I have a 93 F250 (amongst many others) that has a transmission problem. The truck has 460 with an auto trans. It has the overdrive button on the collumn. A few weeks ago I started the truck to let it warm up. I went out and dropped it into drive and the engine died... smoke came out from under the hood. The transmission wire harness had shorted somewhere and melted a few of the larger wires in the harness. Now, as long as I leave the truck in park or neutral, the engine will idle like normal. If I drop it into a gear, the engine immediately begins to buck and the voltmeter is bouncing between 12 and 18v. Funny though, sometimes you can shift it into drive and the truck acts completely normal.... most of the time it bucks and dies like said above. Obviously there is a problem somewhere. I want to replace the entire trans harness, but what about the problem that caused stuff to melt in the first place? Are there any common issues with these trucks/transmissions that I could look into?

The truck was produced 3/93, has 177,000 miles. It's 4wd... Don't know much else about it since I am a manual trans guy.

Ohhh, also, the Overdrive light on the gear selector is flashing.


Thanks Forum.

 

Not too sure and I don't have the experience from my other brands to give a guess but I have seen some smart people on here so you should get an answer to point you in the right direction. Good luck.

 

Tranny is probably an E4OD, check data plate.

Willing to bet harness melted from outside source first. Would take it loose & separate wires with razor blade & tape, then reinstall. Check all grounds & fuses. Check MLPS (Manual Lever Position Sensor) See how it acts & if that takes care of it, replace harness.

All other running/dieing symptoms probly' flow from there.

Good luck

 

I did some research on the MLPS and it sounds like that could be the problem (with the melted wire issue aside). Is the MLPS required for the correct operation of the trans/engine? Could I just disconnect it and see if anything improves? Where is this MLPS located anyway... on the trans itself?

 

you need that part for the trans to work.

 

Man... what happened to the old grassroots automatics of yester year? My dad has an old C4 in his tbird and that sucker is bulletproof! Better than a lot of manual transmissions.

Anyways, about the MLPS... If I disconnect the MLPS and shift it into a gear and the engine doesn't die, what does that round down? I think I am just going to part the truck out... My buddy needs a 460 anyway.

DAMN AUTOMATICS!!!

 

why don't you just fix it?