Clark 664c transmission filter head blew apart...

miketclew · March 17, 2022, 08:27:19 AM

Good morning all,

So, I'm unloaded, headed in for last hitch of the day. Clipping right a long, suddenly power drops. I notice that the winch is pulling the cable in without me asking it to. Shut the machine down, climb off, and see ATF running out the belly. Pull the floor pan and see that the transmission filter canister and part of the filter head is sitting on the belly pan.

I'm puzzled as to which came first though, did the filter head blow-off and somehow cause my winch to starting winching, or was there a malfunction that caused the winch to start winching - resulting in immense pressure that blew my filter head.

While I'm waiting for a replacement filter head, I'm attempting to verify rule out a winch control malfunction. I've pulled the winch control apart and all of the springs look fine, and the gasket appears fully intact.

Any thoughts on which might have caused the other? Was my filter backed up, blew the can/head off and then the sudden pressure drop caused my winch pto to start operating? Or, did something cause the winch pto to start operating - suddenly while I was clipping right along and result in the filter head blowing off? What tests/inspections should I make before attempting to going back to work once I get it put back together?

Thanks

Mike

OntarioAl · March 17, 2022, 08:55:09 PM

I see nobody wants
to be bearer of bad news
What you describe is a massive pressure spike that blew the filter and part of the casing off
so why did this happen well your filter developed a restricted flow and your filter bypass failed.
raising pressure.
You need to find why the filter plugged and the bypass failed
You need somebody that knows this transmission as to explain what other internal damage might have been caused by the pressure spike
I fear and i sincerely hope i am wrong you may be looking at a transmission overhaul
Al

miketclew · March 18, 2022, 07:17:12 PM

Quote from: OntarioAl on March 17, 2022, 08:55:09 PM
I see nobody wants
to be bearer of bad news
What you describe is a massive pressure spike that blew the filter and part of the casing off
so why did this happen well your filter developed a restricted flow and your filter bypass failed.
raising pressure.
You need to find why the filter plugged and the bypass failed
You need somebody that knows this transmission as to explain what other internal damage might have been caused by the pressure spike
I fear and i sincerely hope i am wrong you may be looking at a transmission overhaul
Al

Thanks Al, I sincerely hope you are wrong too.

I thought it was interesting that Davco in Maine has a few filter cans available but no filter heads. I have a replacement coming in from B.C. Harolds logging in Maine sells spin-on style hydraulic replacement heads.

Maybe the filter head became weak/cracked from overtightening. After living in a skidder frame rail it finally failed under normal pressure conditions?

I don't know if there was an increase in pressure necessarily - infact, the can was sitting directly below the rest of the head - almost upright 3/4 full of oil when I got to it as if it just fell off. I realize, I'm the first one who said "blew-off" though .

Anybody out there every hear of these filter heads failing?

Southside · March 18, 2022, 08:10:07 PM

Are the threads stripped?

miketclew · March 18, 2022, 08:30:33 PM

I'll have to get a picture up tomorrow. It's on the other end, where the head was cast around the base of the bolt you fasten the can to. It looks like what might happen if I over-torqued the can. I believe the head is aluminum, while the bolt and can are steel. It's definitely worth posting some pictures of, I've never seen anything like this before... really hope I never see it again :embarassed:.

kiko · March 19, 2022, 12:02:43 AM

That filter head may not have a bypass valve built in. Some if the Clark trans filters did not. If not the filter was likely over restricting flow.

miketclew · March 19, 2022, 09:24:06 AM

Pardon how dirty they look, my son - being a good boy and doing his chores, dragged a 1/2 dozen hay bales over them this morning. They were wet with oil, but just as clean as can be when I them pulled out of the machine. That spring was down in the belly pan of the machine. It seems to fit right in that plugged port spot. Looking at it now, I'm guessing that a bypass could be arranged on that port.

miketclew · March 19, 2022, 10:49:20 AM

I just happened to see under the "similar topics" section at the bottom of this post:

Clark 664 transmission filter in Forestry and Logging

First place I've found that talked about failures with that filter housing

"Plenty of Clark Ranger tranny filters have blown off or cracked the housing in the cold without a proper warmup" - The Wanderer

OntarioAl · March 19, 2022, 11:53:45 AM

Do a google search for Clark 664 c transmission
Down load operators manual from allied system (free)It will give you an insight as to what may have happened winch hydraulic is supplied from the transmission
hope this helps
Al

miketclew · January 30, 2023, 11:36:22 AM

Hey All. It's been just under a year, and I did get my skidder repaired. I thought I would follow up with a few details for posterity - it's the least I can do given how much knowledge I gained just from reading all of the relevant posts from oldseabee.

I had a replacement filter head (canister style) sent to me from Wally's Private Parts out in BC. Came with the canister, when I removed the canister - that filterhead was damaged in the same way :(.

Wally sent me a newer style spin-on filter head with out hesitation when I contacted him about the faulty part they sent.

The short of it is, the only thing that was faulty - initially - on my machine was that the filter head had failed. The only thing I needed to do was replace the filter head, add a filter, refill with ATF and get on with life.

Now for the rabbit trail. When the filter head failed, my winch pulled the line in "on it's own". I was afraid that something had caused the filter head to blow off and I would put a new one on and it would also blow off. So I called a few folks, including Randy (Harrolds Logging) - and a local mechanic who works on Clark Skidders - often - a good mechanic and picked their brains hard.

Between the two of them, I was steered towards a potential failure in the pressure regulator spool/valve (bolted to the torque converter), or the winch control valve. I'm looking for broken/damaged springs, o-rings and/or balls basically. Everything looked good. I put it all back together, brought the machine out of with woods without and issue, then I learned my winch was not working - correctly!

When the filterhead had failed, all the empty chokers went for a ride around the winch drum. To get them out, I tied something off to a tree and chained on to a choker, and drove off - that did the trick. I tried to winch the line back in and I learned my winch now free-spools ALL the time! It didn't hold (accept when machine was off), and it wouldn't winch in at all - at first.

I verified via oldseabee post references (and later, with the parts diagram), that all my hydraulic lines were installed in the correct order. I got my hands on a winch manual (I have a hard copy and a PDF now - which I could NOT find on alliedsystems website). BTW, I'm happy to share the doc.

Finally, with a pressure gauge, I learned that the free-spool line was ALWAYS getting pressure. Which, kept the drum disconnected from the drive train, in the hold and winch-in control position. I put a pressure gauge on the end (as opposed to using a "T" fitting to put it inline). Which left it disconnected from the winch. This let the winch drum and drivetrain be connected again and winch-in and hold functions both worked!

Winch control valve became the primary suspect. After disassembly and inspection, there was a washer in there that had broken and only a few pieces were left! It looked fine when we first had the control apart. Maybe it got damaged going back together??! It's function was to back a spring that keeps the two-part spool in tandem (accept for winch-in, if I remember correctly). Replaced, re-assembled, and we're in business again.

Anyways, here's to oldseabee!