Parts neded to fix shifting issues? | Ford Explorer Forums - Serious Explorations

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Parts neded to fix shifting issues?


March 25, 2003
Reaction score
City, State
Stratham, NH
Year, Model & Trim Level
2018 Explorer XLT
Ok. I know people will think I should search, but I am still not sure what it is I need. My 4R55E has developed a 2/3 shift flare. I have been searching like crazy, but am not sure exactly what it is I need. I have heard that I can use the TransGo kit to fix my issues. I have also heard about the Sonnax boost valve, but I do not have a delayed shift into reverse. Do I need the Superior kit as well? Also I know that I will need new gaskets, but am not sure which ones I need fot the pan, new filter o-rings, and valve body gaskets. I have bought gaskets from and liked their service and prices. What gaskets would I need for the valve body? I think they also carry the transgo and superior kits (under valve body kits) as well as the sonnax boost valve (under sonnax items). Also, would Glaciers valve body rebuild diary for the 5R55E also apply to my 4R55E?

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The 5R55E VB rebuild diary would be a good place to start. Are you getting any codes? Did you go into FMEM mode? The harsh shifts sound very much like the computer going into failure effects management mode (FMEM). Do you have any flashing lights? If you have an old EPC valve, it might be time to replace it.

I have no codes and no harsh shifting. I do have a flare when shifting from 2nd to 3rd meaning the engine revs up a bit when shifting into 3rd. No flashing lights or anything like that.

The 5R55E VB rebuild diary is equally applicable to your VB, including the FORD tsb. My best advice is posted there. Do the Ford Mod, the new separator plate and gaskets from the list there and add the superior kit. It's all there.

So after reading your thread on the VB rebuild, I could use the Ford kit and the Superior, or I could use the Superior and TransGo kits, correct? I am still learning, never worked on a VB before, but feel confident that I can handle this.

Yes to both. I'd do the FORD kit and the Superior. AND a new EPC

Alright, back for round 2. I am still trying to figure out which parts I need for my 4r55e. I have found some part numbers on the site here, but they are for the 5r55e. I am ready to order the superior kit (know which one I need there) from along with a new pan gasket and filter. My only problem now, is figuring out which parts I need for the Ford TSB kit, seperator plate, etc. Anyone able to help?

Gaskets: One 2L5Z-7C155-AA; One 2L5Z-7D100-BA; Plate: F5TZ-7A008-CA.

While for most, this tsb, along with a new EPC solenoid has fixed the problem, it has not fixed it in every case. The 2-3 shift in the 4R55E and 5R55E uses the intermediate band, which is actuated by a servo on the side of the case. This servo's sealing edge can harden due to the heat from the CAT nearby, and leak, causing this symptom as well. BUT, it is PITA to replace with the trans in the Explorer, so try the VB fix first. Even if that doesn't end up fixing your flare, the benefits from the FORD MOD and shift kit will still be worthwhile.

so Glacier, I just need the three part numbers you just listed, the Superior kit, filter, and pan gasket? I just want to be sure I have everything I need before I order.

Well, don't forget the rest of the FORD MOD.... part no. 3L5Z-7M203-JA - the stuff that goes in the valve body. About $14. And you might give consideration to adding the Sonnax Boost Valve, but that one is kind of a toss up in my book on the 4R and compared to the A4LD where I strongly recommend it.