Sanity check on adjusting clutch free play on 39

[adileo]

Hi Folks

Please tell me if I have this right.

- Free play is distance from top of pedal to depress & disengage
- free play should be 1.25 to 1.50
- If too much (more than 1.50) to adjust - remove cotter pin and turn clevis counter clockwise.

I assume turning clevis counter clockwise would move clevis out towards front of car?

I also read (van pelts on this forum) another way to check: run car with car in neutral, count slowly to 20, then put into first gear. Any grinding and u need adjustment

If I have any of this incorrect, please correct me.

[Bob C]

Free play is with the pedal all the way up then push down until you feel the
throwout bearing just touch the pressure plate fingers.

Bob

[Mart]

The above depends on a few things.

That the clutch pedal return spring is in place and will lift the pedal back to a hard stop.
It is a stock setup with the correct linkages, levers, ratios and pedal travel.
The clutch plate is not gummed up and sticky (normally) due to oil residue.

The 1.50 is a guide. If the clutch releases cleanly before the pedal hits the floor you're good to go. It won't release cleanly if gummed up.

The only correct way to tell if a clutch is releasing takes some skill and care to do. I will describe the technique.

With the pedal up, move the gear lever towards reverse gear. Don't bang it in, just approach it. Use both hands so you have good control on the gear knob. Get the gears just kissing so you can hear a noise as teeth touch each other. Not too hard, just enough to generate the noise. Press the pedal down until the noise stops and hold the pedal at that position. Move the lever back to neutral. Now press the pedal to the floor and judge the distance travelled. You have to make a judgement that the travel at release and the full travel are proportionate.

This method proves two things.
That the clutch is releasing cleanly.
That it is not releasing right at the end of the available travel.

If it is releasing, but near the floor, check the free play and for any lost movement in the linkages. A simple adjustment may bring it back to a more acceptable release point.

If you reach the floor and the noise is still audible the clutch is not releasing. This may be because of excessive free travel at the top, or because it is gummed up. This is the point at which you check the free play and set it to the minimum (1.25" according to figures above). do the test again, it should now release (If the play was too great before). If it still does not release, it is probably gummed up.

The test may not be for the faint hearted, but if done with care no damage will be done.

Mart.

[George/Maine]

First thing on a 39 ford it must have the same pedals and a 39 lever on the trans.
I think the lever is about 3 1/2" on trans.
If the lever is longer it moves the throw-out less and grinds in gears.
The floor board must be in then adjust.

[adileo]

Thanks guys

It was raining here today, so I was reading the shop manual and trying to better understand what I read.

From a clutch & pedal perspective my car is as HENRY built it.

Mart thanks for your testing description, I’m not sure if I have the nerve to try it

My car is fine, shifts well with no grinding. I was just seeking to understand and learn.

[V8COOPMAN]

Sponsored Links (Register now to hide all advertisements)

Andy...The "KISS" system would describe "free play" simply as the distance between pedal ALL THE WAY UP, and the point at which the pedal travels downward and just touches the throw-out bearing. In other words, the distance that the pedal moves WITHOUT doing anything noteworthy. DD

[adileo]

Thanks DD for describing it in that manner.

I got it! I really enjoy reading, learning and then putting the lessons to use on these great machines.

One more question. If there is too much play, which way does one turn the clevis? My guess is counter clockwise

[Mart]

It's difficult to day which way to turn the clevis, as it may be misunderstood depending on the viewpoint of the reader. In essence you need to make the push link longer, which would mean unscrewing the clevis, which would, indeed, be anti-clockwise.

When talking about free play, as the clutch wears, the free play should diminish. If the free play is small, clutch wear will reduce it to zero and the clutch will be held partially released due to no free play. Wear will accelerate and a vicious circle of wear will ensue. The free play must be maintained. If it gets too small adjust it to give 1.25" or so. If you have a non standard application and are struggling for pedal travel, you could reduce the free play but you would need to be prepared to maintain it if it starts to get tight.

Mart.

[39portlander]

Andy I know what your going through, I had a similar problem with free play adjustment on my P/U. Very good reply's on this subject as well.

My problem was a worn clutch rod clevis and pin, @ times it seemed alright with "free pedal" and then other times there was too much free play.

I ended up replacing the rod clevis and pin and new spring, the adjustment stays consistent now. I did change my clutch pedal bushing and shaft when I did the transmission, there may be some play in your adjustment from those components.

[Clem Clement]

Take some chalk with you and write some place how many turns and what your measurements are.