Bigkid58

Good Morning I have 95 5.8 auto 150,000 miles, that when you slow down to stop it feel like you have been rear ended.When you first put it into drive it bangs. The orginal U-joints feel tight. I installed a spider gear kit because they looked very worn out. But still have the bang. The truck seem to drive ok when in motion. With the drive shaft off I have about a 1/2 -1/2 inch of play when turning the flange on the rear end.Too loose or normal ? Is it the rear end or do I have an issue with the trans ??? any assistance would be appreciated .
bigkid

Note: I just realized that when I removed the drive shaft, I had pulled the slip yoke out of the trans. It was dry. Does it have to be lubed and with what type of product ? Would this be the reason for the noise ?

thejon2524

Definitley sounds like a trans issue. Make sure your pinion bolt is tightened all the way because that can cause hell with the rear. I would take a guess that its something to do with your trans. I use grease on slip yokes.

Bigkid58

Hey Thanks for the reply. I used bearing grease on the slip yoke. Did not help. I replaced the four gears in the carrier because they had a lot of wear. When I turn the drive shaft by hand there seem to be 1/2 of play at the rear before the pinion gear engages. This a company owned truck and they will not spend the $ to fix it. So if I can't do a simple low cost repair I end up using my own car for company trips. I feel it may be the trans. But I was hoping for the rear end. I can deal with it. Maybe !
Thanks

mitchalvin

The 1/2 inch of play in the rear axle seems a bit excessive, I thought that up to 1/4 was acceptable. If the spider gears were worn out then the rest of the rear end should be equally worn. Transmission problems usually have hard to shift or slipping problems. Hard upshifts or downshifts usually indicate transmission heavy clunking when going from forward to reverse and upon slowing down to accelerating and vice verse indicate driveline or axle problems.

Bigkid58

After walking thru a Pull-a-parts junk yard and playing with rear ends that had the spider gears already removed,I found no movement or very little in the pinion gear and rings. Replacing the spider gears was easy but trying to adjust the pinion gear is another issue. ( should I try ? ) While laying on the ground looking under the truck while someone else shifts forward and reverse, It seem most of the noise comes from the rear end but also there is noise from the tail end of the trans. The clunking only shows up in forward not reverse. This problem just popped up one day.if it the trans I wonder what when bad ?
thanks

mitchalvin

The noise back of the tranny could be transmitted up the driveshaft to the tranny. Usually when the ring and pinion go out there is no adjustment to bring them back in line. To adjust the gear lash, how much the ring gear rotates in relation to the pinion, is through shims moving the ring closer or farther from the pinion. The pinion adjustment changes the mesh of the gears, that is where the pinion and ring meet.

Bigkid58

So if I understand it right, the ring gear is the one that has to be adjusted with shims to allow it engage the pinion gear to reduce the play in the drive shaft ? I have replaced the spider gears. How hard is it to install shims under the ring gear?
Bigkid58

Good old Bill

Pinion depth and carrier backlash is not a game of chance, has to be correct or complete failure of the ring and pinion could result. Being a company truck, I would say go for it, have a ball. Get the best manual available and study it before attempting. Disclaimer, after complete overhaul or what ever, still no guarentee about the clunk. Have seen to many perfectly good rear ends clunk.

mitchalvin

To properly install the shims you will need to pull the bearings off the carrier and put the proper shim the press the bearings back onto the carrier. After getting the backlash correct you will then need to make sure that the wear pattern is centered on the gear, to change this you will need to replace the crush sleeve on the pinion gear. If the gears are worn you might never be able to set the proper specs. If you plan on going through that much work I would purchase a new ping and pinion to start with.

jsmith6752

i am in the same boat. My problem is just like yours. I too replaced the the spiders and added new lube. I bought the truck and now have it in another state for my son to use. I can't work on it at all now. I am worried about leaving it with him. I might try a trans shop for a quick check.Funny that it is much better when it's in 4 wheel drive.....