1970 fastback tranny help

[2Ponies]

Hey everyone. I'm new to the forum and not sure this is the best place to post. I just got a 1970 fastback (Grande Mach 1 clone) with a Cleveland. I'm having trouble with the transmission. It works fine once it warms up but I have a lot of trouble getting it in gear when it's cold. I move the shifter to drive or reverse and nothing happens. I can rev. up and it won't move. Any ideas? Thanks.

[1Blueovalfan]

Sounds like the seals are bad inside the trans. What happens is when it warms up the seals expand and maintain the internal pressure. Sounds like it needs a rebuild.

[jevchance]

Originally Posted by 1Blueovalfan

Sounds like the seals are bad inside the trans. What happens is when it warms up the seals expand and maintain the internal pressure. Sounds like it needs a rebuild.

I agree with this, sounds exactly right. I'm afraid you have a rebuild in your near future.

[91whiteghost]

Find a can of KW Transmedic. It conditions and softens the seals, usually helps.
I've used it in my C6 and it really helped the problem you are having

[Pockets]

If its so bad that is not even going into gear when cold i'd just rebuild it. fix it in a can is good when its just slipping a little but if its not even going into gear then i would look into a rebuild

[2Ponies]

I'm thinking about replacing it with a manual. Ideas? This is my priority fix. I just want to drive it. No dragging, no shows except cruise-in style. It was bucking at the light with foot on brake-- don't like that. Not interested in revisiting this next year either... Thanks everyone for your replies!

[91whiteghost]

the fix it in a can was just a suggestion that may improve drivability while he decides what to do.
the hardest part about going to a manual is finding the clutch pedal assembly.
the rest of the partts are easy to find ( new or used)but be preparred to spend more than rebuilding you Fmx will cost.
American Powertrain makes a completee swap kit for around $3500. It includes a clutch pedal and tranny mount for a T-5
Remember that you need a 28 oz flywheel and the flywheel diameter and bellhousing must match.
you cant't run an 11 inch flywheel in a fox bellhousing , and you can't run a large bellhousing with a 10 1/2 clutch.

[jevchance]

The clutch pedal assembly is available new from most suppliers, it is not hard to find.

You can get a lot of information about the swap and what parts you will need at this link:

Modern Driveline - 5 speed Transmission Swap - T5 and TREMEC TKO conversions for Mustang, Falcon, Cougar, HotRod, Cobra

The rebuild will likely be less expensive, and will likely get you back on the road quicker.

[Pockets]

Pedals are very easily had, modern driveline makes a two piece clutch pedal you dont even need to take the column down to get in. they are $160.
If you have the money to do a T5 swap I would do it. The flywheels are easy to find as well, If you go with modern drivelines hydraulic clutch setup you can be all said and done for under $2000 if you get a good deal on a trans.

I'm in the middle of a T5 swap in my 70' coupe actually, I have a spare T5 for sale if you're interested send me a private message.

[Jeff73Mach1]

I put a Keisler Engineering RS 400 5 speed in my 73 2 years ago.

They make a perfect fit kit that allows installation with no alteration to the car itself.

Considerably stronger than a T-5 it is based upon a beefed up T 45, yet is s nice compact package. It is available in 3 different strengths and with everything you need right down to the driveshaft, or you can get just what you want. Their prices aren't bad, but their customer service is awesome!

[toybreaker]

Go for the 5 speed swap. I am going to do that with my 70 Coupe as well.