Diff rebuild - missing springs
Thread Starter
Drifting
Joined: Oct 2004
Posts: 1,259
Likes: 7
From: Ontario
Diff rebuild - missing springs
I am fortunate to have Norval & son rebuilding my diff. We just did the disassembly tonight which went very smooth with Norval's extensive shop and custom built pinion bearing removal tool.
There was only two springs installed rather than four. Does anyone know if some diff's only came with two springs? We are trying to determine if we should re-assemble it the way it was with only two springs, or install four. I have also noticed some past posts about not using springs at all. Any advise or suggestions would be appreciated. Thanks
There was only two springs installed rather than four. Does anyone know if some diff's only came with two springs? We are trying to determine if we should re-assemble it the way it was with only two springs, or install four. I have also noticed some past posts about not using springs at all. Any advise or suggestions would be appreciated. Thanks
Last edited by Retro78; Jan 10, 2005 at 09:19 PM.
Melting Slicks
Joined: Dec 2000
Posts: 2,635
Likes: 0
From: Union Ontario
All three of the rear diff's I've had i or around my vette have had all 4 springs..... Probably a bubba fix to stop all the rear end chatter.... its a much easier job than adding the posi additive 
Or maybe they dropped out and the axle ate them???
Norval will get you fixed up. If you need springs I have a couple from my original rear end sitting in the basement. But you can probably pick them up quicker at any dealership.
Or maybe they dropped out and the axle ate them???
Norval will get you fixed up. If you need springs I have a couple from my original rear end sitting in the basement. But you can probably pick them up quicker at any dealership.
Melting Slicks
Joined: May 2002
Posts: 2,508
Likes: 0
From: Wisconsin
I'm doing the setup without the springs. gtr1999 can help you out. You'll need the 18 disc clutch pack and posi shim kit. This is the same procedure Tom's Differential uses. This is from gtr1999's rebuild procedure document.
Tom’s Posi Tuning Procedure: purchase a shim kit from Tom’s. Start out using .045” shim behind each side gear. Assemble the carrier without the 4 posi springs or plates. Gather the posi clutches you will be using. Look at the edges of the clutches and you should see where the stamping was done and the grooves are deeper on one side. Sometimes a magnifying glass helps determine the side. Alternate stacking the clutches by the groove depth-deep side against shallow side,deep side,shallow side,etc. The clutches with tabs go in between the solid clutches and follows the same pattern with the grooves. Lube the clutch surfaces with GM posi additive as you assemble them. Use the retainers to hold the clutches together while installing them into the carrier. With the carrier assembled rotate it on the side yoke in the vise. It may be loose or snug. Flip the carrier over and check the other side gear for feel. If the gears are too loose add shims in .005” increments until the teeth of the side gear and pinion gears start to bind. I use a large spanner wrench to rotate the carrier on the yoke. When the gears start to bind remove .005” shim from the side gear you are checking. I remove the shim and grind it on a surface grinder once I get to the point of gear bind. I remove .001” at a time until the gears just start to rotate without any binding. Once you get both sides to this point the carrier is ready for the ring gear.
