I have a 1986 cat 931b that has recently started to shift slowly and get worse after about an hour or hour and half of use. Ser number is a 29Y1, 3F3R. Reverse always works, forward is normal after it finally shifts. Fluid level is full, pressure test approx. 100 psi in neutral or waiting to shift then moves to around 350 psi after shift hot and cold. Pressure stays the same in all gears. Have not checked the transmission screen since reverse worked and pressure seemed ok. After warmed up it may take a minute or two for it shift, then goes fine. Any suggestions on what to check first? I do have a service manual. Thanks
Mike try sending a private message. or email [email protected] Later Bob
Hi Bob, thought I would let you know how the repair went. I removed the valve and replaced the screened orifice, all seals and most of the springs. The screened orifice looked to be in good shape. All of the seals were flat and hard, one of the detent seals tore apart when I removed it. Since reinstalling the valve I’ve used the loader 2 times for 2 to 3 hours each and have not had any problems. I guess a seal or a combination of several was the problem. Thank you very much for the help, you put me in the right place. It also seems to shift faster in both directions, hot or cold. Thanks again
Your welcome Mike, that repair should make your trans last longer too. Later Bob
Hello Bob/Ont, My 931b is slow in 3 gear, does the parts for the transmission control valve come in a kit or buy them seperate?? also the relief valve. thanks, sam.
Sam, there may be a kit but it would need a Transmission Arrangement number (it will be listed on the transmission data plate) plus trans Serial No. & Machine S/No. to give you a definitive answer. There appears to be a mountain of possibilities and it would be too easy to get the wrong one.
Thanks to Bob/ Ont, and Nige, Its best to Ask a PRO like them when a novice like me does not have a clue if something is working correct or not. I hope to get this machine moved to the job site in a week or two, and i want to make sure that everything is as good working as possible. thanks sam.
Hi HEF, well i have been running the old 931b a few days, it does not want to push in first after it gets hot, i have done almost all work in 2 gear. The Transmission is a ( 1AA01874 ) and (7G7599) , If i re-build the control valve will that help?? any advice, i do not have a book on the transmission, sam.
Sam the gasket kit for the transmission control is/was 6V-2214. However according to the system it's been discontinued - that doesn't necessarily mean there aren't some hanging around somewhere. You might try your local dealer to see if they can find you one. Other than that it's separate parts. Sorry can't help you with a peper Parts Manual but PM me your e-mail address and the full machine Serial Number and I may be able to do something for you.
Thanks for the help Nige, sam.
Hi HEF, I found the Kit from a online co., 6V2214, wanted to post a photo so you can see what comes in the kit, sam. Kit 6V2224
Sam, you got the latest version of the 6V2214 kit before it was discontinued. The 3 after the part number tells me that.
Nige, thanks for the help, i do have another guestion, do the o-rings last for a long time ? under normal use/ light use ? sam.
Heat cycles will harden them up over time, but what affects o-rings most is the machine sitting unused for long periods of time.