Clark 664C Tramsmission

[treefarm]

Hi all-been awhile since I've been on the forum! 2 years ago I bought a '78 Clark Ranger 664C. It's runs like a champ, but has developed an odd problem-every so often you put the tranny levers in gear and go to drive off and nothing happens, and being on the same system, the winch is inop also. It's happened maybe 8 or 10 times in the last year, warm weather & cold. It only lasts from a few seconds to a half a minute. Sometimes shutting down and restarting will get things back to normal and a couple of times a quick back and forth in the steering lever will free things up. I know steering/blade, and tranny/winch, operate independently of each other, so that "cure" may have been a coincidence, or may have jostled a common connection between the two systems, if there is one. When it finally does engage, its as if you just shifted into gear normally, and everything is back to working normal. When it is not engaging, there are no strange noises, the engine revs normally, the tranny and the winch just don't work. I suspect a valve is either hanging up or wearing out, but don't have a clue as to where to start looking for trouble, or where the most common weak points are. Anyone got any suggestions? (I suspect Oldseabee will have some things to try :>) Thanks-Tom

[snowstorm]

if it like the clark trans i have there are 3 spool valves. 1 for foward and r.1 for the 3 speeds and the center one is a clutch disconect. if it was used you could rev the motor in gear but it would not move. seabee can tell you what is wrong

[treefarm]

Thanks Snowstorm-it is that same transmission and it runs strong as an ox 99% of the time. If I have some revs on the engine by mistake when it "pops" in, it jumps, and is back to full power-there's no in-between. There's nothing slipping or acting weak, it just acts like it's still in neutral. There's nothing common to each time it happens that I can think of either. It's very intermittent, sometimes going weeks w/o acting up. I did realize this afternoon when I was running it, I never tried moving the center lever into neutral to see if that would have any affect-I haven't touched it since I bought it, so I'll shift that one around too, next time..

Tom

[Bill_G]

It could be a clogged filter or a charge pump issue .

[treefarm]

Hi Bill_G-I'm guessing a clogged filter would have come on gradually? But you did make me think of a piece of crud stuck somewhere that randomly falls into place & blocks fluid flow? It's also one of those things that will be an sob to troubleshoot, as it's usually only for a few seconds and happens so infrequently. Thanks for the suggestions-btw-I'm right up 114 in So. Sutton.

[Bill_G]

I'm south on 114 in the small section of Warner , I used to own 664s , I think 4 different ones over the years . They are one nice tough skidder . I may still have the manuals around , I'll look if your interested .

[cutter88]

I have a 1980 did the same thing the day I bought it it tried to unload it off the float and it wouldn't move I played with that center leaver and away it went so I changed the tranyy oil and filter and have put about 3000 hrs on it and its never did it again... but I cant honestly tell u what the problem was..lol... but any questions u have ask oldseabea he know everything about Clarke and has helped me lots

[treefarm]

Bill_G and cutter88-thanks to both of you for your replies-this place is like coming home! Bill_G-I don't want to trouble you for manuals just yet-I'm hoping, and it's looking like, I'll get lucky and it'll be something like you or cutter88 suggested, fluid and/or filter related. oldseabee helped me out with some basic questions 2 years ago, so I'm keeping my fingers crossed he throw a post at this. Thank you for offering to go to the trouble of digging out manuals, Bill_G-I hope I won't have to ask! And cutter88, next time it happens, I'll try that center lever before anything else, and if it gets it going then an oil & filter change'll be first on the list-probably will be anyway. Bill_G, I never knew about that little piece of Warner that was over that way until a couple of years ago, when someone squawked in the paper about a lack of police coverage, if I remember right. It's a heck of a long way from Warner to over there, for sure! Thanks again guys-Tom

[kiko]

Could be a declutch issue if equipt. Declutch would have line from the brake master to center of trans control valve between forward reverse spool and speed spool. Does it seem to happen after using the brake?

[treefarm]

kiko-Thanks-I don't think it has anything like that on it, but I'll check & see, and to answer your question, no for sure, as I hardly ever use the brakes. It's usually after stopping to do some chopping, sometimes left idling & sometimes shut down. Now that I think about it, it's after it has warmed up for awhile-it's never done it cold, after the first start in the morning.

[thecfarm]

Hydro tranny?There was a member here that had his hydro tractor on a steep hill and it would not move. The pickup for the hyd oil was not strong enough to move the oil and maybe it was a little low too. I doubt this is your problem,but??

[treefarm]

Hi thecfarm-No, I am usually level or close to it, as I usually park where it won't roll, and the tranny's full with no leaks. Thanks for the suggestion!

[snowstorm]

check the oil with it running

[treefarm]

Yup-I do that.

[oldseabee]

Normally, if it is a problem in one cluctch you could look for a stuck bleed ball in the clutch drum, when the clutch is activated, the pressure rolls the ball over an orfice to block it. when the clutch is disengaged centrifical force rolls the ball away from the orfice so the drum can empty quickly. However it sounds like other clutches are affected at the same time. most likely problem is in the clutch pressure regulating valve on the side of the convertor, this valve has to move a spool against a spring to achieve clutch pressure to the transmission before any oil is allowed into the convertor, if the spool sticks or the spring is broken, occasionally you will lose clutch pressure. Best way to check is a pressure guage in the clutch pressure test port, some machines have a plugged hose connected and just plug a guage in there. Pressure should go to 240- 280 PSI with hot oil. If you have normal clutch pressure when the machine is working OK and low or no pressure when you have the problem that valve probably is the problem. The other problem is if the fiber drive gear is stripped and debris binds it to the flywheel, it can slip and grab, you will also lose hydraulics at the same time and have a severe vibration. Another posibility is loss of charge pump flow due to collapsed suction hose, this can be intermitant if the lining has come loose and some times blocks flow.

[treefarm]

Well, after reading that oldseabee. it looks like I've got some work to do! Or someone does-I'm limited in what I can do and troubleshooting would be almost impossible, as it's so intermittent and never lasts more than a half a minute tops. It may have to get sent out to a shop. There's no vibration at all, so I can at least rule out the drive gear, but the suction hose and pressure regulator valve I may be able to handle, so maybe I'll get lucky!. Thanks for your post-your knowledge and willingness to share it is greatly appreciated. Tom

[lshobie]

did you ever find out what the issue was?

[slakwire]

Morning.   Do you still have the 664? Thanks.   Just curious if you have info on spin on transmission filter.