trac-lock from Mustang

[VinnyG]

There is a complete (drum-to-drum) 8.8" 3.08 Trac-lock rear from (poster says) early 70s to early 90s 'Stang on CL this morning at an attractive price. I'm not yet ready to make this upgrade, but it might be too good a deal to pass up. I think I understand correctly that all Ford 8.8 rears are internally the same. My question is how much of this unit I could swap into my GM. Just the center section, center section and axles, or is there a spline difference that would impair my ability to use this rear at all (I seem to recall some discussion of 28 vs. 31 tooth axle splines)? I currently have the 2.73 open diff and I prefer to keep relatively tall gearing, so this would be perfect if it can work. Also, what kind of visual/tactile checks (if any) could I make on this rear axle to determine the condition of the ring and pinion, diff gears, and clutch packs (assume dropping the cover)? If I had to farm out the center section for refurb, roughly how much in hours or dollars are we talking about? Thanks.

Scott

[sly]

just the center's guts and you would have to re-shim everything in the process to get everything lined up right. our cars have 28 spline axles as well. The axle casings do not remove from the center without serious grinding and welding, so just swapping the whole center section over would not be worth it. as far as checks for quality... no leaks first off (that should be a given) and moving one part should allow all parts to move to some degree (no binding) and there should not be any sounds of crunching or points of resistance (spot in the movement when it gets harder to rotate). That's all I can think of.

[SVT98t]

You'd be better off buying a brand new rebuilt diff. The rebuid kits cost around $130. Plus whatever you'd pay for the diff.
You can get a new diff for around $200.
The one I pulled from the junkyard had recently been rebuilt, so I lucked out. I also kept my 2.73s. I like my mileage. I threw away the 3.55s that were on that cop car I pulled it from. Oh well. I don't need 3.55s in my daily driver. Because, that's what the Marauder is for.

-ryan s.

[mcninetyone]

If you're putting this rear end in a whale, I would suggest getting a complete whale rear end in the junkyard which already has the gear and trac-lok you want.

[mrltd]

There isn't anything swapable between an early 70s and a 90's mustang....There were 4 different rears.... 8", 9", 7.5" and 8.8" And the suspensions were completely different. The 79+ were 4 link, the older ones were leaf spring.

79-85 used a 7.5 and 86+ V8 cars use an 8.8, 4 and 6 cylinder from 79-up use a 7.5.

Just make sure you know what you are looking at...

[SVT98t]

Just buy a new diff and keep your gears. It'll save you in the long run. Why would you put a 15+ year old rear end in your 03? Plus the 03's have disc brakes.
Well, everything from 92+ has disc brakes.

-ryan s.

[VinnyG]

Thanks for the advice and education. I passed on this item - seller didn't seem real sure what he had, and I sure don't know enough to make up the difference. I'll continue to look based on the advice given here. I like the car pretty well as it is, so I'm not in a tremendous hurry.

-VG

[gadget73]

agree on buying a new traction lock. Between the price of a used one, the rebuild kit, and the time to put it together its just not worth it to go the used route. When the kits were 50 bucks and the carrier was like 50, it made sense if you did the job yourself but not anymore.

[zoomie]

if you must use a used tracloc, id go looking for a newer limo or 90s towncar those arew the esiest ones i have found for k code axles. i still havnt ripped mine apart but judging from the wieght im almost positive it has a 31 spline axle, but dont quote me on it.

[gadget73]

yeah limo units are 31 spline. Can't use one of those in a stock rear though.

[sly]

but you can swap the entire axle over with little issue... just gotta bend new brake lines.

[zoomie]

yeah limo units are 31 spline. Can't use one of those in a stock rear though.

you can if you swap the whole axle, my car is proof of that. it far easier to swap the axle than swap gears for sure.

[SVT98t]

Its an 03. The rear end is from a way older mustang. Like he said, drum to drum. Im sure the ABS controller/system would approve. And the Watts linkage.

I know the axle swaps are easy on the older models.
Either buy a new diff, or a whale axle in the junkyard. I believe that would be your best option.

-ryan s.

[DsTrBd]

Easy advice just save your dime for "New" kit... Its cheaper in the long run and you will know what you have in it !