Monster Beetle Gearbox Help Required!

[Malakite]

Hi guys I am hoping you may be able to help.

I have recently purchased a Monster Beetle from ebay (VERY exciting!!) and have started fixing it up and rebuilding it etc. I have an issue in that I have built the gearbox twice, yet for some reason it seems very smooth when I check it before sticking the motor in and and the wheels on, yet once I run it in mid air (i.e. wheels off the floor to check it) only one wheel goes round. When I manually twist one wheel the opposite appears to turn the opposite direction which to me indicates that the diff is working, but clearly there is a problem! I am sure one of you Monster Beetle gurus will be able to tell me instantly!!

Also I notice that a couple of tyres slip round their hubs, so whats the best glue to use for this type of thing?!

Many thanks

[Origineelreclamebord]

Check if the hexes for the wheels aren't on loosely and if the cup joints and drive shafts are in a good condition. Other than than I can't think of something at the moment

As for the wheels... I bought some local tire glue, which works great. Cyanacralyte glues also work very well, but it may be difficult to remove the tires when worn in that case. Silicon sealant was not up to the job on my Wild Dagger, neither was Bison Kit...

[mymonsterbeetleisbroken]

If one wheel spins, the diff is working. All the diff gears will be active if one wheel is spinning so to me it sounds like the diff is ok.

But, if it is very worn, and very loose, it may easily transfer power to one wheel only when the rear is off the ground.

How easy is it to turn one wheel and make the other spin in the opposite direction? A good monster beetle diff won't rotate too easily, and if you spin one wheel and then let go, the wheels should both stop (unlike a grasshopper diff for example, where the wheels spin for ages!)

If the diff rotates very easily then it is worn, and the gearbox side plates may also be bent (did you replaced them recently anyway?)

The only other cause would be the axle in one of the trailing arms. It could be binding due to wear, bad bearings or the wheel being too tight on a worn wheel mount. The drive shafts could also be worn and locking up, if they are the original hex type.

CA glue (super glue) will secure the tyres. Just use a very small amount in a few places inside the rim so you can still pull the tyre off if needed.

[mymonsterbeetleisbroken]

Just thought, is the pin that should run through the middle of the diff in there? If it's missing it can cause the problem you're having.

[Malakite]

If one wheel spins, the diff is working. All the diff gears will be active if one wheel is spinning so to me it sounds like the diff is ok.

But, if it is very worn, and very loose, it may easily transfer power to one wheel only when the rear is off the ground.

How easy is it to turn one wheel and make the other spin in the opposite direction? A good monster beetle diff won't rotate too easily, and if you spin one wheel and then let go, the wheels should both stop (unlike a grasshopper diff for example, where the wheels spin for ages!)

If the diff rotates very easily then it is worn, and the gearbox side plates may also be bent (did you replaced them recently anyway?)

The only other cause would be the axle in one of the trailing arms. It could be binding due to wear, bad bearings or the wheel being too tight on a worn wheel mount. The drive shafts could also be worn and locking up, if they are the original hex type.

CA glue (super glue) will secure the tyres. Just use a very small amount in a few places inside the rim so you can still pull the tyre off if needed.

Hi mate and thanks for the response. The diff is nice and tight like you say, its impossible to spin when you stop turning the wheels so thats good news I guess. In response to your other question, the pin through the diff is also in place, and the hex axles seem to also be fine too, nice and tight. Any other ideas?

[terry.sc]

A familiar experience with trailing arms on the ORV chassis. Try running it with the rear suspension compressed so the axles are in a straight line. When you pick it up the driveshafts drop, the driveshaft joints lock up on one axle and only one wheel spins. Quite common on any of the old ORVs with the hex driveshafts. As for a fix it isn't really necessary as the situation only occurs when it is in the air, but you can fit a small spacer under the piston in the shocks to prevent the trailing arms dropping too far.

As for the tyres a few drops of superglue will stop them spinning but an even simpler fix is just to put an elastic band in the two grooves in each of the rear wheels, giving the tyres something to grip on.

[Malakite]

Thanks Terry, brilliant at least that means I can take her for a test drive tomorrow Thanks everyone for your help, fingers crossed she goes

[Malakite]

Hi guys, I know you will be able to help seeing as you own Monster Beetles

I have managed to find out that I need parts:- E3, C11 and C6 & C9 to complete the beetle (thats if I don't get any hex diffs which should sort the slight wheel problem out!). Do you know where I can order these from? I know the Monster Beetle has smilar parts t the Blitzer beetle is it? Or the frog or something like that?! If so I may be able to get these from an online store, a I've not had any joy looking for them on ebay etc.

Many thanks as always!

[terry.sc]

Firstly the Monster Beetle only shares body parts with the Blitzer Beetle, and even then they have different nose cones. They have no chassis parts in common. The Monster Beetle is derived from the Frog. Having had a look in the manual to find out what the parts are, the rear trailing arms and wheel adapters are all standard Frog parts and are available as the Frog C parts from any Tamiya stockist, along with almost all the drivetrain parts.

The rear bumper you will have to watch out for an ebay or try the traderooms here as the E parts were unique to the Monster Beetle kit. Search using the part number, 0005270

[Malakite]

Firstly the Monster Beetle only shares body parts with the Blitzer Beetle, and even then they have different nose cones. They have no chassis parts in common. The Monster Beetle is derived from the Frog. Having had a look in the manual to find out what the parts are, the rear trailing arms and wheel adapters are all standard Frog parts and are available as the Frog C parts from any Tamiya stockist, along with almost all the drivetrain parts.

The rear bumper you will have to watch out for an ebay or try the traderooms here as the E parts were unique to the Monster Beetle kit. Search using the part number, 0005270

Thats great thanks for all of your help