C7T Treefarmer ?

[Autocar]

I have a C7 Treefarmer grapple skidder 1983 I am having a problem with the torkconverter. This past week it blew the seal on the torkconverter filter canister. This has happened two other times in the last two years. I have changed the filter twice this year the torkconverter dosen't have a dip stick and the filler hole is in one H of a spot to even get any oil into it. Ive been putting 4/5 gallion back into it [ untill the skidder moves forward and reverse ] I have called Franklin but don't seem to talk to anyone that can give me how much fluid or what it might be. When it blows it is a super high pressure and before you realize whats happened the engine compartment ,radiator, tire on the filter side is drenched. Three to four gallion in a drop of a hat. Sure makes for a bad day , thanks for any ideas you may have. Bill

 

[Phil]

I'm just guessing as to the cause of your problem but here goes. I think your machine is a direct drive unit with converter, because my neighbor has a similar one. The converter oil system is probably just limited to the converter area, other than the oil cooler. Sounds like there is no reservoir and it's not connected to the hydraulic system. The converter housing should form the reservoir and have an oil level just below the bottom of the converter(maybe a level plug). Should be a charge pump picking up the oil in the sump and pumping it through the converter to keep it full, cool, and purged of air. I'm guessing the charge pressure is maybe 20-30 psi. This oil from the charge pump has got to be filtered and cooled first before it reaches the converter. It's probably a 'full flow' filter, and not getting bypassed oil.

A partially plugged oil cooler, collapsing hydraulic hose(to or from the cooler or filter), or sticking relief valve(sets charge pressure), could make pressure at the filter, too high, even a spike will blow a filter. I would find a port at the filter housing and get a pressure reading. Leave the gauge there, so you can monitor. Also scan the numerous sites that offer service/operators manuals and you might find your info there. I would be concerned about a possible high oil level too, although I don't think that is your problem. If I see my friend, I will ask him how he sets his level and get back to you. Phil

 

[Autocar]

Thanks so much for your reply Phil , your right about the converter housing being the oil tank, so it sounds like we are on the right track. I should finish my truck today so Monday I will pull it into the shop ,at least now I have a direction to go. I would of never dreamed that it had only 20/30 psi.When you talk about a oil cooler are you talking about the radiator area,not for sure but I don't think there's a cooler for this oil but for sure when I get all the iron tore off where a fellow can see better. Also do you have any idea ? Is the relief valve inside the housing or bolted somewhere on the housing ? On top off the housing there is some sort of valve and I believe it has four small 3/8 inch lines leaving from it. I tend to lean towards the relief valve,again I can't thank you enough ! Bill

 

[Autocar]

I couldn't stand it so the truck waited and I tore off all the iron covers to see what was there. The relief valve sets on top of the torkconverter housing. One line 3/4 inch goes to one side of the filter then there is a smaller 1/2 inch that goes from the valve to the hydrostatic transmission. The other side of the filter,that hose is bigger and goes to the torkconverter it self. I believe you hit the nail on the head ! Once I get into it I will let you know whats going on,thanks again Bill PS there is no by pass on the filter housing its only the filter know other way to go.

 

[Phil]

Hydrostatic transmission? This is not the simple set-up that my friends C7 skidder has. If it's an automatic transmission you have, maybe an Allison? Got a picture? This is getting a little more complicated, I really recommend finding a service manual on the internet. The torque converter, whether sharing with the transmission or not must have a cooler somewhere, either in the radiator or plumbed into the engine cooling system, usually bolted to the side of it. A plugged cooler is rare, a plugged hydraulic hose is a bit more common and worth a check. Not all filters are the same either and it's possible to get the wrong one for that application. Phil

 

[Autocar]

Phil it has a Clark transmission Model Number R28328-6 and the transmission dose have a cooler with the radiator. I have looked time and time again for a booklet but then again I don't know alot about computers or where to look. The hoses are a easy look and the check valve is also and as far as filters it is the same ones that I bought in 1996. This problem started in the fall of 2005 then again the winter of 2008 then last week again so it may go for a long time. I will start with everything you talked about.

 

[Autocar]

I ran down to the shop it is called a Power Shift

 

[Phil]

See if there is a decal on the top of the converter. It would be good to have that info. It sounds like your converter is separate from your transmission, probably connected by a drive shaft. If your filter problem has stretched out over a few years, it's not as likely a hose or cooler problem. More likely a pressure setting, spiking pressure, or possibly oil type/viscosity, or the wrong filter.

Too bad you were not posted in a more active part of the forum, to get better advice. The drive train you have is probably common to many types of machines(or skidders) and sometimes info is found by searching this way.

It's quite possible the oil in your torque converter is shared with your transmission. If that were the case, you may have a scavenge pump near the bottom of the converter housing that returns oil to the transmission, and the transmission dipstick is used for oil level. The filter may be a transmission/torque filter, servicing both. Sometimes they mount these anywhere there is room.

Try calling a few of these businesses, ask for a service manager, for advice, have your converter model and tranny # ready, it never hurts to ask. They don't know but what you are considering shipping the unit to them for repair. Ask for a service manual at the same time, for both units. These will have flow charts, pressure settings/check points, good for future reference and helps the resale value of the machine. Phil
http://www.clark-transmissions.com/
http://www.pjpower.com/clark/?gclid=CIbC2MrB8Z4CFcNM5QodVXHwcQ
http://www.associatedpowertrain.com/powertrain/converters/
http://www.bowerstransmission.com/clark_transmission.htm

 

[Autocar]

Thanks again for all your help , at least I have some ideas on where to look. I will up date you with what I learn. Bill

 

[willie59]

I'd like to know a little more about this tranny setup. Is it seperate convertor and tranny connected by driveshaft? Is it a spin on filter or cannister filter? I'm certainly no expert on these things, but seems like an odd setup for convertor housing to be reservoir for tranny. I have worked on some clark trannys that have a slightly high filter pressure with a spin on filter. They would make aftermarket filters fail except for Donaldson filters. May be different from yours though. Also, your unit may have a pressue relief valve problem. But relief valves opening create more heat. Convertors and trannys create enough heat already, more heat from a relief is less than desirable. Instead, many setups like this use pressure regulating valves. They don't create the heat that relief valves do. Could have a broken spring in it creating excessive pressure Your going to have to get some tech info about your unit, like, what psi is the system supposed to be. Surely one of the links that Phil posted could provide some info on your unit.

 

[Autocar]

The torkconverter and transmissiong is seperate,there is a drive shaft between them. The filter is a cannister type. I changed the oil in the torkconverter and it was pretty dirty meaning it was dark in color. But the transmission oil smells like transmission oil and is clear as the day I put it in there. So I believe there two seperate units . And the oil gets plenty hot in the converter there again I believe there is no oil raditor for it. The housing which looks like a bell housing bolted to the rear of the 4/53 is also the oil tank and the drive line comes out the center of it. What I can't figure out is how the two pumps operate with the torkconverter between them and the rear of the enigine. For sure it's a great learning exsperance and to some degree I enjoy wrenching on equipment.

 

[willie59]

If your convertor oil is dark and tranny oil is clear, they're two seperate reservoirs. The convertor oil is probably getting stained from a little leakage of motor oil from rear main seal. If this seperate torque convertor system does not have an oil cooler, that's a problem. Torque convertors generate more heat than trannys do anyday. When you change the filter, does it have the dark convertor oil in it? Not sure why your blowing your filter seal. Maybe a problem with pressure regulator. Another possiblity, you mentioned it had no cooler and oil gets plenty hot. And, you mentioned it takes some time to pass before seal blows. Hot oil will make o-rings and lathe cut rings (seal for you filter can) get hard as a brick bat. Hard seals cannot perform properly and they will fail in time. You also asked how the pumps work on the convertor housing. I assume you mean some kind of external pumps that are bolted to the rear of convertor housing, correct? That type of convertor has a ring gear on the rear of the convertor. Whenever the engine is running, the outer shell of the convertor is turning. The only part that "slips" is the output shaft of the convertor. That ring gear on rear of convertor is used to drive external pumps and shafts.

BTW...welcome to the forum Autocar. :usa

 

[Autocar]

Boy O Boy this is the greatest form sence apple pie ! I have learned more about this machine in the last few days then all the years I have owned it ! Can't thank everyone enough for there expotease. From my understanding this tractor was being built in Canada in 1983 then Franklin bought them and this skidder was moved half built to the satates. So everytime I went looking for parts and gave them the serical number they would run into a wall because Franklin used different parts that did't match what was on my tractor. I am not sure how the newer machines are built but this one is like a tank. Again thanks for all your in put. I am leaning towards a sticky valve,26 years old and as hot and dirty as that oil was thats a good place to start.

 

[willie59]

Boy O Boy this is the greatest form sence apple pie ! I have learned more about this machine in the last few days then all the years I have owned it!

Well, that Phil is a pretty smart fellow. :yup

Hi Phil! :waving


Hope ya find your problem Autocar. We're all a little in the dark on your unit as we're not sure the way your system is set up or it's components. One thing I would do, though, when ya get it sorted out is install some kind of oil cooler on it. A torque convertor needs an oil cooler. Keep us updated on the repairs.

 

[Autocar]

C7T Treefarmer Update

Monday turned into a brutal day with 0 degree windchill and snow but I worked just outside of the shop. I took of the pressure relief valve and under it is a cone shape spring with a cap [rounded top ] and a 1 inch hole with a rubber seal that fits up into the valve bank. Not sure but will check tomarrow the bigger line 3/8 inch goes to the canister filter. A 1/4 or even smaller goes to the dash gages. Another small line 1/4 or smaller goes to the transmission. The valve bank it self ,the 3/8's and 1/4 inch go into the same cavity and so dose the one that goes up into the dash. The cone shape spring with the round cap seems just to push up and seal a hole in the valve bank. The open cavity where the three lines goes into there is a chrome 3/8inch rod that I figure has a plunger on it . Stumped on that but it measures around eight inches long with roll pins driven on the ends, [holding a coiled up spring ? ] After looking at some of the sites you told me about it looks like a Spicer C2000 torque converter. The only difference is where that drive line comes out on the lower left side theres a cover plate there on mine. If this dosen't make any sence to you tonight maybe after tomarrow I will trace the three lines out better but I have had enough for today I need to thaw out Now what I am about to tell you will get your gears turning ! I unscrewed the hydraulic fittings out of the valve bank to see inside it and in the threaded side of the 3/8 inch fitting there was a piece of yellow brass maybe 1/8 inch thick X1/4 inch X 3/8 inch . It was stuck and wouldn't make the turn in the 90 drgree turn. Possible that it may have flipped side ways now and then shutting off the flow ? For sure it was a restricked line like it was. Now where did the brass come from ? It seems like soft brass milled smooth on one side and eather a little rounded or chipped off something. Tomarrow I will trace the line out and see which direction it was trying to travel . Maybe that will give me a clue.

 

[Phil]

I'm sorry, I got sidetracked on my backhoe and haven't been back here to see how you made out. I see ATCOEQUIP has found you, good thing, I was going to PM him for help. He is pretty sharp on hydraulics and our forum expert, not bad with other problems too.

Hard to say about the piece of brass, unless you posted a picture. Usually there is a screen in the oil pump pick-up, and the pump itself would grind up anything on the suction side. A schematic showing hydraulic flow for this torque converter would help determine where it came from.

The line from the tranny may be a sensing line. The valve itself I will leave to ATCO to figure out, I'm not sure. The line to the dash is usually only for a transmission pressure or clutch pressure gauge. I can't imagine any other gauge from the converter needed, just a temp gauge.Phil

 

[willie59]

I see ATCOEQUIP has found you, good thing, I was going to PM him for help. He is pretty sharp on hydraulics and our forum expert, not bad with other problems too.

LMAO! Dang Canucks...they'll say anything about us Southern Hillbillies! Expert?...your the one who has a Tree Farmer named "Daisy", not me! :tong


No, I'm no expert on these things, but all the details are still not here. Not sure, but you said you think it might be a C2000 converter. It should have an external charge pump. Haven't heard that mentioned. Maybe has an internal charge pump? It's possible. You mentioned in your other thread that a large 3/4 line goes from converter housing to one side of filter. That may be the feed to the filter from charge pump. Then the 3/8 hose goes from filter to pressure regulator, the valve body you removed. Then you have 2 other lines connected to that port chamber on the regulator; 1/4 line going to dash (pressure gauge maybe?), and 1/4 line going to tranny. I ain't figured out the line going to tranny since we've already determined it uses it's own oil reservoir. As for the brass piece, if the oil flows the way I described, and it's lodged in the 3/8 line fitting of line coming from filter, then you may have found the cause of filter seal failure. The restriction is happening before oil/pressure gets to pressure regulator. Where did the brass come from? Good question, how did it get past the filter? Unless the filter has a by-pass valve in it. If all this is correct, the piece of brass could be from a wear end plate of charge pump. That's about all the noodling I can think of without more knowledge of the unit. I still can't believe it doesn't use an oil cooler myself.

 

[surfer-joe]

From my experience, tree farmer did not spend any money on items that were not really needed. As most of their market was northern Canada (cold!!!!!!), an oil cooler would fit that view.

 

[Autocar]

Day Two C7T Treefarmer Update

Here we go I traced the lines and put everything back togather today. 3/8 line goes from pressure releif valve to transmission [ On a block that has all the lines for forward1,2,3 and reverce ] 1/8 line goes from preasure releif valve to a [ Drive Oil Gage on dash ]pressure run around 245 the gage goes to 300 if I remenber rightly.Looking at the filter canister the 1/2 inch line on the left side goes to the pressure releif valve.The right side 1/2 inch goes to the right side of a gear pump on the lower back edge of the torkconverter housing. Here's where it gets crazy, the left side of the gear pump goes to the right side of the transmission. Then on the lower left corner of the torkconverter housing there is a 3/4 inch line that goes half way back on the bottom of the transmission. On the lower right side of the torkconverter housing there is a 3/4 inch line running all the way on the right side of the tractor and hookes into a 6X12 box ? with the water pump and two 2 1/2 inch water lines hooking into it. It also where the line hooks on to says [ From Filter ] Then leaving the Box ? says [ To Filter ] 3/4 inch goes to right side of transmission with a T connection at T steel line goes to the rear of the trasmissiom and goes into the top right where the winch drive line comes through. The 3/4 line just goes into the right front edge of the trasmission. Not sure but is the transmission water cooled at the square box ? Is it possible that the transmission has a seperation in it and keeps the two oils from blending ? I would just about bet there's separate oil in the two ! I bleed the air if there was any in the dead end lines and then drove it around for a while.I am more confused now then ever the way it is put togather I am not to sure that it won,t shot off to the moon I called the numbers you guys gave me to find out how much fuild the converter held , the guy said I would have to call Detroit motor division ointhead Beats me ! So I called Ricker Equipment and asked them and they called me back and said they would take a shot at it and say 5 or 6 gallion ointhead With answers like they gave me I wonder where our country will be in another twenty years. But then thats another story !

 

[Autocar]

The one number I called carryed Spicer Torkconverters and I am pretty sure that it is a C2000, this was where the fellow told me to call Detroit moter division Right and left is when your seating in the drivers seat. except the filter where your standing on the side of the tractor looking at it.