Helping out a friend with a '65 Imperial, which as you may know was the last year for the cable-operated shifter. Before I get into the problem let me first say that the trans was rebuilt by somebody who clearly didn't really know his way around Mopars; the fact that a later cast crank-specific torque converter was installed where it had no business being is a good indicator of this...so who knows what else he did WRONG.
The problem: Transmission does everything fine until you've been driving for over 45 minutes or so and have really warmed things up. At this point you can select whatever gear lever position you like but the transmission behaves as if it's still in drive - no neutral, no reverse. Funny as that is it gets better: when you shut the car down and wait around 15-30 minutes (it varies), start her up and things are back to normal. Two other observations made while the car was in the "drive only" state: 1) selecting 2 and L seem to work ok (no upshifts), 2) ignition/starter circuit was open regardless of gear lever position indicating the neutral safety swith wasn't getting triggered or connection was unreliable (ended up bypassing to remove it from the equation).
I know some things but am by no means a transmission expert, with that I have a couple ideas:
When things heat up, something in the valve body is keeping the shfiter cable from putting things in the right position (wrong detent spring, worn or incorrecting assembled parts).
Hydraulic pressure is being misdirected as the result of a half-assed rebuild and things go back to normal only after the misdirected pressure has had the opportunity to leak down.
Joined: Wed Nov 17 2010, 03:28PM
Location: florida
Posts: 1311
i would start with making sure the correct parts were installed.pre 67 torqueflites are slightly different such as input shafts,converters,nss and more.iv seen later model parts installed in earlier tourqeflites .i discovered this when rebuilding my 66.sounds like valve body is wrong for starters
I'm almost certain this is an early vs later Torqueflite problem and there's most likely a list of things the tranny builder got wrong because he made assumptions. If this were my car I'd write off the current trans and start over from scratch. Being that this is a friends car I'm trying to limit my involvement, I'll go as far as swapping in a known "good" valve body to see if that changes things but that's it. It seems that the proper approach would be to perform some pressure tests in an effort to zero in on the cause, however, I'm not about to get roped into chasing down somebody else's f*-ups.
I was hoping somebody might have had a similar experience but considering there's about a million things that could go wrong I should've known better.
I feel sorry for my friend but overall this is a pretty messed situation of the sort I try to never get into. Shows what happens you have a guy w/no mechanical inclination throwing money at another guy who thinks he can build trannys.