4R55E Help...

[Barcuss]

4R55E Rebuild Please Help...

I have just rebuilt the 4R55E Tranny in my ExplorerXLT 4x4. It was leaking from the front pump seal and I had lost overdrive also, so since I had to take it out to relpace the front seal I went ahead and rebuilt the rest of it. I bought a TransStar rebuild kit for it and an ATSG rebuild manual. I went exactly by the book, When I put it back in now it is slipping really BAD. Like it does not have enough fluid in it. It has plenty of fluid so that does not seem to be the problem, but that is waht is is acting like. It slips in Forward and Reverse and that was just going around the block and driveway. I have taken it back out now and everything looks like I put it together right.

So my question is what could I have done wrong? What should I do now?

Thanks for your help and Happy Holidays to all.

 

[Brain]

Did you prefill the torque converter? Sometimes that is a missed step. Do you have a transmission pressure gauge (they only cost around $30)? Did you rebuild the valve body or clean it? Low pressures (and therefore slipping) could be caused by a stuck-open regulator valve....

Did you try all the gears (1, 2, D, as well as the OD, R) and have slipping in all gears or just just OD and R? I couldn't tell from the post.

 

[Barcuss]

Yes, I did prefill the torque converter and it was also new/rebuilt. I called Mr. Transmission and they said to just put one quart in it to get it wet inside and that it would pump the rest of the fluid in the converter. I ended up putting in about 9-10 or so quarts including what I put in the torque converter with my prefill.

No I do not have a transmission presure guage. Where could I get one?

For the most part I just cleaned the valve body. I did replace the orings on the 6 solenoids and I replaced the extension housing lube orfice. I also cleaned the EPC limit screen.

I tried all the gears and it was the same slipping in any gear.

Brian thanks for you response and I really thank you for any help you can give me with this. I am trying to get it finished because we need this vehicle to go out of town for Christmas.

Thanks,
Mike

 

[Brain]

http://www.etoolcart.com/index.asp?PageAction=VIEWPROD&ProdID=788

This is probably one of the cheapest gauges that will get the job done.

The 4R55E has an input shaft speed sensor (sensor on the center support and the blades on the OD planetary gear carrier) as well as the output shaft speed sensor (where the governor used to sit at the back of the case, right in front of the extension housing). Between the two it can sense if gears are slipping (ratios are out of their specified range)....did you get any codes when you ran it?

How long did you drive it around and run it before pulling it back out? Is it possible that the TC just didn't have enough time to completely fill with fluid (you wouldn't get a code in this case)?

EVERY gear slipping would make me think the control pressure is too low, so the possible culprits are:
1) Filter o-rings out of place/leaking
2) Valve body bolts aren't tight enough/bad valve body gasket
3) TC pump/turbine not coupled with enough fluid
4) TC connection to the small pump gear
5) stuck pressure regulator valve (venting too much of the pumped fluid)
6) clogged screen for EPC or prefilter

Did you disassemble the valve body (take of the separator plate and remove all the components), partially dissasemble (remove sep. plate and some components), or not even that much?....I'm just trying to get an idea of what is most likely the case. The pressure regulator valve is sticking out in my mind for some reason.

I feel your pain...I'm trying to get a vehicle ready for the X-mas trip as well.

 

[Barcuss]

I drove it for about a mile or so just around the block, but it ran in the driveway for about 30-45 minutes before I ever took it our of the driveway.

I did take the seperator plate off and clean the EPC limit screen and replace the extension housing lube orfice, but that is about all I did to the valve body.

Is the Pressure Regulator Valve the same as the Electronic Pressure Control?

 

[Barcuss]

No, I did not get any codes when I ran it.

Also when I was driving it I knew it was not right so I never got it out of 2nd gear. When I say it was slipping in all gears, I mean I put the shift selecton in 1,2,D and R and it was slipping in all selections.

 

[Brain]

Is the Pressure Regulator Valve the same as the Electronic Pressure Control?

Nope. The EPC does play a part in that it does regulate how much of a pressure boost is applied to the fluid system, but the main regulator valve is still in there even on the newer 5R55E series (which is controlled much the same as the 4R55E). Take a look at post #88, #93, #95, and #99 at this link (the 4R55E has the solenoids set up like the 5R55E - 5R in the thread for posting purposes):

http://www.explorerforum.com/forums/showthread.php?t=117793&page=5&pp=20

I'll post more later, but this gives you something to look at for now.

 

[Brain]

I'm curious because there were no codes (OD light blinking) showing slippage.....that means (to me at least) that the slipping is happening between the motor and the input shaft.....which leaves only the torque converter. The input and output are monitored, but between the engine crankshaft and the input shaft is not (the TC is the only slippable member between the two). I'm wondering if one quart of prefill for the TC was enough to get the power to the pump. Did it just idle in the driveway for the long period or did you rev it up?

 

[Barcuss]

Well, I let it idle for a while and at the same time I was checking fluid level and adding more fluid. Then it seemed to get to a point where it was full of fluid so I went for a test drive. It was slipping right from the start, when I got back to the house I checked the fluid level again added just a little bit (not even half a quart) of fluid. Seemed to be full again so I started just putting it in one gear after another going from D to R and going back and forth. Also put it in 1,2 a few times. Started going back and forth in the driveway and it was still slipping in 1,2,D and R. Checked fluid and and it was a still on the full mark.

 

[Brain]

I guess I'm still hung up on the TC not being full, which would still let the clutch packs and servos engage, but it would get power from the engine to the clutch packs. Since there is only one hole for the fluid to go into/out of the TC, sometimes it takes a while for the trapped air to get replaced with fluid. The TC is at least half full of air at installation, but in your case it was even more than that. One quart will keep the TC clutch plates from burning up when you install it (which is a good thing), but it will take some pretty serious mixing for the trapped air (at the top of the TC) to get out. Only when the air is replaced with fluid can you expect to have full rated power transfer from the engine to the tranny. I'm thinking that when you were parked and adding fluid, you were filling up the TC to maybe a bit above halfway but that the TC is still lacking fluid.

Are you sure you got the TC engaged all the way onto the two sets of splines and the inner pump gear? No pump would mean no pressure....did you check the dimension between the front face of the bellhousing to the end of the pilot?

I guess if I was in your situation and I was sure I had gotten everything installed correctly, I'd try revving the engine while in park (which is a neutral so no clutches are getting burned up) in order to really mix up the fluid/air in the TC and then check the fluid level again. From your description of it going back and forth, I have to think that the TC is hooked up to the pump so that the clutch packs would have pressure.

 

[Barcuss]

I do belive that I had the TC fully engaged on the shaft because the very last step of the assembly of the tranny is to check that. It says it should be 0.43-0.56 inch and if I remember correctly it was right at half an inch which would be right in the middle of the .43-.56 clearence that the book says I should have.

 

[Barcuss]

Exactly where on the valve body is the Pressure Regulator Valve? Is it inside the same hole where the EPC is or is it another part of the valve body? My book does not mention it at all.

 

[Brain]

If you go to the reverse servo and skip one bore over you'll be there....the pressure regulator vents excess fluid into the top of the filter, so right above the back o-ringed filter connection.

If you look at post #99 you can see where it is. (same link as above)
http://www.explorerforum.com/forums/showthread.php?t=117793&page=5&pp=20

I think it is called bore 208.

 

[Barcuss]

I saw that in your thread but since it was a diffrent body valve than the 4r55e I have I was unsure if I would be looking in the right spot.

 

[Brain]

Yep, same filter, same excess fluid vent location - here's a pic of the 5R valve body with the location circled:

 

[Barcuss]

Brian, you said the pressure regulator valve is sticking out in your mind earlier. I have taken it out and cleaned it and reinstalled it. The Presure Boost Valve has 3 small holes, how does that part get reinstalled. Do I line the 3 holes up with anything or does it matter?

 

[Brain]

At the bottom of the pic where it says "Boost valve inputs", the bottom one has a L-shaped pin in it. That should go into the deepest groove in the boost sleeve...this one shows the deepest groove:

So the inputs should match up with the holes....as far as spinning it on it's axis, it probably doesn't matter because the grooves go all the way around the boost sleeve. There was a pin in it, right?

 

[Barcuss]

This a a photo of the Main Body Valve I have and I don't have a L shaped groove or a pin other than the Valve Plug Retainer, and its not really a pin.

Well I could not get the pic to upload. Sorry

 

[Brain]

That's right...the plug retainer will hold it in, and the spring force will hold it out against the retainer. The ports still match up with the passages, right?

 

[Barcuss]

Yes, I can rotate the Pressure Boost Valve Sleeve so that the holes lineup with the passages int the main body valve. Is that what i need to do?