Common for bad shift solenoids to shift good warm?

[DemoFly]

44RE in a Jeep.

When cold I get typical low line pressure symptoms such as delayed and hard reverse engagement and a second gear hang when engaging the rear band for gears 3 and 4. I also experience surging under throttle.

Once warm, transmission shifts great, albeit it stays in overdrive and 2 prime a little too long before downshifting.

 

[zzyzzx]

Not really. Did you check for codes? If anything, I am suspecting that you are low on transmission fluid, have old transmission fluid, or a partially clogged transmission filter.

 

[DemoFly]

Originally Posted By: zzyzzx
Not really. Did you check for codes? If anything, I am suspecting that you are low on transmission fluid, have old transmission fluid, or a partially clogged transmission filter.

Fluid and filter are new and topped off. Symptoms existed before fluid flush and filter change.

No codes that my scanner can pick up. Its a 1996 grand cherokee.

 

[DoubleWasp]

Not a matter of if, but when for the solenoid pack. Maybe just do fluid/filter/solenoids all in one shot? I used mostly instinct when my pack dumped, and I was right.

 

[Kuato]

I've seen similar shift patterns with dirty trans fluid...if it has contamination (especially water) at lower temps it won't work right.

I know a guy who had big shifting problems in his Nissan, and did a fluid change. It fixed the issue for 4-5k, but then reappeared. He repeated each time he had shifting issues, and after 2 more cycles of this it was fine for more than 150k.

Auto trannies are designed for fresh fluid....keep it that way and things will last longer.

 

[Highline9]

4th gear has no bands. There are 2 clutches in od housing. Put a oil pressure gauge on line pressure port and drive, that will tell you alot. The delayed reverse is probably oil drain back. Let it idle in neutral to fill converter for 20 seconds then reverse should work better. Your trans is very similar to a tf727.

 

[HotDog15]

The solenoids are not electronically controlled? I'm thinking that warmth will let the electricity flow faster, if the solenoids have developed more resistance. Unless this transmission does not work this way.

 

[DemoFly]

Originally Posted By: Highline9
4th gear has no bands. There are 2 clutches in od housing. Put a oil pressure gauge on line pressure port and drive, that will tell you alot. The delayed reverse is probably oil drain back. Let it idle in neutral to fill converter for 20 seconds then reverse should work better. Your trans is very similar to a tf727.

Yeah. It has a Governor pressure solenoid that when closed doesn't allow the transmission to shift hydraulically, and when open allows the transmission to shift. Cummins guys call these transmission valve bodies electromechanical?

From what I have read, the solenoid leaks internally. I haven't found any information about governor pressure solenoid performance improving with heat.

After just flushing the fluid and filter. I'm not too interested in dropping the pan again and investing in a new solenoid and sensor without something a least a little bit definitive. :-/

I guess I could reclaim the fluid.

 

[clinebarger]

Originally Posted By: DemoFly

Yeah. It has a Governor pressure solenoid that when closed doesn't allow the transmission to shift hydraulically, and when open allows the transmission to shift. Cummins guys call these transmission valve bodies electromechanical?

From what I have read, the solenoid leaks internally. I haven't found any information about governor pressure solenoid performance improving with heat.

After just flushing the fluid and filter. I'm not too interested in dropping the pan again and investing in a new solenoid and sensor without something a least a little bit definitive. :-/

I guess I could reclaim the fluid.


The Governor Pressure Solenoid is not just On & Off, It varies flow of Governor Pressure to the 1-2 & 2-3 Shift Valves, The Opposing force on the shift valves is Throttle Valve Pressure which is controlled by the Throttle Valve Cable.

The first step is too re-adjust the TV Cable, If the front & rear Bands have not been adjusted in awhile.....Do that as well!

Replacing the Governor Pressure Solenoid & the Governor Pressure Transducer is a good idea on these units as the solenoid can get lazy after a few MILLION cycles.

 

[zzyzzx]

Originally Posted By: HotDog15
The solenoids are not electronically controlled? I'm thinking that warmth will let the electricity flow faster, if the solenoids have developed more resistance. Unless this transmission does not work this way.

When the transmission oil warms up, the oil viscosity changes.

 

[DemoFly]

Originally Posted By: clinebarger
Originally Posted By: DemoFly

Yeah. It has a Governor pressure solenoid that when closed doesn't allow the transmission to shift hydraulically, and when open allows the transmission to shift. Cummins guys call these transmission valve bodies electromechanical?

From what I have read, the solenoid leaks internally. I haven't found any information about governor pressure solenoid performance improving with heat.

After just flushing the fluid and filter. I'm not too interested in dropping the pan again and investing in a new solenoid and sensor without something a least a little bit definitive. :-/

I guess I could reclaim the fluid.


The Governor Pressure Solenoid is not just On & Off, It varies flow of Governor Pressure to the 1-2 & 2-3 Shift Valves, The Opposing force on the shift valves is Throttle Valve Pressure which is controlled by the Throttle Valve Cable.

The first step is too re-adjust the TV Cable, If the front & rear Bands have not been adjusted in awhile.....Do that as well!

Replacing the Governor Pressure Solenoid & the Governor Pressure Transducer is a good idea on these units as the solenoid can get lazy after a few MILLION cycles.


I have adjusted the TV cable as per the FSM as well as the front and rear band.

Another symptom I am having that I forgot to mention is if I let off the throttle while accelerating in second gear, the transmission will shift into third no issue. If I don't let off, it will either hang in second gear and then hard shift into third, or it will "half-shift" and act as if the transmission is in neutral until shifting into third gear.

From what I have read on the 4XRE transmissions, the transmission isn't actually in neutral in those scenarios but instead it is in first gear.

 

[clinebarger]

Originally Posted By: DemoFly

I have adjusted the TV cable as per the FSM as well as the front and rear band.

Another symptom I am having that I forgot to mention is if I let off the throttle while accelerating in second gear, the transmission will shift into third no issue. If I don't let off, it will either hang in second gear and then hard shift into third, or it will "half-shift" and act as if the transmission is in neutral until shifting into third gear.

From what I have read on the 4XRE transmissions, the transmission isn't actually in neutral in those scenarios but instead it is in first gear.


Thank you....That helps A LOT! You have a serious leak in the Direct Clutch Circuit (Front Clutch in Chrysler speak)
This is most likely from a worn/cracked Front Band Apply Servo Cover, On a 2-3 shift....Direct Clutch oil is routed between the Servo Cover & Front Band Apply Piston, This area is larger than the Front Band Piston Apply Area, And the Front Band is Forced Off/Knocked Off by Direct Clucth oil as the Direct Clutch is Coming On.

That would cause All your symptoms when HOT....Direct Clutch Leak=Low Line Pressure anytime the Direct Clutch is applied.

You can try this as a patch Servo Cover

However....You have already damaged the Front/Direct Frictions, How far you can limp it along is anyone's guess?
The Direct Clutch is applied/holding in Reverse, 3rd, & 4th/OD, Avoid heavy throttle in these gears if you just want to change the Servo Cover.

 

[DemoFly]

Originally Posted By: clinebarger
Originally Posted By: DemoFly

I have adjusted the TV cable as per the FSM as well as the front and rear band.

Another symptom I am having that I forgot to mention is if I let off the throttle while accelerating in second gear, the transmission will shift into third no issue. If I don't let off, it will either hang in second gear and then hard shift into third, or it will "half-shift" and act as if the transmission is in neutral until shifting into third gear.

From what I have read on the 4XRE transmissions, the transmission isn't actually in neutral in those scenarios but instead it is in first gear.


Thank you....That helps A LOT! You have a serious leak in the Direct Clutch Circuit (Front Clutch in Chrysler speak)
This is most likely from a worn/cracked Front Band Apply Servo Cover, On a 2-3 shift....Direct Clutch oil is routed between the Servo Cover & Front Band Apply Piston, This area is larger than the Front Band Piston Apply Area, And the Front Band is Forced Off/Knocked Off by Direct Clucth oil as the Direct Clutch is Coming On.

That would cause All your symptoms when HOT....Direct Clutch Leak=Low Line Pressure anytime the Direct Clutch is applied.

You can try this as a patch Servo Cover

However....You have already damaged the Front/Direct Frictions, How far you can limp it along is anyone's guess?
The Direct Clutch is applied/holding in Reverse, 3rd, & 4th/OD, Avoid heavy throttle in these gears if you just want to change the Servo Cover.


I have been driving it this way for 40k miles. It hasn't gotten any worse...in fact it might have got a little better.

I want to reiterate these symptoms are only within the first 5 miles of driving when COLD. When WARM the transmission operates perfectly.

 

[zzyzzx]

+1 for post from clinebarger!!!

But how DIY friendly is that Sonnax Front Servo Piston Cover Kit?

 

[DemoFly]

Originally Posted By: zzyzzx
+1 for post from clinebarger!!!

But how DIY friendly is that Sonnax Front Servo Piston Cover Kit?

It looks quite simple, except I don't know how to remove the servo fulcrum thing to replace the cover.

The guides I find online all replace the cover with the transmission out of the vehicle. There is a dowel that you can remove on the inside of the bell housing.

The nice thing is I can do an air test easily to confirm the leak before doing any work.

 

[clinebarger]

Originally Posted By: DemoFly
Originally Posted By: zzyzzx
+1 for post from clinebarger!!!

But how DIY friendly is that Sonnax Front Servo Piston Cover Kit?

It looks quite simple, except I don't know how to remove the servo fulcrum thing to replace the cover.

The guides I find online all replace the cover with the transmission out of the vehicle. There is a dowel that you can remove on the inside of the bell housing.

The nice thing is I can do an air test easily to confirm the leak before doing any work.


You have to drop the Valve Body, Which is one of the easiest of any transmission.

Then you will see the Front Band Anchor & Strut, Loosen the Band Adjustment Screw til you can work the Strut out from under the Band, The Anchor will fall out, The Strut Lever will now swing out of the way so you can access the Servo Cover.

I have a tool that I made that bolts to the pan rail to compress the Servo Cover, But you can try a C-clamp & fit it around the case, Or a small jack with a rod too compress the cover.

 

[DemoFly]

Originally Posted By: clinebarger
Originally Posted By: DemoFly
Originally Posted By: zzyzzx
+1 for post from clinebarger!!!

But how DIY friendly is that Sonnax Front Servo Piston Cover Kit?

It looks quite simple, except I don't know how to remove the servo fulcrum thing to replace the cover.

The guides I find online all replace the cover with the transmission out of the vehicle. There is a dowel that you can remove on the inside of the bell housing.

The nice thing is I can do an air test easily to confirm the leak before doing any work.


You have to drop the Valve Body, Which is one of the easiest of any transmission.

Then you will see the Front Band Anchor & Strut, Loosen the Band Adjustment Screw til you can work the Strut out from under the Band, The Anchor will fall out, The Strut Lever will now swing out of the way so you can access the Servo Cover.

I have a tool that I made that bolts to the pan rail to compress the Servo Cover, But you can try a C-clamp & fit it around the case, Or a small jack with a rod too compress the cover.





Dude. You are the coolest person around.

Thank you so much!

Cover is ordered as well as an upgraded borg warner governor solenoid and transducer. Let's do this.