GEN 1 Transmission shifting glitch

[matrix243]

I couldn't find anything on this but remember this was a tsb at one time and can't find the orginal thread.

Tonight on acceleration it shifted from 5th to 6th, glitched half way and dropped into 3rd locking the truck up a bit. After that it wouldn't get out of 3rd. I pulled over shut truck off, turned back on and shifted normal up till I think 5th and did it again. Everytime I get up to speed it seems to drop back down to 3rd.

Any ideas or reference thread?

 

[matrix243]

Not my video but it basically did the same as this guys video.

 

[matrix243]

Saw an output speed sensor might cause this?

 

[matrix243]

How in gods name, the fluid level is low by quite a bit! How can this happen with zero evidence of a leak anywhere? Will have to check again with optimal trans temp but it had to have been close to driving temp. What kind of damage would there be from this?
I keep it in the garage and I've been unemployed for 2 years so I would know if even a drop dripped. No metal filings on stick which I hope is an indicator its still good.

It was at about this level.

 

[CoronaRaptor]

Don't you have the check it with it running and hot? What about the leadframe recall or tsb thing.

 

[matrix243]

Don't you have the check it with it running and hot? What about the leadframe recall or tsb thing.

Yep had it running and pretty close to operating temp. TSB and leadframe was done on it.

 

[CoronaRaptor]

Yep had it running and pretty close to operating temp. TSB and leadframe was done on it.

The only thing I would check if it isn't low on fluid is the the connection into the transmission, make sure the wires are tight. If it's low, and no sign of leak, idk is there a steam vent, lol.

 

[matrix243]

I could not get a clear indicator with the elaborate crazy methods trying not to completely skin your arm totally off of skin from the 1000F cat. This is all I could get.

 

[matrix243]

Doesn't seem to be that far off.

 

[CoronaRaptor]

Looks like it has fluid in there. Check that bulkhead connector into the transmission, remove the wiring and look for any corrosion/wet, etc, put it back on and see if that fixes it, otherwise it might need a new leadframe or transmission rebuild. I'm almost at the point that mine is going to need a rebuild soon. Was towing my travel trailer on a test drive and every time i went up a long steep hill on the highway and then stopped on a hill it smelled like burning brakes, but the brakes were cold, pretty sure the clutches are burning up in the tranny, doesn't do it without the trailer weight behind it.