Quick help with C5 Auto Trans for 86 LX

[tiretread]

Howdy all. Been driving the wifes Mustang around and have noticed an issue with the transmission. As you drive, the gears don't change. The engine keeps revving until I let off the gas pedal and re-apply my foot to the pedal. Then it will usually shift to the next gear.

I have already checked the transmission fluid and it is good. I'm thinking it might need a rebuild. Any thoughts? thanks!

[Walking-Tall]

Sounds like an issue with the kick-down rod function. It's beside and behind where the throttle cable attaches at the throttle body.
First, see if it's still hooked up and has a return spring. The adjustment is for there to be about 0.060" clearance (rod to the transmission can travel an additional 0.060") when you hold the throttle wide open. Adjust with the small bolt that the throttle arm contacts.

And/or as well, see that the vacuum line from the rear of the intake down to the modulator (passenger rear of trans case) isn't leaking, and pull the vacuum line off the modulator nipple and check for transmission fluid. If there's any fluid, it's diaphragm is leaking and you need a new one.

[tiretread]

Thanks, I really appreciate the info.

[tiretread]

Worked like a charm for 2nd and 3rd gear by adjusting the bolt that the throttle arm contacts. Went back home to re-adjust to see if I could get 1st to work easily as well but while in the driveway, the engine just cut off. Unknown reason why. It was so very sudden (and the engine was idling strongly) that I thought it was a fuse or lack of fuel. Well, I had gas and the electricity was still working. I tried to start the car again and my starter went. Sigh. The joys of owning a fox body!

But your info was spot on and I really appreciate it.

[Walking-Tall]

Worked like a charm for 2nd and 3rd gear by adjusting the bolt that the throttle arm contacts. Went back home to re-adjust to see if I could get 1st to work easily as well but while in the driveway, the engine just cut off. Unknown reason why. It was so very sudden (and the engine was idling strongly) that I thought it was a fuse or lack of fuel. Well, I had gas and the electricity was still working. I tried to start the car again and my starter went. Sigh. The joys of owning a fox body!

But your info was spot on and I really appreciate it.

Oh good. Oh, not so good!
With it quitting instant like that, could be a number of things...
I'd check all ignition-related wires, and all electrical connectors under hood for that matter. See that the idle control didn't get bumped and unplugged. A vacuum line breaking or coming off can stall out an engine too, especially the MAP sensor vacuum line...

Good luck with it!

[tiretread]

Well, it seems it's a bigger issue than I thought. Pulled the old starter out and was a bit dismayed that the teeth of the engagement gear looked good and shiney and unchipped/unbroken. Hoping that the solenoid was no good. Nope. Tested that along with the new one and both worked perfectly.

I put the new one in anyways hoping against hope. Got that all done and turned the key. Same as issue as before. Starter is working but nothing is turning over. I did notice that coolant was leaking off of the starter at a moderate drip rate.

I didn't get a chance to hand turn the engine yet, as I had to get out and get some Xmas shopping done. I'll do that tomorrow. If worse comes to worse, I have a 302 sitting in my 85 GT that's not doing anything but gathering dust in the garage.

[IDMooseMan]

Sorry to hear that, but at least this will help narrow down the search.

[Walking-Tall]

Coolant off the starter... starting up top, could be intake gasket leak at the right rear... right head gasket at the rear... block frost plug behind starter...

[JACook]

Could also be leaking at the intake manifold heater hose connection, and running back along
where the intake manifold meets the cylinder head. Seen that more than once...

[tiretread]

Thanks for all the advice. I think I'm just going to park it until I pull the engine and drive train from my 85 GT and swap it into this car. Planned on doing that down the road but now that plan has been accelerated.