Eaton Performance posi installed.

W/T_Deluxe · February 27, 2012

Got my eaton posi installed this weekend. all in all the install went pretty great, and its really nice to have both wheels turn now instead of only one! I will say if anyone ever does tackle anything like this, if you buy your gear oil from GM(which I didnt need to but did anyway) make sure you get an extra bottle. They gave me three and the friction additive and I was about half a quart low. Dont think I've ever had stuff come apart so easy, but hey when you only have 16k on it, I guess it makes a difference!

Thumbs up for improving traction!

Toadz · March 1, 2012

Congrats! How much did it run you if you don't me asking? I should've done this upgrade when I rebuilt my rear end a few years ago.

W/T_Deluxe · March 2, 2012

Thanks! Its no problem I dont have all my receipts in front of me right now but I wanna say all together I have about $550 in it. granted that includes new bearings and races which I didnt need (the ones eaton recommends are the same as from the factory), but I figured I'd rather press the new ones on the posi over pressing the factory ones off the open. All in all I love it thus far. I know alot of guys reccomend the true track but I did a lot of research and prefered the way the eaton posi works. Oh and it was a little more expensive for me because I used GM oil.

Toadz · March 7, 2012

That's not a bad price. Where'd you order everything from?

08 2500 HD · March 11, 2012

I just bought the AMSOIL Severe Gear to change my front an rear diff fluids? Did you have to use the friction additive?

Also, does the Eaton Rear you installed stop functioning as a posi when you hit 20 MPH like the factory GM posi G80?

Doug_Scott · March 11, 2012

I just bought the AMSOIL Severe Gear to change my front an rear diff fluids? Did you have to use the friction additive?

Also, does the Eaton Rear you installed stop functioning as a posi when you hit 20 MPH like the factory GM posi G80?

Are you sure that the factory G80 does not operate at speed over 20 mph, or does it just disable itself when the speed difference between the wheels is in excess of 20 MPH?

dlstewart01 · March 11, 2012

From GM...on the G80

The entire locking process occurs in less than 1 second. The process works with either the left or right wheel spinning, due to the design of the governor and cam mechanism. A torque reversal of any kind will unlatch the governor, causing the cam plate to ride back down to its detent position. Cornering or deceleration during a transmission shift will cause a torque reversal of this type.

If the rotating speed of the ring gear and differential case assembly is high enough, the latching bracket will pivot due to centrifugal force. This will move the flyweights so that no locking is permitted. During vehicle driving, this happens at approximately 32 km/h (20 mph) and continues at faster speeds.

W/T_Deluxe · March 11, 2012

That's not a bad price. Where'd you order everything from?

I ordered the carrier and shim kit from Rons Manchining Service(www.ronsmachiningservice.net). The bearings and races came from Summit Racing, and the oil came from a local gm dealer.

I just bought the AMSOIL Severe Gear to change my front an rear diff fluids? Did you have to use the friction additive?

Also, does the Eaton Rear you installed stop functioning as a posi when you hit 20 MPH like the factory GM posi G80?

Yes, since the performace posi is a clutch type limited slip you do need to use the bottle of friction additive. Now the posi unit I installed works a little differntly than the G80. Mine will engage whenever there is a 100rpm difference from wheel to wheel, no matter the speed. The G80 will lock and can remain locked after you hit 20 MPH if the torque hasnt balanced out yet, however if you have a spin situiation at over 20 MPH it will not lock. With the performance posi being able to engage after 20MPH you do have to be bit careful on snow or icy roads. However I've never had a problem driving with diffs like this on snow or ice because usually i dont try to drive like Mario Andretti...

08 2500 HD · March 12, 2012

I checked my RPO codes but do not have the G80. I did not special order my truck, I bought it off the lot so I got what they had. I want to put a posi rear in, either the G80 or something equivalent, but I'm concerned about what I've read about the G80. I do not want a full locker as almost all my driving is on pavement. I want to be able to turn without that foward bucking motion from the rear wheels wanting to push straight ahead.