Hi All Have a Cat IT62G (II) Serial: AYA Have access to cat ET and no codes present Reverse & all 4 speed clutch pressures + TC inlet + TC outlet + Lube pressures all within spec Oil looks clean, Replaced filter, Sction screen and magnet had some small amount of friction material in it but nothing alarming (17000 hrs on machine) When transmission is cold (below approx 50 Deg C) forward clucth builds full 400PSI no issues When hot forward cluch only builds around 100PSI (on all 4 speeds). Meanwile reverse still builds full pressure in all speeds Heres the thing... you can warm it up by stalling it in forward and its holds 400Psi no problems. then if you go to neautral, then back to forward it only builds back to 100Psi.... Its either building full pressure (400Psi) or basically no pressure (100PSI)... there is no in between Have replaced modulator on forward cluch pack with new mod (didn't fix problem) and also swapped with another working modularor (didn't fix) Im 99% sure its not an electrical issue becuase if you plug the wiring harness reverse plug into forward modulator it still wont build pressure in forward clutch (Meanwile it was building pressure in reverse clutch no problems) Ive also plugged straight 12V DC power into Forward cluch and still behaves exacly as above (Fine when "cold" then all of a sudden not holding pressure at all when "hot") Any ideas why it would work fine one minute then not work at all? then if you leave it for 10 minutes it will start working fine again? There is no gradual pressure drop from 400 down to 100Psi you would expect if cluch seals were bad and oil bypassing as it warms up. You would swear the spool in the modulator valve was sticking when it warms up (but as mention have tried 3 differnt mod valves) If the Clutch disks are sufficently worn can the piston travel too far and bypass oil?
What type/grade of oil is in it.? 17k total hours. Has the transmission ever been rebuilt before as far as you know.?
It’s a new machine to us, but I would believe it’s all the original Powertrain Filled it back up with TDTO 30 when I inspected the strainer and same problem Have checked with ET to make sure it’s not the neutralizer pedal playing up. (there was a service bulletin for this)
If it has 17k hours on an original transmission then it’s way past time it was overhauled (typically 10-14k depending on duty cycle). Was this symptom made known to you before purchase.? A bit naughty if it wasn’t. You appear to have done everything you possibly can regarding the electrical/electronic system. Time to bite the bullet and snatch the transmission I reckon.
Machine came from auction and aside from this issue is very neat and had a full set of attachments- It was a good price so I’m happy with it even in the current condition, Ill look to rebuild the transmission next month - was there anything in particular to look out for? I’ve got access to SIS so I’ll just take it step by step appreciate the second opinion thanks Nige
clutch is engaged wile heating up so probally seals under higher pressure when yo go to N it releases the pressure and wont reseal hot. time to pull trans