Hello, I'm speaking for my friend with a Slash 4x4. There's something odd happening suddenly. If you take apart the rear assembly(as in all you have is the whole front assembly, slipper clutch assembly, and rear diff assembly). They each work perfectly on their own. But once you put them all back together, the rear slipper/diff area aren't getting along very well. Once you install the rear diff assembly with the slipper clutch, the clutch seems to 'push' the pinion in the diff too much and cause a tight mesh between the ring and pinion gears. It's a harsh, rough, highly-resistant feeling when you roll or spin the clutch when it's with the rear diff assembly. I tore down the clutch assembly, and of course the whole rear diff assembly, nothing seems to be out of the ordinary. All bearings are in top shape. There is evidence inside the rear skidplate that the spur gear and clutch backplate is rubbing it. The diff gears are perfect too, hence it rolls fine on their own. I've heard of diff housings being warped and worn to the fact that the gears don't have that perfect mesh anymore, but I can't tell of anything of the sort.
If anyone can help or has had this experience, please pitch in. He is now considering selling his S4 and moving on to a Pede 4x4. He's had many problems with his S4, but they are mainly annoying problems, not so much expensive problems. It's the reoccurring problems that are getting to him I believe, and I understand, but I've been in this hobby for awhile now, so I've grown very patient and observant with anything that doesn't perform right. I try to convince him that it's nothing bad and it normally isn't. But in this case, I'm pretty much stumped, been spending a couple hours just analyzing it as one whole truck and in sections. Have gotten no knowledge of anything causing the problem.
Some pics of the problem area might help, sure the bearing on the slipper isn't shot?
I took the pic w/ my phone really quick. This just shows the general area, the rear diff assembly with the slipper clutch assembly. He just got a new bearing, and the old bearing was just gritty. Still same problem. We've had that bearing go out before, but it didn't act this way. So, I knew it wasn't that even though he told me after he bought a bearing. Every bearing in the clutch/diff area was fine and cleaned.
It sounds to me like the adapter that the bearing sits on has melted. You should replace it with a metal adapter from Traxxas or Kings Headz. Also check to see if the motor mount has been eaten up by the bearing that went out.
Member of the 10,000 posts club
i had simmlar problem found 2 screws 0n rear diff were stripped out put new diff carrier in works fine now part number 5381
We already replaced the sleeve with the TRX Aluminum one. No more problems there since we upgraded. And which two screws on the diff? Is there anything I should look for on the motor mount specifically?
Everything seems solid, that's what confuses me... If I had to describe what it seems like, it's acting like it's pushing too hard against the pinion, which is making the mesh between ring and pinion too tight.
just a thought but have you disassembled the whole truck lately? Maybe the front pinion is in the rear diff housing? Just a thought.
*Proud Husband of United state's Air Force wife.*
Um, not that I know of, but how would that affect the performance? It's been running fine until now, and the diffs haven't been switched. I searched deep in the forum, and other forums about this problem, and have found nothing that's a common problem.
When you say the motor mount is eaten up, do you mean that the bearing isn't a snug fit in the housing anymore? The bearing can easily be pushed out of the motor mount now. But I want to know how that would contribute to the problem. I don't want him to spend money if he doesn't have to.
Mine is doing something similar. I am a new slash owner and just getting back into rc. It rolls and is not locked up at all but makes a weird grinding noise. The sound seems to be coming from the rear diff and so I have taken it apart but nothing seems too out of the ordinary. Looking forward to any help on the subject.
Thank you for sharing, that's exactly what's going on on our end.
I just had a brainstorm! Check which screws you put into the rear bumper. If that screw is too long I think it might rub against the diff gear. Putt out the single screw from the bumper mount and see it it still has the problem.
Member of the 10,000 posts club
Not sure if this would help that possibility, but the rear wheels spin fine on their own when the rear end is separated from the truck. I'll look into it though.