Author Topic: Thunderbird Rear axle code S1 identification  (Read 2546 times)

Offline 67gta289

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Thunderbird Rear axle code S1 identification
« on: September 28, 2023, 08:35:25 PM »
Found a 67 Q-code Thunderbird with an S1 rear axle code.  I see that for the 1969 and later model years, the S is a 3.50 locking, but I can't find it on any list for the 1967 model year.  If you know what this is, please advise.  TIA

See the attached warranty plate.
« Last Edit: October 29, 2023, 08:59:20 PM by 67gta289 »
John
67 289 GTA Dec 20 1966 San Jose
7R02C156xxx
MCA 74660

Offline krelboyne

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Re: Rear axle code S1 identification
« Reply #1 on: September 28, 2023, 09:20:43 PM »
Thought that they were 9-3/8" ring gear rear ends?
Scott Behncke - Carcheaologist
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1968 GT/CS 302-4V San Jose 05B
1968 Cougar XR7 Dearborn 09A

Offline J_Speegle

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Re: Rear axle code S1 identification
« Reply #2 on: September 29, 2023, 12:26:35 AM »
Thought that they were 9-3/8" ring gear rear ends?

Saw plenty of 9 3/8 rearend/third members in yards over the years. Not sure when Ford changed from the 9" to 9 3/8" and found 9" on 66's and 9 3/8" on 68's.  ::) Also to add possibly to the confusion is that in year 1966 they installed 9" and 9 3/8" during the same production year. Sorry did find info for 67 - later years appear to not have as much published research and info. Found the following inside a 66 discussion a poster made.

"In '66 a two-digit code began to be used, with the second character either a number (non-locking) or letter (locking)."


Lots of guys pulled them in yards only to discover they would not work in the Mustang, Cougar, Torino .... rearends if that is what your looking for. Have the curved upper reinforcement rib in the third member and I think they are all use 31 spline axles.

Checked the MPC from the year and there were no two characters listed. Looking at T Bird sites/forums it appears that two digit/characters is normal for some years though have not found site or post with a decoder ring. At the same time found pictures of door tags with just single characters.  ???

Here is what the front and the insides of the 3rd member/pumpkin looks like on a 9 3/8" Does it match what you found?



« Last Edit: September 29, 2023, 01:04:02 AM by J_Speegle »
Jeff Speegle

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Offline 67gta289

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Re: Rear axle code S1 identification
« Reply #3 on: September 29, 2023, 07:27:32 AM »
Thanks for the discussion.  In my initial post I did not state the axle size, because the car has still not been picked up yet (by a friend of mine).  Once I get eyes on it and get some data I'll close the loop.
John
67 289 GTA Dec 20 1966 San Jose
7R02C156xxx
MCA 74660

Offline RoyceP

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Re: Tunderbird Rear axle code S1 identification
« Reply #4 on: September 30, 2023, 09:33:52 AM »
I pulled a 3.50 open 9 3/8" rear from a '68 GT-E I was restoring recently. The center section fits Mustang / Cougar 9" housings no problem. The axles from full size Ford / Mercury / Thunderbird are the wrong length and the wrong size bearing so those will not fit. The 9 3/8" is probably stronger than the 28 spline 9" case but not as good as a C4AW nodular case 9".
1968 W code 427 Cougar XR-7 GTE Feb 23 Dearborn C6 / 3.50 open
1968 R code 428CJ Cougar XR-7 May 13 Dearborn C6 / 3.91 T - Lock

Offline 67gta289

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Re: Thunderbird Rear axle code S1 identification
« Reply #5 on: October 29, 2023, 08:59:05 PM »
Just to close the loop on this one, I can confirm that the S1 coded axle was a 9-3/8" carrier. 
John
67 289 GTA Dec 20 1966 San Jose
7R02C156xxx
MCA 74660