Case 2390 power shift issues

[LeeM]

Hello, I’m hoping someone can shed some light on an issue I have encountered. I recently found a 1981 Case 2390 and have been going through and getting all fluids/filters changed and up to date. The tractor sat for the last 6 years, and had the transmission rebuilt about 100 hours prior to when it was last used.

I pulled the RPS34 and cleaned it, as well as the spools because I could tell a couple of them were sticking. Got it put back together and all gears/ranges work great except for PS2 (power shift 2). When moving from PS1 to PS2 or from PS3 to PS2, the engine immediately lugs down, and it doesn’t matter what range the tractor is in. I have an idea of what the issue may be, but wanted to inquire here first. Thank you for the help.

 

[mEl]

The 4 ranges are irrelevant as the RPS 34 is entirely independent and acts the same whether in range or not, Ps1=C1-C2 Ps2 =C1-C3 Ps3 = C2-C3 Clutch down=C4 R= C2-C4. Bogging as you describe it would seem to indicate C3 pilot spool is sticky and keeping the clutch engaged, put a 600 LB gauge in C3 test port, there should be no pressure 1 but is active in both 2 and 3 range, you can work on that on the tractor. Just a quick note, do NOT over torque the cover screws pt you could possibly bind the spools.Keep us posted.

 

[LeeM]

Thank you for the reply, I’ll see if I can locate a test gauge. On the RPS 34 cover, there are several solenoids. Are those where the test ports are? Forgive my ignorance, this tractor is quite new to me. Out of curiosity, do you happen to know the torque spec for the cover bolts? I am waiting on a service manual but it will take several days to arrive. I will add a picture of what the cover looks like with the solenoids.

 

[mEl]

I really have no idea on those pressure switches, I do not see what they hook to, they are not solenoids as they are only hooked in one place, Is there any extra lights in the dash or in an added panel. One could use switches to turn on lights to show which clutches are engaged at any time. Never seen that before.

 

[LeeM]

No, no other lights or panels. The tractor does have an after market hydraulic fwd assist, they must be part of that system. I can trace out the wires and see where they go.

 

[LeeM]

Ok, the wires from those switches go into a loom which is definitely part of the fwd assist. I pulled the C1 and C3 spools again and cleaned them up with Emory cloth and they seem to be very smooth. There is a good amount of oil draining out of the ports but the spools stay up in the port; should they just fall out? I’m just not sure how loose they should be.

 

[mEl]

did you see if there is pressure on C3 in low range, please do not emery the spools, the spools are never rough and the problem as others have stated on here from time the problem is embedded metal filings or whatever in the aluminum valve body lands. the spools have a sharp edge to wipe the bores and emerying can dull the edges. If C3 has pressure in low powershift the pilot spool has to be sticking enough to stay open. Those spools will usually fall out on their own, they are threaded to put a machine screw to remove them and that is how to clean the bores, by repeatedly moving the pilot spool till it moves freely. if there is voltage to those pressure switches when the ign switch is on you could hook a test light to the switch and watch if C3 is energized. there should be no light in low, just a thought as it looks like you need to remove a pressure switch to install a gauge in C# test port. Just so we know, would you post why you removed the body in the first place, describe what symptoms you had then please.

 

[LeeM]

I have not been able to locate a pressure gauge as of yet. I initially removed the valve body because the clutch/inching pedal was completely frozen up. Once I eventually got it freed up enough to move the tractor, when clutching, it acted as if the brakes locked up and came to a very abrupt stop just when clutch was depressed. After cleaning everything and putting it back together, those symptoms stopped.

 

[mEl]

Ok, when you do a pressure test on C3 get back to us

I have not been able to locate a pressure gauge as of yet. I initially removed the valve body because the clutch/inching pedal was completely frozen up. Once I eventually got it freed up enough to move the tractor, when clutching, it acted as if the brakes locked up and came to a very abrupt stop just when clutch was depressed. After cleaning everything and putting it back together, those symptoms stopped.

Re reading your first post I may have guided you wrong, so let's back up, C2 is working normally as it is used in Low PS but has to drop out when 2nd powershift is engaged and 3rd powershift would work as C2 is used there also. I am thinking now that C2 not dropping is the culprit. if 1 powershift is ok C3 cannot be the problem, don't know why it took me so long, C1-C3 is second range and C2 sticking in could cause your difficulty, I am surprised that someone didn't catch that and call me a dummy! Oh well, I was working on these in the 70s-80s and have been retired 11 years, probably not as sharp as a few years back. just turned 80 Jan 7.

 

[LeeM]

Oh no worries, I’m just really appreciative of the help! Ok, I’m waiting on a pressure gauge to be delivered this week so I can get a reading on the different ports. In the mean time, I pulled the C2 spool, cleaned it very well again and had no change in the bogging down issue. I even swapped some of the other spools around with the one in C2 and had the same result. The spools slide easily in and out of all the ports. Nothing feels like it’s hanging up. The cover cap screws are not over torqued either, I loosened and re-tightened to ensure they were not over tightened. Is there a possibility the retarding screws are out of adjustment?

 

[mEl]

If the retard screws were tightened too far in it would cause it to stay bogged down or to have a long bog and then a release, if you have any doubt, back them out several turns and try it, just mark the screws and count the turns. if properly adjusted you should hear a slight surge when making the 1-2 and 2-1 shift. A thought, there are a couple different gaskets used in different transmission serial number runs and a difference there could cause problems if you have replaced them. Does reverse work normally? A mechanical problem with C-2 causing it to be stuck would defeat your clutch pedal operation in 1ps and reverse.

 

[LeeM]

Well it would seem that the C2 retard screw was in too far. I backed it out one full turn and it shifts beautifully now! It has a slight surge now, as you mentioned it should. I cannot thank you enough for all of your help!

When shifting from PS2 to PS1, there seems to be a slight hesitation before the surge and shift; do you think the C3 screw needs to be run in a little?

 

[mEl]

You have to be careful about the amount of surge, the retard screws are sensitive to viscosity changes as the oil temp changes. If the powershift retards are set up in warm temperatures there is a possibility that in severe cold when the retard screws have to deal with thick oil that the clutches cannot disengage quick enough and you can get thrown through the windshield on a downshift. I think that C-3 is the culprit there. Set the retards so there is no pause in the shifting between ranges either up or down. It would be good if you put the clutch combinations to memory so you could self-diagnose, anyway, glad to be able to talk you through it. As far as the pause and surge, I would see if it has a smooth shift with minimal surge and not get too heavy on C-3 for reasons mentioned above. When possible, put it under load and see how the shift feels. As long as you do not feel a break in power on the down shift let it on the not so much surge side to avoid too much clutch interaction,

 

[LeeM]

Ok, those are all excellent points about the clutch combinations, surge, temp, viscosity etc. I will continue to tweak both screws to get them shifting more smoothly with not excessive surge. Again, thank you for all of your help! I’ve enjoyed reading your comments on other discussions on the site as well. There’s plenty of learning for me to do on this “new to me” tractor.

 

[mEl]

Glad to be of help, I was there when they were introduced and got out at about 2014 but we had become a utility dealer before that so I worked on the later electric power shifts but refrain from answering many posts on them as hydraulic issues and electrical issues are both at play there and diagnosing can get complicated.