Loose driveshafts?

[SleptOver]

Hello, this is my very first post btw. But I have an Issue? With my TRX-4


I don't know if this is normal, I didn't notice it before I changed to all metal parts..


https://youtu.be/Bc5-GTf01_o



Basically, I have all aluminum axles, and currently I am using stock bearings. I bought a shim set, that is on its way. All 4 wheels have the same amount of slack. I can pull/push the wheels in/out about 2 millimeters
Is this normal ?

I have opened the portals a few times, and I can't see anything missing. well, at least nothing that stands out to me. It's all lubed well, with chainsaw bar sprocket grease (very light grease)


I do have a set of new bearings too, but they would be the same size as the stock ones.

[high plains drifter]

Both my trx4's have a bit of play but not at all as much as yours. I wouldn't be too concerned although I'd want to know where the discrepancy is. Typically the more aftermarket brass and aluminum parts you start putting together, the more out of whack the overall tolerances become. I'd compare stock and aftermarket parts with a set of calipers but yeah... that's a good deal of play.

[SleptOver]

Well, the slack comes from the shaft moving in the bearing. to get rid of it, I have to put shims behind the wheel hex I believe, that would increase the overall width of the thing as well.

[high plains drifter]

Indeed. I would check to see if you have a lot of play in the axle housing too... even though that's not this particular issue. I'd guess that where the bearings seat inside the c-hub is milled a little deeper than the OEM plastic one. Not sure it's worth noting but I have also seen thickness discrepancies with bearings themselves despite listed dimensions supposedly the same from one manufacturer to another.



Anyway... Hopefully the shims will correct your issue.

[SleptOver]

The gears mesh beautifully, so that's not an issue, and the shaft is held in the bearings no problem, there just seems to be a lot of lateral slack. Changing the outer cover to the brass one, did not change anything, so, if there is an issue, it's with the inner portal hubs.

[HumboldtEF]

This kind of play shouldn't cause any issues. Theres usually some in/out play at the axle but this is a bit more than typical.

Shim it if it bothers you though. Just make sure you dont shim it too tight and create drag/friction, try to tighten it up but leave a tiny bit of play.

You should be able to use something like these: https://www.amainhobbies.com/yokomo-...c-s50a/p585165

If you just get .5mm thickness shims you wont be able to get a close as with the above kit that goes down to a .13mm thick.

[SleptOver]

Like I said, I did order a shim set.


Though, a bit larger set than that.

Reassuring to hear, I decided to buy a 5mm half shaft extension kit from hot racing too

Perhaps they will be a tighter fit ?

[HumboldtEF]

Originally Posted by SleptOver

Like I said, I did order a shim set.


Though, a bit larger set than that.

Reassuring to hear, I decided to buy a 5mm half shaft extension kit from hot racing too

Perhaps they will be a tighter fit ?

Sorry I missed that.

Generally Hot Racing copies the stock parts so its unlikely to be any different than stock. The differerence you've noticed is very likely from the aftermarket portal boxes themselves (possibly deeper bearing pockets).

EDIT:

Originally Posted by SleptOver

Well, the slack comes from the shaft moving in the bearing. to get rid of it, I have to put shims behind the wheel hex I believe, that would increase the overall width of the thing as well.

You should also be able to shim from inside the portals if you dont want a wider track width. From the inside you have the bearing 1 / gear / and bearing 2. Put the shim between the gear and bearing 2. You'll need to test out how much shim can be added here. Too much and it will bind up.

[SleptOver]

Originally Posted by HumboldtEF

You should also be able to shim from inside the portals if you don't want a wider track width. From the inside you have the bearing 1 / gear / and bearing 2. Put the shim between the gear and bearing 2. You'll need to test out how much shim can be added here. Too much and it will bind up.

True, I plan to put plenty of light grease in there too, make sure it's lubed good, I didn't mention it, but I ordered new half shafts for the portals, again from Hot Racing, with 5mm spacers to widen the truck somewhat.

[SleptOver]

Well, the shims did it, had to shim some more than others, but I left a bit of sideways slack.

https://www.ebay.com/itm/363845551973?var=633071040854

Bottom, second from the left, was a perfect match.