Clutch adjustment

[DICK SPADARO]

I have read your post, my initial observation would be that you need to shore up your clutch adjustment to be sure that it is done correctly. Make sure that the pedal fully depresses and there is not a floor mat something else keeping the pedal from completing the throw. As a guide,your pedal should be fully disengaging the pressure plate about 3/4" from bottoming out. Increasing the viscosity of you trans gear lube will help somewhat but somewhere you are still getting the drag of the clutch disc to spin the input shaft even when the pedal is full depressed and supposedly disengaged.
From my experience with this issue it seems to be more centered around the input shaft bearing in the crankshaft. If this bearing is going bad it seems to bind up on the input shaft snout and the rotation of the engine is enough to spin the defective bearing on input shaft and cause the gears to drag when shifting into first or reverse.
I prefer the use of a bronze bushing style bearing over the ball style crank shaft pilot bearing unit.

My first step would be to recheck the pedal throw adjustment and if you need a little extra to disengage remove a little free play from the released position.

[ford1]

not to get pushy, but if the clutch worked before replacing it i really would suspect the new clutch is the problem, guys on here have had the same problem as you after replacing the clutch that was made in china, they are to thick and wont let the clutch get free of the flywheel

[37ford4dr]

you know my clutch adjustment seemed to go in and out.....so pulled out the clevis pin and it had a huge groove cut in it.....so as it turned it would change the feel of the pedal.....a new clevis pin helped out alot. bob

[bbrocksr]

Quite often a disc will get "bent or sprung" during installation and will not release due to the "runout or wobble".
Bill

[CP]

i wanted to update you on with all the suggestions i got.

I adjusted the clutch pedal as best i could with 3/4" to 1" top play.

I slightly adjusted the floorboard where the pedal arm was hitting to allow for more throw.

i added the lighter weight oil to the tranny.

i have had no problems hot or cold since.

thank you all again CP

[Henry/Kokomo]

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This was mentioned in a previous post BUT - is it possible that the new clutch disc is too thick or it swells a bit with heat? A thicker disc would require more throw to open the space between the pressure plate and the flywheel wider in order to eliminate contact with the disc. The previous poster mentioned that discs produced offshore were sometimes thicker. Depending on the origin of the replacement disc, that could be an issue. FWIW

[Hoop]

If the clutch were thicker ... wouldn't the type of pressure plate have something to do with it?

The original style has adjusters on the fingers (as Flamingo already mentioned) which would dial out any "thickness" issue with the clutch disc. The height is set to the surface of the flywheel.

No?

Seems to be OK now, but there are still details we don't know.

[Curt Cummings]

I am building a 32 pickup with a 59a engine and 39 trenny. I have the engine running in the frame with everything hooked up. I raised the rear wheels on jack stands so I could check the clutch linkage, sound of the transmission and rear end while shifting through the gears. Everything worked great until everything got hot and then it would not shift without grinding so hard I didn't want to jamb it in gear. I have installed a new clutch and pressure plate. These posts are very helpful tech tips. Thanks to all who posted to CP's questions. !!!

[JSeery]

Dick Spadaro posted on this thread, the old days!

[Flathead Fever]

Cool, It sound like you have fixed!

A binding pilot bearing can also spin the input shaft with the clutch pushed in. Sometimes the grease will get old and caked up in and cause the input shaft to still rotate with the engine when the clutch is released. A misaligned transmission (unlikely) could cause a bind between the pilot bearing and input shaft. Anything you can think of that would cause the input shaft to rotate with the clutch pushed in. There are only a few possibilities. Most of which have already been mentioned

I have had just about everything you can think of go wrong replacing clutches at work. Some of those phone guys would only get 2000 miles out of a clutch and back then almost every vehicle in the fleet was a manual trans. I would replace at least one clutch a week. Every once in awhile I would get a defective part or clutches that were boxed wrong. I learned to check everything first before that trans went back in.

First. Never ever let the parts store have your old core parts until you are done with the job and you no that everything is working perfect. If you give the old parts away and then you have a problem you have nothing to compare the new parts to.

Second. Make sure the linkage is good and has no play. Make sure the linkage parts are all correct. Where you get into problems is when you start building hot rods from twenty different year Ford's.

Third. You don't need to surface the flywheel every time you replace a clutch but its a good idea to do it. Its a judgement call and has a lot to do with who was driving the vehicle last. Any dark blue hot spots in the metal will grab the clutch disc differently than the surrounding metal. They can make the clutch grab real hard and jerky. Better to have them ground away. You should put a dial indicator on the flywheel surface and check the runout before you remove it. Have the flywheel machined, have that done first thing because it can take a couple days for a machine shop to do it. Make sure the crankshaft to flywheel mating surfaces are clean and then evenly torque that flywheel down using a torque wrench. Then check the runout again. While you have dial indicator on the flywheel you might want to check the crankshaft endplay

Third. I've seen people replace clutches but not the pilot bearings that was severely worn. I don't think they understand how important that little bushing is. Always, replace the clutch, the throwout bearing and pilot bearing together. Always make sure the new pilot bearing slides onto the input shaft and spins easily. If its snug your not going to be able to shift the trans. Its better to check it now than trying to put the trans in for an hour and then finding out the input shaft does not fit into the pilot bearing or the trans grinds with the clutch disengaged. I stick a little bit of disc brake caliper slide grease on the input shaft. Just a little , you don't want it getting slung all over your new clutch disc.


Fourth make sure the throwout bearing fits the front bearing retainer and slides easily. That there are no worn spots in the bearing retainer collar for the bearing to hang up on. We use to use white lithium grease where the throwout bearing slides on the collar but I think the synthetic caliper slide grease is better option. If its a flathead replace the return spring with a new one. In fact on any car replace the clutch return spring. they are always breaking.

Fifth. Stick the old clutch disc and the new disc on a flat surface next to each other and make sure they are the same height. They should be the same except for any clutch lining wear.

Sixth. Make sure the clutch disk fits on the transmission input shaft and slides real nice. Stick just a little of that caliper slide grease on the splines. Run the clutch disc back and fourth and remove any excess grease. You don't want the grease slinging off when its spinning.

Seventh. Make sure you have the clutch disc installed in the correct direction. On some clutch discs its impossible to install them backwards and on others it is. Use a clutch alignment tool to center the disc and then evenly tighten down the pressure plate bolts. Make sure you have the correct clutch pressure plate bolts. Make sure the alignment tool still slides in and out easily when you are done tightening the pressure plate. I use an old input shaft rather those wooden and plastic alignment tools.

Eighth. If you can, try to measure the pressure plate fingers to make sure they are even. On"normal" manual transmissions,not the flatheads I would adjust the linkage so the throwout bearing was tight up against the clutch fingers to hold it in place and centered. Otherwise they falloff or get misaligned when your trying to stuff the trans through them. The flathead throwout bearing design was brilliant. They should have kept it that way!

Ninth, If your having problems getting the trans to slip in stick it in gear and turn the tailshaft to line up the splines. At work when we had a stubborn trans, mostly on the F-600s trucks we would hook up a remote starter switch and spin the engine while somebody wiggled and pushed on the back of the trans. That usually worked pretty good.

Tenth. Stick the trans in high gear. Have somebody depress the clutch. We had a pedal jack to hold the pedal down so one person could to this. Spin the output shaft and see if it spins freely. That way you know the clutch is releasing before you put everything else together and then find out its not releasing.

Obviously you need to have the correct weight gear oil in your trans but the type of gear oil will not make any difference when trying to put the trans in gear when your stopped. That's because nothing in the transmission should be rotating.

As far as the clutch disc being to thick, it does happen. At work on a fleet vehicle that I had zero emotional attachment to. I would set the parking brake, put it in gear and then let the clutch out until it just started to rub wear away some of that fuzzy new lining. A couple of times it did actually work. I don't know what the flywheel and pressure plate looked like when I got done?

[Tinker]

Originally Posted by Hoop

If the clutch were thicker ... wouldn't the type of pressure plate have something to do with it?

The original style has adjusters on the fingers (as Flamingo already mentioned) which would dial out any "thickness" issue with the clutch disc. The height is set to the surface of the flywheel.

No?

Seems to be OK now, but there are still details we don't know.

Wouldn't that be the reason for the clevis adjustment. the pedal to floorboard is a set adjustment (granted things like new carpet, etc in the way). The 1" play is just loose pedal play before engaging the linkage.

yes pressure plates matter for sure. Maybe the new ones are not adjustable...
I think Fort Wayne in texas rebuilds original 3 arm adjustables if you sent the pressure plate. Balance too.


Don't know??? Interesting discussion anyway.

[38convsedan]

Should brake/clutch pedals be even?

[TonyM]

Originally Posted by G.M.

I have found a lot of flathead clutches are SHORT on adjustment due to the clutch pedal arm hitting the wood floor. Almost every 39 I have had this problem plus others I looked at. This makes the range of operation confined to a smaller stroke and very hard to adjust and never gets full movement of the pressure plate. Some just removeing the rubber bumper worked but most I had to cut some of the wood where the pedal is bent to almost a 90. I cut a slot in the wood with a ruff cutting tool in the air grinder. What a differance when it gets full stroke. G.M.

Yes, I asked a couple guys about the floor issue and no one knew what I was talking about.

[Karl Wolf]

Originally Posted by FRANK PKNY

Drill it out and use roll pins.

I did this, the pins collapse...
Karl

[Tonic]

Can someone really get clear solution

My 24 bolt59 ab 10" f1 tranny

Pedals dont know year... floor grinded a lot that almost whole long part of pedal is in cabin.
Release bearing is short pulled with spring.
In rear position when i press pedal bearing needs to move about 1/2" before touching fingers.
At that point fork already leaning towards engine. Not much movement left before pedal is on the floor... if i look from left side. I think clutch lever is pointing about up, when bearing reach fingers...
If we say it reach fingers at 12o'clock and pedal is on the floor 10,o,clock
Longest in-out travel for release bearing would be between 2 o,clock and 10 o'clock

Previous owner knw issue... bearing was running all the time and started to keep noise.
I did loose adjustment so much, that bearing was loose (rotates with fingers as pedal is up) and i could not put it on gear. Lot of grinding to floor and works bit better, but not perfect. Clutch pedal rubber now 1,5"-2" higher than brake


1 meter snow here at finland, so i would hame time... do i need to machine "long" type bearing holder, what moves bearing almost 1/2" closer to fingers, that when i press pedal, its start to do its work

[Tonic]

jalopyjournal.com/forum/threads/flathead-transmission-clutch-issues.344648/page-2

new photos... still root cause not finded

[19Fordy]

Originally Posted by Karl Wolf

I did this, the pins collapse...
Karl

I found that replacing the pin that holds the clutch release fork (7515) on its shaft (7510) by drilling and tapping both the fork and the shaft for a Grade 8 fine thread bolt and lock nut works fine. Did this 35 years ago. Still works fine.

[Tonic]

Something more..
F1 crossmember (Dropped about 1" comparing to frame)+pedals i assume.

For me it looks that i should modify 30 tudor floor corner by pulling it back. Or make block between crossmember and pedals.

Is there anyone who have made same and clutch
Works fine? Model a wooden floor and only holes for pedals? I cant post photos yet but in hamb i have photos.

[GB SISSON]

J Seerey posted on this thread, The old days!