5R55E shifting process question..

[ranger7ltr]

Does anyone know if it is possible to determine when a servo or band is disengaging and when a clutch is engaging?

I have a bit of a shift flare on the 3-4 upshift...The tranny is solidly in 3rd and when it is time for the 4th gear shift to happen, the flare hits...And if I back off the throttle when the shift is going to happen the flare doesn't happen...I just don't remember to back off the throttle soon enough...I have changed the vb with updates from Central Valve Bodies and that didn't change the 3-4 shift flare problem...With the updated vb from Central Valve bodies came new shift solenoids, TCC solenoid and EPC solenoid...I guess I should have stated that as well...
If anything the shift quality is more fluid and seamless unless I am under 3/4 or more throttle...Then I have the distinct feel of each shift but still with the 3-4 shift flare...

I also changed the o-rings on the reverse servo because of a 2-5 second delay in reverse engagement and that didn't seem to make any difference either...

What I am wondering if the intermediate servo is releasing early or if the direct clutch is engaging late...When I have changed the fluid there is no abnormally high amount of sediment in the pan...In fact the fluid is pretty clean...

I have the o/d and intermediate servos but have not replaced them yet...I guess preventative maintenance would dictate replacement with 175k on it but I do not want to replace parts if I can't see a clear need for the replacement...

 

[ragajungle]

just a thought.. what if you swap the 3-4 shift solenoid for another - they all have the ame connectors... if it follows to another shift point then...

 

[ranger7ltr]

With the updated vb from Central Valve bodies came new shift solenoids, TCC solenoid and EPC solenoid...I guess I should have stated that as well...

And with the vb change the 3-4 shift has not changed at all...That is why I am trying to find out if there is a way to determine when the shifts occur...

 

[PopRichie77]

Ok, rule out the valve body. Is the intermediate band adjusted correctly? There could be leakage or damage to the High clutch. The High clutch is used in reverse is it still slow engaging?

 

[ranger7ltr]

yep the reverse delay did not change symptoms...

I am assuming you are calling the direct clutch the high clutch...I did notice that both 4th gear and reverse have the direct clutch in common and those problems did not change after changing the vb...

I may still change the 2 servos and both the od and intermediate bands have been adjusted even slightly tighter than spec and there was not real change...

I have lived with this problem for almost 2 years but I am looking to replace the unit and rebuild the old one to find what is actually wrong inside this tranny...That is if changing the servos does nothng positive to improve the shifting...

 

[2000StreetRod]

ATF temperature sensor

When I was attempting to diagnose my 3 > 4 flare I performed a data log of all the PIDs I could find that might be helpful. I was disappointed that there was not a PID for each of the solenoids. I thought that the torque converter clutch might be part of the problem. I have studied the data log and learned from the "Unlockflag" PID that the torque converter never locks until the ATF temperature exceeds 69 degrees. I was surprised to learn that the torque converter would lock in all gears dependent on engine load. Early in the drive when the ATF temperature was 92 degrees the torque converter locked 0.2 seconds after shifting from 3rd to 4th under light load. Later when the transmission temperature was above 105 degrees the torque converter did not lock until 1.5 seconds after the upshift under a comparable load. Have you noticed any difference in the flare when the ATF is cold vs warm?

According to my ATSG 5R55E manual the PCM uses the ATF temperature to determine whether a cold start shift schedule is necessary. The cold start shift schedule allows quicker shifts when the ATF is cold. The PCM inhibits torque converter clutch operation at low ATF temperatures and corrects EPC pressures for temperature. Maybe your ATF temperature sensor is defective.

 

[ranger7ltr]

Temperature does not make as great a difference as I would think...

The first time I drive the truck the flare is not as bad...The first 3-4 shift is mildly there without much of a flare...Then every other 3-4 shift is a flare if I don't back off the throttle..

Temperature of the fluid or the air has the no discernable effect on the tranny...The first 3-4 shift of the day is less severe flare-wise and then the rest of the drivetime the flare is there...

That is why I was trying to determine if the intermediate servo might be leaking down early instead of the direct clutch taking longer to engage causing the 3-4 shift flare...I was also wondering ,to that end, if the old servos have lost the ability to hold fluid pressure long enough...I should change the od and the intermediate servos as a matter of course since they are the only old replaceable parts still in the tranny...

Did you change your servos when you did the vb replacement? I remember your thread but don't remember all that you did to the unit while you working on fixing it...

 

[ragajungle]

Just another thought... there is a site that sells servo bore repair kits made out of brass. The steal OEM servos wear into the trans casing -

 

[2000StreetRod]

valve body update

No I did not change the servos. I did install the reverse servo D rings. I also did the Ford TSB to replace the separator plate and the piston and remove the screen and spring/valve. I did not adjust the bands to reduce the number of variables.

According to the band/clutch application chart the 3 > 4 shift involves the intermediate band release and the direct clutch application. It seems to me that your flare results from the weak/slow application of the direct clutch after the release of the intermediate band. I doubt changing the servos will help.

 

[ranger7ltr]

According to the band/clutch application chart the 3 > 4 shift involves the intermediate band release and the direct clutch application. It seems to me that your flare results from the weak/slow application of the direct clutch after the release of the intermediate band. I doubt changing the servos will help.

As with other automatics, I believe there is a certain overlap of shifting operation. This is why I have been reluctant to change the servos as I am thinking the direct clutch is probably the slow engager here but I am looking at the possibility that the intermediate might be losing pressure as soon as it is engaged and not holding while the direct clutch starts to engage...

One other issue is the delay of reverse engagement of 2-4 secs also leads me to the direct clutch...I also changed the o-rings on the reverse servo to the viton D-rings and there was no change in that action as well...Still have the delay...

I think the next course of action is to test the hydraulic pressure and see if there is any need or benefit to upping the pressure to get the direct clutch engaging on time if this is indeed the problem I am having...

 

[2000StreetRod]

Wrong about servos

I just reread the Sonnax 4R44E & 5R55E troubleshooting tips that state always install new servo pistons for no/slow reverse trouble. Also, a 3-4 flare on 5 speed can be due to the servo pin bore is worn on the intermediate servo or the spring on the piston is too strong. That may mean that if the intermediate band is not adjusted correctly it might cause a flare. My ATSG manual specifies the intermediate band should be adjusted by torquing to 10 ft-lbs and then backing off 2.5 turns.

 

[2000StreetRod]

intermediate band adjustment

I just checked the Ford Explorer Shop Service & Repair Manual 1996 - 2001 compact disk I received yesterday in the mail ($5.99 & free shipping on eBay) and it specifies the intermediate band should be backed off 2.0 turns, the same as the front band. I would put more faith in the shop manual since my ATSG manual doesn't mention the Explorer as a vehicle using the 5R55E.

 

[CDW6212R]

FYI, the TransGo kit also specifies a different band adjustment. They typically call for a tighter adjustment of bands and clutches.

I know have a flare in my 2/3 shift, after warm up. This is the first problem I have had, so I'm starting from scratch to hunt it.

 

[ranger7ltr]

This is why this forum absolutely rocks...

I just reread the Sonnax 4R44E & 5R55E troubleshooting tips that state always install new servo pistons for no/slow reverse trouble. Also, a 3-4 flare on 5 speed can be due to the servo pin bore is worn on the intermediate servo or the spring on the piston is too strong. That may mean that if the intermediate band is not adjusted correctly it might cause a flare. My ATSG manual specifies the intermediate band should be adjusted by torquing to 10 ft-lbs and then backing off 2.5 turns.

I have read this bulletin probably a dozen times and I was under the impression the worn servo pin bore problem was only with the 5R55s, W, and N series trannies... I also missed the recommendation of changing the servos as well...Different eyes see more clearly...

I will be doing the servo change in the next few weeks to see if the vb swap was only part of the fix...

BTW does anyone use the alignment pins to reinstall the vb? I know I didn't and I don't usually second guess my work but I am wondering if I am causing a new pressure loss issue...

 

[2000StreetRod]

Alignment pins

I did not use any alignment pins. However, I was very careful to visually align the holes when fastening the separator plate to the valve body. I also inserted all of the valve body mounting bolts except the reverse servo plate bolts before tightening any of them finger tight to make sure no bolt threads were binding against the valve body. I then pressed the valve body against the case and finger tightened the bolts. Next I inserted the reverse servo plate bolts finger tight and then began torquing the normal valve body bolts in 4 increments. I waited until the next day to let the gaskets compress before torquing the 5th and final increment.