jasona

Hi everyone,

For my 21st birthday in 1992 (not a typo!) my father bought me a second-hand Tamiya Monster Beetle. I was absolutely thrilled, as having longed after my friend’s Tamiya “Holiday Buggy” 12 years before, here was my first “decent” radio-controlled car. However, I’ve been trying to get it to work ever since!

Here’s the problem:

It runs OK for a couple of minutes, then all of a sudden there’s no drive. You can hear something spinning around and grinding inside the gearbox, but there is no drive. It’s not the drive shafts spinning around in the output cups (part SA9, page 10, step 16 in the original manual), there’s no actual drive TO those output cups – the output cups themselves are not even turning, the loss of drive is somewhere inside the gearbox (which I understand is the same as the Tamiya Frog).

Here’s what I’ve tried so far to fix it:

• I built up a brand new complete gearbox out of brand new parts. I found all the new parts on eBay and built a completely brand new gearbox. This didn’t work, the same thing happened.
• I bought a complete second-hand gearbox off eBay that was known to work, coming out of a working car. Without daring to disassemble it in any way at all, I fitted in my Monster Beetle. This didn’t work, the same thing happened.
• I tried the same thing again with another complete, assembled, supposedly working second-hand gearbox off eBay but again: OK for the first minute or two, then no drive and the noise coming from inside the gearbox.

Some other pointers:

• The axles/half shafts/drive shaft (part SA10, page 12, step 20 of the original manual) are new
• So are the output cups (SA9)
• I’m using the standard motor with the correct 10-tooth pinion gear
• It’s an ESC, not the original MSC, so no harsh torque changes
• I don’t ever reverse it and then slam it into forwards to pull a “Wheelie”

So I’m stumped! I’m completely stumped! I really want to get this working though! Why?

• It’s great fun to drive!
• Sentimental value with it being a gift from my late father – I feel like I shouldn’t give up on it
• I see plenty of other people enjoying perfectly reliable Monster Beetles (YouTube), so surely it’s not too much to ask?

Are there any aftermarket bits I can get hold of to upgrade it or make it more reliable?
Are there any modifications I can make to make it more reliable?

I’d be really grateful to hear from anyone who can help and I’d be thrilled to finally have it reliable as it’s so much fun! I have loads of other models, but I still really like this one!

Thanks in advance.

tolofrhr

I'm gonna ask a dumb question here... Did you check the grub screw on the pinion? I have found that it's the simplest things that mess it up. Check the motor shaft to see if it is stripped also? Hope that helps.

jasona

Will do, thank you!