Cat IT24F transmission problems

[Bob/Ont]

Thanks that is very similar to what I recall but they just pushed in and had a plate on top to hold it in. Now to me it seems the orifice has blown out of the old one. I was concerned the orifice was clogged. Now if the part blown out is the orifice the trans should hard shift(snap into gear fast and jerk you in the seat) If you still are running on initial pressure some debris from the old orifice is clogging up the passage from the orifice to the load piston. The load piston is on the opposite end of the spring as the modulating relief valve is and after a shift clutches fill to initial pressure as yours does now. Oil pressure then comes through the orifice that controls the time of clutch fill and clutch building to full pressure.
Later Bob

 

[Mobiltech]

You should be able to tell which one is new and old as the new one is clean and shiny and you can see the bottom piece is missing out of the old one

So just to be clear , we are talking about #13 in this picture?

 

[Bob/Ont]

That's an ICM trans by the look of the valve. Where is the trans ECM? in the shifter? I would also check the trans neutralizer switch and or wiring. A short or bad switch will neutralize the trans. If the ecm is in the shifter I have seen a bad alternator(overcharging) kick them out of gear and need recycling through neutral to drive again.
Later Bob

 

[tekemp]

That's an ICM trans by the look of the valve. Where is the trans ECM? in the shifter? I would also check the trans neutralizer switch and or wiring. A short or bad switch will neutralize the trans. If the ecm is in the shifter I have seen a bad alternator(overcharging) kick them out of gear and need recycling through neutral to drive again.
Later Bob

Ironic you should bring this up a mechanic that used to work for the company I do pulled the control valve apart on an IT24 for this exact reason and after he gave up I got out to it, turned out it had a bad connection at the trans ECM fuse holder the entire time. Also had the over charging alt. Quite a few times.

 

[strick442]

Sorry I was away for awhile,, I got the transmission back in and it's working better than it has since I've had it.. Now all my pressures are correct and I have all the reverse gears and 4th forward gear.. It appears that a combination of the screen office and a bad deal around the suction screen cover were to blame for my low pressure issues.. However now the transmission tries to lock up when it's in forward gears 1, 2, 3 (forward low clutch)..
I've changed the selector spool and solenoid and it hasn't helped.. It seems odd that when you engage the transmission in any gear 1-3 forward the machine will go forward 15-30 feet and lock up(almost as if it's trying to go into reverse at the same time)..
I know it's not the service or park brake because I disconnected all the brakes and it doesn't do it in reverse or high forward..
I hope it's not something internal to the trans.

Anyone have any thoughts??

 

[strick442]

I also forgot to mention that the neutralizer switch is working properly, and I'm unsure of where the ecm is exactly,, I think it's behind the seat because there is a rectangular looking computer with a large bundle of wires coming out of it.. There are no active codes stored and the charging voltage is 27 volts now but there was an inactive code stored for voltage being too high,, looks like it has a new alternator on it now..

 

[Bob/Ont]

Drive the machine and when it jams up shift to 4th, if it frees up the new clutch you activated is the one that's dragging. Also get it rolling in 4th then go to neutral and see if it keeps going free or starts dragging. Look to see what clutches are being used.
Later Bob

 

[strick442]

Ok bob, I did what you said when I go from 4th to neutral the trans goes into neutral and quits pulling like normal.. When I go from 3rd to 4th the transmission quits dragging and works normally.. When I start in 1st and shift to 2nd when it drags you can tell it shifts but it still drags.. Shifting from 2nd to 3rd it feels like it is dragging very little at this time..
All reverse gears seem fine and 4th forward seems fine..
All pressures are within specification..it doesn't seem to shift too hard/quick not is it slow to engage..
Thanks again... Hopefully The issues get worked out soon because this machine is being a nightmare... It's been at my shop about 6 weeks.

 

[Bob/Ont]

You need to find the clutches used for each gear. One common to 4Th and reverse, pressure oil is leaking into it some how and making it drag. Was any clutch pack worn heavy? I don't know if it's a housing or the valve body.
Later Bob

 

[strick442]

All the clutches/clutch packs looked good with no signs of wear so I didn't replace anything in them..
I blocked the machine up off the ground so all 4 tires can turn and engaged the machine in 1st gear and ran it until it stopped pulling/locked up..
When I unplug the solenoid for 2nd gear the transmission releases itself a but won't engage in any gears until the plug the solenoid back in..
I repeated the test to unplug 3rd gear and 4th gear solenoids individually and the machine done the exact same thing..
When i unplugged the reverse solenoid the transmission stayed locked up and would still engage in other gears so I'm guessing the problem isn't in the reverse pack.. The issue must be that the 3 forward gears are dragging against each other..

Hopefully this will shed some light on the issue.

 

[Bob/Ont]

When you unplug a solenoid it would shut down the trans computer(open solenoid fault) Try to take the coil off of the valve and then run the machine. This is going to be hard helping from a distance. It may not help on your machine but on another one that had a cracked clutch housing had a rise in lube pressure when oil leaked through the crack.
Later Bob

 

[strick442]

Well now that you mentioned the cracked clutch pack I remember having the valve body assembly off the transmission and was doing an air test using 150psi to see if the clutch packs would engage and the reverse clutch pack tested ok with no leaks but when I put air into the oil port for the forward low clutch, there was some air leaking back out of the forward high clutch hole thru the trans case.. I didn't give it much thought because when I air tested the clutch packs out of the transmission I didn't notice the leak.. So more than likely if I have air pressure leaking between the forward low and high clutch then either my transmission case has a crack in the oil passage or the clutch pack shaft has a crack in the oil passage..

 

[Bob/Ont]

See if someone can check the valve out for you, the cheapest and easiest to change.
Later Bob

 

[strick442]

I've been fighting this loader for like 6 months and still can't figure it out.. finally bought another good used transmission, but it didn't come with a valve body and I can't seem to find a good, used complete one..the loader is doing the exact same thing it was doing with the old transmission, so
I'm guessing the transmission wasn't the issue.. I have a cat service manual and I've done all the electrical tests and troubleshooting but can't seem to figure it out,, there are no diagnostic codes active, all the wiring has been checked, new solenoid installed and everything passed the test,, all pressures are good, there is no trouble shooting in the manual for the symptoms my machine has..

I'm guessing maybe something cracked or faulty in the valve body??
I've had it apart a few times and can't find anything wrong..
Anyone have any ideas?