Topic: Trac Loc/Equa Loc Dif

[BillM68FB]

I am a newbie member, and this is my first post so please accept my apologies if I have done this wrong. I am the proud 3rd owner of a 68 J code Fastback that I saw about 25 years ago parked in a co-worker's garage, He'd stopped driving it in 1983 with just over 83,000 miles on it. Since we regularly end up seeing each other on camping trips I have made it a point to ask him every time I see him when he was going to sell me "My Mustang" after many years of doing that I almost passed out when on Memorial Day weekend in 2021 he answered with "Well I think I am ready now" needless to say I was at his house with a trailer and a check within 2 weeks. I have spent the last year+ restoring it and just recently had the opportunity to buy a Trac Loc/Equa Loc Dif from a fellow Mustang club member that looks to be in great shape. Unfortunately, after I had already wrestled it into place, I discovered that it does not seem to have a "Fluid fill" plug on it like my open Dif so I am thinking it must have come from a car that had the fill plug on the Axle housing like I know some GT 350's had (I do not have the tag for it) I think I could add the fluid through the end of one of the housing shaft's or the by taking the Pinion gear assembly out however the obvious drawback to this (and feel free to point out all of the others I haven't thought of) is that it will be a real pain in the ___ to ever change the fluid again. Anyway, I am throwing this out for your thoughts/comments.

Thanks
BillM68FB

[OldGuy]

Your situation is not new or unique. You clearly can not remove the pinion assembly to add fluid as the cavity surrounding the pinion assembly is common to the volume where the gear lube is stored and maintained.

I've known of guys that have removed one axle and poured gear lube into the axle housing. This operation requires the opened-end of the housing to be higher than the opposite side so that the fluid will run into the pumpkin area of the housing. It is a slow fill and you will not be sure of the fluid level because there is no way to check it. All you can do is assume that, by putting the recommended amount of fluid into the housing, the ACTUAL pumpkin fluid level is satisfactory.

My recommended approach (I know you don't want to hear this) is to install the gear set/differential into a third member that has the required fill plug. You will then be able to fill your rear end properly, without having to remove an axle, and be able to periodically check/refill the fluid.

I wished that I had better news for you.

Frank 

[Bob Gaines]

I am a newbie member, and this is my first post so please accept my apologies if I have done this wrong. I am the proud 3rd owner of a 68 J code Fastback that I saw about 25 years ago parked in a co-worker's garage, He'd stopped driving it in 1983 with just over 83,000 miles on it. Since we regularly end up seeing each other on camping trips I have made it a point to ask him every time I see him when he was going to sell me "My Mustang" after many years of doing that I almost passed out when on Memorial Day weekend in 2021 he answered with "Well I think I am ready now" needless to say I was at his house with a trailer and a check within 2 weeks. I have spent the last year+ restoring it and just recently had the opportunity to buy a Trac Loc/Equa Loc Dif from a fellow Mustang club member that looks to be in great shape. Unfortunately, after I had already wrestled it into place, I discovered that it does not seem to have a "Fluid fill" plug on it like my open Dif so I am thinking it must have come from a car that had the fill plug on the Axle housing like I know some GT 350's had (I do not have the tag for it) I think I could add the fluid through the end of one of the housing shaft's or the by taking the Pinion gear assembly out however the obvious drawback to this (and feel free to point out all of the others I haven't thought of) is that it will be a real pain in the ___ to ever change the fluid again. Anyway, I am throwing this out for your thoughts/comments.

Thanks
BillM68FB

The pre 67 diff center sections did not have a fill plug and depended on the fill plug made into the rear end housing as a fill point. The housings deleted the housing fill plug in approximately may 1967 of 67 Mustang production. Most likely the center section that the Trac Loc/Equa Loc Dif from a Mustang club member started out from a pre 67 car. Date codes in the casting will confirm this. You will have to fill by removing one side axle (raise that side slightly) and filling with exact amount. As far as draining you will have to do like most all of us do regardless of fill plug or not and drain by separating center section from housing and letting the oil drain out to a catch pan . Of course it is prudent to put a new center section gasket on at that time.  At least you don't change oil in the rear end typically on a street driven car for many 10's of thousands of miles.

[BillM68FB]

Bob & Frank
Thank you both for getting back with me, it's nice knowing my methods would work but after sleeping on it I think I am going to just slap my original back in (I wish) since I haven't yet put the axles in because, 1- It's a known quantity, 2- It solves the servicing issue, 3- I am just using it as a cruiser and, 4- My wife is very vigilant for noise, and I can already hear her if this one chatters on turns - What is that noise! what did you do now!!! etc. etc.

Bill

[RoyceP]

My'68s all have fill plugs on the differential case. I rarely use that. I put one jack stand a couple notches lower than the other, then set the car down on jack stands. I leave the axle in the lower position, and dump the grease in the higher position just prior to inserting the axle. It's the easiest way I knw to fill the rear end.