Help..X stuck, cant post in 911 forum..tranny inop

[Dash Riprock]

Help..X stuck, ..tranny inop - Pictures added

I tried placing this in the 911 forum and it says I cant do it. If any Moderators see this, feel free to move it.

My 95 XLT was heading home from a camping trip and the tranny started to slip on the mountain hills. It seemed to downshift reluctantly and when it did there was little power increase. Finally, it started slipping everywhere and that was that. I currently have no gears at all, including reverse. If the truck is allowed to cool down considerably or is started while cold, it will engage Drive very slowly and creep but within 15-30 seconds will start to slip and refuse to budge.

I have to make a quick decision to allow this to go to repair or try to fix something myself. Ive read alot of posts on here about tranny problems and many end with a shrug and "oh well, 2k down the drain". Id like help narrowing this down to see if I can do it myself. I am an able mechanic so with the right tools, I should be able to do what is needed.

Some specifics. The fluid is at the correct level. It is semi-new. By that I mean that I changed it a few months ago, but did not do a complete flush (pan only + filter).

The tranny had problems recently( o/d light flash, shift flare, slow shifting -documented on this board elsewhere) that was caused by a radiator leak which allowed the tranny fluid to overheat. The partial tranny fluid change, and the fix to coolant leak (heater control valve) seemed to bring the tranny back.

My novice understanding of transmissions, (greatly helped by the posts of Glacier, Brain, and others - thanks) tells me this cant be a failure that cant be fixed. The tranny made no grinding, crunching noises, there was no lurching, surging or intermittant operation. If I am correct, the tranny consists of a Torque Converter which makes a fluid lock, if that fails or no fluid exists in the TC, I believe it would match my problem, no? I dont see it as being bands and valves, because my understanding is that these components affect certain gears, or combinations of gears. It seems unlikely that every one of them failed. How about the fluid pump? Is it possible that no fluid is getting to the TC?

Id appreciate any ideas or things to look for. If ive omitted any info, please ask.....Ill be here all week.... Thank you.

 

[Doug]

Do a search, Explorer auto's fail pretty often. I've never rebuilt an auto transmission but there is alot of stuff in there and you need to know what you're doing. There are some guides out there that tell you how to do it, some of them are posted on this board.

 

[project92]

does the fluid smell burnt?

 

[Dash Riprock]

does the fluid smell burnt?

No not really. Ill compare it to new when I get home. Its still reddish in color from what I can tell

 

[Dash Riprock]

Last night I tested the pump by disconnecting the supply line to the radiator. Trans fluid flowed well so no problem there.

Can anyone take a shot at what component in the trans has failed? I'd really like to learn from this.

 

[Glacier991]

I'd be curious to know the pressures at the line tap and the EPC tap. I think you have a control body problem somehow.

 

[Dash Riprock]

I'd be curious to know the pressures at the line tap and the EPC tap. I think you have a control body problem somehow.

Not sure I have a fluid pressure gage but I can try to get one. I will say that I ran the drain hose off the radiator to an old empty quart motor oil bottle and started the engine for maybe 3-4 seconds and it filled the bottle up 1/2 way.

Are you speaking of a specific line tap, and sorry, but, whats the EPC?

Im definitely going to pull the pan this weekend so if you can think of anything I should look for specifically, Id appreciate it. Thanks

PS If anyone knows of a good transmission guy in hte Long Beach/Southbay area of So Cal, please let me know.

 

[Glacier991]

There are two plugs where you can screw in a transmission pressure gauge.. one is the "line tap" the other is the tap for the EPC, Electronic Pressure Solenoid. The line pressure tap sits behind the linkage where it goes into the case. The EPC tap is on the rear of the transmission case, mid way up on the side (passenger side).

Are you a 4R55 or 5R55 ?

 

[Dash Riprock]

There are two plugs where you can screw in a transmission pressure gauge.. one is the "line tap" the other is the tap for the EPC, Electronic Pressure Solenoid. The line pressure tap sits behind the linkage where it goes into the case. The EPC tap is on the rear of the transmission case, mid way up on the side (passenger side).

Are you a 4R55 or 5R55 ?

Ahhh, not sure. Its a 95XLT 4.0L 2WD. I thought I saw somewhere on this forum that my year/model was the 4R55, Ill have to research that.

 

[gavin]

If it won't shift into any gear, it's possible the Transmission Range Sensor (previously known as Neutral Safety Switch) is shot. It's about $50 from the parts store... they will also look it up as Neutral Safety Switch.
when you drop the pan, if there is a nice layer of BLACK, that could mean some of the clutches are burned up. If it's a light layer of gray, it's fairly normal.

 

[Glacier991]

Well, actually the TRS is not simply a new name for the neutral safety switch. True it took over that function too, but it also provides the computer information for what gear is being commanded, such that the neutral safety switch aspect is only a small part of what it does.

 

[gavin]

Well, actually the TRS is not simply a new name for the neutral safety switch. True it took over that function too, but it also provides the computer information for what gear is being commanded, such that the neutral safety switch aspect is only a small part of what it does.

I didn't feel like getting into that yet, since the question to "what is the TRS?" never came up

 

[Dash Riprock]

Thanks guys, the more options the better and the more I can quiz the mechanic the better as well.

One question, what explanation could there be for the fact that when I go start it up while cold, it will shift and drive, forward and reverse for 30 seconds or so, then slowly start to fade until it doesnt shift at all and wont move. Thats my big question. If the clutches are fried, why do they allow movement when cold? Because ther is no oil there yet?

Also, as the 30 seconds go by, the transmisson will barely shift into gear, let alone move once it makes it there.

Im dropping the pan today so Ill see if its obvious or not.

 

[Dash Riprock]

Took the pan ff yesterday and it looks like I have my answer. The pan is full of black ferrous grit and small chunks of metal. I took pictures for your enjoyment.

The first pic is the pan, you can see the magnet strip in the lower right and the gritty appearance of hte pan surface:

The second pic is a close-up of the pan again, you can see the glop of black clutch material grit and various small bits of metal.

And the third pic is a close-up of the magnet. I assume that pillowy, corrugated shape is caused by the shape of the magnet. At the top you can see how deep the material is after I ran my finger through it. To the left is my Craftsman magnet pulling away the metallic clutch material.

Looks like Ill be needing a rebuild!

 

[Brian_B]

I did not read the entire thread, but actually I have seen worse. Sometimes there are huge chunks of metal parts laying in the pan. Something grenaded inside them when you see that though. Yours looks like its just worn out overall. You need a rebuild.