Rear wheels not turning
 

I ran my 8T today she was doing fine running like a banshee. I noticed my rear wheels were not spinning. Front was doing all the work. Thought no biggie grub screw cam loose, Not. So I figured it was the diff took out one and popped in a new one. Still the rear wheels don't turn. What I mean by that is. If I turn the fronts the center diff turns and the rear wheels turn. However if I turn the rear it does not even make the center diff turn. Not even the axle is turning. Any Ideas?

Upon further inspection my center diff is toasted. This would be the second center diff in as many weeks. Literally ripped the center diff in half last week. What am I doing wrong 7-10-5 fluid. This time the center diff rear out drive pulled the casing sleeve from the diff and of course ripped up the gears. Which replacing the diffs isn't a biggie. I have atleast 6 spares however I wont to quit tearing them up. I had been having problems with the rear being really loose. The power seemed to be split 70/30 to the rear. I had been working to get it to be more 60/40 towards the front. Now this is my backup (bash) Truggy so I can do allot of experimenting with it. My race Truggy is in mothballs waiting for spring.

Are you running the HD Diff cups? If not that is more than likely the start of the problem.

What engine with (size) is in it? I have seen .28's with so much power, they actually just shred the drivetrain, and the diffs

If you've got a strong .28 you will shred diffs if running standard cases.
Get some hd cases Clicky Here

Nothing wrong with the grades of oils your using...same combo as I am with my HD cases and had no probs....upgrade to HD Cases and you should be good to go......

Great Ideas, However I am running the HD diff cases. I am running a Trinity Platinum A. Drake edition in this buggy it's a .21. It has allot of power but not that much. Keep your Ideas coming I really need your help I am stumped. Just in case anyone ask yes I have new bearings in everything. Also the rear diff case and diff and shaft were brand new. So was the center diff case and gears. Was being the optimum word in this case. That's why I'm so baffled. Oh and because this is my bash Truggy I am running Badland tires on it.

If your diff cross pins aren't broken take a look at where they are machined for the other pin to fit. I just built a new 8ight 1.0 buggy and all the crosspins were machined wrong allowing the spider gears to bind up inside the diff cases. I had to call losi and get them to send out new ones and I'm praying the new ones will be right. I've built 5 losi buggies and never seen this before. If yours is doing the same thing that could explain the center diff blowing because one side will bind and cause a failure. What happens is the spider gears will lift up on one side and bind against the outdrive, causing it to tear up stuff.

I ran the HD diff cups in my 8B. I thought I was all set. first time out on the track, with the new cups, did a small lawn dart on a landing, and car acted funny. Checked the car, and seen fluid all over the chassis. Turned out, the flex from the chassis was enough to push the metal insert (where the bearing rides) into the cup, and seperate the two. I was surprised that it cracked that so easily.
I went back to the old style cup in the center, and never had a problem again. The HD cups worked fine in the F/R though.

Ive been running the HD cups in truggy for a whole season with no issues. :nod:

Ok this is not a blast you are much more skilled. I do remember you saying not to use the HD diff cups when I asked about them. Yes it was for a buggy and this thread is on a truggy. It seems to me that buggies and truggies go through about the same abuse and the HD cups would add alot more weight and it wasnt worth it. Based on a few threads that I have read it seems as this problem is more predominate when using the HD cups.

My comment above was a reply to itsshemp's issue...as ive never had that issue....i just stated that i run the HD's with no problems...and I do in fact.. all 3 diffs....i'll eventually get rid of them and go back to the losa3500's...and another reason i used to have them was i ran a .28.... now that im back to .21's i can easily go back to the old cups...and HD's in buggy would be Overkill...Not needed.