Ford Truck C6 Tranny Problem - Tilted Forum Project Discussion Community

wisj2 · 06-24-2004, 01:29 PM

I have an old 81 Ford F100 with C6 and 300CID 6 banger. Been a damn good old truck but I tore something up today.

I'm a land surveyor and was in some pretty rough territory laying out new streets for a new subdivision, limbs and stumps all over the place.

Leaving work today with the transmission in Drive it would not shift to second. I can manually shift to 2nd as normal, but it still won't go into high gear when I move the shift lever back to Drive.

I'm thinking I must have tore up some linkage under there, but I don't know what to look for.

Any help would be appreciated.

MSD · 06-24-2004, 02:03 PM

An automatic transmission only has one linkage. What probably happened is that something shook loose inside, or a worn clutch pack finally gave out under stressful driving. However, it may be simpler than that.

The first thing to do when a Ford automatic transmission gives out is to flush the fluid out and replace the filter, then replace the fluid with Mercon V fluid. If that doesn't work, you're probably going to have to take it to a mechanic.

wisj2 · 06-27-2004, 09:58 AM

Turned out to be only the vacuum line to the modulator. Easy fix once I crawled under in the right spot to see the problem.

The rubber hose from the modulator was broke off right at the end of the metal vacuum line from the intake manifold. 3 minutes and I'm shifting normally again.

Signed: Happy in Oklahoma!

06-24-2004, 01:29 PM	#1 (permalink)
wisj2 Tilted Location: Oklahoma	Ford Truck C6 Tranny Problem I have an old 81 Ford F100 with C6 and 300CID 6 banger. Been a damn good old truck but I tore something up today. I'm a land surveyor and was in some pretty rough territory laying out new streets for a new subdivision, limbs and stumps all over the place. Leaving work today with the transmission in Drive it would not shift to second. I can manually shift to 2nd as normal, but it still won't go into high gear when I move the shift lever back to Drive. I'm thinking I must have tore up some linkage under there, but I don't know what to look for. Any help would be appreciated.

06-27-2004, 09:58 AM	#3 (permalink)
wisj2 Tilted Location: Oklahoma	All fixed now... Turned out to be only the vacuum line to the modulator. Easy fix once I crawled under in the right spot to see the problem. The rubber hose from the modulator was broke off right at the end of the metal vacuum line from the intake manifold. 3 minutes and I'm shifting normally again. Signed: Happy in Oklahoma!

06-24-2004, 02:03 PM	#2 (permalink)
MSD The sky calls to us ... Super Moderator Location: CT	An automatic transmission only has one linkage. What probably happened is that something shook loose inside, or a worn clutch pack finally gave out under stressful driving. However, it may be simpler than that. The first thing to do when a Ford automatic transmission gives out is to flush the fluid out and replace the filter, then replace the fluid with Mercon V fluid. If that doesn't work, you're probably going to have to take it to a mechanic.