Tranny or clutch?

[mydirtkids]

Bought our son a new 2010 DRR 90. 6th tank of gas and won't move. Tranny fluid smells burnt. Can't get clutch off tonight, but why the smell? On jacks, the variator works, belt turns, can't hear any unusual noise when I mannually rotate rear tires.... New to the mini, just need wrench time.

The 2010 comes with a slipper.. could that have failed, but don't see clutch engage.

Thanks for any help out there.

[Coley'sdad#8]

torque the slipper sprocket nut to 100-105 ft lbs
watch the center of the sprocket while you throttle it and see if it spins. you might have already burned the disc's out of it.:(

[EthansDad]

odd. my guess is also on the slipper sprocket. What I'd do is see what's moving and what's not. If you take the CVT cover off, you can crank it and see if the clutch is engaging. don't rev it too high with cover off, just enough to see it come off stall and start spinning the rear clutch bell (outside part on the rear pulley needs to spin to engage tranny/rear drive).

If that is OK, then put your cover back on and see if the counter sprocket shaft is spinning when you get to engagement speed. might be best to do this on a stand. If it isn't, then you might have an Tranny issue. very unlikely. when the trannys go bad, they make a lot of noise. You can also visually look at the counter sprocket if it spins a bit while on the stand to make sure its in round - or spins in a nice circle with no wobble. if it wobbles, then tranny is shot.

some things to test, but again my money is on the slipper, and yes you probably need to replace the shoes in it. Also, if you don't have one, buy a torque wrench to get that 100-105ft/lbs on that nut. anything less, and you are back where you are now.

On the tranny oil, did you replace it after you ran it a few times? the oil that comes with it is really no good, and you should dump the tranny oil after a few runs anyway to get out all of the junk that comes in the tranny. change your oil, use a gear oil (75-90w) of a high quality. I use amsoil sever gear 70-90w.

-EA

[mydirtkids]

Got it apart, found out why it smells like burning rubber...

Clutch bell attaches to shaft or primary gear in transmission. This shaft drives the main reduction gear. The main reduction gear (two gears on common shaft) drives the final drive (a gear on a shaft that the tranny slipper sprocket is attached to...drives chain).

PROBLEM is BLESSING that saved bigger bucks and time.
Here it is....

Slipper failed..or we exceeded its design capability. Thankfully some protection was still there...

The main reduction gear discussed above is a small machined gear/shaft and larger gear...one assembly. The large gear (only one visible in parts catalogue) is pressed on the shaft. The gear slipped, cause friction/heat (burns tranny gear oil). Quad does not move.

At first I wonder why the heck is this not one piece. Expense? No. Then I wonder why this was not a key cut (prevent slipping). Then it dawned on me. Well, the case is more work and money to replace. If the pressure is not released here, then the case would probably fail.

Failed part $63.00....son making first race saturday...you know the rest of the saying...priceless!

My inexperienced thoughts...
Slipper clutch was designed to help prevent tranny failure when the kids land on the gas. Well, prior to that (thankfully still in design) some protection is there to save tranny with this gear.

My slipper (factory stock) is still torqued to recommended 95. These people designed it, and I don't know it like you guys do.

I do know the main drive gear assembly is cheap and easy to fix. Does anyone else torque to 100 or 105? If the slipper is too tight or fails, what then.. what if my main gear did not fail? Just asking, not sure what setting is better.

Hope this helps someone.. Thanks for all the help.. You people make it easy to love this sport!!!

[irwin3e]

just my 2 sense. if i was you i would spend the extra money now and buy a wileymods slipper sprocket. i havent heard of any of the stock slippers lasting, mine included. got the wiley sprocket and havent had a problem since.the extra money now may save you in the long run!good luck!

[mydirtkids]

Sweet... I will try one, just hope I can get something together by Saturday. Thanks for the guidance!

[raidernut]

We weld all our gears to prevent that problem and we use the wiley mods slipper.

[Logan #34's Dad]

We weld ours also. If used the stock slipper with success though.
Also, The large gear on the sprocket shaft will slip too. IF you want you little guy to land on the gas, you could do the slipper sprocket AND the Hetrick/DC slipper bell. Just a thought.

[jungleboy213213]

Same exact thing happened to me...Bought a new 2010 DRR and after the third race, burnt the clutch pads up (It cost us a possible win). When I took it apart, one of the pads come off in 3 pieces. No big deal, ordered new one and replaced. Now, before every race or practice, I check the torque on it just to be on the safe side. I've been torqueing it to 95 lbs, but I think I'm going to bump up to 100.

[EthansDad]

what gears do you weld? can you explain that a bit more? Also sounds like we need to try that wileymods slipper sprocket. we have not had a full slip failure yet, but sounds like its common.

-EA

[mydirtkids]

I was looking at the gear, welder, gear.... GONNA DO IT! Oh well, just parts! I do have a spare tranny on his other bike!! Hetrick clutch? Yeah, for now if he aint scared to land on the gas, well all the power to him and his 52 lbs!

Are you guys welding the wiley gears too? And the final gear to the sprocket? Where is that helmet... torque wrench..::devil: