So what are my options here, 9" tracloc clutch wear?
 

This is the third member out of my car, it's a tracloc diff with about 15,000 pretty hard miles on it, lots of autocross and several hard track days on it. Last summer I put new bearings in it chasing a vibration, there was a little bit of pinion bearing wear at the time. It's been good since but the posi has been getting weaker and weaker, I'm able to drive through it on exit on both left and right hand turns lately.

It really took some abuse at the USCA event last week and I noticed considerable backlash or play on the pass side axle to diff. The driver side and drive shaft backlash feel good still. I pulled the third member today and found I can do this using the axle to move the spline on the pass side while the driver side and yoke don't move.



The gears look great, and there was very little foreign substance in the gear oil I drained out of it though a cheesecloth.

I think it's just wore clutches in the tracloc but know almost nothing about how they work. Is it worth just rebuilding the posi or spending the $750-1000 to upgrade to a trutrac?

I was looking at a total upgrade because I feared I'd find plenty of carnage inside, once I got it out and after seeing the gear oil, I'm rethinking that now.

What say you? Can I rebuild this myself? Can I find a reputable shop that can rebuild the posi at a reasonable price or can I replace the posi with a trutrac myself with having to turn to a professional to set it up?

Remember, I'm on a budget here...and somewhat of a timeframe to get it back to the track.

The good news is, the new tapered bearings on the axles seemed to have held up real well.

I don't have any experience or knowledge of the Tracloc but Summit has this rebuild kit: http://www.summitracing.com/parts/yga-16027/overview/

.........or install this in and hope you get lucky with the set up. http://www.summitracing.com/parts/dtl-913a586

I have a very good rear old differential guy here local and I've heard too many bad set ups by so called 'professionals' so I didn't hesitate to take my 12 bolt out and deliver it when I changed ring and pinion ratios.........guess what, it's silent and the lash is beautiful.

So I have found a freshly rebuilt tracloc posi unit here locally that I trust has been rebuilt with extreme performance in mind, and I can get a deal on it. I'm leaning this direction as a stop gap until I can afford to upgrade to a trutrac.

I'm wondering now if replacing the tracloc is something I can do myself or if I should still take it to a diff shop to get that install\swap done?

I've never had a 9" center section apart before, is this the kind of deal where I can just keep track of the shims as I take it apart and get it back together just like it was before?

Take a look at the Strange S-Trac. Many good reviews with a lifetime wty. It is what I went with after researching. I have no personal experience yet but all indications are positive.

http://i305.photobucket.com/albums/n...pswzdw3ryy.jpg

http://i305.photobucket.com/albums/n...psta8j2omn.jpg

Its fairly easy compared to a GM unit. No shims to set back lash. Rotating plate and lock bolts. Just figure what you need to get the pinion gear centered. You can calculate the shims used by the depth written on the gear face and what shims and depth on the old gear.

If the only thing I'm changing out is the carrier, new tracloc for old tracloc, can my internet friends walk a newbie through this?

Should just be apples to apples right?

Measure your old backlash.
Remove diff
Swap gear to new diff and add new carrier bearings.
Reinstall diff matching old backlash
Verify pattern
Beat if for another 15k miles.

As long as the backlash is the same, the pattern should be identical. If it's not, the gear isn't flat or something odd.

Edit. I read your post above. The 9" used screw in adjusters on each side of the carrier, not shims. You move both to move the diff side to side to set backlash. You also create the preload with them. It's actually easier than shims.

Oh same gears, just what mean mike said. Go by backlash. But when ever I use the old gears I always mark the teeth so they mesh as they came out.

Thanks guys... I found out that a local shop I use and trust has a guy that is very experienced at setting these up for road racing and autox use. I'm going to take my third member and the newly rebuilt trac loc my friend has to him and use his best judgement as to whether I should let him rebuild my clutch pack or just install the new unit.

My concern is getting the clutch preload just right so the torque bias is strong enough to keep torque on both wheels during corner exit but not so strong that it's dragging a tire during a corner.

I don't want to learn this myself with trial by fire, I'd rather defer to an expert and blame him if it's wrong. :D

I can't add to your "issue" Lance --- but to others reading this -- please note the use of PETROLEUM vs SYNTHETIC gear oils.... cone and helical gear rear ends require PETROLEUM gear lubes. NOT synthetic.

I've posted this info on Lat G before... and while it seems "odd" - since it's common for us to want to use "the best"... and we have come to embrace Synthetics. Not all applications want it. It's TOO slippery.