I recently sold my ford GT and purchased my winter project car which is a 94 Z with a 6 speed, I paln on doing a few mods like cam, ex, injectors, the usual bolt ons and head work and yes gears. I have heard that the rear end is the week link. I have M/T drag radials already for spring, I don't plan on going to the strip every weekend, but I do want to hit it a few times not to mention having fun on the street. How quick and reliable are people running with the stock rear along with 4.10's or 3.73's

thx,
Jonesy
Niles, Mi.

 

well i have a 94 ta and i put 4.10 gears in it and other things (read sig) and i have been bracket racing it for 3 years every weekend. i leave on a 2-step and a foot brake. i do preload the rearend which really helps. my gears look new. the car runs 8.0's - 7.90's.

 

It depends on the car. My car might be the bad case, but I have had the rear end rebuilt twice. The first was because the stock 2.73 geared rear was making a funny noise (like a tuning fork, when you got off and on the throttle) and the dealer said the lash was in acceptable limits. Its the only 7.5" 10 bolt I've had that has made the noise.

I had MTI rebuild the rear (new bearings) and put in 3.73 GM ring & pinion and a torsen differential at the same time. It lasted awhile, but I kept having pinion seal leak problems, and after 3 seals being replaced, the pinion bearing went out (they must of messed up the crush sleeve.) Sounded like someone was running a huge a** drill under my rear seat.. I thought for sure it was going to lock up since I was 30 miles from home, but I did 40 mph and made it.
Anyway, they (GM dealership) replaced all the bearings (the ring&pinion and torsen was alright), but I kept having pinion seal leaks. They then thought I had a crack in the rear housing, but they replaced the seal one more time and it was leak free for about 20K miles.
I used to autocross the car regularly, so I guess the rear end does not like that....lol
James

 

Ive heard 4.10s break easier than 373s or stock gears.

 

M6+M/T DRs+abusive launches can spell a quick disaster for your rearend. Some people's differential live to tell the tale, so to speak, and others don't. I would at least start setting some money aside for the future in the event something does break, then you can upgrade to a 12-bolt or 9inch.

 

I dunno... Shawn and Jordon both made their bolt-on cars that were running 12.7's w/ 1.9x 60' times last until they advanced on to bigger and better things. Both were running stock clutches if I'm not mistaken.
However if you do put a rugged clutch like a Ram or Spec then it's only a matter of time or distance before the diff. pops.

 

Don't listen to guys with an auto tranny when they say how well the rear end holds up. The auto is MUCH easier on the rear end than a M6 when trying to launch hard.

The rear end can hold a lot of power, that's not the issue. The issue is the abusive launch you can generate with the M6.

In my opinion, if you are getting better than 1.9 60's with the M6, then you better be ready for something to happen.

Dan