The Stovebolt Site Forums The Shop Area Engine Shop Locked up in reverse? Stumper!

I'll start with this is not truck related, but there are some awfully smart mechanics on this board and I value your advice.

My daughter called and said her car, 4 speed Saginaw and a 3.55 open diff, was stuck in the garage and wouldn't move in reverse, but would go forward. I got a chance to try it and sure enough, it would move in 1st. Put it in reverse and revved it, loading the clutch and engine as much as I dared, and the body lifted like a brake torque with an auto, but the car wouldn't budge. The brakes were not stuck since we stuck it in neutral and the car pushed easily both forward and back.
Getting clever, we pushed it backwards down the inclined driveway and I let out the clutch while it was rolling and engine idling and it worked fine - no crunch, whine, bang or anything to indicate something breaking loose. It drives fine now and I was unable to get it to repeat.
I want to fix it before the trans/rear? blow up and leave her stranded but I haven't a clue where to start looking. I've blown up spider gears and the car won't move at all.
OK - it is a Corvair, but as far as the transaxle is concerned it's just a Saginaw and the open diff with no driveshaft in-between; the output shaft is directly connected to the pinion.
Anyone hear of this before? Any clues?
Thanks in advance.

It probably was a linkage or shift fork problem. I'll bet something is worn or out of adjustment enough to allow it to remain in a forward gear AND engage reverse also.

Check the shift lever pivot and all linkage pivot points for looseness and remove any you find. If you don't find anything in this area it might be wise to take a look at the shift forks in the transaxle.

It may be just a Saginaw, but it has three shifter shafts, a selecter shaft, a dozen detent balls and springs, four shift levers and the usual three shift forks. You obviously have a '66 or newer Corvair or at least the trans is.
That said, I don't think you would get "the body lifted like a brake torque" if the trans was locked in two gears.
This may sound wierd, but I'd be inclined to take a good look at the rear wheel bearing hubs.

The "body lifted like a brake torque" effect comes from engine torque and will happen with a trans brake on a drag car, same as locked in two gears, cause that's what it is.

He could hand push it which means the brakes,bearings, ujoints and axles are probably ok,
So, must be something in the transaxle.

it is probably sift linkage go under the car and move them by hand and check it .the factory shifters on saginaws are just short of junk when new when they get some miles (and a few gorilla shifts )on them they will do really strange things.also a lot of the problem on some cars is the fact that the shifter mounts to the floor pan instead of the tranny so when you gas on it it twists the linkage so hard that you cant shift till you let up on the gas.

V6, the corvair Sag has an internal gear selecter. A single shifter shaft sticks out the front of the case and works a lot like a modern 5 or 6 spd box.
Ken. A trans brake on a race car will twist/lift the body when the trans brake is released. On a car with the brake on, the engine block is trying to turn counter-clock-wise (pull up on driver side motor mount). The engine crank is trying to turn clock-wise, drive shaft clock-wise and axle clock-wise. The right rear wheel is being pulled up into the body(tire spins) and left wheel pushed down(no tire spin). Not taking into account, leaf spring wrap or control arm action as the case may be.
If trans is locked, the torque is against the trans case. The only thing opposing the engine from turning is the clutch or torque converter and therefore, no body twist.

I didnt know we were talking about a corvair.thats a whole new world entirely.the saginaw shifters i was refering to are usually found in camaros/novas/vegas and their buick/pontiac cousins.the shifter bolts to the floor pan the linkage attaches to the tranny.when you reaaly hammer it they will bind up so bad you cant shift them cause the motor and tranny torque to the right.sloppy motor mounts dont help either.

Richard, Yep I understand all of that. But, the motor mounts are what keeps the engine from rotating. And they transfer the torque to the body/frame. All I'm saying is that you don't have to have the brakes locked to cause 'body roll'. Just get in your rear wheel drive car (engine has to be oriented front to rear), put it in nuetral or park, rev the engine quickly. Didn't your fender move up and down? Sure did.

Getting back to Chuckthetrucks problem.
As I said before, this is what I think is about to happen.


[img]http://home.earthlink.net/~roadruner/CorvairHub.jpg[/img]
[img]http://home.earthlink.net/~roadruner/Hub.jpg[/img]
The bearing locks up permanently and spins in the hub.

Disclaimer: Not mine. I don't work in the house.
I hope no one gets excited. It is a 6 cyl. chevy from the 60s.