Desert Truck transmission issues

[cokeman]

I picked up a new DT a couple weeks ago. After a couple runs I decided to install the 4800kv brushless system from my broken Speed T. A couple days later I destroyed the stock idler gear and replaced that with a hardened steel gear from Robinson Racing. Yesterday I stripped the teeth of the diff gear. Is there an all steel diff gear available for the DT? I have the slipper really loose to try and lessen the stress on the trans but I think the Xcelorin system and lipo power may just be too much for this truck. Too bad because it was a lot of fun at 40 plus mph. Any suggestions?

[packhntr]

I picked up a new DT a couple weeks ago. After a couple runs I decided to install the 4800kv brushless system from my broken Speed T. A couple days later I destroyed the stock idler gear and replaced that with a hardened steel gear from Robinson Racing. Yesterday I stripped the teeth of the diff gear. Is there an all steel diff gear available for the DT? I have the slipper really loose to try and lessen the stress on the trans but I think the Xcelorin system and lipo power may just be too much for this truck. Too bad because it was a lot of fun at 40 plus mph. Any suggestions?

I upgraded my DT to a XXXT-CR tranny with ball diff. After I installed a Tekin RSPro w/8.5 I decided it would probably be a good idea to upgrade the diff gear to a hardened aluminum one from Robinson and the idler to the Hardened steel one from Robinson. This is where I ran into a small problem. The gears didn't mesh just right. After swapping out the steel one with the stock and the aluminum diff gear with the stock one and comparing the mesh, I narrowed it down to the Hardened steel idler gear. It is out of round ever so slightly....just enough to cause excessive binding in the system. That is most likely causing you plastic diff gear to be destroyed. I contacted Robinson and they will send out a new one once they receive the bad one. Unfortunately, I have not had the chance to do so yet as I have been swamped with to much to do and to little time! Just contact them, let them know what's up, and mail it to them in a padded envelope.

[cokeman]

That's strange. My steel idler is not out of round at all. You would think they would all be the same. I looked it over closely before I put it in.

[packhntr]

That's strange. My steel idler is not out of round at all. You would think they would all be the same. I looked it over closely before I put it in.

You won't be able to see .001". Yes...that little can cause bad gear mesh. You can't see if the center of the bearing hole and the center of the gear teeth outer diameter/ root diameter are inline....if they are out of alignment by as little as .001" it can cause improper gear mesh and ruin the weaker gear...in this case the plastic diff gear. I would suggest getting a new plastic diff gear, clean out the tranny case very well, rebuild and install the diff. with the plastic idler gear. spin the gears over by hand.....you should feel no binding at all. Then replace the idler gear with the steel one....again rotate by hand, if there is no binding, then the idler is ok. If you feel any binding, grinding or anything out of the ordinary, then the gear is bad and needs to be replaced. It takes a bit of time and patients, but it is the only way to narrow down the problem. Let me know how it goes.

[cokeman]

I just finished putting it back together. The gears spin freely so I left the steel idler in it. I'll let you know if it blows up again.
Thanks

[packhntr]

Please do. I know a lot of people don't use any grease on teh main gears, but I like to use Tamiya's Ceramic grease....slicker than snot on a door knob! Great stuff.

[cokeman]

That's funny. Yeah i used HPI gear lube on it. It;s holding up so far.

[packhntr]

That's funny. Yeah i used HPI gear lube on it. It;s holding up so far.

I only use the Tamiya Ceramic grease on the top, idler and diff gears....not inside the diff gear...it doesn't have enough resistance and the diff spins to free and you lose to much control. For that I haven't really found a lube I really like....that's why I udgraded to a XXXT-cr tranny case and ball diff.....more consistant. (for me anyway)