I have a 1980 C3 with TH350. It's been running fine but this morning I noticed that I couldn't go into third on the normal shifter slot, I had to kind of drop it between 3rd and 2nd and it would engage and drive fine. But just this evening it stopped going into reverse or nuetral. It's either Park for forward and when driving it shifts gears just fine just no revers or nuetral. The shifter feels very sloppy through the full range of movement. I looked at the cable and shifter and all looks fine. I checked and see that the shitfer arm on the transimission is going through it's full range of motion but just not engaging. Any suggestions? I'm hoping it's something easy to fix if I drop the pan.

Funny thing is I just bought a TK600 this week and I'm waiting to save up some funds for the other items I need to do the conversion. My Wife is convinced that I did something on purpose since I told her I'd wait until early next year to complete the project. One of the few times I'm actually innocent.

I'd like to see if there is an easy fix to get another few months before swapping to 5 speed. I'm looking forward to having it but not doing it.

TIA

 

First...start the engine/once it reaches operating temperature check the transmission dipstick to make sure the transmission is not LOW or is not OVER-filled with fluid. Turn OFF the engine for further troubleshooting.
You really need someone to sit in the car/wheels blocked so car cannot roll forward or backward more than 6" to 8".
Make sure the shift arm on the side of the transmission is in the PARK position to begin the troubleshooting.
Have the person in the car move the shifter according to your instructions while you watch the cable where it connects to the shift arm on the side of the transmission.
Make sure the shift arm actually moves and "Clicks" as you instruct the person to select different positions with the console shifter.
YOU may have to roll the car slightly back and forth to get the trans to shift IN and OUT of PARK and REVERSE.
ALSO hold the cable to feel any movement or slack in the black sleeve or in the inner cable when your assistant moves the console shifter.

IF excessive slack (More than 1/8") is felt in the cable or the black housing find the reason for the slack and correct/repair THAT problem (the problem may be inside the console shifter mechanism)/


NOTE: There is a "keeper" inside the shifter mechanism that can pop aloose which lets the black cable housing move uncontrollably....the keeper would need to be reinstalled and slightly crimped.

AT THE TRANSMISSION there should be very little slack where the cable linkage attaches to the trans, shifter arm.

The troubleshooting listed below CAN BE DONE FIRST if choose to do so........
Remove the transmission pan slowly and catch all the fluid in a CLEAN container so the fluid can be smelled to determine if it is "burnt" from overheating......or if there is any metal/fiber contamination in the fluid or in the bottom of the pan.
Check the notched metal "gear" selector INSIDE the trans. to make sure it is not loose...sometimes the retaining nut will loosen and allow the notched selector to "flop around" causing the transmission to act the way you described above.
Replace the filter (make sure there is only ONE rubber seal inside the suction port where the filter fits onto the valve body if the filter is designed to use a rubber seal.....TWO seals will cause unwanted air to be sucked into the valve body

Let us know what you discover.

 

I did check the fluid and it's good. In fact once I put it in forward it shifts fine. I jacked up the car and disconnected the shifter cable on the transimission and the level on the transmission is flopping so I'm draining fluid and will remove cover to see what I find. Feels like something just came loose so it may be the nut on the inside that secures the shift selector bolt but I'll advise once I find what it is.

 

check shifter linkage.
you wrote how you moved the shifter between gear detents

 

I dropped the pan and found that the nuts on inside is shift selector shaft was very loose and that was causing issue. Tightened that all running perfect. I appreciate the help and suggestions. Gotta love it when it’s an easy fix.

 

I was amazed how much torque is applied to the selector shafts nut to keep it from backing off!

 

Just wanted to bump this thread. Thanks to doorgunner for all the suggestions. I have a 1987-ish transmission/350 motor that won't go into reverse. I haven't had a chance to have someone shift it while I watch, but it looks OK shifting while I'm under the car. I will confirm.

I bought the car several years ago, and it just sat. Several quarts of ATF leaked out, so I added. Naturally, I added too much, and had to drop a corner of the pan to drain. I drained probably a quart, added half quart, and now while running and hot, and the dipstick measures right at the top of the fill line. Still no reverse. It swear it had reverse the other day before I started messing with the fluid level. Any thoughts? Filter?

Is there any way the dipstick is the wrong size?

Thanks,

dunney

 

did you run it through all the gears while the engine is running prior to checking fluid level?

 

In my case it was just a loose linkage just inside the transmission lower cover. I took off the cover, added some locktight to the nut and tightened it. Very simple to so. Hopefully your's has similar issue.

 

Thank you so much auggiedoggy and joserpaq for responding.

I’m pretty sure I ran through the gears and re-checked the level afterwards, but now I’m not sure. Next time I wrench I’ll check it. I know if I have it in the lowest gear, and rev to about 2000, it will catch and drive forward.

I was *hoping* not to have to remove the pan, but it’s trending that direction. I’m still leaning filter, but I’ll look for that nut floating in the pan.

Any other suggestions are always welcome.

thanks - dunney

 

The linkage seems fine on the outside, I ran through all the gears, and checked the fluid level. The level was high, so instead of dropping the pan again, I used a turkey baster to remove some fluid from the drain tube, maybe a cup.

Every time I start it now, it will go in reverse and forward within the first few minutes. However, after about 5 minutes, it won't move in any gear. If I check the tranny fluid, it's still high, reading around the "F" in Full. If I remove more, it reads lower on the stick, but eventually goes back to above the fill line. This doesn't make any sense. Does anybody have any idea what the hell is going on here???

 

Alright. I shamed myself into it. I'm dropping the pan and everything within a 10 foot radius is spattered in red fluid. It's like a frickin' crime scene.

I don't have the pan all the way off yet, but I don't see anything that looks like it might have a nut that is MIA or loose. It would be on the drivers side, no?

Any thoughts?

 

Which nuts were loose? I don't see anything loose. Please help!

 

in my case it was the nut that connects to shaft that turns shifter lever right inside transmission. It was very obvious once I took off cover because the nut had backed off enough to allow the lever to come loose.

 

Hmm. OK. thanks. I don't see anything loose in my guy.