I need help shimming my diffs. I bought these:
FLM Ultimate Front Hybrid Bulk
FLM Ultimate Rear Hybrid Bulk
I have tried searching, and some sources tell me I need 8x10mm shims:
while others tell me I need 13x16mm (post #9):
Can anyone ABSOLUTELY confirm what worked for them? I'll probably have to order shims, so I don't want to be waiting weeks on a part that turns out to be wrong. Thanks!
Sig edited for awesomeness. NC
You will want both. 8x10mm for the pinion gear to line it up with the ring gear and 13x16mm to shim the diff inside the flm bulk. I would get 13x16mm ones in a couple different thickness and make shure you get enough of them.
zball, heres some more info on shimming those diffs.
ann, heres a few notes on how i shimmed my flm uhb diffs.
(1)Use the gaskets that came with the flm uhb to shim the diff first. Add or remove as needed untill the gears mesh together and turn smooth and theres no binding when the ring gear is tightened down. You should be able to hold the output shafts with your fingers and turn in oppisite directions and have a nice smooth feel. A very slight notchy feel in one small spot is ok, they will wear in. But only very small! Once you have it shimmed take it apart one more time and add your diff oil of choice and reassemble.
(2) I shim the pinion so the teeth line it up with the ring gear. You want to make shore the pinion teeth make good full contact with the ring gear.
(3) Then Just like 50 says, Start adding shims to the ring gear side untill it meshes with the pinion. Keep in mind whitch side the ring gear is on. I think its driver side rear,pass side front. Either way the front and rear have to be oppisite so the tires all turn in same direction. Make shore when doing this that the bearings are fully seated in the housing. sometimes they can stick a little. Once you get that shimmed so the gears mesh as close as possible with no notchy feeling or binding, take it back apart and add shims to the other side of the diff to remove the diff side to side play in the bulk. Then reassemble tighten screws a little and see how it feels. The pinion should have a nice smooth feel when you turn it. and little to no backlash. And again here if theres one small spot thats a tiny bit tight and a notchy spot its ok. BUT ONLY SLIGHT you dont want them actually binding up. It is my expieriance that they usally will have one spot that will hit and start to bind first. Thats what you want to find and shim so you just barely feel it.
And a few more little notes that might save you some headaches
To get an acurate feel of the gears, like 50 says you really should tighten the three screws that hold it togtether just a little each time you make a shim change. You will probably put it together and take it apart quite a few times untill you get it to feel right. You also need to to rotate the pinion around a few times when checking so it goes all the way around the ring gear.
After you get the diff shimmed in between the bulk so there is no side to side play and the pinion feels good with just a tiny bit to no backlash. Put a little grease on the ring gear and hopfully put it together for the last time. Till you break it in. LOL Then you can do it all over again. After its been used for a while its a good idea to take apart and check for play and gear mesh. They will wear in over time and abuse.
A lot of people also put a small rubber oring or shim behind the drive cup on the pinion shaft to keep the pinion from moving in towards the ring gear. This is a good to do and loctite the the cup on there good and tight
Well i cant type worth beans and this has taken me forever. LOL But glad to help another E-maxx guy.
Did the best i could to explain it. Hope this helps you out. If you search you can find some pretty good vids on this too.