I’ve got a 2005 D6R XW, my grandpa bought brand new in 2005. 3600 original hours (believe it or not), been a farm dozer all its life. Lately it has started acting up. When cool, the dozer has all 3 gears in forward and reverse. But once it gets warmed up, it hits a point, you shift to 2nd in either forward or reverse and it slams into gear, and locks up in it. This goes along for 3rd. It seems to bog and try to move but it just won’t let it. I changed the transmission oil, and it had some parts of clutch in it, but not a overly whole ton for the amount of hours we have on the oil, and for the age of the oil. Still did not fix the problem. Any help whatsoever would be much appreciated, I’m stumped and a bit frustrated with it.
Please post a Serial Number and answer the question do you have 2 x 600psi pressure gauges available.? Also what oil are you using in the transmission.?
Did it look or smell burned?
AEP00681, Cat TDTO 30 weight, I do not have gauges, but I could probably get my hands on a set
Smelled a little burned, came out awfully dark if you ask me
It should clear and bright in appearance and a light straw colour, not dark and opaque. Apart from the smell that's your first clue that it is burned. That's the correct oil. Just checking. Where exactly did you find the clutch material.?
Yes, it was far from bright, and light in color. Clutch material was in the suction screen for the transmission pump
In that case it's time to hook up a couple of pressure gauges. they need to be capable to read at least 500psi. Do the tests with the oil warmed up to normal operating temperature. Test the main relief valve pressure (P) first, followed by the speed/direction clutches. Two clutches (1 speed + 1 direction) have to be engaged to select any gear. The clutches references are as follows: - #1 - Reverse direction #2 - Forward direction #3 - 3rd speed #4 - 2nd speed #5 - 1st speed Also attached some transmission troubleshooting procedures that you may find useful.
Did you remove the square plate held in place by 4 x 3/8" bolts at the lower section of the rear case above the Wishbone draw bar, inside is a mesh screen that collects lots of black bits of paper, if they are found your clutch packs are stuffed, the 3rd speed to fail is not common as it near never gets used and can be subject to an owner delete choice, check the screen then run the pressure tests but be aware the shift valves on the transmission use P.W.M. pulse width modulation to work, think of it as a low voltage fast flashing light and you understand it. best of luck.
That's the arrowed one below. If you haven't removed it yet then you should. You will need to drain the oil first though. Take photos of whatever you find.
When I changed the oil, I removed that plate and cleaned the screen. Lots of black gunk in there, screen was pretty full
That “black gunk” was most likely the remains of the 2nd & 3rd speed clutches. I reckon it’s transmission out time. Sorry to be the bearer of bad tidings.
I had a sinking suspicion. Thank you all for your help. Anyone know anybody in the Central Iowa area who works on dozers and would want to tackle this? I would hate to know what cat is going to want for it.
How good are you with tools.? If you could get the tranny out and out it back in again you’d save yourself a load of coin. The other bad news is that in a multiple clutch failure such as that debris gets everywhere in the system. It really requires all the transmission lines to be cleaned, the cooler to be removed & cleaned, and normally the transmission pump to be replaced. In your case with only 3600 hours on the tractor you would probably get away with a strip, inspect, & reseal of the pump. This is not a small job if it is done right.
Sounds like it is not relieving the pressure from 1st speed clutch or the clutch discs are just sticking together due to failure causing the clutch to stay engaged. That is why it is locked when trying 2nd or 3rd speeds. It will lock up with 2 speed clutches locked at the same time. Would need to check 1st speed clutch pressure when locked up in 2nd speed. If it still has pressure then it could be a modulator valve.
If the information from the OP is correct regarding finding a shed load of clutch material in the transmission scavenge screen is correct then the transmission is coming out either way. At the time the transmission is overhauled the 5 clutch modulation valves should be replaced. It’s SOP on a transmission overhaul.
When you unbolt that square plate that has the screen behind and find loads of black flakes the transmission is a knacker job, if you want to tackle the removal then refit we will tell you all you need, if you want to rebuild it we will also tell you how to do it, I am a few months off 70 and can get those transmissions out with no help by myself on site in 4 hours if I am busy, 5 hours tops if I stop for coffee, so a young man like yourself should cream me, it's your shout chap, is the Tractor an LGP?
Thank you guys for all the help. I am thinking that I am wanting to tackle this myself, just don’t have loads of time at this moment. Thinking it will be a good winter project. Tractor is a XW, not a LGP.
Not to go too deep but here are the instructions for removing the transmission. There are other sections to disassemble, reassemble, and reinstall it. Also parts manual prints will be available. The FT1897 Bracket I have a drawing so you can fabricate it. There is also a tool required for removing the axle shafts but it can also be fabricated. Apart from that pretty much everything else required to disassemble & reassemble the transmission you can fabricate.
I'm too far away to help.
The tube you bolt on to the round plate location is a simple thing to make but needs to be a good bit of tube not thin crap, the tool to remove the axle shafts is just a bolt welded to a solid bar, the tool you need to pull the drive collar off the shaft can be a length of flat strip steel with a short (1" to 1"1/4) 90 deg' bend on the end, from the back of the Tractor 2 shafts come out of the left side and only 1 shaft comes out of the right side, I connect a hydraulic hose with an On Off tap and a quick connect pressure test coupling onto the test point on the high pressure oil filter with the open end placed in an empty barrel, then start the engine and open the tap stood by the door, this pumps the oil out until you hear the pump spluttering then shut off the engine, another 5 to 6 U.K. gallons drained from the rear right hand plug will be enough to allow the transmission to be removed, always remove the Wishbone hitch and get the thing well out the way, the job is easy enough and nothing more than a few bolts, you will need 2 lifting lugs and a 50 mm spanner to undo the oil feed line, as I said I can do this job easy in 4 hours by myself so plan another job for after Lunch.
Well I got a quote from the dealer… sure glad I was sitting down. $157,000!?!?! Is it just me or does that sound a little high? I could buy two dozers in the same shape with a few more hours on them for that.
What exactly were they quoting for that price.? I hope the quote was detailed.
Transmission removal, overhaul, and complete power train clean out
That’s not very detailed. What caveats did they put on the price.?
Surely some mistake for a D6R trans at $157k?
If they are quoting to do it by the book then included in the price there will be a Reman transmission, new pump, reman transmission cooler, labour & materials to sponge gun all the powertrain oil lines, loads of D&A to clean out the contamination, etc, etc. I was hoping that the quote supplied to the OP would be sufficiently detailed to enable us to pick it apart a litlle bit. It's somewhat disappointing that it isn't, but I've been disappointed before.........
Getting really frustrated with the dealer. Won’t put anything in writing, just verbally. They say “it’s worst case scenario”. Won’t know the price till they get into it they claim. If you ask me I don’t have a good gut feeling about any of it
It's basically CYA. They're frightened to put anything in writing in case it blows up in their faces when they finally get the transmission apart, so for that reason the quoted price is somewhere in the stars. All the knowledge is right here. With help from this forum you don't need to be afraid to tackle this repair yourself.
For a $157K I would File a new D6R out of a Solid Block of Steel, I would expect to have about 6 to 8 days work in sorting the Transmission, that is pulling it out, stripping it down and listing the parts needed, sorting the Torque case by checking the amount of crap in the housing and looking for any bits in the small screen behind the pipe, flushing out a few oil lines and replacing the oil cooler, flushing out the filter case and fitting new filter, rebuilding the transmission and refitting with new modulation valves, then getting it E.T. set up by doing the clutch pressure calibration then the clutch fill calibration, you will never get all the pipe work spotless that is what the filter is there for, non of this is hard even a Donkey like me can do it, the oil pump might need looking into it's only a few O rings to sort it after inspection, or just leave it and test pressure at low/high idle.
‘file a new D6 out of a block of steel’ Brilliant Tony
Update: got pretty frustrated with the dealer, told them that I need a for sure number and none of this “what if” numbers. Said some things over the phone, sure got them going. Now they are coming out to figure out exactly what failed in the transmission. I will keep you all updated with what exactly they find.
Whatever they do and tell you, get it all in writing.
Save your coins and fix it yourself Chap.
What they actually said was 'we ain't interested in doing it' But if we do we're going to make mega bucks.
Sounds like the place I was talking to about helping with my rezoning application. Gave me an estimate so high I'd have to be completely bonkers with a suitcase full of money to accept it.
Or to put it another way - “we don’t like doing business with farmers“. No offence intended.
Got a update… Clutch 1&2&3 pressures reading fine Clutch 4 and 5 have some odd stuff going on Starting with clutch 4, pressures vary, starts at 320, drops to 50 psi, then goes clear up to 375 psi Clutch 5 has pressure all the time, at 370 psi
Under what conditions exactly are you measuring the pressures.? Was the transmission oil at normal operating temperature.?
You can mess about with 5 gauges plugged on to all 5 modulating control valves but it will not change or prove nothing when you find loads of black flakes in the rear most mesh screen, if you have flakes in the mesh the transmission is a knacker job, drop off the wishbone hitch and get that case emptied, your wasting good daylight sticking test lines on it, the clutch pressures are not the same in every position that why you run a clutch pressure calibration then a clutch fill calibration, different clutches different pressures.
Operating temperature
Clutch 5 having pressure all the time makes sense for the problem you’re having. That is first gear clutch. If it doesn’t release you will have a lock up of the trans when second or third apply. You must have a stuck modulation valve on 5. Probably got a piece of crap in it.
The numbers 1-5 on the illustration below correspond to the five modulating valves for clutches 1 through 5. I'm not sure if you can actually get at the modulating valve for #5 clutch through the access panel at the top rear of the transmission. You may have to remove one or more of the other modulating valves in order to gain access. If you do then mark which one went where on removal and make sure when reassembling to put each valve back in the same location from which it was removed. Unfortunately there is no view of the inside of the modulating valve showing the spool, but if you remove the coil #3 then remove the guts of the solenoid valve that should give you access to the spool inside the valve body.
Just a question Nige does this machine have the plastic position sensor for the transmission control??
Do you mean this one.?
possibly I've seen those things do some pretty weird stuff had a dozer one time engage three clutches at one time, no codes the only way i found it was looking at status. Just a thought when you said number 5 was powered all the time
That wasn't me, that was @Mobiltech I think the suggestion is that the spool inside the modulating valve for #5 clutch might be seized by some contamination and therefore have said clutch permanently pressurized even when the solenoid valve is not powered up electrically.
You can get a line onto all the modulating valve test points easily, but as I said before if the back filter screen has bits of black paper in it the transmission is a knacker job, the modulating valves can be pulled to bits and cleaned out to some degree, but the bits of black stuff will soon find its way to mess them up again, all that heating up oil temperature and studying the gauges is going no place, pull out the lid and drain down the high pressure transmission filter via the bottom plug into a clean pot, then check out what you find, tell me more about Post 11.
This post started on the 21st of October, the transmission could have been stripped, rebuilt and back working easily by now, a little thing to think about is the modulating valves in the U.K. are around £500 each and need the 2 calibrations to work correctly, so don't start wasting cash on them if the system is full of crap as they will fail in no time, to do a big hit on the transmission repair would be way less than £20'000 if the pump is not scrap.
to the OP. If you want to see a how transmission is pulled (yes I know this is a D6N not a D6R but they are not that different) take a look at this video.
You can easily reach in through the back plate and remove any or all of the modulation control valves, I f I recall the 1st speed valve has the red wire to it and should have 320 psi to it, you can strip the valves to bits and blow them out if they are O.E. valves, but the common cause of them failing is bits of plate entering them as the transmission fails or coil knackered, the other valves you could swap them about with that at set at the same pressure are C1 and C2, these are the forward and reverse control valves the forward is a blue wire with reverse being green, this is just off my head so it is worth checking.
The Video was sort of fun to watch but what can I say, firstly he made no comment about removing the drive shaft coupling and the seal plate behind it, he never used a test point to pump out the trans'oil as this saves a lot of time, then he made hard work filling the case with oil as lots of it could have been poured in via the back plate, he should have washed it off before bringing it into the Shop, also he should have tested all his clutch pack seals with Shop Air at around 60 psi, this would have soon shown up the seals he fitted incorrectly.
With the price cat quoted I’m pretty sure you fly out any person on here that has the knowledge and the want to and be at least 100000 ahead
That’s what I thought also, that D6 looks rough
@nffarms58 Contact Nick's AG & Construction Repair. He's based out of southern MN and a previous Ziegler Cat field guy. He could repair it right for a fraction of the cost of Ziggy's Cat house with no rework.
Thought I would update you guys, we did pull the tranny, flushed everything, lines, cooler, etc. Was a total 2nd gear failure. We still do not know what caused it, but there was a broken wire in the transmission. There was absolutely nothing left of the clutch pack for 2nd gear.
Were the modulating valves replaced while you had the transmission tore apart.? What exactly was the broken wire, for a modulating valve or a speed sensor, or what.?
Totally overhauled the transmission, new valves, harnesses, clutch packs, the whole works
Worth noting as well, we dropped the torque converter and went through it
Find anything relevant, or was it just simply tired.?
We dropped it just to make sure it was clean and was not contaminated. Nothing was tore up in there, just preventative
The Torque shaft speed sensor is a common thing to fail, that's the sensor that sits vertical on the drive shaft housing, I like to set this one with a tad more clearance than the spec'.
Did you do the work or have the dealer rebuild the transmission? Dealer labor rates has gotten high.
I found a private guy who went out on his own. He’s been great to work with and has been very reasonable. Sure beats dealer rates