Need help with my Bronco

[KRStone]

My son drives a 1987 Ford Bronco 5.0 liter EFI with auto trans, 4x4.

It has a bad 'stumble' under accceleration and sometimes under cruise that feels like the trans is shifting very poorly. Loud hard thump. Sometimes downshifts with a hard clunk too.

Fluid is the right color, doesnt smell bad, and just a bit on the high side but not foamy.

I will try anything and post pics for help.

KRS

 

[DonFitzwater]

If you've ruled out engine problems, sounds like the old AOD trans is going south. They are a good transmission but still have some issues. It's not like other, newer rigs that had engine management systems that would cause strange shifting caused by engine running issues.

 

[KRStone]

Well, I got it sorted out.

Replaced spark plugs.
Replaced distributor rotor.
Replaced distributor cap and wires.

Before i started it up I removed the old wires from the old cap. The cap had two corroded terminals hiding under the rubber boot. Wow. Previous owner must have powerwashed the engine.

Totally fixed the jerking during acceleration.
Still a thump on downshift, I need to locate and pry on the motor and trans mounts.

Runs good now. Oh, and i removed that ridiculously small snorkle from the airbox, I doubt that 5.0 was even breathing with that tiny orifice.