48 2.0 Gearbox/Diff Pinion Gear Bearings

[RustyUs]

When I was going through the buggy and doing bearing maintenance (back on 5/27/2020), I found something that didn't look right. Even though I had to use some heat to make the job of loosening the set screws easier, the diff pinion gear started to work its way loose from the grip of the center/rear uni joint, and front diff coupler set screws. There is enough wiggle room for the bearings to start walking out of the gearboxes at least 2mm as seen in picture below. The bearings won't come out all the way out (I think), but enough to concern me.

 

[TBuggy]

This exact thing happened to me except it was the rear end. Luckily I saw in time like you did. I cleaned it up and put some more thread lock on it and haven't had an issue since.

 

[RustyUs]

The picture in first post is of the front gearbox, but the rear bearing did the same thing on my buggy.

 

[Skynet5]

Yup. My rear has done this twice. First time I noticed due to a loss of power. Thankfully I didn't melt the centre diff.

2nd time was just from inspection before going for a run.

 

[RustyUs]

After following some MT410 threads/basher groups, I found others having same issue, and was offered some insight into this... Thread 'Bulletproofing the gearbox'.

I did things a bit differently, but fixed the diff pinion gear/bearing from moving by itself again. Apparently, flanged 5x11x5mm bearings are not very common. And, trying to find rubber shielded ABEC 3 flanged bearings in that size are even harder to find at a decent price

.

I'm very happy with the flanged bearing taking up the potential slack if the uni joint set screw works its way loose.

5x11x5mm flanged bearings

With three 0.13mm shims between the flanged bearing, and uni drive shaft, only 0.1mm of forward/aft movement is possible if the set screw works its way loose.

Still got plenty of room (hopefully) for any chassis flexing that may occur.

 

[RustyUs]

Two months have gone by since using the flange bearing in the gearboxes, and I don't worry about the couplers/bearings budging anymore.

 

[ozzie31220]

After following some MT410 threads/basher groups, I found others having same issue, and was offered some insight into this... Thread 'Bulletproofing the gearbox'.

I did things a bit differently, but fixed the diff pinion gear/bearing from moving by itself again. Apparently, flanged 5x11x5mm bearings are not very common. And, trying to find rubber shielded ABEC 3 flanged bearings in that size are even harder to find at a decent price

.

I'm very happy with the flanged bearing taking up the potential slack if the uni joint set screw works its way loose.

5x11x5mm flanged bearings

With three 0.13mm shims between the flanged bearing, and uni drive shaft, only 0.1mm of forward/aft movement is possible if the set screw works its way loose.
View attachment 5193

Still got plenty of room (hopefully) for any chassis flexing that may occur.

I noticed this on my EB48 2.0 the other day. Drove perfectly fine, but would rather prevent a failure. Do you have a part number for the shims?

 

[RustyUs]

I used CRC CLN4735 5x7x0.13mm shims. There are a lot of different brands out there with different thicknesses. Tekno, Kyosho, Sworkz, Yokomo, Xray, Reds... etc., etc., etc. I would have got the Kyosho shim pack that has three different thicknesses in it, but the CRC pack was dirt cheap at the time.

 

[ozzie31220]

I used CRC CLN4735 5x7x0.13mm shims. There are a lot of different brands out there with different thicknesses. Tekno, Kyosho, Sworkz, Yokomo, Xray, Reds... etc., etc., etc. I would have got the Kyosho shim pack that has three different thicknesses in it, but the CRC pack was dirt cheap at the time.

Thanks! Just ordered some.