Machine would intermittently quit fwd. and rv. until totally quit. Tech said to check pressure at top port which read zero, tech said pump is bad. Pump was replaced and new hyd. fluid with same result, no pressure at all, zero. Is there a screen or filter somewhere preventing fluid flow that we are missing or where to check? Any help greatly appreciated, thanks.
What is going serial number?
OK, plate is tough to read but here are all the numbers I can read: *8PB01842*8G8950 *45V65765* *ICEC2376* 320D1
The canister on the bottom front of the trans has a suction screen in it. It has a hose going up to the pump. Check that it is clean and not sucking air at any joints . Its by the arrow in the picture. Sorry for the poor picture.
OK, I see an oval cover plate on tank right next to suck hose. If the screen is behind there (in the tank), I think draining the tank would be required? I ran engine with pressure port open and did get flow just to see, very foamy with air bubbles and pockets, but no pressure.
There is no canister and can't make out picture but thanks anyhow, I will be draining the trans tank and removing that cover plate and see if there is a screen/restriction in there, man I got to get this thing going, got to fix it, no more money to incompetent technicians.
Yes, the tank screen was completely fouled/plugged. Cleaned reinstalled and put in new fluid...STILL no no pressure or forward reverse. Now what to do next?
If you haven't changed the trans filter do that next . What was the screen plugged with?if it's clutch material you will probably need to rebuild it. At the very least you will need to clean the control valves and check the orifice in the modulation valve.
Thanks Mobiltech, I saved the debris from the screen and will post/pic what was in there, I am concerned about the shape of the fluid that came out of the tank that was "new" at the time. Machine sat for a year after owner replaced fluid and it looked like chocolate milk/water mix. About cleaning,, umm if the entire system has this sludge mix, cleaning just the control and mod valves, filter re. would push it all to circulate to create pressure again, and then drain , flush refill, good to go/?
Here is a picture of what the screen looked like, metal shavings from?. I cracked every line and orifice and have good flow, still no pressure and no fwd./rvse. I'm going to need a schematic of the components/flow of this drive train if someone has please post or e-mail me. I'm stuck.
Check the pressures on these ports (B) Converter inlet (P3). (D) Speed clutch (P1). (E) Direction clutch (P2). (F) Transmission lube. If youre checking pressure at the filter housing on this model It looks like you will only be seeing lube pressure Right Side of Steering Clutch and Brake Control Valve (3) Steering clutch and brake control valve. (A) Priority valve. Note: A port on the left side of the valve at the same location may also be used to check pump/priority
Got these pressures, I can't locate 3 port A, unless it is against frame side and can't get to it, and don't understand on D and E, piston plug removed/installed. All pressures taken with just the port plug opened and gauge installed. B= 100psi. max rpm D= 375psi. in gear, 425psi. in neutral E = 325 psi F = 5+?..using 3000 psi gauge so it flickers a little near zero
Those pressures are good. The hydraulic side is ok so it should be driving. Does the torque output shaft stop turning when you put it in gear and does the engine lug down?
Nothing happens when put in any gear. Umm, the output shaft does not turn at all. Engine free revs like in neutral. All linkages are good.
Do you see any movement at all on the shaft between the torque and the trans as you engage the trans or shift? Watch carefully for a jerking motion, with those flakes you might have plate linings come off and piled up jamming a clutch or two. Trans has to come out anyway. Later Bob
If the shaft from the torque converter to the trans never turns and you have good pressures then you have a torque converter problem. Possibly shaft broken or splines gone.
No shaft movement, nothing. So, it would be fair to think the clutches are jammed preventing movement?. Anyway to unjam w/o pulling trans? What's involved with with this kind of repair?
It will need to come apart but first remove the drive shaft and make sure the converter will spin, then let us know. Later Bob
OK, was able to disconnect drive shaft. The converter spins and started engine and shaft spun freely. Trans shaft will not budge.
That debris in the screen is the left over from what is jamming some of your clutches up. The trans can only turn if two clutches are engaged. One speed one direction. Pull it out and take it apart. Major clean out job too, all lines and cooler plus case too. Later Bob
Thanks, I have been a material handling equipment tech and worked on lots of machinery but never a dozer. Before I get into trouble, do i need at least a forklift to pull trans or does it come apart in sections once the back cover is removed. I guess I'm asking what to expect when I pull that cover. Any particular sequence of dis-assembly? A parts blowup would help me tremendously. Also, I would like to tow this machine about 200 feet to work on it in a flat and dry landing, would pulling the axles make her towable?
Yes take the axles out to tow and to remove the trans. We had a pipe about 2 feet long welded to a disc that fits the back of the trans with 6 bolts. Take both flanges out together and you get the trans and bevel gear in one. It has rollers to support it coming out, rest it on a block then lift it up in the center. Later Bob
So I must remove the axles to pull the trans? Wish I could see that contraption you fabricated!
Before you pull the trans , take the driveshaft off and start the engine to see if the torque converter output yoke turns.
Get an extra cover for the pto and weld a piece of 2" pipe to it 2' long, drill a hole in the end for an eye bolt. you also need to take a 4' long piece of pipe and weld a 5/8"nc bolt into the end to the end to pull out the inner axles. Pay attention to what side they came out of. Be sure to get both back flanges out together then take the bevel gear off of the trans when out. Later Bob
Yes thanks, I have done this and the yolk spins freely with the engine running.
The second picture is of the pipe being used and the first picture is how you hook onto the top of the trans after you have it out to the end of the rails in the trans case
Stand the trans up on the back case, remove the hydraulic control valve stack, remove the three bolts holding the cases together and separate the bevel gear from the trans.
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Thanks for the pics. I am wondering where the clutches are located. All those metal pieces stuck in the pump screen came from? Also, what do you think the trans weighs, 1,000 lbs.? Axles? Trying to match/obtain the correct hoisting equipment. I know I can do this but need help from someone who has done all this already.
The weight is 950 pounds. When you separate the bevel gear and trans you will see the clutches.
Alright then, when I can do this I will post where we are, thanks for your help!
OK guys, I am ready to get going on this trans pull. Question, to pull the axles, i noticed oil level fill plug is at top of both plates. So, i guess remove the outside bolts to pull axle assembly, crack seal and drain oil that way? Can an axle be pulled by man or do i need a lift?
Axle is light, there are 4 of them and you need a 4' pipe with a 5/8NC bolt welded into it to get the inner ones out. Keep track of where they came out of. Later Bob
Thanks, I pulled the outer axles no problem and see the inner ones in about 2 feet, will need to get that tool made to yank em out. So with just the outer axles pulled it is safe to tow her to a workable area now or do the inner ones have to be out too?
Yes but do it slowly and have a machine chained behind it to hold it from running away down hill or into the towing machine. Later Bob
Right. OK then,will be working on getting tow machine to site and pull bar made and for the trans also. Thanks Bob for your help and quick replies. Will post on progress.
Finally got trans out! Now the fun begins. Not sure how to start dis-assembling to get the clutch pack out, the correct procedure that is?
PM me your machine Serial Number and your email address. I can send you the disassembly procedure for the transmission.
Got trans torn down, bottom planetary locked up from gears that broke apart and jammed up. Some discs are worn, others are like new.
Make sure you replace ALL the clutch piston seals while you are in there, even if they look good.
Getting Parts list together, can't seem to find part # 3845957 shaft, need 12ea., other than paying list price at Cat dealer. Also, looking ahead for trans fluid fill, didn't Cat change their recommended fluid to a TO-? affordable one for this antique?
That's a Classic Part #. Have you tried Offroad Equipment - www.offroadeq.com - for the original Part Number 9W-6044..? Anything SAE30 meeting Cat TO-2 specification or better will do for that unit. You may find trouble getting TO-2 these days, it will more likely be TO-4
Thanks Nige, I found all the parts now which also has the best bottom line on offroadeq. I am awaiting Cat Account to get processed so I can search their parts system/diagrams as the one I have is just general, no exploded view is what I need to verify for sure I'm ordering the correct parts. Something doesn't jive with the diagram now in comparison to what is apart on my workbench. For instance, this trans has 4 pistons, 2 are different from the first 2 with 2 seals each but I only see 2 pistons on the diagram. Also there are 16 specific clutch plates in the trans and the parts list call for 17? Manual appears to match serial #? Will search for fluid locally for starts.
Are you using the Parts Manual printout that I sent to you..? That was specific to your transmission S/N IIRC. The parts manual for the Planetary Transmission As is in 2 parts. Did I send you both of them..?
Yes I did receive both. I overlooked part 2. That is where they were hiding:cool2
Would you have an "exploded view" of this trans? I want to be sure this thing is correctly assembled. Not 100% confident. Also need torque specs for the clutch pack bolts, thanks
Sorry, no. The sectioned drawing from the Parts Manual is all I have. I did send you the Disassembly & Assembly instructions though, right ...? Follow those and you should be on the right track.
Right, double checked and am sure reassembly is correct, all looks good, just can't find the torque specs for those 6 "pack" bolts, I know they were TIGHT! Next comes the machine, cleaning out the case and all the fluid lines before i can re-install trans.
If there is no specification for the torque on a particular fastener mentioned in the Disassembly & Assembly intstructions then the torque required is the "standard" torque for whatever is the bolt diameter. If you post details of the bolt diameter or Part Number then it will be easy to find out what the torque should be.
Nige I was close, I guesstimated 85 ft. lbs. checked the standard table, turned out to be 80 lbs. for the 1/2" grade 8's. Very good help, sometimes we get so bogged down with the complicated we overlook the simple things!
Transmission is back in machine. Can't get axles in all the way, right inner needs to come to the right 2 inches but it seems to be bottomed out and will not go any further, left inner in and left outer sticks out that needed 2 inches. Axle's were marked coming out and put back reverse order. I'm stuck. Any suggestions ?
Put oil in the trans, start the machine and push in shafts while you drive slowly and the splines will line up. Later Bob
OK that worked, case full, axles in. Big problem now. Only 3rd gear engaging -FWD & REV. Nothing from 1st and 2nd. I ran 3rd gear back and forth and all of a sudden all gears started working fine... but machine will only want to turn left that is, when I pull back on left control, left track is controllable and right track continues to turn, however, pulling back on right control, little to no right turn occurs, right track jerks a little but does not stop and left track continues normally..Now here's the *** moment.. I got aggressive with the right control by yanking it back many times and all of a sudden she went hard right! Now, the right control works fine, and the left doesn't, now when I pull back on the left control to slow/stop it's movement, the left track only totally stops ALONG WITH the right track also stopping, so the left turn cannot be accomplished at all. When I release the left control, the engagement is not smooth, but a direct bang, and machine now wants to only travel with the left track running slightly faster than the right track (in all gears/speed) resulting in a constant slight right turn. She will not track straight. Also, the brake control was working fine and stop both tracks evenly until this episode, now when I step on brake, left track will stop but right track only slows down but will not completely stop! I checked all linkages and they appear normal and tight. Oh brother, now what?
I also noticed that the right control lever on the steering/brake valve body "clicks/stops" in a position about 1/4 way moved back. It never had this "stop" before the left control was working fine switched over to the right control working only. Left control is smooth throughout. I started it up today to see if I'm missing anything and found that upon putting trans in gear, the driveshaft stops turning as if I pushed down on the brake pedal and the machine does not move. After increasing engine rpm, putting trans in neutral and re-engaging into gear driveshaft keeps spinning and machine drives. Does anyone have a diagram of this steering/brake control system? If this is even the problem, pulling it out looks to be a nightmare. So to re-cap: -Machine pulls to the right in FWD/REV. -Left steering control stops both tracks, upon release, left axle slams hard into gear -Right steering control stops right track only (normal), but has that new "stop" in it's travel -Stepping hard on brake makes machine want to turn slightly to the left
I think you have some maybe a lot of the debris from the failure still in the system. I have not been following this repair closely, have you replaced or cleaned the oil cooler and washed all the lines aswell as the converter out? Later Bob
I cleaned the case,screen/tube,filter housing, pumped fresh oil through pump and ran engine/purged/flushed old oil out of system through open filter housing till clean oil was present. Did not remove or take apart anything else like the steering control valve, it looked extremely difficult do to it's location. Did not know about "oil cooler" or where it even is. I think I screwed up?
Check for two big hoses going to the lower rad tank. I would struggle the valve out and clean. Take apart carefully keep track of parts. Later Bob
I see 2 hoses, there is no valve just basic hyd fittings to rad. Steering brake box got purged out, didn't help. Ran machine and went to move small earth mound solid 4 ft. she would dig no problem about a foot then right track would stop and left track would continue to turn, when machine got hot forget it both tracks would stop completely. Cranking up rpms doesn't help just creates a whistling sound from transmission. It took multiple gear re-engaging to get it to move so seems logical there is a restriction some where and heat makes it worse. Then the puzzler how can the left steering control stop the right track? Steer valve spools hung up with debris? Checking trans pressures would be a place to start again?
The steering clutches need oil pressure to lock up. I suspect the three seal rings inside are worn out. Torque inlet relief is a ratio valve so low P1 pressure will make low torque pressure, oil will bypass torque and cooler and get hot. There is dirt in someplace. Later Bob
It sounds like the right steering clutch is staying released all the time. Are you sure the right steering valve is returning all the way or did you bend some linkage when pulling on it hard.
I pulled the top cover on the steer valve and you are correct, the play in right lever is from what appears to be the spool is not returning up to seat. Is it possible to dis-assemble this valve in place without pulling the whole thing?
Have you disconnected the control linkage from the valve to see if the problem is in the linkage.
OK, to all that are following this repair, steering/brake control valve was pulled today (along with pulled muscles!). Partial dis-assembly revealed the right clutch spool was stuck partially open, jammed up with contamination, I persuaded the valve spool out and no damage,scratches or nicks thank goodness. It is obvious the entire control valve needs to be Mr. cleaned, so that's the plan. Then re-install. A special thanks to you guys who have been instrumental with your guidance and wisdom helping me thru this immense undertaking for sure.:notworthy
Control valve was contaminated with pieces of metal jamming spool from returning and sludge. No damage, unbelievable! Installed and machine now is driving. Got an issue again (no, really), on the initial start up, driveshaft spins trans in neutral (normal), upon putting in any gear the driveshaft stops as if the brake is being applied. Then after several tries of all speeds, usually in 3rd she will engage and drive. then all speeds drive fine. After she's warmed up when changing speeds all speeds do not engage at all, within a moment or two they all come back normal again. Also she drives steers very sluggish at low rpm but responds quickly as rpm's are higher. Something is still out of whack, oil flow? restriction?
Get some gauges on the brakes and clutches, check at high and low throttle. levers in all positions. Come on back and we will know. Later Bob
Gonna have to wait till I can replace the only pressure gauge I had made up for this machine. Some knucklehead swiped it off machine. 'nother lesson learned
Have you had the transmission pump out yet? That could be the source of your metal in the steering valve.
The pump at the bottom of tank that has suction hose to it was replaced with a rebuilt one when the machine originally quit driving by the owner. That is the trans pump right?
With the amount of contamination you've had in your transmission and the lines, IMHO everything needs to come off, be opened up and cleaned out. Not only does it mean the system wiull be clean it also allows you to determine the condition of every component in the system.
I agree with Nige on the cleaning of the whole system. I know it sounds painful but from what we are reading here you will just be chasing your tail if you don't do it. This would include replacing the cooler.
These guys are Very Good And Pin Point everything ...I had the same situation in a away ..and metal shavings or tiny pieces found there way though the whole system..and I know its time and more money but knowing its clean and gone ..helps
All clean. Trans pressures good, 300 - 375 psi thru all speeds. Dug up 3 tree stumps and she quit driving...again! I moved the park lever down just a little bit and bam she started driving. So, not sure what the correct adjustment is but I took out the throw where she dis-engaged. Also, on a different system, what is the trick to get the blade "float" to work or should I start a new thread?
If you want the procedure for adjusting the park brake/transmission lock control + the transmission speed control linkages drop me a PM with your email address and the machine Serial Number. The blade control should have 4 positions - Lift, Hold, Lower, & Float. The Float position is as far forward as the lever will go past the Lower position. the lever should be spring-biased into the Hold position. Maybe again it's nothing more complex than making the correct adjustments in the linkage between the lever and the control valve. At least ensuring that the adjustment is correct would make a good starting point for troubleshooting your problem.
Would like to see a picture of the "contaminated with pieces of metal jamming spool from returning and sludge". As you mentioned the pump was replaced, did you disassemble the old one to see what it looked like inside? Would be nice to know how it looked. If it is anything like a D6C and just about all Cat trans. pumps over the years 4-3/8 bolts and it's apart in one minute. And if needed for a core only a few seconds more to reassemble. That way you would have some idea of what is going on in the system. Did not go back through all 5 pages of this topic, did you remove and clean all strainers and magnets and filter?
Old pump was originally replaced by owner and the "core" taken. I never saw it. Yes, all has been cleaned. Here's a couple pics from control valve.
Thanks got it. The blade control lever linkage was simply loose and not allowing float detent to work. Tightened up and easy fix for sure! Will work on trans linkages..racing against the rain clock so...will post when gone over.
OK linkages all good, ran machine 40 hours. Can only run easy about 4 hours straight before she quits driving. Trans case gets very hot, so logically, the oil cooler is restricted (trans pieces(. I see in the parts lookup that the cooler and radiator are separate but look like one part in machine. Anyone have the service page how to separate it, also parts diagram showing it & cooler line to filter housing? 8PB01842...thnx
Yes to both questions. Send me a PM with your email address.
How about the new filter, much metal in it? Has the torque been off and cleaned out? How do the cooler lines feel, both hot or one a lot cooler than the other? Later Bob
Excellent thought, Thank You!!! I mean the machine still quits driving after she gets hot BUT, yesterday, she would not clutch right...until she warmed up 5 minutes? New filter I will cut apart but when looking at, it looks very clean. TC no has not been touched, but drain plug drop revealed clean oil. Will check on the cooler lines this weekend. I remember the trucking guy said his dad had this same machine which had similar problems, is that true or like inherent to this model? He jumped into and drove this thing like he knew what to expect,ie. sluggish from the get go, crank 'er up a bit for starts and all is good... until she gets hot. Thanks guys let me run and get more data, Nige, Thanks for the PM help, I'm not sure on the cooler correctness, will inspect all this weekend and let you know. This has been a fiasco, but i guess we're getting there..BIG thought on Bob/Ont ..do you think TC is causing issue even if pressures are good?
What Bob is pointing out is that a failure like the one you had in your transmission (known as a "hard" failure because metal parts let go big style) will deposit small metal shavings all around the power train oil system which includes the torque converter and the cooler as well as pump and lines. Sod's Law says those little bits of metal will get into dark corners nowhere near drain plugs. UNLESS you get 99.9% of those particles out of the system it will most likely cause another failure of something in the system or simply, as it has in your case, leave you with a machine that "does not drive right". That's why after a hard failure the complete system has to come apart and be cleaned, or risk the consequences.
Sad but true! You can flush with a lighter weight oil and change filters till you are blue in the face and next time you are in the slop up to you know where and you absolutely have to finish the job today that one little chip is going to pope free and the results will ruin you weekend and beyond!
Hi All, I'm back! This machine was put away for the winter and just fired up as the ground now is workable. Everything you all said about what needs to be done, needs to be done! Remember, I offered the owner that I would "get her going again", which I did and explained that she has drive-ability issues again because contamination from the cooler(which is fouled out) is letting pieces loose and now the right track works intermittently, and the brake now doesn't work, pedal goes to floor. Since the owner didn't initially want to pay for a cooler replacement(or anything else for that matter) and now that he has the machine back and realized that it is a useless 12 ton chunk of steel after trying to run it, NOW he wants to properly pay to fix it the right way! Does anyone have a service diagram to do the oil cooler replacement? Thanks