Powershift transmission Original issue: Transmission would not engage when transmission fluid warmed up (180-190F). Added fluid changed transmission fluid, no effect. Suspected Transmission charge pump. While waiting for pump and other things, ran dozer until tranmsission rose to about 170F but before began slipping and/or not wabnting to engage. Parked dozer. Next day came back to move it to the garage to put in nrew charge pump. Would not move. Could hear going into gear, drive shaft would stop turning, and dozer would not move. Put in new charge pump, made no difference. Increasing idle causes motor to load (black smoke). Drive shaft (in forward) does try to creep a little. Current pressures: Drive Shaft: Spins freely in neutral, stops spinning in gear (F or R) Transmisison Charge Pump: 50-75 psi in neutral, 0 psi engaged Rear ports: Lower port (rt side): 0 psi at idle, 300 psi gear engaged High port (lt side): 250 psi at idle, 350 psi gear engaged Any new thoughts?
Drive shaft stopped turning, no real slippage sounds like something is bound up, brake(s), linkage for brake(s) a parking control that is not disengaging or a final that has finalized. There is something amiss AFTER the hydraulic system. Try putting in gear low throttle and making it turn If you have room, to either side to see if any movement, if none start digging into the brake system.
"Try putting in gear low throttle and making it turn If you have room" I have room but the drives shaft does not turn so cannot make a turn, Have tried playing with the brake handles but nothing. At high throttle, in first gear, the drive shaft and tracks try to move, i.e., they move very slowly. But engine under strain and have only done this once or twice for very short period. I am not a mechanic but do have a assembly/dissasembly manual.
You should really drop the coin to get a technician to look at it. Could save you literally hundreds in repair costs not chasing phantoms as could be something more simple or well expansive above your abilities. While you are trying to work it to figure it out may damage something else in process, so let a tech at it next chance you can call one.
I agree with you but not so easy around here. The nearest CAT dealer is 2-1/2 hours away and IF they come, they charge you per hour from the time they leave the office. Hence, you have a 5 hr charge even before they arrive. I called a few local people that work on dozers in the area, but none have time to take a look at it.
Recheck your pressures in gear, brake pedal released, pull 1 lever half way back to block oil to that steering clutch. Note: the machine might move! Then pull all the way back to block oil to that brake. Next do the same with the other lever! A change in trans pressure of more then about 20 psi indicates excessive leakage in that clutch or brake.
Being a dumba--, which port do I put the pressure guage. I opnly have 1 but think need to order a couple more. I assume you are talking about the ports in the back of the machine (transmission) but which one? Bite the big one and ordered service manual.
Start with the high (left) port which is called P1.
Will try to run the pressure tests in a day or 2 as it will take 2 people and the only one around to help me is away for a couple of days. Will do the pressure tests when he is available and get back to you. A local guy that works on dozers told me to pull the outer axles and see if the driveshaft rotates. That will isolate the issue to the brakes or drive. What you think about that? Let me also add something I had completely forgotten about. The brake handles, one of them (the lft) springs back all the way, feels like it is spring driven. The right does not and is loose in like the mid position, but otherwise operates just fine (broken spring?). I had noticed that sometimes when applying the left brake to turn, the dozer really slows down and the engine starts to bog down (yes, with black smoke). Pushing the rt handle all the way forward and the lft brake works perfect. My thoughts were they were binding with each other or something. Was going to open up the side panel to see what the linkage was doing, but other problems were a priority. Could this be related? More evidence a brake issue? Thanx
Yes, the lever not returning could be at least part of the problem!
koecon, YOU ARE ON THE RIGHT TRACK !!! Start engine. Engage gear. Play with brake/steering levers. Dozer moves !!!! By moiving levers to half position, lft/rt, I was able to move dozer about 30 yards forward and about 20 yards backwards. Engine working hard so didn't push it hard. Seems to me that the brakes are locked????
BTW. The parking break rod seems to have been broken long ago. Maybe bouncing on the rocks has moved the plunger/valve ?? Going to check that out now
Yes check that but I'm still concerned about high oil leakage in a clutch or brake. You do need another gauge because the trans pump pressure can not be less than the P1 pressure! Maybe an intermittent problem also.
Going to run pressure tests tomorrow. But here are some more interesting facts. As I said, the parking brake rod has been broken long ago and the linage is completely frozen. However, the rod that heads down to wherever is free (this I assume is what actually sets the parking brake). I can manualy (with a bar) move it up and down. But, whether up or down, seems to make no difference. Screwing around with the levers and stuff, the dozer now moves forward, not happily but it moves. Interestingly it moves in a straight path. Brake does not work anymore! When I step opn the brake, it could care less and continues in its straight path. Again, although moving at high trittle, it is not happy (black smoke). Whatever is holding it back, seems to be uniform, i.e., affecting both sides equally.
Sounds like the brakes are pretty much fully applied and you are driving through them. In first gear you should be able to do that but not in second and third.
Correct, only in first gear. Struggles in reverse.
From above, the pump pressure (at filter) is about 75psi at idle. P1 is about 300 psi at idle. Will do more testing tomorrow afternoon. How do I release the brakes is the big question...
By memory that's not possible! I might need to look at a schematic to varify.
Does machine relax once you shut it off and pull on levers? If so you've got good brakes and sufficient pressure. Sure sounds like a linkage issue. Fixed many a machine that was simply bound up. I'm not intimately familiar with this machine like I am a D11 but they function similar. Pull the floor out of it or whatever you need to get to where the linkage goes from the levers to the control valve. The lever that you flip down to lock out the left and right levers also applies the brake. It may be bound up and stuck on. Get all that free and working correctly before you mess with anything else. I've seen some with linkage so worn and stiff we added bungies to it as a return to help release brake when safety lever was flipped up to operate. If machine pulls good on both sides when working you shouldn't have a steering clutch seal leaking or excessive wear. If it pulls good on one side and not the other then I'd be more inclined to think you have a bad seal or worn out parts. Kind of repeating where you're headed but I've seen it before and been told it had to be internal only to have fixed it without even hooking a gauge up. FYI the test fittings should be male PD. On big machines there are four, one each side brake and one each side steering clutch. Should see around 300 give or take 15-20 if it's anything like the 11.
Those pressures are possible because the filter only supplies lubrication oil. Have you inspected the pump suction screen and filter for debris from a component failure?
Changed the transmission filter early on (one of the very first things I did). The filter was clean with no debri or anything else. Have not pulled the suction screen as I believe you have to drain out all the tranny fluid (31 gallons?) to do that. Recall that this recent issue of dozer not moving was a spontaneous occurrance and did not happen while working the machine. The dozer was working fine, steering normal lft and right, etc., Shut off and next morning did not move. Thus, I would not be very suspicious of a slow leak or a partially clogged suction cut, etc as these would (I would think) be gradual failures during working.
strange, unless I write something here, the above post of mine does not appear..
UPDATE : YOu guys have been great. I managed to get the dozer back to the barn so I have power tools, powerwashers, welders, etc to do some work. The dozer did not like it too much, particularlky going up hill and I could only really move in 1st gear but made it with out too much strain. May have learned a few things on the trip. First, I really did nothing to make it move. I played with levers and valvesto make sure everything was moving free. But did nothing that would have changed anything. The brake(s) are definately at least partially engaged. I beliebe this because the dozer is obviously "dragging" and when moving and taking ot out of gear, it is liker slamming on the brakes. Abruptly stops the second it comes out of gear. I believe it is both brakes because the dozer moves in a straight line, I can steer rt & lft, but when I let go, we go in a straight line. This would suggest to me that both brakes are applied equally. Agree???? I don't think it is the barking brake as this has been broken since I owned it. The valve is free (moves up and down) and automatically returned to the up position (disengaged) Now moving the dozer and making a sharp right turn (90 degrees), the dozer would not turn and had to literally jam the handle back to engage the brake. After m,making the turn and releasiong the handle we were back to normal drag. After that it did steer but upon releasing the handle it would feel like the brakes were slammed on before releasing and moving forward again. So, we have something not right with the rt brake/steering and something causing both brakes to be at least partially applied. The brake petal (B) and the rt brake (A) both go into box C (see photo). I am just guessing because I am not a mechanic and know less about dozers as this is the first one I have ever owned. Does this all sound logical that the problem is in box C (whatever that is officially called)? Isd there anyway to test this hypothesis? Any thoughts and advise would be appreciated.
I do not have a layout on one of these but sounds as you are on the right track. As to the straightline, can still be just one brake dragging as the steer works by releasing a clutch to the side you want to turn to and these machines generally have no differential just a spool for the bevel(ring) gear. Needless to say, anything bound or binding up needs to work free on these to keep from having problems.
Dont believe it is the parking brake. As I said, it has always been broken, the valve (outside lever) at casing, moves up and down freely, is in the up (disengage position), does not move further up (even with a crowbar). Is there anyway to test the operation of that box (C)? Plan to take the top off to see what is inside after I clean things up abit. Also plan to do some oopressure checks on P1 and P2 today. Still have no idea where the check points are under the floorboard to check as suggested
Box (C) is the steering clutch and brake valve and there should be test ports or plugs on the front to test pressures. I think you will find a problem with the parking brake valve inside that valve.
there are only plugs (look like freezeout plugs) on the front. Parking brake does not go into this box Parking brake linkage is screwed and would need to find parts or modify to get operational (but again, valve is free and unengaged)
What is the machine serial number?
On an 8PB the parking brake valve is bolted to the steering clutch and brake valve down low on the valve. It has a spring and poppet inside that may be the issue. A bad poppet, seat or spring will cause this issue. There are 4 plugs below the ones you saw to remove and install 6V3965 test nipples in to test clutch and brake pressures.
Koecon, there are no other ports than the 3 shown in the photo below. Is 6V3965 a part number? Not look really appealing to pull these plugs!
I am going to separate my posts into 2 (maybe 3 separate ones. So, FIRST POST: Other than screw with linkages, I really have done nothing. Because I felt it was work too hard for too long, I had parked it near the barn with [plans to move it today. This morning, the dozer is working just fine (minor issue) – the brakes were not dragging and the dozer had all the power it had in the past. I hate fixing things without any idea why. But, first things first – fix all the handles and levers. Took apart all the linages associated with the brakes. Every single bearing is shot – essentially nonexistent. Hammers, crowbars, oil, and wedges to get it all apart. I need all new bearings. See images 2 (parking brake) and image 1 (brake/steering) If anyone has the parts manual for this machine and all the bearings, that would be a big help . Plan on calling cat but without a parts diagram, might be difficult. Guess I need to invest in a parts catalog, but in the meantime, any help would be appreciated. Will see where we are when all the linkages are back to good working order without any slop. Again, if anyone has the part numbers for all these bearings , it would be a great help Above, what left of steering/btake bearings Above what left of parking brake. Broken rod not shown Thanx again to everyone.
SECOND POST: Pressures: P1 (back of transmission, left top port) Low idle: 50 High Idle: 350 Apply foot brake: 350 Rt brake ½: 350 Rt Brake, Full: 350 (drops to 250 for split second as lever moved back to free position) Lt Brake, ½: 350 Lt Brake, Full 350 (drops to 250 for split second as lever moved back to free position) In Gear (low rpm): 45-50* In gear (high rpm): 350 NOTE: transmission not engaging at low rpm (deaccelerator fully depressed) P2 (back of transmission, right lower port: Low idle: 0 High Idle: 0 Apply foot brake: 0 Rt brake ½: 0 Rt Brake, Full: 0 Lt Brake, ½: 0 Lt Brake, Full: 0 In Gear (low rpm): 0* In gear (high rpm): 350 *transmission in gear but not engaged. `This is kind of a new development but may simply be because fluid is a little low from when I changed the pump.
Down another 4 to 5 inches! The 6V number is for the test nipples, need machine serial number!
50 PSI is too low, could be low oil or a leak, need machine serial number!
9DB01002
Here are linkage parts pages! Enjoy. https://mega.nz/#F!wQIm1CxB!sKQyXbcvhhpg6ndq3_7QXw
koecon, Thank you so much for the effort you put in getting these schematics. Unfortunately they do not show what I need. I need all the components, the bearings, seals, spacers, etc., within the linkage shown in the image attached. It took about an hour on the phone with CAT, buit I have a bunch of bearings and stuff arriving in the CAT box tomorrow. We will find out tomorrow if they are the correct ones. Other than that linage there and the parking brake linkage (which also has bearings, seals, and spacers), everything else is tight. We shall see in a few days. Thank you and everyone else again.
The exploded view shows the shaft, bearings,seals etc. and a parts list should be with it. Anyway if we helped please click the like button to show appreciation! Good luck and hope to hear back from you!
Ebay is a great source for manuals for your machine. Here's some parts books for sale on there, it cuts down on the dealer phone ordering time and hassle: https://www.ebay.com/sch/i.html?_od...anual.TRS0&_nkw=d4h+9db+parts+manual&_sacat=0