How to shim the diffs : )

Colinevan · #1 09-11-2006

Well iv had enough of replacing the pesky rear bevel gears on my zx5. Sooo i thought i must be doing something wrong somewhere along the lines.

I basically replace both the diff bevel and the shaft bevel and add 2 shims per side to get a feeler for how much play i have. If it feels a little tight the mesh i.e the drivetrain is significantly tighter, i will try swapping over the shims so that i achieve a nice happy medium...... HOwever should i be having the mesh a little tighter ???

I will be honest and say that my slipper only slips very marginally, so i may need to re adjust to slip more.

Have many other users had much joy with the bevel gears, or can anyone offer any tips or advice etc.

Ps - does anyone grease the gears as iv been advised not too.

Thanks

Col.

TEAM ONION · #2 09-11-2006

I shim mine so there is only the slightest amount of backlash(play) between the two gears, I also use a very small amount of silicone grease to smooth up the whole thing. Its all about experimenting, to tight and it goes slow, to slack and it will tear itself to bits.

barnyard · #3 09-11-2006

This is the method i used for the nitro TC3 and bj4, different car but the same principles apply

1. shim the input gear so there is minimal play without binding on the gearbox ie when the shaft binds up remove 1 shim.

2. shim the diff so there is minimal play

3. adjust the shims on the input so it is equally shimmed front to back

4. with the input gear in place mesh the diff to have minimal backlash without binding by altering the the shims on each side of the diff, using all the shims needed in step 2

jim76 · #4 10-11-2006

I run mine with no grease at all and one thick shim moved from the inside of the gear to the outside to tighten the mesh. Once you have run a pack of cells through the car the gears will bed in and the mesh will be slightly looser than at first.
This was advise given to me by a UK Kyosho team driver and i've had no trouble.
But make sure your slipper is taking up some of the strain

Greg · #5 10-11-2006

No grease in mine, but run all the shims on one side as I've gone through so many diff gears. After doing that I haven't stripped a gear. Mates done the same and so far so good.