Front diff ring/pinion slipping

[KHthe8th]

Hello, so this Sendero is my first crawler and I've run into an issue where my front ring and pinion gears are slipping when they run into a rock on an incline, or if I hold a front wheel and give it a little throttle. If I hold a rear wheel there is no slipping in that axle though.

I searched through some threads and saw about shimming the diff so I did that on the pinion gear and it helped some, but it still happens in a quite repeatable and predictable pattern. It didn't seem like it was possible to shim the ring gear over at all from when I was looking at it.

My only other thought is I should order a new ring and pinion gear in case one or both are worn down at all from where it has been slipping recently? I can't imagine this is meant to happen.

 

[Phyro]

You might also check the axle housing. It might be tweaked a bit, which could cause cause issue. There is a hard plastic version available as a replacement.


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[KHthe8th]

You might also check the axle housing. It might be tweaked a bit, which could cause cause issue. There is a hard plastic version available as a replacement.


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Ah I actually already have a metal front axle cover and it seats in very nicely

I did throw on the stock one just for fun and it slipped with that one too.

Half of me wants to swap the front and rear ring and pinion gears to see what happens, but the other half of me doesn't want to mess with the currently working rear axle and diff

 

[Piranhaboy]

How do the bearings feel? Could have enough slop to be effecting the mesh.


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[KHthe8th]

How do the bearings feel? Could have enough slop to be effecting the mesh.


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The one on the inside didn't feel great so I replaced both just to see but it didn't solve the slip. Made it slightly better, but I'm wondering if it's slipped too much now that the gears are worn down just enough

 

[theone13]

I had a similar slipping happening on my ifs converted builders kit, and after tearing apart the front diff I found the inner pinion bearing had failed and fully exploded. It had damaged the ring gear a bit, so I replaced the ring and pinion and put a new bearing in obviously, but haven’t tested it out yet. No idea why or what happened, it’s actually the first complete bearing failure I’ve had in 10+ years.

 

[KHthe8th]

I had a similar slipping happening on my ifs converted builders kit, and after tearing apart the front diff I found the inner pinion bearing had failed and fully exploded. It had damaged the ring gear a bit, so I replaced the ring and pinion and put a new bearing in obviously, but haven’t tested it out yet. No idea why or what happened, it’s actually the first complete bearing failure I’ve had in 10+ years.

That actually sounds very similar to what happened to mine. Just taking a closer look at the bearing now the inner ring is no longer attached to the outer ring, and a couple of the tiny ball bearings came out while holding it. I ordered a new ring and pinion but they're a week out from arriving. I'd be curious if switching those out in your rig fix the issue when you test it out

 

[KHthe8th]

Taking it apart and cleaning off the grease it would seem there are definitely a few teeth chewed up on this ring gear

Also dumb question but I can't seem to figure out how to resize my photo? Sorry it's so gigantic

 

[theone13]

Taking it apart and cleaning off the grease it would seem there are definitely a few teeth chewed up on this ring gear

Also dumb question but I can't seem to figure out how to resize my photo? Sorry it's so gigantic

Yep, that’s how mine looks too. I don’t get it, other people beat on their trucks and I’ve only driven mine 2 times, oh well.

 

[KHthe8th]

Yep, that’s how mine looks too. I don’t get it, other people beat on their trucks and I’ve only driven mine 2 times, oh well.

Yea I'd only taken this truck out a half dozen times or so and it seemed to come out of nowhere. No idea how our bearings failed in the way they did, but hopefully it doesn't happen again.

 

[Phyro]

Moisture was what killed my first set of bearings. It got both the pinion and spur bearings.


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[KHthe8th]

Moisture was what killed my first set of bearings. It got both the pinion and spur bearings.


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Did you do anything different to prevent it from happening again? I did run through some water last week with it, but this bearing is pretty sealed inside the axle, and the outer one (against the driveshaft) didn't show any signs of damage

 

[Phyro]

Honestly I haven’t yet. Was going to look at some sealed bearings to replace the open ones, as they are really exposed on the IFS dif


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[Steve g]

I take all my bearings, pull 1 seal off, and pack them with marine grease, then put the seal back on. This prevents water from damaging them, and lasts much longer then the little bit of oil they come with. It does rob some power, but it wasn't noticeable for me on my crawlers.

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[binarysolo]

I had ongoing issues similar to this and ended shimming the ring gear inside the diff housing because there was side to side play inside the housing. I thought maybe it was the original housing, but it was the same when I bought a new hard version. Since shimming the ring gear it's worked great.

 

[Crush]

Blew a rear diff on my Trailwalker. click click. soo I replaced with

https://www.associatedelectrics.com/element/parts/details/42066-ASC42066-enduro_pinion_gear_8t/

https://www.associatedelectrics.com...ils/42058-ASC42058-ft_enduro_ring_gear_spool/

https://www.associatedelectrics.com...59-ASC42059-ft_enduro_ring_gear_machined_30t/

haven't had a problem since. running the hw fusion and 3s for power

 

[MOguy]

go with the upgrades Crush has linked to.