With the updated instructions, the shimming of the diffs went just fine, plenty of shims to use (plenty of the .1mm left over). Have 2 of the .2mm shims.
CLEAN EVERYTHING WITH MOTOR SPRAY including the diff case and crown gears.
Like others have said, there is light oil all over the parts to protect them, so clean them up really good. I like when they get cold from the spray evaporating.
GREASE! I use joint axle grease and slime lube in combo to create a grease concoction that will definitely seal the diff, no questions. Some just use a synthetic grease, whatever your fancy, just don't use silicon oil alone.
Make sure apply grease where the oring sits, the tunnel, the outdrive shaft, under the gasket, on the gasket... pretty much everywhere!
When I tighten the diff down, I see small amounts of grease coming out, maybe a little silicon oil.
BEARINGS... Ok, so the front and rear diff use flanged bearings... nice. However, I noticed that they have about 2mm of play on the shaft once its all put together.
I checked the diff cases for installation and shimming there, and everything went together just fine, no need for shimming out the play, the diff cases seemed almost "perfect" fit for the diffs... and are the diff cases "dremeled" inside? They seem very smooth and looked like material had been removed? I do this on other diff cases when brand new.
Once I had the diffs screwed down, they were a little gritty, borderline notchy, but definitely can turn them by hand. After break in, I'll check them again, but they should be fine. FOLLOW THE INSTRUCTIONS!
Also, the diff outdrives themselves have an extra circular notch around the shaft. At first I thought this is where a 2nd smaller, thinner oring goes, but this is not the case, there are no smaller orings to place on the shaft.
My Thunder Tiger S3 (ttr) diffs do this, and this is basically like having 2 orings on each shaft in the diff. Seals extremely well with grease. I have never had a diff leak on me.
So, I tried to put one of my ttr small diff orings on, it fit, but the outdrive shaft, did not fit in the diff case tunnel
diff mod fail.
The Serpent diffs, seal up only by the oring inside the diff.. the orings are slightly larger than the groove they sit into, which is how they end up "sealing", once they are "pressed" in with the diff outdrive shaft installed.
the ttr diff in the photos is the odd looking one. Overall, this is a diff that is 6 years old, has been rebuilt 17 times, its the rear diff in my ttr S3 nitro buggy.
It has never leaked, it has the same screws, crown gear, input shafts... even orings! It has conical cut gears. Not bad from a buggy back in 2004!!!! no wonder it won the 2006 ROAR NATS! GO MAIFIELD!
It is about 10-15% larger than the Serpent diffs in the photos.
** See the dark smudges on the orange mat? Thats the oily residue from cleaning everything, including the shims!! I lightened up the photos, so there was even more dark smudges... lotta oil!
Unfortunately, I did run into a snag... I managed to strip one of the screws on the rear diff! It was almost in.. and I fudged the handle on 2mm tip. I tried to back in out very carefully, but it stripped again. 4 times, then I just took my dremel cutting wheel and made a groove and it took me almost an hour to get the bastard out. Then... I get to find a new m3 screw.. because there aren't any EXTRAS in the kit!!! lucky I have some from my ttr S3 nitro buggy that NEVER STRIP!
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