wedge655no2

I have a question for my rear diff in my truck. I have found the RPO codes for it and not sure if it has a posi rear end and what kind it has. If it does have a posi what is the RPO code to find out what it is with out taking the cover off.

My next question is. Is it possible to take a zexel torsen rear diff case and put it in my rear end housing to make it a posi rear end? And what are the possible cost in doing this? I have found a whole zexel rear diff complete from backing plate to backing plate for $275.
What are some thoughts......
Thanks

therewolf

Thread search this in the Silverado Section.

This topic has been done to death.

Are you certain that since the vehicle left the factory,

no one has changed the diff already?

IMHO, while modifying an existing rear is do-able,

(and many Z71 badged Chevys are already LSDs while a

quantity are not) You may be better served changing the

rear and front diffs as a whole, rather than modifying

the existing unit.

But let's look at basics, shall we ? "Z71" is an RPO code of it's

own. Is the service parts ID sticker still in the glove box?

Make sure, first, that the Z71 RPO code is there.

Second, will the mod you are discussing change the twist

rate of the rear in any way? Because you need to keep the front

diff matched closely to the rear diff, or kablam goes the transfer case...

Also remember the "more power" higher gear changes come at the cost of

much higher highway RPMs and abysmal gas mileage.

wedge655no2

No I am not sure if it has been changed already. But I am not going to be changing the gear ratio. Just the traction capability. I am pretty sure it has a eaton posi in it right now. And all I want to do it make it have a stronger and more dependable posi and one that won't blow up as easy. I have heard that the eaton posi are bad and they are not all that dependable.

SWHouston

The G80 is usually condemned because most people don't understand how it works. It wasn't designed to be a full time positrack. When you reach about 20mph it goes back to standard drive on it's own. This is an economical function. Anytime you start locking or forcing one wheel to do what the other is doing (exactly) you're going to loose gas mileage, because you can't help but "turn" the vehicle a little or a lot. AWD has overcome this to a point, but, the standard Spider is, and probably will always be the most economical drive, until they get the electrics working properly.

PS: what I meant by "turn" is, actually turning, or, compensating for variations in the road surface.