help help i have a 79 1stgen rx7 and i juest put a s3 rear end on the car had every think reconditioned and the axles redriled to 100x4 however thear is a strane nose from the back of the car when i'm driving on the road is gets realy bad at 80ks so at first i thort it must be the drive sharft so i got it replaced, however still hae same nose and the car is not very stadle on the road so i took it for a wheel alimend and i the rear axle had +2.8 of toe and the left and -2.0 of tow on the right the man told me that the rear end is bend by 0.8 which he says is ok but the wheels are juest not pointing strate?


help i dont think i can ajuest this

 

your differential could be going out...

-greg

 

its a brand new torque biasing differential from
http://www.gurumotorsports.com/

 

nevermind then
hehe

 

that looks like a serious piece of hardware. Do that ship to the state?

 

Whats the damage $$$ on those lsd's?

-greg

 

Did you put oil in it? Sorry, had to ask.


can you adjust the end links to fix the Toe in/out?

 

This being a solid rear axle car, the only thing that can be causing a rear misalignment would be one of several links that tie the axle to the chassis. The differential would have little or nothing to do with it, since it is a fixed member of the axle. In the rare case that this would cause a problem, you would have to bend the axle shaft where it connects to the differential, and this would still track straight - but would exhibit more toe-in than set at the factory - so that's likely not it.

If you jack up the rear end and use jack stands for safety, you can get under the car and look for damage. This may be caused by backing over a curb, or striking a curb with one of the rear tires when cornering. It doesn't take much, since the trailing links are not heavy duty racing parts - they're street car parts.

There are 4 trailing links on the rear axle - 2 on each side, combined with a lateral link comprised of 2 links and a bellcrank which is mounted to the right side of the differential pumpkin. The trailing links have rubber bushings that mate with the chassis mounts on the car, and you'll want to look for bent or otherwise damaged links that will change the alignment of the rear end. Check both sides, and look for clean metal scrapes that would indicate contact with something to cause bending of the link rods. Also, check the rubber bushings to determine if a bushing has been damaged and ejected, which would also lead to serious 'banging' coming out of the rear end under acceleration, braking, or turning.

If the links look good, then check the lateral links and bellcrank. These are designed to locate the rear end side-to-side during cornering, and have little to do with rear-end alignment, unless you've tweaked one of the rods, which could cause the differential to be pulled to one side - resulting in a misalignment.

If all of the links look good, then you'll need to start looking at the live axle itself to see if there is damage. If you hear grinding out of the rear differential during acceleration or braking, this could be indicative of a bent live axle housing that is causing binding of the inner and outer shaft bearings and incorrect meshing of the diff gears on that side. If this is the case, you'll likely need to replace the entire live rear axle, as it will be hell to get it perfectly aligned once again.

The rear trailing links (and lateral links) are non-adjustable, so you will not be able to 'realign' this unless you find a damaged part. Have a friend drive the car while you follow behind in another car and see if your car tracks straight. If not, it should be visible from behind to see which way the axle is 'shifted', and from there you can focus some more attention on the side that needs it.

If the car is shifted to the left when viewed from behind, this is likely damage to the left side links, vice-versa if it's shifted to the right when viewed from behind. HTH,

 

Torque Biasing Differentials are $1500

more than I paid for my car but damn are they nice.

Ill just have to deal with the stock viscous one for now.

 

its full with 75/90 redline oil
and yes the diff is nice much beter than a normal lsd and with the large axles its the strongest rear end you can get in a 1stgen with out going to non mazda parts