1968 Tranny question - 68 GT/CS

[Tequila]

Sorry, if this is duplicate qn as there is another active thread on C4 tranny. Heres my situation. I recently had my car towed for some rust repairs and got the car back. I was getting ready to replace the brakes and noticed the rear wheels are spinning even while the gear is engaged in park. Is that normal?

I thought the rear wheels lock up while in park. I have never driven this car before so i am not sure if it was already like this before or something got disconnected while the shop was replacing out the front floor boards. The car was sitting idle for about 15 years prior to my ownership. Everything appears to be connected and the the transmission linkage appears to be engaging when shifting. Its just that the wheels keep spinning all modes.

Any suggestions? Where should I start? The engine was frozen so I am slowly bringing it back to life so I can't start the car to test anything either. Are there other things I could do to troubleshoot? Thanks in advance.

 

[68 special]

I would start by checking the shift lever and see if it is connected or not. If it is disconnected to do the floors, it could be in neutral.

Bret

 

[robert campbell]

A non-positrack rear end will allow either wheel to spin when in park. That is normal. If this happens and you have a posi rear end, it is way worn out!!!

Rob

 

[Tequila]

Hi Rob, Thanks so much for the helpful info. The shift lever is connected and I can see it engaging at where it is hooked up to the transmission. How would I know if I have non-posi or posi rear end? Do they look different? Thanks again.

 

[rvrtrash]

If the car is on jack stands, and you spin one wheel "forward", the other wheel will spin in "reverse".

Steve

 

[Tequila]

If the car is on jack stands, and you spin one wheel "forward", the other wheel will spin in "reverse".

Steve

Thanks Steve. It does exactly what you described. Does that mean its non-posi? Do you know if the factory made them non-posi? Sorry, I am not very familiar with them.

 

[CougarCJ]

Thanks Steve. It does exactly what you described. Does that mean its non-posi? Do you know if the factory made them non-posi? Sorry, I am not very familiar with them.

The overwhelming majority of the Mustang rear ends were not traction lock (positraction) from the factory. Also called an 'open' rear end, noted by axle code with a number, instead of a letter (typically).

 

[robert campbell]

My guess is it is also an 8 inch vice 9 inch rear end. Posi track 8 inch factory rear ends are extremely rare. If you climb under the car, there may be a factory tag on the 10 bolts the secure the center section to the rear end. Take a rag and a wire brush and you can post the numbers you find. Also if you have the original door tag on the drivers door near the latch area, post all of those numbers. As Scott said a number in the rear end code denotes a non-Posi. A letter will be a Posi.

Actually this is kinda fun stuff for you. You are seeing what is original to your car and such. A fun treasure hunt.

Rob

 

[Tequila]

I couldn't find the factory tag on the axle. It does have the following codes on the assembly "C7OW 4025A 28". The door tag has the following codes: T 2A 15U 53 2 W".

Yes, it is indeed fun to find out more about this car. The happiest moment was when I opened the marti report confirming it's a true cali special. The saddest moment is when I tallied up what I spent so far on it and remaining estimate to complete the restoration

Thanks for all your help.

 

[Ruppstang]

The 2 = The axel which was a 2.79:1
Highway gears but good MPG

 

[Tequila]

Thanks. Interesting. The car at one time had a roll cage in it so it probably meant they were drag racing(?). With such gear ratios is drag racing possible? I wonder if "C7OW 4025A 28" means anything.

 

[Ruppstang]

With out looking it up, the casting was made in 1967 and it was a 28 spline axel. Goggle search is you friend:smile:

 

[66hcs-conv]

If the car has or had a roll cage in it, and drag raced, NHRA says that a car capable of going 9.99 seconds or 135 mph must have a roll cage. That is a fast car!

Somebody may have installed the cage as a wanna be racer. BUT if the car was raced, I doubt very much that a 2.79 rear end was used.