Hi all , after advice regarding harsh shifting of our 980h serial number mhg06517 . From 1-2 harsh from 2-3 not to bad from 3-4 fine going down 4-3 fine 3-2 harsh 2-1 fine . Carried out fill calibration all ok , changed the number 5 modulation valve ( second gear ) re done fill calibration no change , noise being the pinion coming on hard in the diff as if gear change to aggressive any one have any ideas ? Oh and pressure reading is the same 320psi for all 6 clutch packs Cheers .
It would appear that you have ET. Customer or dealer? There was a flash file update to address harsh shifting; 355-7177. Can you/ have you install(ed) it? Do all the parameters, especially the input parameters on the run screen look reasonable?
Thanks cmark I'll check the flash file tomorrow. Only have customer et so will need to get cat out to flash it if that's the case , was the flash file mentioned in a service mag or service letter or Tib? What parameters are you specifically speaking off ?
The input parameters are generally pressure, temperature and operator controlled switches and sensors. Any of these can potentially give erroneous but valid inputs which can make the software incorrectly modulate the transmission clutches. If you told the forum a little about your background and level of expertise, we could possibly better tailor the advice to give you a quick resolution.
Flash software is mentioned in a Service Mag - SEPD1339 of 7/10/2011. No Service Letter unfortunately. text goes as follows ....... the transmission output signal can be adversely affected under certain circumstances. These conditions may result in complaints of harsh shifting, usually during directional shifts. New software is now available which can help prevent speed signal issues, therefore reducing shift harshness. Have you checked the transmisison output speed sensor(s) for Diagnostic Codes and/or contamination..? Remember that there are 2 of them.
Ok already has that flash file . Going forward to reverse is fine and neutral to any gear is fine . Inputs are all good . It can be done just sitting with the foot on the right brake pedal and put in forward than go up the gears worse coming down the same way from 3-2 . I tried doing my profile but it came up saying I haven't been cleared so I'll try again later , thanks all for the advice so far
What are your torque converter and transmission temperatures reading in the ET run screen?
hi,I couldn't see your s/n but in some models you have an option through ET for soft shift you can see this in your config files also check your trans temp in the status groups to see if it looks reasonable. I have seen these go out of range but not enough to log a fault code Regards mark
76 degrees tranny 77 for t/c
I'll have a look but haven't seen anything so far that says I can change to a soft shift . Tranny temp is fine
Have you checked the condition of the transmission output speed sensors to ensure they are not contaminated..? Also has this harsh shifting issue started suddenly or has it got worse over time..?
Suddenly . To the point the operater stopped using it thinking the Uni joints were about to let go
OK, that seems to point to something having failed rather than having deteriorated over time. Did you pull the TOS sensors and have a look at them..? Do you have oil analysis done and if so what are the reports like on the transmission oil..? Has the transmission oil & filter been changed since this problem manifested itself..?
Oil and filter have been changed , sos done waiting on results , haven't checked the sensors as yet due to the fact it does it sitting there with foot on brake and status screen on et shows 0 km , it doesn't do it when you go neutral to any gear but if you just cycle the gears with it in either direction that is when it happens mainly coming from 3rd to 2nd
It will be interesting to see the results of the transmission oil analysis. I hope they are including a cleanliness code test in it as well. The fact that it does it with the machine stopped would seem to rule out the sensors, but I think I'd still pull them for a look either way. Do the drive shafts "jump" more, for want of a better word, when you shift the machine 3rd-2nd at a standstill than they do for any other shift..?
I just re-read your symptoms again from your OP. By any chance did you pull oil samples from both diffs and have you carried out a mag plug inspection of both diffs and all four final drives, just to rule them out..? From the OP you said all 6 clutches were giving the same pressure reading of 320psi. A datalogger might help so that you can see the pressures ramping up to the 320psi final reading..? That might give you some indication of a clutch that is performing differently to the other 5 in the transmission. I appreciate that you've done the fill calibrations for the 6 cltuches. Do you have Access to a Click Box that can be used to set the Hold and Ramp values for the clutches..?
Yes it does jump ( unload than reload) more than the other gears
Did you pull the diff and final drive magnetic plugs just to check for any metal particles..?
Click box? Are you referring to a scroll box if so yes if not most likely no . As for the diffs and final drives I ruled them out due to it being only in regards to second gear. Not to say it can't be them but if it were chances are the fault would be common in all gear changes and especially going from reverse to forward and vice versa where as that is the only time there is no problem ( smooth as )