Good Morning, I've got a 6T transmission with the first speed clutch slow about coming up to full pressure. I've replaced the modulating valve but no change. It comes up to 120 psi, pauses for about 20 seconds then goes to full pressure 320 psi. All other clutches perform as they should. Any help will be greatly appreciated. serial number LAY00967, 5100 hours.
I assume there are no active Diagnostic Codes.? 1. What's the main relief valve pressure both at Low & High Idle.? 2. Has the accumulator precharge pressure been checked.? 2. If #1 is within spec have you attempted a clutch calibration, not just of the 1st speed clutch but all the others as well.?
No active active codes during calibration, however it will not complete the calibration process, at the end of the calibration code E17 is displayed. The accumulator has not been checked nor has the main relief been checked. I will be back at this machine first of next week and get these pressures checked. Thanks for your help with this matter.
Are you attempting to calibrate using ET or with a Click Box.? I think it’s possible that you have a leaking clutch piston seal on the 1st speed clutch.
I'm using a clicker box. I agree with your thoughts about the piston seal. Once the clutch is at full pressure, 320 psi, its good to go, no slipping at all, however if you go to neutral long enough to dump the clutch pressure then back to first foward it takes a little bit before it gets back to 320psi. If there is no hesitation in shifting from foward to reverse then back to foward its good to go, Thanks
Lack of Nitrogen, but still needs a clutch fill calibration with a Lap Top and possibly the latest Flash File, the modulation valve might be a knacker job so a spare is always handy.
It's been a while since we talked about this transmission but it turned out to be the first speed clutch piston seal. It took a while for the owner to make the repair but it's back up and pushing dirt. The accumulator had to be replaced as well. Thanks for the help.