Hello, i have a cat 922b with clutch pressure problems, it will start out at 250 psi, use it a while no set time, and then all of a sudden will loose pressure, i can shut it off and wait just a little bit and restart and it will come back to 250 again, but usually does not last as long as the first time. I have new 15-40 motor oil in the trans, changed the filter, and cleaned the screen (had nothing), and this made no differance. Have any ideas to my problem. Thanks Brent!
15w- 40 oil in the transmission ? Pretty sure that ain't the right oil to start with.
in the book it calls for straight 30wt, if it is below 32F you dilute with kerosene, so i just used a multi viscosity that they did not have in 1964. Brent.
I am thinking weak spring in control valve, or bad transmission pump. Brent.
Sandhills.... that oil should work fine for you , double check rating, it should be a TO2 if TO4,, so much the better, I'd say its a transmission pump laying down on you.. sadly to say they don't last forever. Take a pressure on the pump and follow it, if it drops of as you've stated , replace the pump. Pump change isn't too bad a job, couple hoses and bolts and she's out,,,, just the same they are heavy little buggers... good luck Gramps
Thanks so much for the info!! that is kind of where i was leaning. Brent
No problem Brent,,,, just let us know what the final fix turned out to be...
i can do that, maybe a week or two before i get it done, i am not using it any more for a while. Brent.
If you do dig into it I suggest when you rebuild use an SAE30 oil that meets TO-4 specification. Multigrade oils, especially engine oils, do not have the additive package required for transmission clutch service. It's very difficult for multigrades to meet TO-4 specs. Even in cold weather you should be fine with a 30 grade.
I am using 15-40 john Deere oil 50 plus, and it says it is a ci-4, i am really not sure what that means. What good name brand oil runs the TO-4? I am in the sticks here so it is a 75 mile drive to a town of more than 200 people. Thanks Brent.
I checked it out and it is spec out to cat TO-2 so i think i will be alright. Sorry for asking what To-4 was i found out it is cat oil number. Thanks again for all the help! Brent.
API CI-4 is an engine oil service classification, that would be logical as the oil is a multigrade viscosity SAE 15W/40. The latest word in engine oil specification is API CJ-4 Plus. TO-4 is a classification for transmission oils. Originally it started life as a Cat specification but later became an industry-wide standard for all power train oils. Some (but not many in my experience) oils can meet both engine and transmission classifications. TO-2 (aka Transmission Oil #2) was the former specification and has now been replaced by TO-4 with improved additive packages for modern powershift transmissions. However your 922B will be of an age where it was most likely designed to run on TO-2 oil originally anyway, so any oil meeting TO-2 should be fine to use in the tranny, even a mulitgrade. I checked out your J-D oil by the way and you're right, it does meet Caterpillar TO-2 specification. So it should do you fine in your loader. I wonder if you have a seal somehwere in the transmission control valve somewhere that has gone hard and lets go when it gets hot ..?
That maybe be, i do recall that i would fall down sometimes to a 100-150 then come back up, i was not just staring at the gauge because i was using it so could not watch it all the time, the trans works very well lots of power until the pressure falls off, and you don't notice it until it is under 100. Seems once it fall under 100 it falls clear off and never recovers, until i shut it off wait a while then i seem to come back around. I have only owned the machine for a few months and it just started this. That is the reason i am after some ideas and you guys been great help! Thanks again Brent.
Looking forward to the update! This thread is a great learning experience for a guy who is looking to know more about heavy equipment. ;D
I will update all when i have chance to get the new pump in, i have it, but a little on the cold side here right now, and i don't have a heated shop to do it in. If i needed right a this time i would get it done, but since i don't i am waiting for a warmer day, Thanks and stay tuned. Brent
Sounds more like the clutch pressure regulating valve acting up or the pump is losing its supply for some reason. A pump is either worn out or not, if it is shot then the pressure would be low all the time. Don't know about your machine, if the pump supply is external or internal, external check for a collapsed suction hose. Have heard of a rag left in the sump and getting sucked up into the suction screen then when you shut it off the rag drops off.
Whenever you get time man, not trying to rush you at all of course, just interested for the outcome.
I'm inclined to agree about the pump not being the cause. The transmission pump on the 922 is mounted on the top of the transmission case, and the hydraulic pump is attached to the transmission pump sharing a common drive, so the whole lot has to come off to get at the transmission pump.
Yea check pr valveon bell housing,suction strainer in drop box
Is there a check up to the pump? I checked the screen when i replaced the oil and had nothing in it, i did look it over the other day and it looks like someone has already done the pump, it is not cat yellow like the hydrualic pump, not saying it might not be bad. I am starting to think maybe i am loseing hydraulic suction for some reason, i usually just have to shut it off wait a minute and refire and go, it seems to be worse if you don't keep your rpms up. Anymore ideas or direction is greatly appreciated. Thanks guys for all the help Brent!
As soon as it shuts down check the oil level. Could be internal leak in convertor that is filling the case faster then it can drain back to the sump and the level is dropping below the suction screen. Has this happened since you bought it? Possible it has the wrong dipstick and just not enough oil in the system.
I have owned it 4-5 months it did not do it at first, but did not run for long period of time at first. I am sure oil level is right because i added 8 gallon per manual requirements and that seems to show full like it said to the dipstick, the dip stick looks to be factory, and not just any dipstick would work. I will check oil level as soon as i loose pressure and see what it is saying. Thanks for the ideas Brent.
when you check the oil hot with the engine running , leave it idle for a minute or 2 after you park before dippining it, if you dip it as soon as you pull up it will under-read for sure.
I check it right after i changed the oil and it was right on the full mark maybe even just a tad over, i have never checked it when the pressure dropped though, i only did it after i ran it and let it set for a bit at idel and it always checked fine. Thanks Brent.
I would double check your suction side of the system. If there is a hose in the line, replace it regardless of appearance. Seen a few that will seperate internally when flow is present. Really dont think you have a pump problem. Personnaly I would get some regular 30Wt trans oil in there too. Iknow engine oill will work, but it will work longer with trans oil. NAPA carries a 30wt trans oil and so does Cenex if those are eaier to find for you.
thanks for the reply, i have some TO-4 oil to put in it, i was going to add it when i done the pump change. I think i am going to do some hose changing and try to find any check valves or springs that maybe week or need attention before i do the pump. I have a parts book just need to do a little studying when i get a chance. Happy new year to everyone. Thanks Brent.
I know this is a very late reply, just never done anything to it, It worked as is never had time and never ran long periods so was OK. I did finally put some Lucas trans, conditioner in it. It seem to have fixed the problem. I think it was an o-ring in the selector because you could shift in different direction or shift speeds if the pressure started to drop and it would come right back. Hope this helps. Brent