Lost Reverse!

[63LeSabre401]

I have a 63 LeSabre, with a stock 401 and 2 speed Dynaflow auto. Bith the motor and the trans have been great for as long as I've had the car. No problems ever. Fluid level has always been fine, no leaks.

Anyway, yesterday I put her into reverse and hit the gas. I didn't hit the gas very hard at all, but the tires chirped and she backed up a few feet just before I heard a faint clunk, and then no more reverse!

By the time I got home, I noticed it was it was really hard to get into Park. Everything else works fine, and it drives great. The trans is still normal when regular driving, no slipping or anything, just now has no Reverse and no Park.

We jacked her up and disconnected and messed with the linkage a bit, and now it goes into Park fine, and has full travel through all the gears but still no Reverse.

Just to clarify, it will go into Reverse, and the backup lights come on, but the car doesn't move when I step on the gas, it will roll freely though, as if it was in Nuetral.

What could the problem be? Any ideas???

Thanks!!!

[LAST1987GN]

I hate to be the bearer of bad news, but sounds like might of broken the reverse band. Do you have someone that can inspect it for you

[63LeSabre401]

I hate to be the bearer of bad news, but sounds like might of broken the reverse band. Do you have someone that can inspect it for you

Is that a repair that can be done with the trans in the car, or does the whole thing have to come out? How hard is it to replace the band?

Thanks.

[322bnh]

Your service manual will give you troubleshooting guidelines for loss of reverse. My experience is only with 1955 dynaflow. You will need to do pressure checks. Could be a problem with the reverse servo which should be servicable without taking the tranny out of the car; band problem usually requires disassembly.
Willie

[63LeSabre401]

Your service manual will give you troubleshooting guidelines for loss of reverse. My experience is only with 1955 dynaflow. You will need to do pressure checks. Could be a problem with the reverse servo which should be servicable without taking the tranny out of the car; band problem usually requires disassembly.
Willie

Thanks Willie. How do I test the Reverse Servo?

[322bnh]

Again for more specifics, consult your service manual. The 55 valve body has low and reverse servos and all this can be dropped after removing the pan. The servos actuate levers that apply the bands and you may be able to see enough of the band to tell if it is being actuated.
I don't know what is worse: pulling a dynaflow or standing/crawling under one with tranny fluid dripping in your face.
Willie

[Roberta]

You may want to look at this fix Here (http://www.autotran.us/dflinkrep.html)

[Mr62Buick]

There is a metal band clip that breaks in the tailshaft part of the trans...