Hello, I have an 2003 Evo 8 and about 51,000 miles. Whenever I launch, it pulls really hard, but my friends say and I also have it on camera, that my front wheels spin like crazy and the rear don't. But in the rain or snow, all 4 spin. So my question is, is my center diff out? Or is the stock viscous center diff favor the front wheels more than the rear, because it seems like the differential distributes the power a lot more to front as they spin, and rear don't.

Please any input on this would be appreciated!

 

It happens to my car sometimes depending on the conditions. I think its due to how the weight is transferred to the rear of the car, giving the rear tires grip, while removing grip from the front.

So the fronts will break free.

 

its called weight transfer. When u launch most of the weight tranfers to the rear wheels making it grip more than the front. dont tell me u never did a donut or drift a little in ur evo? ur notice there plenty of power to the rear wheels

 

You also have a open front differential which means the fronts spin easier.

 

thanks a lot guys for the input, i just thought that maybe my diff was out, and yes, when i did do donuts, a lot more rear spinage than the front....

 

If your TC was out there would be no debate on the subject. You'd KNOW.

 

yea i just thought maybe my actual center diff was out like the coupling or whatnot...

 

today i went out and showed my buddy hugh who is very knowledgeable about evos and showed him how crazy my front wheels spin and he said my center diff is basically very worn out!
so, i looked at sheptrans.com and they offer a t-case rebuild and it says how they
Replace spider gears with heavy duty treated gears
New seals
Reshimming
Neodymium magnet
We also upgrade the cross shaft retaining pin to a 5mm pin We also reshim the frt diff and replace all seals
would that basically fix my problem and my center diff would grab like it's supposed to??? or do i actually need to buy a center diff?? thanks..

 

No the open front diff will send the torque to the wheel with the least resistance allowing that one wheel to spin...hence why people upgrade to a limited slip when rebuilding their transfer cases.

To the original poster, this is normal. The weight transfer unloads the front suspension which removes a lot of grip from the front end.

 

Your center diff is fine, this is normal when launching a car. If you want better hook-up at the track you'll need to ugrade your suspension not your center diff. The Shep build is for the front diff. Nothing is done to the viscous center diff.

 

Well if its for the front differential, then why do they request the t-case to rebuild, isn't the center diff in the t-case?

Thanks

 

Because both the center and front diff are in the t case.

 

Actually only half of the center diff is in the T-case. It's hard to explain without having a cut-away diagram of the transmission.

It's not a traditional differential like the front and rear.

 

O, ok i understand, so basically the t-case rebuild wouldn't touch my center diff correct? Because all i read about it is how it works on the front differential, so is there any service out there that can do a center differential rebuild or fix, just wondering for future???
and how much are oem evo 8 center differentials, 2003 viscous one's....??

 

I've never heard of anyone getting a rebuild on a center diff. It's not one component but actually a few seperate pieces in the t-case and trans. As I've stated before, I doubt you have anything wrong with your car. I've made over 75 passes at the track and nearly everytime the front wheels spin due to weight transfer.