tc02c evo idler gears
 

Have just started to use my t c02c evo. I brought it brand new but guy had already built it. Now i finished it off and got it working. Used for first time last week and within 4 laps of the track at very light speed, when landing from a jump one of the idler gears stripped . Ok so i stripped down cleaned out debris and replaced gear. Tun tonight and same thing as happened . Soft landing and atripped. Any one had similar problems or can point in direction of may have been put together wrong or may be the problem. Any help much appeciated. Thanks

There are various idlers, the alloy or white ones are easily up to the job. Speak to Kev Lee at inside line models. He will sort you out.

You can also buy the 3 low gear conversion from az mechanics. Also buy the 40t pom gear from az and you wont strip any gears any more ;-)

You need to shim one of the idler gears over to one side. Have a look at the case - one of the layshaft bearings will slightly raised (non slipper side), and will rub on the idler causing it to fail. There's load room to do this and it will solve the problem.

Clean all the gears - I use clutch cleaner And use a scalpel and make sure every last bit of debris is out of the teeth of the the diff and layshaft.

Bendy plastic gearbox casings are not good for gears.

In order for the idler to fail as you describe, even the black ones, I would expect that there is some heat involved. It could be, as stated in the posts above, that the layshaft bearing is rubbing on the top idler. There was a fault on early casings and I don't know if it is cured yet. This will cause heat but I would have thought that you would have noticed the rough feel of the gearbox when you built it. Some people chamfer the edge of the top idler to clear the protruding bearing but if it can be shimmed over then why not? I would have thought that to add shims to the non-slipper side you would also have to remove material from the boss that locates the bearing on the slipper side of the casing, which may cause the idler to rub on that side of the casing instead.

If the layshaft bearing isn't the culprit then it may just be that your particular casing isn't holding the gears in their correct mesh. This means that you will get some heat generated. The previous failures could have permanently distorted the casing. It's a thermoplastic, so when it reaches the temperature at which it softens it will move under load and not come back. In this case, the gears will always get hot but the white POM idlers or the aluminium version, as stated in the previous posts, will probably stop it from failing.

BTW, is it the top idler that fails?

Thanks for all replys. Yes itd the top gear that has stripped on both occasions. I have replace gear now with white coloured gear from some spares i had lying round. Have just happily used it for a few good runs. Doing at least 30 laps in total with no issues.

If you bought a full evo then it should have come with metal gears. If you have the conversion then it's whatever was in the car. It's not the gears - it's the bearing.

Didnt notice anything when apart and turns nice and free. Will see how it goes i guess.

I raced this car for around 3 meetings wtih no issues at all. I built the car with the white idlers as I didn't like how rough the gearbox felt with the alloy one when the car was new.

On its 4th meeting a landed off the double, not very hard and obliterated both gears. As you have said, the bearing protrudes and with case flex, touches the bearing. I've currently went back to the metal idlers, although the car is noisy now.

Good tip with the spacing, worth a try.

The car may be noisy because the idler might be rubbing against the bearing. This will cause it to fail over time. Run a white idler next to the layshaft - layshaft, plastic, metal, diff. Shim the gear away from the bearing. Job done.

Could well be. No one looked into a narrower bearing? Think I might look into that too.

Yes, I did.

There is a 3mm wide bearing that would do the job.

Could anyone tell me where they've got to with this please?
Has anyone tried the narrower bearing option?
Thank you
Tim

http://www.rcbearings.co.uk/index.ph...roduct_id=1596 :thumbsup:

Thanks Clive. Is this consisted the best solution then?

Definitely, works brilliantly.

Thanks Allan. Does it require additional shimming to take up the slack?

Only if your slipper side bearing is loose in the casing.

If it is a good fit, then the shaft is positioned by that bearing; as when the slipper is tightened it pulls the shaft through the bearing until the internal spacer comes up against the bearing. It is then trapped between the internal and external spacers. If there is still end float after the slipper is loaded then it is because that bearing is loose in the casing.