988F now refuses to operate in any of the forward gears. Have swapped solenoids and valves between forward and reverse and still no change. Machine can operate in reverse. Seems to engage the forward gears but with no movement. Thinking it might be the forward clutch pack in the transmission. Screen and magnet have small metal shavings and also small particles of what appears to be clutch pad. Filter light also comes on. Any ideas?
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CAT 988F Transmission issues
- Thread starter 988Driver
- Start date
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- Tags
- 988 988f cat wheel loader
Nige
Senior Member
Remove the filter, cut a section out of it and go looking in the bottom of the pleats for loads of small black particles.
Does the oil smell burnt..?
If we get deeper into this a Serial Number would help.
Does the oil smell burnt..?
If we get deeper into this a Serial Number would help.
Oil doesn’t smell too bad and the transmission hasn’t been getting hot. Filter only has a small amount of metal shavings. The other day I changed the oil and filter. Filter light stopped illuminating, however after about 10 mins of use it started up again and consequently about 30 mins later no forward.
Serial 8YG00184
Serial 8YG00184
Have you checked pump pressures? If you have a seal blown out it will lose pump pressure in that gear or direction. The other thing to check would be the transmission controller. That is located behind the cab under the window. Remove the panel and it is right there. If you have any electrical issues the controller will read out related fault codes. Have seen controllers go out causing the same issues. What kind of environment is this machine in? Is it in a very wet or corrosive? Salt? If so, start checking wiring harness connectors.
Bob
Bob
Have discovered a faulty valve in which the spring hasn’t been working properly, hence bringing about a conflict between forward and reverse. Have since replaced the filter, cleaned the screen and looking to replace the oil. Am wondering what I could use to flush the transmission rid of shavings and debris? Cheers
Nige
Senior Member
What Part Number of filter are you using right now..?
Hi Bluox, after fixing the previous issue, the loader is now not moving in forward and reverse at all. I seem to think that I have no pressure in the system and the pump is possibly not working. Had been working fine up until this morning when i started it.
Reasons for thinking this:
Any other ideas would be greatly appreciated. Cheers guys.
Reasons for thinking this:
- After no movement, I checked the screen and found not enough debris to warrant a disruption to oil flow.
- Oil seemed relatively cold even after 5-10 mins of engine running
- Not a huge amount of oil coming out of the screen pipe.
Any other ideas would be greatly appreciated. Cheers guys.
Mark250
Senior Member
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- victoria,Australia
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- heavy equipment technician
Are you saying that after you fixed the broken spring the machine was ok for a period of time and then stopped moving in forward and reverse?
Did you swap the solenoids or the complete vale assembly?
Mark
Did you swap the solenoids or the complete vale assembly?
Mark
Mark250,
Yes mate. Started working and was going well. Found a bit of what appeared to be clutch debris and fine metallic shavings in the screen which was expected. Worked it for a bit, seemed fine. The last day the machine was used it was very sluggish to start off, with slow movement in forward. Reverse seemed alright. Cleaned the screen again it reletively clogged with crap. Cleaned it out and machine returned to normal. Today when I went to use it again, there is no longer any movement. But it does seem that there is no pressure coming from the pump.
Yes mate. Started working and was going well. Found a bit of what appeared to be clutch debris and fine metallic shavings in the screen which was expected. Worked it for a bit, seemed fine. The last day the machine was used it was very sluggish to start off, with slow movement in forward. Reverse seemed alright. Cleaned the screen again it reletively clogged with crap. Cleaned it out and machine returned to normal. Today when I went to use it again, there is no longer any movement. But it does seem that there is no pressure coming from the pump.
Mark250
Senior Member
- Joined
- Aug 30, 2015
- Messages
- 1,243
- Location
- victoria,Australia
- Occupation
- heavy equipment technician
its a concern that the screen keeps blocking up. sounds like it is too late to do much except rebuild and prevent any further damage
have you done any pressure checks ?
do you need testing info?
have you done any pressure checks ?
do you need testing info?
kshansen
Senior Member
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- Mar 11, 2012
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- 11,165
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- Central New York, USA
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- Retired Mechanic in Stone Quarry
Not familiar with the 988F, but I was thinking the screens are on the suction side of the pump so would not expect any oil pressure there.
Would strongly agree with Mark on the idea if you keep finding debris in screen the more you run it the more parts that will be damaged.
komatsukid
Well-Known Member
Start by checking pressures.
Dave Neubert
Senior Member
Yep check pressures but it sounds like rebuild time