980G AWH Auto shifts 1-2 no problem, display says it goes into 3rd but trans stays in second. Switch to manual mode… trans says it’s in 3rd but is for sure in second. Goes manually into 4th. What am I looking for when I check pressures. I cant remember the procedure. Was also going to swap solenoids around.
First thing I would suggest before starting into the electrical system is to take a look in the transmission suction screen. If you find it like the one below you'll know exactly what the problem is........
That may not be a bad idea… Maybe I’ll drain the oil and pull the screen out. I have no active codes just one from about 100 hrs ago pertaining to the 4th speed clutch. Only happened 1 time… 100 hrs or so ago 1403.05
If you first rule out the possiibility of a mechanical failure of the 3rd speed clutch then it has to be electrical somewhere. 1403-05 does not seem to be related to your current problem.
That’s what I was scratching my head about too. I thought maybe a piston seal for one of the clutches. That you would see checking pressure possibly, I just couldn’t remember the procedure. I will def check the screen first
Thing is if the piston seal failed then the screen ought to have a fair amount of burned friction material in it. I would suggest to check the screen first. If you eliminate a failed 3rd speed clutch then it will be time to turn your attention to the control valve & solenoids.
Not sure if you have to drain oil to pull strainer. It's been a few years since I worked on these but know some of the loaders have the strainer up high enough so it can be pulled with out loosing much if any oil. Nige what do you think?
It might be high enough. I’m going to go work on it tomorrow. I’ll compare the height of where the screen is to the oil level in the gauge. I’m thinking I’ll have to drain at least a few gallons. I know the screen isn’t in the greatest most accessible spot so I’d hate to get a bath while squeezing in there between the frame and rear tire!
If the screen is high enough, loosen the tank cap and release any pressure built up in it.
You don't... fell into that trap a few weeks ago... should of gone straight for the screen first. Squeeze up between the wheel and frame with a 9/16th... That pic looks familiar Nige
Strange that ........
Pulled the screen out today. Didn’t look like the one pictured above. In the picture I took… cleaned the screen with brake clean dried it out and tapped it off into the clean pan (green one in picture) there is some debris in there. More than you would normally see when you pull the screen out. So I ended up draining all the oil. Changed the filter, refilled with new oil. Drove it around a bit. I could initially get 3rd gear if I shifted it while coasting downhill. Climbing the other side of the hill with it in 3rd wou could feel the thing slipping and then grabbing. Soon after that I lost 4th gear completely, engine just revs out in fwd and rev. in 4th. So now… no 3 & 4 gears. I’m thinking if I were to pull the screen again I might find more clutch material. Do you think it’s toast? Still no codes on the electric side. Haven’t touched any of that.
The transmission on that loader needs two clutches engaged for any gear. One is a direction clutch (F or R), the other a speed clutch. The six solenoid valves are all identical. I think it is possible to have a defective solenoid valve and not show a Diagnostic Code. AFAIK the DC is only an electrical check of continuity of the solenoid coil. TBH after seeing what came out of that screen I'd suggest first swapping the solenoids between 3rd speed (solenoid #4) and forward direction (solenoid #2). If the solenoid valve currently installed in the 3rd speed position is bad you should lose all forward gears
I can try swapping the solenoids. Losing 3rd & 4th gear now has me kinda thinking it’s something internal. But swapping solenoids to verify is cheaper than an unneeded overhaul.
Tried doing some solenoid swaps today. No dice still no 3rd or 4th gear. When in 3rd on the display it says 3 but actually it’s in second. And the machine jerks slightly when you put it in 4th fwd/rev but doesn’t move at all when you give it throttle. Pulled the screen again today. Had a few more of those thin black strips of material in it.
Running it a bit more…. The machine only has 2nd gear fwd/rev. 4th gear it just revs out, no movement. Pressure on P1 and P2 were in spec for second gear. It doesn’t change until you go to 4th then it drops to 0 in 4th. My next move was to pull the valve body and see if there is any spools that are hung up. If I don’t see anything there. Probably be getting the trans rebuilt.