Originally Posted by GREGORY!

maybe the copper one will be better for low traction tracks?

Originally Posted by YmeBP

Which one do you need a square one or the pin one? I have a box going to AU early next week i can stick in there for you.

Originally Posted by GREGORY!

i am telling that because it will be leave some flex in the main chassis.
what do you believe?

Originally Posted by mcsquish

Mike Here is everything I checked:
-replaced the plastic chassis brace (I replaced it with an aluminum one)
-make sure you aren't using too long of a screw in the rear chassis brace. You will think it's tight, but it may be hitting the bearing.
-make sure the motor is not moving. Again using too long of a screw will cause issues.
-replace the clutch bearings. It may be a bad bearing causing the clutch bell to move away from the spur.
-make sure there isn't too much slop in the 2-speed. It may be shifting so hard that it is causing the issue.
-I had issues with using the Kyosho TI 2-speed shaft (others have not) with it flexing. I now run the YBSlow, it is made from good quality Titanium.
-replace the rear bulkheads, the bearings that the 2-speed shaft over time can open up the plastic and have a little movement.
-I set my mesh tighter than I used to. I set it with just the 2nd gear on and just loose enough it isn't grinding (the gears will wear in) then check it again with both spurs installed. If the mesh is too tight on 1st gear i will leave one engine screw just loose enough I can pivot the engine and loosen the mesh. I also usually will remove the pipe so I'm not fighting that.

It ended up being that I needed to replace the rear bulkheads. The first time I replaced them I didn't have any new ones and got a set of "lightly" used ones from a friend (big mistake). The 2-speed shaft bearings had opened the holes just a tiny bit to allow movement.

I hope this helps. Let me know if you need other ideas, I know this was a very frustrating problem.

Originally Posted by mhavlena

OK Guys. here's the story:

Appreciate all the advice, what I've done:
1) I changed the rear bulkheads, however, I investigated the old bulkheads are there is no evidence of slop, none that I can see anyway.
2) engine mount screws are good, not too long, have had that problem before.
3) One-way bearing is new, so no problems there.
4) I'm not running in my engine, not too rich at all.
5) changed the main 2 speed shaft and the 2 speed, no slop noted
6) clutch bell bearing are good, spin freely and no evidence of wear.
7) put new pinions and spurs...oouufff
8) chassis? don't want to have to change that...no evidence of tweak
7) chassis brace? why should I change to aluminum? more rigidity? don't have one.

I have a feeling that I improperly installed the 2 speed shaft (main shaft), there are set screws for the brake hub and 2 speed holder, there was a little play (left/right) movement with the spurs, perhaps this is the reason? and oh ya, as I was busting gears, I had to re-tighten the 2 speed holder...never happened before, don't know what could have caused the holder to get loose all the time, perhaps the play between the spurs?

Has anyone else ever installed the main shaft with a little play between the spurs?

Thanks Guys!
Looking forward to your responses...

Originally Posted by barg

Have you meshed your gears tight?

I stripped around 50 2nd gears over mulitple cars before I found the mesh was the issue.

As for the aluminium brace I dont think you need it. What you can try is counter sinking the holes in the plastic one and using countersunk screws. This will help the brace lock in to position and not allow any movement.

Originally Posted by Brian Bosley

by correct, he means that your gear mesh should be so tight that it sounds like its binding slightly when you spin it by hand. also take 1st spur gear off and be sure that the mesh is the same on the inside 2nd gear and look down from the top to be sure they are square.

my car always has a slight binding sound when the gears are new, they will wear in but they are not actually binding because they spin freely. you will know what I mean when you try it.

Originally Posted by barg

Have you meshed your gears tight?

I stripped around 50 2nd gears over mulitple cars before I found the mesh was the issue.

As for the aluminium brace I dont think you need it. What you can try is counter sinking the holes in the plastic one and using countersunk screws. This will help the brace lock in to position and not allow any movement.

Originally Posted by mcsquish

Mike Here is everything I checked:
-replaced the plastic chassis brace (I replaced it with an aluminum one)
-make sure you aren't using too long of a screw in the rear chassis brace. You will think it's tight, but it may be hitting the bearing.
-make sure the motor is not moving. Again using too long of a screw will cause issues.
-replace the clutch bearings. It may be a bad bearing causing the clutch bell to move away from the spur.
-make sure there isn't too much slop in the 2-speed. It may be shifting so hard that it is causing the issue.
-I had issues with using the Kyosho TI 2-speed shaft (others have not) with it flexing. I now run the YBSlow, it is made from good quality Titanium.
-replace the rear bulkheads, the bearings that the 2-speed shaft over time can open up the plastic and have a little movement.
-I set my mesh tighter than I used to. I set it with just the 2nd gear on and just loose enough it isn't grinding (the gears will wear in) then check it again with both spurs installed. If the mesh is too tight on 1st gear i will leave one engine screw just loose enough I can pivot the engine and loosen the mesh. I also usually will remove the pipe so I'm not fighting that.

It ended up being that I needed to replace the rear bulkheads. The first time I replaced them I didn't have any new ones and got a set of "lightly" used ones from a friend (big mistake). The 2-speed shaft bearings had opened the holes just a tiny bit to allow movement.

I hope this helps. Let me know if you need other ideas, I know this was a very frustrating problem.