I recently acquired a 1980 980c project, shifter seems to be stuck in neutral, stick will not twist to change thru the 4 speeds. Shifter works when cables unhooked, cables seem fine, linkage seems bound up in valve body, any ideas? Thanks in advance.
You will need to disconnect the cables at the transmission and see if the control valve spools can move. You may have to remove the operator seat & plate from the floor of the cab for access from memory.
I was just thinking is it possible the machine was on fire at one time? I think your best plan of attack is to pull the valves out of transmission and free every thing up we used to polish the spools with crocus paper
Hi, I did remove the seat and access panel and removed the cover off what looks to be the lockout solenoid, I will dig deeper this weekend and let you know what I find. the last owner said when the loader quit moving he dumped the fluid and found a nut or clip in the screen, I will see if I can get the parts he found for identification. Thank you DieselFit!
Thank you Pittsburgh Cat Man, the machine was not burnt, the last owner said it just stopped moving and when he dumped the fluid he found a nut or clip in the screen, I will see if he still has the pieces so I can ID them. I believe the valve body will need to come out for inspection. Thank you for the help and I will let you know what I find.
Hope he still has the parts to try to identify what they are and where they came from! Been many years since I worked on one of those but I'll try to keep an eye on what you find on the chance my old brain has any ideas! If you pull cover off the transmission maybe post a picture or two might refresh someone's mind on something.
Thank you Sir, much appreciated! more to come.
Take the cables off at transmission see if you can make the spools with a screwdriver in the hook where the cable goes if you can move the spools the next thing put cables back on and you need to check transmission pressure if you get around 70 pounds instead of 350 at p1 let me know
Good Morning Pittsburg Cat Man, I finally got around to the old 980c, spools freed up, changed trans fluid and filter, checked P1 tap on top of filter housing and got 35 psi warm in any/all gears forward and reverse, at idle, needle pulses around a bit at half throttle but never above 55or 60 psi. there is a small oil leak around the starter, I have been told the bell housing has oil in it? excuse my ignorance but this is all new to me and I did have the starter out and could have messed up the seal. I did cut the old filter and did the vise squish, no clutch material, no aluminum, just some not a bunch of shiny metal flakes. A "buddy" says it could be the transmission pump? I am hoping that's the problem but I could never get that lucky!
I think I would pull the little cover on the top cover on transmission check p1 and p2 if it’s around 60-80 psi pull the control valve flip it over there is a screened orfice they break and plug the load piston witch gives you a low pressure like you have on the bright side if that’s it is a lot cheaper than a pump
Thank you, I will give this a go and get back to you. Troy
Ok, under the round cover on top of the transmission, P1 20 psi warmed up at idle in neutral, fwd,rev, any speed. 160 psi at high idle again any speed fwd or reverse. P2 , 0 psi at any speed in any gear. Does this help any? Thank you, Troy
I did notice the fluid was low before I started testing today, filled it and got the above readings, I rechecked the port on the filter housing and got better readings, 49 psi warm in any gear in any speed, about 220 psi full throttle in any speed, any gear.
I think I would pull the pressure control out check the orfice and check the spools and springs while it’s out replacing o-rings on tubes would be a good idea
One more thing the small bolts are 5/16 12 point you can lift all of the valves and manifolds out in one piece by just pulling the 9/16 head bolts remember you have to slide tubes out of valve I always pulled all the bolts that sucker is heavy in one piece
Thank you Sir, I will tackle this next. More to come, thank you again! I owe you big! Troy
One more thing, I do have the big service manual, but what are the "tubes" you said have to be slid out of the valve? Thanks, Troy
You will see them when you pull the top cover two larger ones and one small one have to pull a plug on outside to get smaller one look at disassembly assembly for transmission in your service manual
Got it!
Hello, update on the old 980, valve out and all apart, thank goodness for the service manual! Not to bad of a job. I'm no transmission guy but I didn't see anything that made me think "wow, that's not good!", The spools don't look worn, some of them were kinda stuck especially the neutralizer valve, I'm going to Ziegler Friday, hopefully they can get a seal kit for the valve? The little plastic screen you mentioned is still intact but probably brittle from age, that should be in the seal kit. Along with all the new o-rings. What am I missing? Do you think it could be the left brake and the neutralizer valve that is causing the issue? Thank you, Troy
Kinda stuck could cause a lot of problems I think you will find it will be separate seals changing the orfice is a must they can be bad the little piece on top could be loose or their is a little piece that fits inside screen that is attached to top piece that some times breaks off
I think you’ll find that there is no seal kit for the valve and that you will have to buy everything individually by part number.
Thank you Nige, I will stop at the Cat dealer today and look into ordering parts, none of the springs are broken so would you suggest replacing them anyway? My service manual did not mention the little screen/orifice part? would/could the neutralizer valve being stuck and or the left brake pedal hanging up cause the 0 PSI at P2? I read a different post somewhere that had same problem with same machine that ended up being a bad torque converter... Thank you, Troy
Yes, because the function of the transmission neutraliser valve is to dump P2 pressure. That’s how it disconnects the drive. The left pedal operates the neutraliser linkage in addition to being a brake pedal.
If you had read the powertrain System Operation section of your service manual you would already know this…..
I am still new to this loader and still learning, I apologize for for my ignorance and very much appreciate all the help and experience offered up on this site. Thank you! Troy
You are very lucky to already have a copy of the service manual. You need to do some bedtime reading of the sections regarding the powertrain to help you understand better how it functions.
Will do, more to come. Thank you Sir!