Clutch pedal issues, plus converting 3-speed to 4 speed

[Mr_C]

I have a 71 convertible, 351c 2v, 3 speed, car. It was a fairly optionless car (manual drum, manual steering, 3 speed, etc) but between me and the previous owner, it is finally coming around (power steering, disk brakes, and power brakes and 4 speed toploader being installed now).

My current problem with the car is the clutch assembly seems to return to about 80% of the way up and then sort of hangs there. If you pull it back with your foot it will snap up and bang fairly hard. At this point, the clutch pedal is a few inches higher than the brake brake pedal, which seems wrong. I previously thought it was just missing a rubber bump stop, but now I don't think so, After looking under the dash, it appears someone else has tried to fix this issue by adding an extra spring, but that didn't really help.

Tonight I started pulling the dash apart to do a bunch of upgrades. I have to take a lot of this apart to switch over to the power brake pedal assembly, so now is the time to look at the clutch issue also.

Additionally, I recently purchased a 4 speed toploader to swap out the factory 3 speed. I have been operating under the assumption that all of the clutch linkage will work with either tranny, but I may be completely wrong here. The tranny I have originally came out of a 72 mustang, but it wasn't in that vehicle when I bought it so I don't specifically have the clutch linkage parts that came with the car, and the parts I do have may or may not have come from this vehicle.

So, my questions are...

Is this a known issue with the clutch that has a solution?

Do I need to get any other parts for the clutch before installing the 4 speed?

I am currently fixing some things on the dash and installing the brake booster/pedal. I had planned on completing that project before starting the tranny swap, but I don't want to have to dig under the dash twice if it can be avoided.

And a pic of the car in question just to make my post more interesting....

thanks,

 

[Doug The Dog]

I wonder if your pressure plate is not fully releasing? I once had a clutch pedal that wouldn't release all the way because the bushings in the pedal hanger were worn out. had to replace it. There is a spring attached to the pedal hanger and the clutch pedal. I'll attach a picture of what the pedal assembly should look like. Not sure if this helps, but it's a place to start.

-Travis

 

[Mr_C]

Travis, your picture helps more than you realize. I just realized that the clutch assembly mounts to the same bracket that the brake assembly mounts to. The bracket that I have is from a automatic car. I will have to check to see if those holes for the clutch pedal exist or if I am going to have to measure those out and drill them as well. I knew I was going to have to cut the brake pedal to be narrower, but I didn't realize I was going to have to mess with the clutch pedal at all. I guess this is the time to get this fixed right!

Also, I suspect that the spring may be broken, which is why it doesn't return all the way. Now I have a better idea of what I am getting into as I pull this thing apart. I hope to have that assembly out of the car tonight.

 

[rocket366]

3sp vs 4sp

I did this in the 80s

Depending on the trannys

Input splines may be different

Output splines may be different

Speedo gear type may be different

of course shifter and mounting plate

I got a 4sp with shifter and I think I was

lucky that the splines were the same but I

think I had to change the speedo gear.

Paul

 

[OMS]

Also I think the 3 speed has a 10 or 10 1/2 inch clutch

4 speed is an 11

drive shaft is different too

 

[Mr_C]

Thanks everyone. I was hoping that the splines would be the same since they are both out of mustangs, but I guess that isn't necessarily the case. I hadn't considered that the driveshaft would be different lengths. Hopefully I can just shorten the one I have if it doesn't fit (or I will have to order a new one). I have a clutch and flywheel for the new tranny, and I was planning on swapping out the new clutch anyway so that isn't a big concern. This isn't looking to be quit as easy of a task as I was hoping.

The power brake swap is also a lot bigger of a project than I expected. I got the steering column out tonight and finally got the brake/clutch assembly out. It certainly wasn't a bad idea to take all that out as there are a few worn parts that need replacing.

The clutch rod shows some pretty significant wear on both the top and bottom sides. The timing is good for fixing that.

Unfortunately, I don't think that the brake assembly bracket (or whatever that is called) is going to fit in my car. According to the marking on it, it is out of a 73, and mine is a 71 (if that makes any difference). The problem is it is shaped slightly different. The good news is I think mine will work by just swapping the brake pedal (and trimming it).

You can see that there are additional plates spot welded to the each bracket that are different. What isn't as obvious is that the curvature is slightly different as well. Fortunately, I don't think that is going to be an issue.

Lastly, my original issue (the pedal coming too far up) seems to be caused by a missing rubber bump stop on the clutch pedal. Where the 2 pieces of metal are contacting there is a hole in the pedal as if it should have a bump stop there. The large spring actually is there and looks to be in good condition. Now I just need to source a new bump stop.

 

[OMS]

Thanks everyone. I was hoping that the splines would be the same since they are both out of mustangs, but I guess that isn't necessarily the case. I hadn't considered that the driveshaft would be different lengths. Hopefully I can just shorten the one I have if it doesn't fit (or I will have to order a new one). I have a clutch and flywheel for the new tranny, and I was planning on swapping out the new clutch anyway so that isn't a big concern. This isn't looking to be quit as easy of a task as I was hoping.

The power brake swap is also a lot bigger of a project than I expected. I got the steering column out tonight and finally got the brake/clutch assembly out. It certainly wasn't a bad idea to take all that out as there are a few worn parts that need replacing.

The clutch rod shows some pretty significant wear on both the top and bottom sides. The timing is good for fixing that.

Unfortunately, I don't think that the brake assembly bracket (or whatever that is called) is going to fit in my car. According to the marking on it, it is out of a 73, and mine is a 71 (if that makes any difference). The problem is it is shaped slightly different. The good news is I think mine will work by just swapping the brake pedal (and trimming it).

You can see that there are additional plates spot welded to the each bracket that are different. What isn't as obvious is that the curvature is slightly different as well. Fortunately, I don't think that is going to be an issue.

Lastly, my original issue (the pedal coming too far up) seems to be caused by a missing rubber bump stop on the clutch pedal. Where the 2 pieces of metal are contacting there is a hole in the pedal as if it should have a bump stop there. The large spring actually is there and looks to be in good condition. Now I just need to source a new bump stop.

I have new clutch rods

Don

 

[Mr_C]

Thanks Don, I am not sure if I am going to order a new one or just repair this one (I was hoping not to have to leave the car in pieces too long). I did go to your page and find the part (and some others).

Do you know where I could get the rubber bumper that goes on the clutch? No one seems to sell that. I might have to go to the local hardware store or harbor freight and see what I can find.

thanks,

-Matt

 

[barnett468]

Do you know where I could get the rubber bumper that goes on the clutch? No one seems to sell that. I might have to go to the local hardware store or harbor freight and see what I can find.

thanks,

-Matt

you can use a hood bumper

or a trunk lid bumper and glue it with weather strip glue . . cut it to the desired thickness.