Overdrive shifting rough at highway speed

[jhumbertoap]

Hello everyone,

I have a 2002 XLT Explorer (4X4). A hadn't had major issues with this truck in long time, until recently.

At highway speeds, this is above 60mph, the overdrive engages pretty rough; you can feel a "vibration" that "shakes" the entire car.
Sometimes, if going up a hill or with any extra load, it hesiates to engage the OD and the OD light starts flashing.

No issues in other gears or at lower speeds. It is very smooth.

Any inputs will be greatly appreciated. Great forum.

Thanks.

 

[CypherSTL]

Mine was doing the same thing. 60MPH I was doing about 3000RPM instead of my normal 2000RPM. A grand later replaced broken bands, solenoids, and torque converter, etc.

 

[Explorer_Phil]

Bad News

Unfortunately, that's the exact same thing that happened to me. First it was OD shifting roughly, then all gears. I was barely able to limp into a shop before it stopped moving. Transmission is going out, that's what the blinking light means.

 

[jhumbertoap]

Mine was doing the same thing. 60MPH I was doing about 3000RPM instead of my normal 2000RPM. A grand later replaced broken bands, solenoids, and torque converter, etc.

Mine it's not there... yet.

At 65mph without any extra load the engine runs at 2100rpm, which is normal.

Then I set the cruise control at 65mph ~ 72mph. No issues.
Then comes a hill (extra load), and the OD disengages; rpms=3100 now, which is normal.

Then the slope of the hill decreases and the tranny tries to engage the OD again. That's where the problem starts; if the OD engages, it shakes the whole truck (pretty rough). But sometimes struggles to engage and that's when the OD light starts flashing.

In a few words, keep the engine running below 2500rpms and it's OK.
So what can be the most likely cause of this issue?

"Slipping" torque converter?
Faulty solenoid pack? (but only above 2500rpm?)
Overdrive servo?
Other?

What's the logical approach to discard possible causes and minimize expenses? It can't be all at the same time.

 

[pipewelder74]

Start with the easy stuff. Check your fluid level--I KNOW its a pain in the arse without a dipstick...Just unscrew the CENTER plug (inside of the larger plug) on the bottom of the tranny pan, if fluid comes out- your "OK" level-wise...

Realistically, Since you've jacked the thing up to check the fluid--ALL FOURS AND LEVEL--It is pretty easy to just drain the tranny, remove the pan and swap out the solenoid block and valve body. Roughly $400-$500 total for both and new fluid. http://www.tpsautoparts.com/

There is a good chance that you have a broken or less-likely loose belt.
This requires a tranny drop and partial disassembly to replace a $20 part.
A loose belt can be easily tightened, but chances are if the belt is loose it's because the strut clip on one end is broken. I can help walk you through doing it if you have a decent tool set and some basic know-how..

Additionally, a "bad" torque converter is pretty unlikely..just because it doesn't really do much mechanical work. It just throws oil at vanes. More likely to have a problem with the valve body- which controls the torque converter and the tranny, or the solenoid block which controls the valve body..

 

[jhumbertoap]

Start with the easy stuff. Check your fluid level--I KNOW its a pain in the arse without a dipstick...Just unscrew the CENTER plug (inside of the larger plug) on the bottom of the tranny pan, if fluid comes out- your "OK" level-wise...

Realistically, Since you've jacked the thing up to check the fluid--ALL FOURS AND LEVEL--It is pretty easy to just drain the tranny, remove the pan and swap out the solenoid block and valve body. Roughly $400-$500 total for both and new fluid. http://www.tpsautoparts.com/

There is a good chance that you have a broken or less-likely loose belt.
This requires a tranny drop and partial disassembly to replace a $20 part.
A loose belt can be easily tightened, but chances are if the belt is loose it's because the strut clip on one end is broken. I can help walk you through doing it if you have a decent tool set and some basic know-how..

Additionally, a "bad" torque converter is pretty unlikely..just because it doesn't really do much mechanical work. It just throws oil at vanes. More likely to have a problem with the valve body- which controls the torque converter and the tranny, or the solenoid block which controls the valve body..

Thanks!! That's sounds like a very logical approach... exactly what I was looking for.

 

[2000eddiebauer85]

Please tell me did you find what was wrong? my Eddie Bauer is doing pretty much the same thing the only thing its not is the lights not coming on. the push button will not work to take it out of o/d. the vibration happens when it shifts into and less out of. seems to be getting worse. slowly. I'm praying it wont be major, and i pray it will last till tax time to fix. i know that sounds cheap but being laid off and going back to school with three kids makes money tight. Ty in advance.

 

[jhumbertoap]

Sorry.. not good news. I took my truck to a tranny shop that a good friend recommended. The main issue was the servo bores worn out.
That said, with more than 100K on the tranny, I asked them to replace those parts more likely to fail in the near future. So they also replaced the torque converter, did valve rebuilt and don't remember what else. $2900.00 total, including $220 for 75K miles warranty.

The "good news"... it works great! But it was an expensive repair.

 

[2000eddiebauer85]