5R55E, Tranny Guys are Stumped, help?

[dustinjorge]

5r55e in a 1995 Explorer XLT 4x

So the short version of a long story is I paid a small fortune to have my tranny rebuilt after it burned up. I had them put in a shift kit, aux cooler, and HD clutches. Basically I asked them to 'give me the works'... and it wasn't cheap. About 13 months later, tranny failed again. Shop took it back to fix it under warranty (which is only 12 months)... good guys. Fast forward to today (approx 2.5yrs later) and they've had it 4 more times, and fixed it 4 more times, for nothing. The first time it failed, I pulled off the highway and stopped at a light, then no go. Most commonly, the O/D light starts flashing then I pull over and when and if he (my tranny guy) tells me to try to drive it I have nothing (similar to the first time). Twice it has not been able to 'find gear', erratically shifting up and down before failure. It all happens very quickly and I know better than to just drive around with O/D light flashing so I usually have it towed out to the shop. This is a reputable local shop (used by local pd) and I have no doubt in their abilities.

The last time this happened a bus full of HS kids started yelling "That's why you don't drive a Ford"... I'd rather not repeat that.

The issue has varied (MLS, pump issue etc), but the common theme lately is that the - and I'm not a tranny guy so I'm trying my best to remember - Overdrive seal has blown out. This they've noted on two different occasions, which is why it stuck in my head.

I'll be picking up the truck again tonight... and this time my tranny guy kept it and drove it for a couple weeks (at my request) to make sure I'd not be dead on the road again immediately. He replaced the 'seal' or whatever, also said he replaced the cover to make sure there wasn't a burr in it. Additionally, he told me that this was the last time for free... fair enough.

So I'm curious what I could have done to this truck to make it hate the tranny so much? Which leads me to my question:

Years ago, my pops and I tried to install a truespeed calibrator when I went up in tire size (yeah I know, gear, I have it now)... but in doing so we extended the VSS wires into the cab from the engine compartment (tapped underneath/soldered, ran up and back). When we couldn't get the truespeed to work correctly, we just capped them off under the dash and called it good. I notice no change or abnormalities in the speedometer, there's no codes for anything VSS related (or any for that matter).

Could the additional resistance from the extra wire length be messing up the signal to the PCM in such a way that during high speed operation (overdrive) the tranny is not operating correctly and 'blowing itself up'?

TL;DR - Could VSS wire length cause faulty readings and cause a tranny to continuously malfunction to the point of needing 6 repars?

 

[dustinjorge]

I may not have put this in the right sub-forum, won't be offended if someone moves it.

 

[Dono]

I'm going to 'Report' this thread so a Mod see's it and can move it in to the transmission section.
There are some super smart transmission guy's there that should see this once its moved.

 

[transman304]

You're really not giving much info to go on here. I have no idea what an overdrive seal is referring too. I understand you are just relaying info from the shop but may be find out exactly what is having a repeat failure may help in diagnosis. I will tell you that the 1995-1996 were plagued with computer problems. Also I don't feel the extended VSS wire are not an issue. Someone else my reply and know exactly what you are experiencing. Good luck.

 

[CDW6212R]

I would restore the VSS wires since they don't need to be extended now, that can be corrected in the PCM tune for tires if needed.

Without my information, I'll guess that with the trans "burned up," something is not right in the VB. I'd replace the VB from a known good 5R proper model(avoid the first two years).

I'm about to have to learn to rebuild my 99 version. I plan to install every Sonnax upgrade besides those for over sized bores(require super high dollar tool to install, for each part). Also Sonnax recommends a trick to help to avoid gaskets blowing out. It's on their site, they show installing set screws into the case passages above the prone area where the gasket can blow often.

It's all preventative measures, there are no real upgrades for hard parts, serious power gains etc. You do what you can, the shops clean everything as much as possible, and you hope the remaining parts are up to the task.

With multiple failures, the VB is usually the suspect set of parts. Those many many dozens of parts have to be just right, perfect fits with no leaking etc. The shop should be able to make everything else right, the VB is much harder, few shops have fluid pressure testing machines for the VB, and the trans.

 

[dustinjorge]

I know the valve body was rebuilt... and checked multiple times thereafter. The seal that keeps blowing is the one that surrounds the overdrive piston. From my understanding that causes pressure to creep around the seal and results in the trans trying to engage multiple drives. So the servo, piston, seal, and cover were all replaced this go-around. Because this has happened multiple times I've been trying to figure out if there's something I did along the way that could cause this. Apparently, though, they didn't replace the cover last time, and though he said it looked fine he replaced it anyway since it could have an unseen burr in it.

The truck is running and driving great at the moment. We parked the 4R and Sub in the garage this weekend and drove around in the weekend warrior for a few days... and it seems to be running great. Also as noted, the trans shop kept it for a couple weeks and ran it through a couple tanks of gas.

Problem is, it always seems to be running great then goes downhill fast. It's hard to be optimistic on repair #5 but I'm trying.

I asked my tranny guy if he thought the VSS wires would cause the issue and he said 'I highly doubt that, based on the other mods on your truck, you used wire light enough in gage to cause any type of issue.' lol

I think I will re-connect the VSS wires to be sure.

 

[CDW6212R]

That OD seal letting go sounds like the kind of case wear that makes people rebuild another trans, or see if there is a repair for the bore. Sonnax has a lot of such repair items, but I don't know if the OD bore is one of them. All of those items require their special tool kit, and those are often $300 or so, which is why I haven't noticed any details about them. Check out the Sonnax site to see what they have. After a couple of times having the trans go out again, I'd have been wanting a different unit to rebuild. I hope that shop has it right this time, it is a big job to remove and install a trans.

 

[dustinjorge]

I'd definitely have thrown a reman in at this point if I was paying for all of this... the shop really has gone above and beyond and repaired this thing for nothing each time. I'm hoping it's fixed now, unfortunately if it's not the truck is going to be a part-out or cheap sell since I can't afford to replace another tranny in it at the moment.