2004 V8 4x4 Explorer - 5r55W Tranny - Kicks Hard

I recently brought a 2004 Explorer XLT V8 4x4 with 94000 miles. When buying it I noticed during one shift into reverse, the truck kicked hard as the transmission appears to have engaged violently. The sales guy thought it was a normal operation of course and I wasn’t too concerned since the truck had a warranty which would cover it if the tranny proved to have a problem.

Well I’ve noticed a few interesting things with the tranny since driving it regularly and am ready to take it in for work. I wanted to be fore armed with information so that they don’t try to pull one over on me or waste both our time.

First, I’ve noticed that when driving and I’m accelerating at a normal brisk pace (no WOT just probably about 30% to 40% throttle) when the truck gets into the 2k to 3k RPM range the truck seems to be slipping then it kicks forward like someone rear-ended it. It happens most strongly in the around 40ish mph range. Could this be the shift flare issue I’ve heard around the forums? Being it happens in the 40ish mph @ around 2.5k-ish RPM can I assume this is affecting the 3-4 shift? This does not happen everytime, but it happens more often and more forcibly when under moderate to brisk acceleration in the 2k to 3k RPM range at around 40ish mph.

Secondly, as stated above when I shift into reverse, the truck will intermittently chunk into gear and it will feel again like the truck was rear-ended. With the truck parked, I’ve tried shifting into reverse with the brakes applied and even with the brakes not applied and it was the same experience. The same thing happens whether I’m shifting into reverse from Park or from Drive.

Based on all my readings from this great forum, my best guess for the most probable cause of these types of problems is a degrading solenoid body assembly or a VB gasket blowout. I would appreciate suggestions on what else would likely cause the two intermittent problems so I can guide the service technician, which is not a Ford specialist, on what to look at and test.

Thanks in advance for all suggestions.

"First, I’ve noticed that when driving and I’m accelerating at a normal brisk pace (no WOT just probably about 30% to 40% throttle) when the truck gets into the 2k to 3k RPM range the truck seems to be slipping then it kicks forward like someone rear-ended it..."


This sounds like actual slipping to me...the RPM rise and then the harsh transmission engagement.

The "flare" issue is an RPM rise followed by a perfectly smoooth engagement into gear (ALMOST like a slip...think of your tires slipping in the snow and then slowly gaining traction) to the best of my knowledge, I could be wrong. I DID have the flare issue and the rebuilt VB fixed it.

Have you checked your fluid level at operating temperature? Has the fluid/filter ever been changed?

This is why I can't WAIT until I can purchase a FORD truck, NEW, with 2 miles on her. You NEVER know what the previous owner did or how they treated the vehicle.

Rob...I figured more people would have chimed in by now!!!

Come on guys, someone has to have an idea!!!

Thanks for the insight 35Remmy. I'm sure more will chime in during the week.

Something else I've noticed. When I was towing a light trailer with an ATV yesterday; I tow with the O/D off. When it was off, did not experience the slipping or it was very very slight. When I forgot to turn the O/D off for a few blocks, the slipping / surge was back and strong.

Diagnosing this problem in fairness would be easier if you had more information about line pressures, EPC pressures etc. These trannies have multiple tap points for pressure gauges.

Just as the computer can electronically UP pressures in what is called "Failure Mode Effect Management - or FMEM" when that happens the shifts are awful almost like you describe. I'm not saying your in FMEM, but that there is a good liklihood your pressures are the issue. I'd want to investigate that first and follow the protocols to address that if it were to be the case. You do not have any codes present I will assume and dismiss FMEM issues.

Otherwise in the 5R55W, harsh shifts can implicate an incredible number of parts - and I doubt they are at issue in your situation.

My best guess is a spool hanging up in the VB.. likely a pressure regulator or something. A pressure test would verify that. You'd also want to test line pressure and pressure at the Pressure Control Solenoid C Tap to see if the solenoids are operating properly.

Further pressure testing and diagnosis needs an NGS tester to access the pressure control solenoids electronically.

I'm betting on a pressure issue - the where and how of that is the bigger Q right now in my mind... but let's confirm my initial theory first.

My moms 04 v8 is the same way. 66k on the clock. Some of her symptoms...
-delayed shift out of park, always firm
-firm shifts 1-2, 2-3,3-4 unless your on the gas pretty good
-3rd gear vibration at slow speeds. (whole car shudders 1-2 seconds like rumble strips)

Took it to the dealer, they checked pressures and found nothing. They said the only way to fix is total rebuild.

Thay have a TSB for the 02's for a solenoid pack replacement and computer reflash but nothing for the 04s.

In your Mom's case I'd change out the fluid and add friction modifier... probably cure the shudder. I bet a VB replacement would fix the rest.

Thanks Glacier991 for the information. I am inclined to agree with the possible pressure issue.

Here is some more information on the intermittent hard shift problem: When I was driving to the dealer yesterday to have the tech experience the issue as I replicate it for him, the d@#m thing ran great, I couldn’t for the life of me get the tranny to kick at all on the way there (naturally) so I just turned around and went home instead of dropping it off. When I got home the hard kick into reverse finally reared its head again (it didn’t happened on the way to the dealer…of course). Today I was driving it to work and it kicked hard once on the way in what appeared to be the 2-3 shift. It might be happening more often in Los Angeles rush hour than the free weekend roads…I’ll keep looking into this theory.

One thing I’ve noticed that jives with what Glacier99 is suggesting about the line pressure is that even when it’s shifting correctly, the shift in the 2-3 and 3-4 is slow. I know when I’ve installed a shift kit or a computer chip in my other cars, which would raise the line pressure, the shifts in those cars would happen more rapidly while this truck feels sooo slow.

I’ve hooked up an OBDII device to read the ECU’s codes and there were none. I really want to drop the pan and change all the fluid and clean the VB and everything else out but I am loath to do anything detectable by the dealership in case they use that to reject honoring the warranty.

I’ve thought about testing the line pressures but I don’t have the tools for that job yet, can anybody suggest a pressure gauge which will work for this project? Also can anybody tell what size nipple are used for the two tap points in the image below?

Again thanks in advance for your suggestions and help!

BTW...Forgot to mention it, but I checked the fluid level and it is fine. The fluid looks old but not burnt...it's a deep red color.

You need a 0-300 lb gauge. it is 1/8 NPT.

It's been awhile since I posted on this issue. Been rather busy as of late. Anyway, here are the latest updates on the issue.

After getting under the truck to adjust the bands and check the line pressures, I determined doing these things will leave marks which will allow the dealer to know that the tranny was "messed" with. So instead I brought it dealer. At first they tried to pass the issue as "normal" operation, but after I pressed them on it and gave them a TSB on the hardshifting into reverse, they sent it to a tranny expert.

As per the TSB the tranny guy replaced the solenoid pack. With 600 miles on the replacement solenoid pack, the tranny shifts an order of magnitude better. No more delayed or hard kick into reverse and no more intermittent slam into the 2-3 or 3-4 shift.

Perhaps this helps others.