Hey Folks! Figured I'd ask the experts since I'm kinda stumped....Any how, I just moved back to the U.S from Japan, and was loath to the idea of picking up more debt via a car loan since I've been car payment free for the last 5 years, I'd figure Id buy a beater. So I did, found a clean bodied 2000 Ranger XLT 4x4 with the 4.0 for a grand. Just had transmission problems....figured it be worth the effort to strip down the 5R55E, and do a minor overhaul/inspection.Per the ATSG 5R55E Techtran Manual mainly to save cash, but also casue I wanted to do it, I've rebuilt manual transmissions before, just not an automatic. (I'm a Crew Chief in the USAF).

Symptoms:

The guy who sold it to me told me it wouldn't go in drive or reverse. After I picked it up, I dropped it into 1st and and shifted and moved slowly with a lot of rpm, with a lil bit of shudder. After some finagling I got it to go into reverses, same with shuddering and low power(high rpms to get it moving), In Drive itll bump like it will get into gear...and when I rev the engine itll kinda lurch a bit then give up...According to some of the maintenance documentation provided, the truck had a re-manned unit installed 80k (2012) miles ago, but no new torque converter.

Fast forward, I tore the unit down found the steels/frictions to all be in good shape except for the low/reverse brake clutches were worn with some hot spots in the rings. but other than that, I didn't see any other issues. I had suspected the torque converter from the beginning, and the lack off issues in the rotating assembly seemed to confirm that. I get it all back together, adjusted the bands to spec and filled it up, and now I have the same issue.

Although, no shuddering anymore, it shifts into first just fine and moves, I can get it to get into reverse much easier. I pulled codes and got P0731, P0733, P0734, basically gear 1, 3, , 4 gear incorrect ratio, with a P1780 (Overdrive Cancel Switch out of self test range) and P1103 Brake switch out of self test range, and p1000 OBD Readiness test not complete..I believe the last three are nuisance faults.

The truck seems to shift fine into first and when I manually command it to second, except there's a delay, In reverse it still has a delay to get it into gear and it shifts better after I've had it in another gear, has more power but still needs high rpms to get moving, going into drive is the same.

I'm leaning towards a EPC solenoid, I think if I understand how this transmission works, that poor line pressure will prevent the bands from engaging firmly and cause ratio mix matches due to slippages in the outer drums...does that sound right? and by coincidence...would this cause the sudden onset of these problems if it went out?

Any help would be appreciated.

-Galen

 

It reads like the sprag(one-way) clutches are bad, you pretty much have to replace those when you "tear down" a trans, also new Ford pump and OD drum for the 4R and 5R

Yes all automatics run on fluid pressure, since day one, 110psi for forward and 160psi for reverse on these, I think, and yes the EPC solenoid does adjust the pressure but mechanically it should still shift into 1st when you put shifter in D, and Reverse when you put shifter in R regardless of EPC unless there is a big pressure loss somewhere in the valve body
I don't take these apart but was told if it shifts into 1st manually and moves thats the coast clutch working, but doesn't in D that's a sprag failure

 

Thanks for the reply, I'm in the process of doing a line pressure test, but I checked the one way clutches and they engaged as advertised...oh..heres hoping I dont have to pull it again....#costoftuition

 

So, just got done with the Line Pressure test, I get around 160 in reverse, all other forward gears are under 100 with most around 60 except when I drop it to manual 1st.. didn't do a stall test...for safety reasons..

 

This page has some pressure numbers: https://atracom.blob.core.windows.ne.../2003_5_50.pdf

And here: https://www.explorerforum.com/forums....428970/page-2

 

Update!!

So yeah, you were right, after a last ditch effort to replace an epc solenoid, It defiantly shifted better, but....slipped in Reverse and Drive, less than before....but still undrivable. I dropped the transmission again, and tore it down, found the O.D (front) sprag was not engaging, I could get it to engage lighly by give it a firm twist...but unlike the reverse sprag, which locked up with no effort at all. This seemed a lil deceiving, most of the research I did on this show exploded sprags...mine wasn't, everything looked how it should, except after I took a close look it was bound up in the cage somehow, none of the teeth were free to move/lock like the rear sprag, In addition to that I found the intermediate drum band was burn a bit, and some hot spots on the drum. the OD Drum seemed fine. The servos were still soft. But this Transmission has at least 80k miles on it, So im gonna order new bands/servos, O.D drum, sprags for the front and rear. My main question I have now is should I replace the O.D planet and center shaft? the the inner race on the planet didn't look worn, no burrs or irregular surfacing, pits etc...Also, can you recommend a good parts supplier?

Thanks Again,

-Galen

 

After fiddling with the OD Sprag clutch, I removed it and was able to get the teeth free'd up, I reinstalled it, and now it works!...but I've got new parts on the way so its getting changed...I wonder what made it get bound up...re-looking at the pictures...I wonder if it was installed upside down..the brass cover wouldn't seat inside the race, I flipped it around so the tabs were on the bottom, and the lip for the cover was on top, now it seems to work fine.

 

Good stuff but odd it didn't work and then did, even flipped, not sure I would be so trusting of a part like that in a rebuild

There was an internal sensor, 2 wires, on the rotating assembly, make sure it looks OK, you can test with ohm meter, not sure of the replacement cost, another hard to get to part, input speed or turbine speed sensor I think it was called

 

Thanks, I ended up putting in new bands, servos, and a new sensor. From the looks of the old sprag, my best guess is that it got in there cockeyed, as one of the metal retainnig nibs was missing, also some of the wear on the sprag pins was uneven(like it was tilted)..drives great now though! best 1600 dollar truck I've ever bought!

 

Good work

Thanks for the update and the fix

 

Super detailed posts. Your first auto tear down too. Thanks
Is the ATSG manual a repair guide? What kind of gauge (and fittings) are used to measure the pressures?
Appreciate any info.

 

Thanks again,

I used this kit from Harbor Freight: https://www.harborfreight.com/engine...kit-64872.html The Engine and Transmission Oil Pressure Test Kit. I used this manual of of Amazon : You will also need a clutch spring compressor, and order to get to certain seals in the drums, also from Amazon: Other then that, basic hand tools, get a good torque wrench. I changed out the parts that RonD recommended. I also found out...to not go through any of the big three auto stores for parts....go here. https://transpartsonline.com/[/url] they will have everything you need, they don't gouge on shipping(free after 150 bucks) I called them up to verify some information, and the guy working there was super helpful. but if you are looking into replacing sprags, plus sensor, plus overhauling(bands,servos, steels/frictions) you'll spend around 250 bucks in parts. I made the mistake of going with oriellys/autozone/advance....and there markup is crazy, so after the first round, was around 200 for the overhaul kit, I had to go back to transpartsonline to get servos/bands/some frictions etc. I had to work through alot of conflicting information on what's the difference between a "rebuild kit" or an "overhaul kit" vs..banner kits etc....lots of terms getting thrown around with no baseline....so next 5r55e I rebuild, cost me about half as much as the first!...but that's the cost of tuition. Hope this helps.

-Galen

 

A +, thanks for the details. G&K