John Stranahan

iTrader: (27)

Mike-I'm going to try to order the Yokomo oneway for the Tc3 at my local hobby shop. I have a different part number SP3938-6

Yokomo

Mike D

I got my part number from here:

http://www.yokomousa.com/phpBB2/viewtopic.php?t=813

tirbolag

anyone ever tried the yokomo graphite drive shaft for the tc3? i don't remember the part number, but i know i saw a pic here somewhere...

CRASH

iTrader: (26)

I removed two shims from each input shaft, one from each side. Freed it up pretty good. Still does not spin like some other peoples. Do you also need to soak your bearings or will it break in more as you run it?

I have only ran mine once.

Thanks,
Tony

John Stranahan

iTrader: (27)

The bearing seals will breakin more as you run the car. The balls will also make channels in the grease which will help. I suggest sticking to greased bearings with teflon seals for club racing. If you want to free up the drive train a little use non contact metal shielded bearings for the wheel bearings. These bearings are fairly short lived anyway. You really won't notice much difference on the track, though.

rcpilot

Hi Guys, I am having a very strange problem with my spool in the front. It is fine while going straight but as soon as I turn the wheels there is a very loud hitting sound as if its draggin or hitting something pretty bad. I have spent a whole afternoon trying to figure out the problem but couldn't. With a standard diff this problem doesn't occur, as soon as I put a spool it does. I have tried different spools aswell and even tried locking a standard diff and this still occurs. I have checked my bearings and cvd's and there all fine, even tried out 3 different diff cases top and bottom. I have tried different ring and bevel gears aswell and just can't figure out the problem so if anyone could give me some advice I would greatly appreciate it. I have never had this kind of problem in 5 years that i have been rc'ing and I'm just stunned.

Thanks in Advance.

John Stranahan

iTrader: (27)

rcpilot-does this happen on the track or only on a car stand. On a car stand a locked diff may chatter at the wheels when you turn them pretty far. This is more or less normal and is the result of the CVD not being a true constant velocity joint. On the track it does not seem to be a problem.

rcpilot

This happens both on the track and car stand. It sounds like the gears inside are binding up pretty bad. The thing is this problem didn't happen before, only now its happening. I have no idea why its happening, i haven't changed anything.

CRASH

iTrader: (26)

What would be the best spur gears to have for the TC3. Not brand but size. I know the 112 requires modifications, but what about a 106, 108 or 110?

Just trying to get an overall better gearing selection for the car.


Thanks,

DaveW

iTrader: (1)

A 96, 100, and 104 are all you should need. Unless you are running in a concrete kiddie pool, and need a 110 spur to get some grunt out of your motor comin off the corner!
- Dave

CRASH

iTrader: (26)

Thats pretty funny! Thanks for the input.

Later,
Tony

John Stranahan

iTrader: (27)

RCpilot-to check the gear train grab an outdrive to hold the diff still and rotate the input shaft back and forth. There should be a little play. Rotate the diff a quarter turn and repeat. Do this at four spots or so. If you always have a little play then the gear mesh is OK. If it is always tight remove input shaft shims. When I put the gear on my oneway the screws created little burrs that did not let the gear sit flat on the oneway's flange. The gear failed the test in one spot but passed in others. There was lateral runout. I removed the gear and scraped the edges of the holes to remove the burrs to cure the problem. Since you have experienced the same problem with several locked diffs this may not be your problem. Disregard wheel chatter noise at high steer angles on a car stand with a locked diff.

Removing additional input shaft shims.

Once you have some play in the diff gear mesh, removing additional shims just moves the contact pattern farther out on the gear teeth and weakens the assembly without reducing friction any further. The TC3 gears seem to tolerate this abuse, but the Tamiya EVO III has serious problems with the ring gear.

rcpilot

John, thankyou very much for you help, I took your advice and just disregarded the wheel chatter and went out on the track. It turned out that the chatter on the track was comng from the wheels hitting the shocks springs slightly which made them bounce up and down but I fixed that a long time ago and the noise sounded exactly same as the diff chatter. So everytime I saw the diff chatter in the pits with the soloid diff I thought it was gonna be like that on the track too, I was littlerly changing everything on the front end and couldn't believe it, still that noise, I was stunned.

Anyway thanks again.
Martin.

John Stranahan

iTrader: (27)

RCPilot-you are welcome.

I have been using a set of plastic bones on the rear of the car since it was new without a failure. If you use a locked diff or oneway the rear diff is lightly loaded and the parts seem to last a long time on the rear. A oneway accelerates the wear on the front dogbones. A locked diff accelerates the wear and breakage even more. I tried a set of plastic bones up front in 19 turn class to see if they would hold up and maybe provide a fuse to protect my outdrives which are no longer available for the associated one-way. They did not last through my practice packs before the CVD pin ripped throug the plastic cup. No other damage. Did not even hit anything that I recall. Put the Aluminum Associated bones back in. A couple of the guys are using the IRS bones with locked diffs. You seem to need to often screw with the drive pins and pin pillows which are easily damaged.

So why is a locked diff so much harder on the bones. When you crash and suddenly stop a wheel. The other three wheels and motor continue to turn and try to twist the locked dogbone in half. Things break. With a oneway you have one fewer front wheel trying to twist the dogbone in half as it can freewheel. The rear and the motor are still locked into the stopped wheel by the oneway bearing and the inertia causes the damage. With a standard diff up front the opposite front wheel can happily spin the drive train to a slow stop in most crashes without any damage. The only thing you can do to help things is to quit the throttle just before you crash. The drivetrain still has considerable inertia built up, though.

John Stranahan

iTrader: (27)

I have a suspicion that outdrives break on the one-way and dogbones bend when the bumper is pushed back far enough in a crash to brake the wheel to a sudden stop, then the driveline inertia does the damage. I purchased an RPM bumper to try and save my discontinued outdrives. I also replaced the trinity foam bumper which had softened and also partially ripped through the body post. This was probably the cause of recent dogbone damage. Here is a pic below of the RPM bumper. The advantage of this bumper is that it extends farther to the sides to prevent bumper contact with the tires.


Cut down motor Clamp

I also recently cut down my factory team motor support clamp/heatsink, which I suspect does little to remove motor heat. It does add weight to the proper place in the car, but this might be added lower in the car. I posted a picture on the TC3 thread yesterday 3/17/2:20 AM. The removed material weighed .4 ounces. The car handled well with both of these changes. No changes to the setup. TC3 thread page 153