Question: Changing from Auto to 4 speed

[del23t]

What problem will I face changing my 1981 corvette to a 4 speed. I have a 1980 parts car with all the 4 speed equipment, however removal of the pedqal assembly is also giving me trouble and will the rear end be OK from the Automatic. Any help would be apprciated.

 

[MDKyleZ]

What problem will I face changing my 1981 corvette to a 4 speed. I have a 1980 parts car with all the 4 speed equipment, however removal of the pedqal assembly is also giving me trouble and will the rear end be OK from the Automatic. Any help would be apprciated.

I've never done this switch on a vette but I did on an 82 Trans Am. The two bigest problems I faced were correctly rewiring the neutral safety switch to function and the fact that the auto and T5 five speed needed different driveshafts in both strength and length.

 

[del23t]

Thanks, I found information on the drive shafts being different, I have the one from the 4 speed. My biggest problem right now is getting the pedal frame bracket removed from the 4 speed car, I believe I got all the visible bolts out but it's still in there pretty good. Thanks for the reply, I'll let everyone know any future problems I run into

 

[jrzvette]

I believe there is a small difference in the blocks. The 4 speed cars have a boss or indentation for the clutch pedal assembly.

 

[del23t]

Block Indentation

Thanks for the reply, this car has already had the engine changed, it now has a Jasper 383 engine in it now, hope it has the indent you were speaking about. Thanks again:W;help

 

[JohnZ]

I believe there is a small difference in the blocks. The 4 speed cars have a boss or indentation for the clutch pedal assembly.

All small-blocks have the drilled/tapped boss for the cross shaft ball stud.

 

[del23t]

Thanks, that was one of my biggest worries having then drilled block area for the clutch ball, any ideas on how to remove the clutch pedal assembly and mounting frame and is this change to a 4 speed able to be done in say a weekend, I do have access to a lift, just wondering on the time frame and work envolved. You folks are great, keep on doing the corvette thing, this is my first one I'm working on. My second vette so far.

 

[ironmoo]

Anyone done this to a '82? Wonder if the switch would be identical to a '81?

 

[pbcanney]

If you have an '80 with all the parts, it shouldnt take more than a weekend. You have the uber-rare crossmember and 2 year only shifter bracket on the '80.

I swapped my '81 2 years ago. The one thing I should have done was pull the dash. I dont bend like I did 30 years ago.

There's more to the pedal removal than the bolts under the dash. There are 4 under the hood in the wiper well.

and yes, there is already a hole in the steel firewall for the clutch pedal rod. You just need to find it inside the driver area and drill out the fiberglass

 

[rodgerh]

Hey I'm going thru the same thing.I took out the dash ,steering colum and booster.Can you tell me if the holes are in the frame for mounting the brkt for the Z bar?I understand weld on and some bolt on.I have a 79 vette.

 

[del23t]

Hey I'm going thru the same thing.I took out the dash ,steering colum and booster.Can you tell me if the holes are in the frame for mounting the brkt for the Z bar?I understand weld on and some bolt on.I have a 79 vette.

They are there in my 1981 it appears, I haven't completed the job yet, just getting all the new parts together, let me know if you have any other problems I might run into, I will be trying to do mine without removing the dashboard, but will probably have to remove the steering column. I also understand that the drive shaft need to be out of a standard and the universals are a different number from the automatic, just some hints on things I've found out.

 

[rodgerh]

Good to know,I have the frt yoke that came with the 4 speed,,Thanks

 

[6880 Mike]

Hey I'm going thru the same thing.I took out the dash ,steering colum and booster.Can you tell me if the holes are in the frame for mounting the brkt for the Z bar?I understand weld on and some bolt on.I have a 79 vette.

The clutch bracketry is welded on for 79 and earlier cars; it bolts up on the 80-81 cars. Might bolt up on the 82s if they left the required holes in the frames.

The AIM will show the location of the clutch rod hole, the size required, and where to drill it. Ditto for backup light switch wiring.

 

[rodgerh]

I guess I'm new to this .Whats or where do I find AIM.Sounds like I need it.

 

[JohnZ]

I guess I'm new to this .Whats or where do I find AIM.Sounds like I need it.

That's the Assembly Instruction Manual - you definitely need it - you're flying blind without it. All the usual Corvette parts houses have them.

 

[redvett]

Better check the trans cross member it may not be removable and thats a lot of cutting and welding.

 

[6880 Mike]

...you're flying blind without it....

Amen to that.

 

[JohnZ]

Better check the trans cross member it may not be removable and thats a lot of cutting and welding.

If the car was an automatic originally, it came with a removable trans crossmember.

 

[del23t]

My 1980 came with a 4 speed and it had the removable cross member, not sure about the 79's, my 81 that I intend to change to the 4 speed also has a removable cross member. One of the above quotes stated that the 1980had a special cross member so i would guess that the 79 might need a different one. Let us know how you make out.

 

[problemenko]

I'm in the process of changing my 79 from an auto to a 4sp. The crossmember is a bolt in making at least this part of the change less painful. The rest however is, well, challenging.