I ran into a strange problem today when I went to pickup my 77 from an exhaust shop.

I have an L82, and a TH400 transmission. After the car started I tried to shift it from park into drive, but was unable to do so. I could shift into reverse, and neutral but I could not physically pull the shifter back to engage drive.

I say this was a sudden issue because the day before I took it for exhaust work I could shift up and down all the gears without any resistance or issue. At first I thought maybe the linkage was pinched by the exhaust work (nothing else changed so that was my first dumb thought hah) But after looking under the car the exhaust work is nowhere near the linkage. In fact, I was not able to manually move the transmission lever (what do you call the part that the linkage connects to on the drivers side of the tranny?) past neutral.

I managed to drive it home, by moving the shifter back into reverse, neutral, reverse neutral, and so on ... maybe 4 times, then I was able to (pulling like hell) get it to just click into drive.....

I drove home just fine and it shifted through all the gears no problem.

So now its back home, and I can JUST barely get it to click into drive with either the shifter linkage, or manually with a wrench on the lever under the car. I can in no way go past that into 2nd or 1st.

Anyone ever heard of this problem ? Any input on what would suddenly bind up and stop that movement ?

The car has 67k miles on it, and I don't know the history of the trans in terms of maintenance it always shifted fine and was easy to click into drive, I guess I'll be dropping the pan shortly ??

 

I wouldn't think so. My money is on them screwing up your shift cable some how. I'd pull the cable off the tranny and see if the tranny shifts good and run the shifter through the motions too. Should narrow things down.

 

did the exhaust shop do any welding? I would definitely do what was suggested above and look very closely at the cable.

 

They did do a fair amount of welding. They fixed a leak at the drivers side exhaust manifold and re-bent some piping a little to pull it up off the ground (I was scraping the road if I hit even minor bumps). They also replaced all the old rusted pipe couplers with nice clean welds. So they welded 4 or so spots all the way back each pipe.

Its too dark in my garage tonight to get a good look even with a flashlight, tomorrow morning ill back it out into the sun and take a good look. Anything I should look for in particular ? I cant understand why I can shift it into reverse / neutral but not on to drive, I would think if the cable was damaged it would not move at all?

 

Yep...the welding ended up using the shift cable as a ground.

JIM

 

So here is what I found today after taking a good look, I don't claim that what follows makes any sense at all:

I could not see any damage to the linkage as I followed it under the car. I inspected the connection to the transmission best I could with a mirror from all angles, I then moved the linkage around a bit a foot or so back from the transmission, I was able to move it a bit, but it felt solid.

Still unsure what happened I got in the car and tried to pull the shifter through all the gears, it again stuck right before drive. I heard the various detents click, but it would not click into drive. After taking it back and forth a few times it started to click into drive and each time took less and less force, finally maybe 6 times into it I was able to pull down into 2nd and 1st, although it pulled hard. After this major breakthrough, 10 or so more cycles through each gear got it feeling just as smooth as before the problem started!!

What did I learn ? Nothing ! I have no clue what caused it nor what fixed it. Can the linkage get bound up by moving it around ?

At this point everything is back to normal, it will easily switch gears using the shifter, and I can see no damage to the linkage under the car. Can I call this good ? Or is there something else I should dive into the next time I have it up on my dad's lift? (regarding this issue, there is always SOMETHING that can be done when its on a lift, the fun of owning a classic hah)

 

There is a 'lockout' cable from steering colum to the tranny. I'm guessing that the new pipe is putting a bind on that cable so that it won't release the tranny. Or, the welder disconnected the cable and forgot to reinstall it. Without question, the shop that did the exhaust work is at fault.