ok so I have a old piece of iron I am working on. Its a straight case 850 with several issues. My first question is what does the stock oem key look like that fits this dozer just dont want to order the wrong key. Backstory this will be a full rebuild from bottom to top. Current main problem is torque convertor I do believe.
Welcome to HEF @Tnfarmertravis This should be the key you're looking for - (part #D35092 complete switch & key set)
Thank you for the quick response sir.
So here is some backstory, the dozer i purchased worked just fine original owner loaned it out. That person then sank it in a mud hole and left it submersed for a good while. I have drained all fluids and replaced multiple times until all fluids were clean. The problem the machine now has is it will move forward and reverse, but it stalls and the driveshaft stops spinning. I can drop in neutral and put back in gear then it will move again. now when it stalls if i really add additional throttle it will move but doesn't have much torque. I have checked strainer and replaced the filter behind the seat, also I have pulled charge pump and it seems to be tight and fine. I then pulled the side panel off the torque converter to see it spinning when the machine stalls the flex plates and torque converter both are still spinning, this leads me to believe the torque converter is not producing sufficient pressure thoughts? that cavity was also dry like its supposed to be. No external leaks on the dozer other than a few small hydraulic drippings from lines needing replaced. if water got in the torque converter could it have ruined it? I know i have drained it now and has new oil in it so i know its good. also my gauges on the dash all unfortunately were smashed in by the gentlemen grandson, looking for replacements with not a lot of luck so far, so i do not know what pressure it is generating. I have read elsewhere to pull the transmission pressure regulator valve and the relief valve assembly what does this do and what should i be looking for? I know this is alot in one post but just excited to find knowledgeable folks, been spinning my wheels for far to long dont want to spend a ton of money on new torque converter without knowing its bad for sure.
Welcome to HEF; If you have a pressure gauge 0-600 psi range plumb it into torque converter to see what pressure is.
I will try that tomorrow. Thank you for your response.
Ok so I plumbed up a pressure gauge on the torque converter. When I first started it up it idled at about 38psi raise the rpm to 1800 to 2000 and it would push 55 psi. But once it warmed up it would not go above 40 psi in any gear position or amount of throttle most of the time it would hang around 38psi at best. Lowest end I seen was around 25-26psi. Most of the time this was when I was shifting Thoughts ?
Also the transmission pressure is as follows. Idle 215 psi 1800-2000 rpm 280-290 psi In gear high low and neutral 255-260 psi No change as machine warms up really.
Your pressure is low. Could be the pump. Could be leakage inside the converter from worn parts. If there was any mud inside the transmission - it can never really be completely flushed out - it gets into everything, (valves, clutch packs) especially if the machine was run with mud inside it. Also, if it has been run with mud inside it, there is usually alot of wear caused to aluminium/alloy items. In my experience, short of pulling things apart & cleaning it all out & replacing worn items - you may never get the machine to operate correctly. PS - hopefully the grandson got his @ss kicked
Oh he did for sure, now when you say my pressure is low are you talking on the transmission side or the torque converter side?
The Converter pressure is generally low, & it will differ during range selection. The transmission is good in neutral, but is lower when engaged - indicating leakage. (shaft end cap seals OR clutch pack piston seals OR both) Also, with the transmission you need to check each different range - low, high,(L&R) fwd, rev.(L&R) & do it at an idle with minimum amount of pump oil flow, comparing pressure from neutral to when gear is selected - it should be the same. Each change should show the same pressure & each track take the same time to engage.
Thank you sir, very thorough response. I greatly appreciate your help.
The pressure did stay relatively the same at a idle. I dont think mud was in the transmission it was more of a water intrusion. Oil was milk basically. Also I ran it just now for 20 to 30 mins as the machine got warm and everything got to tempature all of the pressures went to crap. Across the board all pressures fell out, the only thing producing all the pressure is the pump, maybe the pump is faulty once it gets to temp? Whats your thoughts?
Did you flush the transmission and change filters until the oil is clean ? Is the check valve (#13) in the filter ?
Yes the check valve is in, and the transmission as well as every fluid in the machine was flushed and replaced multiple times.
Years ago I had a customer bury a 1150 dozer in a creek bottom and left it there for an entire weekend. Water had infiltrated the entire drive system and we spent thousands trying to get the transmission working right. We never could get it working for more than a few days at a time.....then even more money spent on cleaning. The machine eventually had a complete tear down and rebuild of the torque and transmission at over 25K.
well this really pops my bubble unfortunately. At least I'm not in to deep on it.