Clark 664C

[Chrbat33]

Hello everyone,this is my first time posting on here.in having trouble with a Clark 664 c it won't move at all in either direction.i believe torque converter is good stub shaft is spinning fast and can't stop it even at idle,hydraulics and trans pump are working fine so not the fiber gear,wondering if anyone has run into similar problems before thanks

[lshobie]

Can you confirm it is actually going into reverse and forward?  does it seem like it is binding?  does it rev and try to move or do rpm wind up freely

[Chrbat33]

Rpms go up as if it's not in gear at all.i had shifter valve off everything looks good and spoils work freely.also had clutch pressure regulator valve off just to check,haven't gotten around to pressure testing that yet but the winch works which leads me to believe proper pressure is getting to the shift valve.this happened out of nowhere one day during use just stopped in middle of skid road.ive also had all shift linkage off to make sure full amount of throw is getting down to valve.i can see maybe one clutch going bad but to have both at same time makes me wonder.also put new tranny pump on.seems to me it's not going in gear but I'm kinda at a loss

[Neilo]

It might be bogged.

Sorry. I don't know Clarkes, but give as much information as you can and there is lots of experience here to help.

[Maine logger88]

Is your travel mode in neutral?

[allaboutsawdust]

A pressure test will tell you a lot. At low idle you should be in the 250 +/- psi range . There is a test port on the output side of your filter and another test port on the pressure regulator valve. We had something similar to your problem happen and all it was one of the lines flaked apart inside and a piece got stuck in the relief valve. I have a hard time believing in your case that both clutches went at the same time I would start by looking for other problems first.

[lshobie]

Could it be the fiber gear?  I've just read something about that: https://forestryforum.com/board/index.php?topic=75334.0

[rockwall]

My 664B won't go if I'm low on ATF fluid in the transmission. If not low, could it be the fiber gear?

[Chrbat33]

Thanks guys for all your replies.i think I will start with a pressure test on regulator valve and then maybe look for a clogged port somewhere.i did put on new suction hose and a new return hose..also had torque converter out,didn't see any problems anywhere yet

[ClarkF66]

Like Mainelogger88 says; are you sure that the transmission high/low lever is engaged? I have seen Clarks where the lever has been removed and the owner thought it had just two speeds in each direction. You are probably fully aware of this, I just thought it worth mentioning.