its your lsd. Most likely the small gears (there are 6-8 off them). The FD LSD is a great road race unit but sucks BAD for drag racing although I went mid 10's on one.

So dont rebuild it, pull the entire case because you need to clean all the metal out. If you want to save a few bucks get a TII lsd and put that inplace. Just bolt on your 4.1o gears and pinion. i would have a shop shim it but maybe you are able. I have cut 1.4's on the TII with no issues.

Good luck and hang in there, we all break parts racing-just part of the game.

 

yea actually traction is the worst for our cars. have seen many friends blow diffs left and right when drag racing with slicks or radials.

 

Are there any "drag" LSD's out there that are "bullet-proof"?

 

By TII, do you mean a diiferential out of a Turbo II RX7? Why are they better? I do not know anything much about LSD's.

 

You can pop the diff cover off and have a look without removing it. I skipped this step lol...
http://www.wrex-racing.com/images/my...wrex_diff1.jpg
http://www.wrex-racing.com/images/my...wrex_diff2.jpg

As you see in this pic the Torsen failed(split completely in half) and took everything out with it.
http://www.wrex-racing.com/images/my.../DSCN3162b.jpg

When you launch hard something has to give... Many will tell you the drag radials are part of the problem and to run bias ply tires(ET Streets), then again I have heard drag radials are fine from some of the 'top' racers, they actually recommend filling them up 30+psi so that they will slip some and spare anything from breaking in the drive train.

 

Bottom line really, the stock torsen is not made for hard launches. T2 are the clutch-type vs the Torsen in the FD. Seems like ppl have pretty good luck with them.

My new setup:
http://www.wrex-racing.com/images/my...f_bracing2.jpg

 

I talked to Cam at Pettit Racing. He said the trick he learned back when he was drag racing rotaries in California, was the "line-lock". Once he was able to pre-load the differential, he quit breaking stuff (as often). He used the stock torsen LSD's. He agreed that they are really made for road racing. I talked to some pro dragsters, and they all agreed that, even though expensive, a built 8 or 9 inch Ford with straight axles and coil-overs was the way to go. I just bought another used Torsen LSD with low mileage. I'm going to try more air, slipping the clutch, and maybe a line-lock.

Anybody with any advice on how to do the clutch slip, line-lock, or hand brake preload thing, I am all ears.