (oops!), I could use another nut (if anyone has a spare PM me, this one is the kind with a thin-looking nut with a thin raised locking edge~Reply #21, image 1 has the type of nut I need, like the one on the MANUAL steering idler arm in the picture) UPDATED 1/20/2015 I found a nut source, see next post.

I have read that the bushings can still be bought at Napa, I see other vendors sell them too. Any recommendations? Are Ford NOS available?

Murph's (John's) observations and photographs seem to match closely what I have found out in my research.
Title: Re: 67-70 Manual Steering Idler Arm Mounting Arm -Re: Original Take Off Idler Arms
Post by: 67gtasanjose on January 23, 2015, 12:19:54 PM
I located a source for the thin locking nut. 9/16-18" HUG-LOCK, also used on some very early Chrysler power steering pumps and other General Motors power steering pumps before about 1972. This helped me find one in the salvage yard, I hope it helps somebody else too.
Pictures below, Nut on LEFT (both images) is the original, one on the right is off a 72 Chrysler PS Pump pulley.

AMK sells them NEW:
9/16-18 GR-8 HUG-LOK NUT, PHOS
OE: (LWA) 6026656 (CHRY)

AMK# B-10537
Title: Re: 67-70 Manual Steering Idler Arm Mounting Arm -Re: Original Take Off Idler Arms
Post by: J_Speegle on January 23, 2015, 05:22:54 PM
I located a source for the thin locking nut. 9/16-18" HUG-LOCK, also used on some very early Chrysler power steering pumps and other General Motors power steering pumps before about 1972. ............

Thanks - would have never thought about looking on PS pumps for a nut for an idler arm.  Now just have to find a yard with those other types of cars  :o
Title: Re: 67-70 Manual Steering Idler Arm Mounting Arm -Re: Original Take Off Idler Arms
Post by: Murf on January 23, 2015, 06:20:49 PM
The discussion of this nut brings up the question of it being dyed red to indicate a critical torque spec. or left alone.  Most if not all of the front suspension/steering fasteners are marked with red dye - should this one be included in the list of "critical torque" fasteners?
Title: Re: 67-70 Manual Steering Idler Arm Mounting Arm -Re: Original Take Off Idler Arms
Post by: J_Speegle on January 23, 2015, 06:26:48 PM
The discussion of this nut brings up the question of it being dyed red to indicate a critical torque spec. or left alone.  Most if not all of the front suspension/steering fasteners are marked with red dye - should this one be included in the list of "critical torque" fasteners?

Don't believe so John - at least I've never haven't seen them dyed or on any list that shows that they were marked that way. The number/volume of those items really increased during 68 production - then increased a little more during 69
Title: Re: 67-70 Manual Steering Idler Arm Mounting Arm -Re: Original Take Off Idler Arms
Post by: 67gtasanjose on January 23, 2015, 06:57:16 PM
The discussion of this nut brings up the question of it being dyed red to indicate a critical torque spec. or left alone.  Most if not all of the front suspension/steering fasteners are marked with red dye - should this one be included in the list of "critical torque" fasteners?

Don't believe so John - at least I've never haven't seen them dyed or on any list that shows that they were marked that way. The number/volume of those items really increased during 68 production - then increased a little more during 69

+1 on what Jeff mentioned. (going by every NOS, restored, used and otherwise idler arm in my research)

This item (the nut) was part of the Idler Arm as an assembly. The nut is not in any assembly manual I have seen. Since I do not have a MPC for anything, I cannot verify it isn't in one, but I sincerely doubt it is in any MPC  (my unconfirmed suspicions has the idler arm supplier as TRW).
Title: Re: 67-70 Manual Steering Idler Arm Mounting Arm -Re: Original Take Off Idler Arms
Post by: Anghelrestorations on January 28, 2015, 05:55:55 PM
I wanted to back up a few comments on the replacement locking nut.  I rarely see this style used and had to search thru a dozen idler arms I have until I finally found one that uses it.  Has anyone found a source for the more common locking nut I have pictured here below?  I never spent any time looking for this yet but at some point will need to...

(http://i191.photobucket.com/albums/z213/azscj/IMG_5332_zpslf2trhqq.jpg)
Title: Re: 67-70 Manual Steering Idler Arm Mounting Arm -Re: Original Take Off Idler Arms
Post by: jwc66k on January 28, 2015, 06:06:36 PM
I wanted to back up a few comments on the replacement locking nut.  I rarely see this style used and had to search thru a dozen idler arms I have until I finally found one that uses it.  Has anyone found a source for the more common locking nut I have pictured here below?  I never spent any time looking for this yet but at some point will need to...

(http://i191.photobucket.com/albums/z213/azscj/IMG_5332_zpslf2trhqq.jpg)
A picture is worth a thousand words, but the size required is priceless.
Jim
Title: Re: 67-70 Manual Steering Idler Arm Mounting Arm -Re: Original Take Off Idler Arms
Post by: 67gtasanjose on January 28, 2015, 07:11:31 PM
A picture is worth a thousand words, but the size required is priceless.
Jim

It should be a 9/16" 18 (fine thread) lock nut if the shafts are the same.

I do not see it at AMK
Title: Re: 67-70 Manual Steering Idler Arm Mounting Arm -Re: Original Take Off Idler Arms
Post by: Anghelrestorations on January 28, 2015, 09:05:43 PM
Yes....its exactly the same thread just the locking nut is different.  I never seen in as available in the AMK catalog. 
Title: Re: 67-70 Manual Steering Idler Arm Mounting Arm -Re: Original Take Off Idler Arms
Post by: jwc66k on January 29, 2015, 12:03:05 AM
I found two nuts that "may" fit the bill. In the picture, the upper nut is "similar" to the nuts on 64-66 Strut rods, 34426-S7. The second nut, shown unattached, is "similar" to the nuts used on C4 transmissions - "manual control valve" - 377330-S Ref Sec A70.4 P13. Both are grade 5. The thickness is the next question, 34426-S8 is 0.473/0.496 in thk, 377330-S is 0.349 in thk. Check the thickness of your samples. Those are the only two 9/16-18 I've documented with those two locking styles, there may be others.
Jim
Title: Re: 67-70 Manual Steering Idler Arm Mounting Arm -Re: Original Take Off Idler Arms
Post by: 67350#1242 on March 24, 2015, 12:57:26 PM
Thought I would add some information I've discovered recently while playing with these idler arms:
There are 2 different Ford engineering numbers cast into the arms being discussed;

C7ZA-3355-B = Mustang arm, both manual and power arms - each with different size bores on the center link bushing end.
C7OA-3355-B = Fairlane/Torino/Falcon arm both manual and power - same bore difference but about 1/4" shorter than the Mustang arm.

Service replacement arms without cast eng. numbers:

C7ZA arms have a faint 283 number on the arm - all else dimensionally the same as the factory arm.
C7OA arms have a faint 183 number on the arm - looks same as the 283 but again is about 1/4" shorter.

This info is from carefully examining NOS replacement arms of both types, and comparing to factory pieces.

At first glance, the 183 and 283 can appear to be  188 and 288 but the last number is a 3.

I believe that TRW was one manufacturer for service parts - if you can find a vintage TRW part # 18686 with the nut and crimped threads it will be virtually identical to the C7ZZ-3350-A service replacement power steering arm (without eng # but with 283#).  TRW 18687 is for manual steering.

Vintage Perfect Circle part # 268-3497 and 268-3498 for power and manual arms also  have the 283  on the arm itself, as if from same source.
Some, if not all of the Perfect Circle arms had a 3 hole bracket, even for power steering - which is confusing.  Even though it had 3 holes, the other dimensions (length, etc) same as 2 hole bracket.
I think there is a Perfect circle 268-3498 manual arm now on EBay. for reference.

Well, that's about all I have - again, this is just my personal experience and thought I would add it to the thread.
Kurt.
Title: Re: 67-70 Manual Steering Idler Arm Mounting Arm -Re: Original Take Off Idler Arms
Post by: 67gtasanjose on January 20, 2017, 07:47:41 AM
Thought I would add some information I've discovered recently while playing with these idler arms:
There are 2 different Ford engineering numbers cast into the arms being discussed;

C7ZA-3355-B = Mustang arm, both manual and power arms - each with different size bores on the center link bushing end.
C7OA-3355-B = Fairlane/Torino/Falcon arm both manual and power - same bore difference but about 1/4" shorter than the Mustang arm.

Service replacement arms without cast eng. numbers:

C7ZA arms have a faint 283 number on the arm - all else dimensionally the same as the factory arm.
C7OA arms have a faint 183 number on the arm - looks same as the 283 but again is about 1/4" shorter.
R
This info is from carefully examining NOS replacement arms of both types, and comparing to factory pieces.

At first glance, the 183 and 283 can appear to be  188 and 288 but the last number is a 3.

I believe that TRW was one manufacturer for service parts - if you can find a vintage TRW part # 18686 with the nut and crimped threads it will be virtually identical to the C7ZZ-3350-A service replacement power steering arm (without eng # but with 283#).  TRW 18687 is for manual steering.

Vintage Perfect Circle part # 268-3497 and 268-3498 for power and manual arms also  have the 283 on the arm itself, as if from same source.
Some, if not all of the Perfect Circle arms had a 3 hole bracket, even for power steering - which is confusing.  Even though it had 3 holes, the other dimensions (length, etc) same as 2 hole bracket.
I think there is a Perfect circle 268-3498 manual arm now on EBay. for reference.

Well, that's about all I have - again, this is just my personal experience and thought I would add it to the thread.
Kurt.

I have in my hands today a NOS service replacement C7OZ-3350-B (Ford paper tag in place) and can nearly confirm it as this poster claims in the previous comment: "C7OA arms have a faint 183 number on the arm - looks same as the 283 but again is about 1/4" shorter.", but I can only confirm it as about 1/4" shorter than the factory type with dual bushings I have on hand at this time.
I say "factory type" only because the only example I have on hand to compare the length with does not have Ford engineering numbers or a FoMoCo logo as others have found on certain examples.

FWIW, this C7OZ service example does have the faint "183" that looks much like it is "188" as this previous poster has stated. Another note is that this "Fairlane" version (C7OZ), the one bushing is pressed FULLY SEATED, where as the "Mustang" version (C7ZZ) would be centered, not fully pressed in and seated against the bushing flange (I hope this makes sense to those reading) I have read elsewhere that certain FORD big cars can be adapted for use to Mustangs if the correct bushings are pressed in the same manner as the Mustangs were.  The correct manner is (as pictured earlier in this thread) with the center link bushing fully seated agains the bushing flange and the mounting arm bracket bushing approximately centered into the bushing's sleeve (not seated against the flange)

Title: Re: 67-70 Manual Steering Idler Arm Mounting Arm -Re: Original Take Off Idler Arms
Post by: 427Fastback on October 06, 2020, 12:21:41 AM
I saw the post in wanted for a idler arm..The thread got locked before I could reply...I have had this in a box for decades..It is not NOS but its pretty nice considering I live in B.C. Canada
Title: Re: 67-70 Manual Steering Idler Arm Mounting Arm -Re: Original Take Off Idler Arms
Post by: Bob Gaines on October 06, 2020, 12:26:08 AM
I saw the post in wanted for a idler arm..The thread got locked before I could reply...I have had this in a box for decades..It is not NOS but its pretty nice considering I live in B.C. Canada
That one is for manual steering and not power steering like the previous post was about. Your arm in the picture is slightly different dimensions and the frame rail side mounting arm is shaped different .
Title: Re: 67-70 Manual Steering Idler Arm Mounting Arm -Re: Original Take Off Idler Arms
Post by: Bob Gaines on October 06, 2020, 12:27:30 AM
Also the pink daub is identification for manual steering. Yellow is the identifier for the power steering arm.
Title: Re: 67-70 Manual Steering Idler Arm Mounting Arm -Re: Original Take Off Idler Arms
Post by: J_Speegle on October 06, 2020, 12:46:53 AM
Appears to be a 67-70 version - with all the other details already mentioned

You will also notice the cutout in the idler mounting bracket.

Since we already have a thread will be adding this thread to the main one and in turn you'll be able to see everything already posted ;)
Title: Re: 67-70 Manual Steering Idler Arm Mounting Arm -Re: Original Take Off Idler Arms
Post by: Bossbill on October 06, 2020, 03:52:38 PM
Also the pink daub is identification for manual steering. Yellow is the identifier for the power steering arm.

Like this (see pics).


Generally threads are locked if the item in question is no longer needed or if the person doesn't want the ad to become a discussion point. I believe I stated in the first line that I was no longer looking.

But, thanks for thinking of me.

Title: Re: 67-70 Manual Steering Idler Arm Mounting Arm -Re: Original Take Off Idler Arms
Post by: 427Fastback on October 06, 2020, 07:32:15 PM
My mistake on the idler arm...I should have clued into the pink paint..I am happy tho as I have oem pitman arms and center links for manual steering..