Armortek

Has anyone done much running with an M3 and found that the wheels stop rotating ?

At one point when running at the SW Model Show, only two out of the six wheels on one side were actually turning.

I've spent a couple of hours today trying to get the wheels off, and found that the axles are jammed into the wheels. I had already noticed that you could see the nuts on the ends of the axles turning when driving, so the axles were rotating in the suspension arms rather than the wheels rotating on the axles.

Most of the tyres have come away from the wheels, so I've ordered some more rubber strengthened glue.

I was hoping to take it to the Open Day but I'm not sure I'll have it back in time for that. Several of the axles need to be replaced due to the damage to the threads from all the hammering it took to get them out

Adrian.

I have not run mine a lot nor for long distances but have felt those loooong bearing surfaces in the wheels would need special attention
with time. I considered putting a small ( M3) setscrew on the backside intersecting the bearing to facilitate lubrication but never implemented this.

Also as I made my own axles and had made holes on the outboard side I had also thought that I might have threaded the bottom of the hole
also to conceal a setscrew. The setscrew would effectively function as a cap. The idea here was to drill a small hole intersecting the outer diameter of the axle also to facilitate lubrication but again I never implemented this. I'm thinking now I should have done one or the other...


Hearing of your experience I might revisit my maintenance schedule...

Jerry

Hi Adrian.
its a pity to hear about the Grants wheel issues after such a good wkend's running. My sherman is a 2005 model and not had the same issues. Once a year I take off all the wheel axels. I repack the axle bushings with fresh heavy grease (Castrol bearing grease). except for one of the top return rollers which I just oil the axel, gives a nice sherman track squeak. I refit the locking nuts with Thread lock, being careful to not tighten the nuts (hand tight then a 1/4 turn). When it comes to removing the nuts a bit of genital heat releases the Thread lock

Best rubber glue I found is Loctite 480, once applied leave overnight with the rubber clamp on the rim. Jubilee clips are the best to use for clamping. 6years on and still tight LoL

Happy Tanking Dave N

Hi Adrian.
its a pity to hear about the Grants wheel issues after such a good wkend's running. My sherman is a 2005 model and not had the same issues. Once a year I take off all the wheel axels. I repack the axle bushings with fresh heavy grease (Castrol bearing grease). except for one of the top return rollers which I just oil the axel, gives a nice sherman track squeak. I refit the locking nuts with Thread lock, being careful to not tighten the nuts (hand tight then a 1/4 turn). When it comes to removing the nuts a bit of genital heat releases the Thread lock

Best rubber glue I found is Loctite 480, once applied leave overnight with the rubber clamp on the rim. Jubilee clips are the best to use for clamping. 6years on and still tight LoL

Happy Tanking Dave N

I replaced the brass wheel bushes with oil impregnated bronze along time ago. Brass isn't a good bearing on steel axles especially if they rust - they will seize. Also the brass bushes tended to spin in the aluminum wheels so Loctite bearing retainer should be used on the bushings.

Lastly,a thin layer of grease on the axles helps prevent rust and keeps the bearings lubed. If I recall correctly, sometimes the wheels themselves rubbed on suspension parts -so a little clearance machining was necessary. This is on the original Sherman, which is very similar to M3 running gear.

I use a rubber cement on the tires, which allows them to be peeled off, not Loctite 480 which is much more permanent. 480 is a rubber toughened cyano and will hold great, but will ruin the tires if you ever try to remove them.

I managed to clean up the axles yesterday morning and they seem to have come up well.


There is still some slight scarring at the ends, where they were rotating in the suspension arms, but there didn't appear to be any corrosion.

I also ran an M6 die along the threads to clean them up, and to repair the one damaged whilst it was being hammered out of the wheel

I've cleaned up the wheels as well and hope to get them all back together today. I cleaned the bores of the brass bushes with a wire bottle brush and only one bush came loose, so I'll glue that back in.

I was toying with replacing them with needle roller bearings but I think these bushes are smaller than the ones in the Sherman wheels, and I'll be replacing the wheels with the correct ones later anyway, so it wasn't really worth the £70 it would have cost for the bearings.

Hopefully, I'll be able to get the other side done today and have it running for the Open Day.

Adrian.

The tyres had been glued on with patches of glue.


I think that the tyres could flex, like a caterpillar walking, and slowly peel themselves off the glue.

I've reattached them by placing them on the wheel, inserting the nozzle of the glue bottle between the wheel and the tyre and running it all the way round, then turning over and doing the other side. Hopefully that will keep them in place.

Adrian.

One problem re the tyres coming off is that they are glued on over paint.
The glue sticks to the paint, not the metal wheel. You will be much better off removing the paint first.