I had a Eaton 19557 8.5 posi unit, GM 8.5-342 gear set, GM8.5 HD complete install kit w/races and bearings. Install all new internal parts including new bearings, races,seals, gaskets, new Eaton Posi3.42 ring and pinion gears. Setup ring and pinion gears. set up ring and pinion to proper pinion depth and correct backlash. set up and check for proper gear mesh pattern. Reassemble complete with axles,backing plates etc. 80/90 gear lube MOT-MGPLSF friction modifier. So why does it wine when I let off the gas?
Sorry about the spelling. WHINE, I did not do the work I paid a performance co to do the work I know nothing about gears that is why I paid to have it done. It was done when I stared the frame off. And now years later it is on the road and I find this Whinny noise & the co. is out of business.
The work order that I put in the post say's Set up and check for proper gear mesh pattern. Set up ring and pinion to proper pinion depth and correct back lash. That is what is written on the work order.
Hard to say without seeing it,but “if” they set everything to the numbers scribed on the pinion,it is usually wrong. Those are simply a starting point. Where are you located?
Just North of Mpls MN. Work was done by Cheny Performance he was the NHRA champion Racer and I always saw a lot of engines, Trans, etc at his shop as well as High performance cars being worked on, so I am surprised that there is a issue with it. He also did the transmission and that works great. Do you have any idea of cost? I have less than 100 miles on the car since the frame off. Thank you for your time & the helping hand.
Are you sure they are GM gears, the original ones? Many new aftermarket gears can whine due to faster machining process by aftermarket suppliers. How loud is it and are you sure its the rear end?
Here is the parts list that is on the invoice. Now this was done in 2-14-06.so it has been many years doing the frame off. All I know is what is on the invoice (1) EAT19557 8.5 posi unit (1) GM8.5-342 gear set (1)GM 8.5 complete install kit wraces and brgs. I trust that this is what was installed. This was a reputable company and did good work. You can look them up on google Cheney Performance, Inc. Ham Lake, Mn 55304 I wish I could find out what happened to them maybe Jim W knows.
If you stop driving it,you should be able to save the gearset,as long as the pattern is corrected. Otherwise,it will try and recut itself,and basicly eat itself up.
Closest to you would be Jim Weise, TSP. Give him a call: Tri Shield Performance Buick Performance Specialists Call (320) 629-8999 Looks like you may know him.
I bet the The backlash is too wide. You can pull the cover and put a dial indicator on the ring gear tooth ...rock it forward and backward to see the distance to the coast to drive side touch. .006-.010 should be ok. if you are in the .015 range thaT IS YOU WHINE...bUT YOU HAVE TO WONDER WHAT THE PATTERN LOOKS LIKE AND DEPTH IF HE GOT THAT BACKLASH WRONG TOO.... sORRY TO HERE YOUR HEADACHE. tHIS IS THE REASON i am SO BUSY. gOOD AND BAD. Oh man I hate the caps key next to the A key. sorry for the caps
