5R55E - Lost D, R, and Man 2 but Man 1 works

[TiredOldTruck]

Title says most of it, here's the details: I was driving home and the trans lost power for a moment, then came back, and after I braked for my exit, I couldn't accelerate in D anymore. No codes. I put it into Man 1 and was able to drive the last 1/4 mile back home and started testing things out - the engine revs freely and without any odd sounds in R, D, and Man 2 but I get no engagement. I can put it into Man 1 and drive without issue.

I pulled the pan/VB today and examined everything, the seperator plate is intact and undamaged, the check balls, solenoids, puck, and springs are intact, clean,and undamaged. All electronic solenoids are dead-on in-spec resistance-wise, and the TSB deleting the screen and installing an overflow BOV looks like it was performed.

No burned smells, wire harness is in excellent shape, no obvious glittery bits in the pan either.

The EPC has some wiggle room to move in and out with the bracket installed, but not side to side and the bracket does not appear cracked or worn at all.

I've had some miscellaneous symptoms for a while like it taking a moment or two for the trans to engage when putting into D(if I let it idle for a moment first this doesn't happen), thumping while engaging from P to D(again, idling a moment fixes that), the 2-3 flare, and a couple very hard shifts up and down when I've had to punch it on the highway to avoid an accident.

I've also had more-frequent issues with it not wanting to crank while in D until I jiggle the shift lever a bit. I went ahead and ordered a new neutral position switch in case it's finally gone bad (220K on it), but I can't test that until everything is put back together and refilled.

What else could be the problem? I saw something about a sprag on the output shaft or in the planetary gear portion, but this is my first foray into transmission repair so I'm unsure.

 

[JK080]

These are the classic signs of a failed input sprag, this sprag is located in the front of the transmission in the overdrive section. When it fails you will loose forward and reverse, manual low will engage because the coast clutch is applied and supports the sprag. The only way to get to this sprag is to remove the transmission and disassemble it, pretty much rebuild time.

 

[TiredOldTruck]

Craaaap. Do they just wear out on their own, or is there something I might have done to prevent it?

There's a specialist shop close to me that rebuilds for ~$350(not counting labor, but dropping and reinstalling this thing isn't too terrible, I've done it before), guess I'll be pulling it and taking it over there. I could probably do this in my own, but since it's my daily and it's about to start storming here(can't ride the Shadow around in thunderstorms)- would it be better to have a pro do it and not chance blowing it out because I forgot to do something?

 

[JK080]

For 350. you might get a new sprag and a pump gasket, we spend more than that on parts when we do them.

As long as it fixes what its doing now that's fine but its not a full rebuild for sure, its just a repair.

 

[TiredOldTruck]

Good to know, it's hard to have a sense of what is reasonable, too-low, and too-high unless you're familiar with the process. Their site said it covered all new seals, friction plates/steels, and bands, so I imagine it would be up towards the $600-$700 mark to do the sprag replacement while they're in there?

Also, thanks! I've been wanting to switch up to a 4x4 truck for a bit(I do a lot of back country camping and 4x4 would be nice on some of those roads), so it may be a better deal overall to just drop it, get it repaired, and sell the thing.

I gather the sprag failure is just something that happens eventually, regardless of the trans' model year? If I do go for another Ranger and there's anything I should/should not do to prevent it happening I'm definitely curious. Or, when you have these transmissions, just expect and budget for a rebuilt trans after a certain mileage?

 

[JK080]

I gather the sprag failure is just something that happens eventually, regardless of the trans' model year? If I do go for another Ranger and there's anything I should/should not do to prevent it happening I'm definitely curious. Or, when you have these transmissions, just expect and budget for a rebuilt trans after a certain mileage?

Yes.

The sprag failure is a common failure for this transmission and so is broken bands and broken pumps, valve body issues and a few more too. The only thing you can do to help prevent the sprag failure is to manually start off in low and shift up through the gears, this engages the coast clutch drum to help support the sprag. Thats why it still moves forward even with a failed sprag. Thats a lot of work to do that every time so I would just do that under heavy throttle or load.

All transmissions have weak spots, some more than others, most failures we see come from unavoidable circumstances like broken parts, bad converters and worn out valve bodys, things that just happen under normal use. Converters and broken parts can be a instant failure at any mileage and worn valve bodys tend to be higher mileage issues.

I would budget for any kind to major repair like a motor or transmission especially after the factory warranty expires, you never know. You know how many times I hear it was fine yesterday?