Clutch Spring Adjustment

[BarnesvilleT]

The answer to my question is probably in the archives somewhere but does not seem to show itself by searching.
I have had my T for just over a year now and still classify myself as a newbie to the passion. Have a 26 Coupe and when I got
it there was a '22 engine in it and probably the transmission to match. It drives good up to around 30 mph. Then a significant vibration
takes over and I back off to 28 or so. I was told it was probably the flywheel so I am in the process of rebuilding a 26 engine and have acquired a 26 transmission that will go in sometime this summer. So much for background info. Learning more and more about the transmission I discovered that the gap between the clutch flange and the brake drum was like about 1.25". I decided to start from scratch and adjusted the gap back to 13/16". I now have some shuddering right after shifting to high. It goes away as speed increases but was not really there when the clutch spring was much tighter. The question is... Should I tighten it back up to where it was (wide gap) or replace the spring with engine and transmission still in the car. Then reset the gap back to 13/16" and see what happens. I have read this can be done but requires some special tools and such. I read the service manual and it kind of describes what is needed. Everything I read says to adjust to 13/16" but you can tighten if needed but it never says how much to widen that gap. Hopefully this all makes sense.
Bill H.

[speedytinc]

Widening the gap is tightening, putting more spring tension to lock up the clutch.
Thats done by tightening the slotted setscrews on each of the 3 fingers.
Careful to adjust each finger the same fraction(s) of a turn.
Try tightening those fingers by 1 turn @ a time. Normally 1/2 turn, but you have a ways to go if the previous setting was 1.25".
See if the slip(shudder) goes away or is @ a reasonable level.
The stock clutch was designed for "controlled" slip. A little slip is good, but the clutch must stay locked during acceleration once in high.
Go back & read the section in the T1 manual on a slipping clutch adjustment. & what you should expect in a proper adjustment.
If you cant satisfactorily limit much of the excessive slip, your next move would be to replace that weak spring.

Part of your problem could be your shifting technique. When shifting from low to high, the throttle is closed when the pedal is released, then increase the throttle & get up to speed. If you shift @ high rpms, the clutch will be slow to lock up also increasing disk wear.

[BarnesvilleT]

So if I understand correctly the 13/16" would be the setting if the spring were new
and you can increase that distance to compensate for a spring that is getting weak.
I do have the shifting technique down pretty good. Had an experienced T driver
show me the proper way to do it. At this point the clutch is not slipping but just
shudders right after the shift for a short time. Once past that shudder it accelerates and gets
up to speed pretty good. I will go ahead and tighten the spring up one turn at a time and see how it reacts.

Thanks for the input and shedding some light on the issue.

[Jerry VanOoteghem]

Honestly, there is no way that everything is okay when you have to have the gap open to 1.25" I really didn't even know it would go that far without the adjuster screws falling out. Either the spring is incredibly weak, or broken, or you have Turbo 400 clutch discs that are shot, or the spring retaining cup is broken, or ...?

[BarnesvilleT]

Jerry you are right that there must be something going on. I don't know if the clutch is a Turbo 400 until we pull it in a few months. I think I will order a new spring and retainer and get ready to try and replace it. In the meantime I will adjust the fingers a couple of turns and see what it does. Will post results in a day or so.

Thanks for the input.

[Jerry VanOoteghem]

Just to be clear, is this where you're measuring a 1.25" gap? In this photo, someone has devised a tool to quickly gauge the gap. The length of the brass rod is 13/16".

[Dan McEachern]

There is no need to adjust the clutch if the transmission is not slipping in high gear. Best way to check this is drive the car, shift into high gear and when speed is about 20-25 MPH, open the throttle quickly. Make sure the engine is up to normal operating temperature. IF the engine speed suddenly increases and the car speed lags, the high speed clutch is slipping and needs adjustment. Adjustments should be ½ turn on each screw until the slipping stops. Of course you should make sure that the slow speed clevis between the low pedal and the clutch arm is adjusted correctly prior to any clutch finger adjustments.

[Norman Kling]

One more thing to consider. The length of the brake rod adjustment. If the parking brake is too loose the clevis will hit the back of the crankcase which will cause the brake pedal to be back slightly when in the forward position. This will affect the linkage between the low pedal and the transmission and not allow the clutch to completely release. Usually most noticeable when you first shift from low to high, and the engine is pulling hard in high gear. Try tightening up the brake rods in half turn adjustments and see if that fixes the problem. It might not be the spring adjustment at all.
Norm

[BarnesvilleT]

Jerry that is where I am referring to. Right now the gap is just over 1". It was at the original
1.25 when I first noticed it. I then adjusted it back to 13/16" using that same tool in your photo.
I drove it and then got the shuddering (it did not really shudder when it was originally at the 1.25").
Then I increased the gap to where it is right now at just over 1". The shuddering is there but goes away
after a short time as I accelerate. Then is smooths out up to about 30 mph.
To Dan's words about it doesn't need adjusting if it is not slipping.. it does not appear to be slipping
but I will try opening the throttle quickly to see what happens. Up to now I have been accelerating
slowly. To Norman's thoughts about the brake rod adjustment, do you mean by tightening to shorten the
rod length.
Bill H.

[Norman Kling]

Yes tighten them just a little, now enough for the brake to drag. You can look under the car with the lever forward all the way and if the clevis hits the crankcase flywheel housing, shorten just enough that it doesn't touch it when all the way forward.
Norm

[George Mills]

The number you are chasing is for pretty much all new...a full height clutch pack...and a spring having the proper force load. Also, is the quantity of clutch plates correct?

Yes you need to check for interference from other areas or something else dragging...but after that the tune in is exactly as mentioned. 1/2 turn on EACH finger screw...re-pin it...close it up...go for a ride long enough to get 'er warm.

Do this again and again as each time the slip/shudder should get less. A word of caution - - - how do you drive? If you are trying to feather it into high gear I'd suggest you do some reading as the feathering/shudder thing is actually counter productive. I say 'do read' as everyone seems to have their own way of 'dumping' the clutch.

My preference is I use my pinkies for the sticks when low is starting to run out of room...flip them up, do a real 'clutch dump' almost as quick as like taking my foot OFF...then bring the spark back to a high speed place while bringing the fuel down right behind it. Works for me...no slips/no sputters...provided your carb screw is set right - but thats another story. (1- you might want to eliminate this idea by enriching the carb by 1/4 turn or so, it will burn a little more rich - but also not be too lean when it needs a gulp. 2- do check your fuel filter in the potato, or bypass any aftermarket fuel filter used. I worked on one for someone where it was hiccuping like h*ll on an upshift causing a stutter...all else checked out. The potato filter had 'some varnish' but that wasn't it. The aftermarket glass bowl filter, however, when removed had the car running fine...)

On bringing the fingers in time and again, I'd ask for further comment, as my way is totally 'shade tree' but my own experience over playing with this stuff for 50 years and many cars now is that walking it in on the finger settings stands the chance of being loose enough for start and a short ride...then an actual lock-up of the plates once it gets hot and you lug low to then dump to high. No issue, it just stalls...hard...lol. For me, that results in a full turn 'out' on all three fingers...pin it there...put the cover on and forget it from there...others can comment freely on this approach....

[BarnesvilleT]

George thanks for your input. I will try the pinkie technique next time I take it for a drive. I have the clutch dump down pretty good
although I have not been adjusting the spark just the throttle. After the input I got yesterday I did tighten the clutch fingers 1 full turn,
put it back together and took it for a ride. I also checked the brake rods to make sure they were adjusted as suggested and finally
adjusted the clevis connecting the pedal and clutch arm. It turned out that it was the best the car has ever run. The shudder was
pretty much non existent and I was able to run at a very slow speed in high to take corners without having to go back to low.
I am thinking that the clutch spring has just gotten weak over time and it is time to replace it. From what I understand once the new spring
is in I would adjust the three fingers and put the gap back to 13/16".

Thanks to everyone for the input. Now I have to pass all this info onto my son so can carry on the passion.

Bill

[Norman Kling]

The problem I am referring to is the bolt on the clutch arm coming out of the transmission is slightly on the ramp of the cam which is attached to the brake cross shaft. When the parking brake lever is all the way forward if the rods are too long is that the edge of the bolt is still on that ramp by a fraction of an inch.
Norm

[BarnesvilleT]

Hey Norman I did check what you are describing and when the parking brake lever is all the way forward I am clearing the ramp completely. When I was putting the car back together I originally did have the problem you are describing and did have to shorten the rods. It was pointed out to me by someone that gave me the "how to drive the car" lessons. Goes to show that when we get our first T we definitely have to rely on seasoned owners for input and it is very much appreciated.

Bill