Bad clutch shudder

edhd58

edhd58

Well-known member
Okay, I know part of this is may be my fault.
I just want to know if I am thinking along the right lines to fix it.
The clutch in my 42, G 6 cylinder, has shuddered or chattered or whatever you want to call it almost from the day I got it all back together.
I either got some grease on the flywheel, Or the leaking rear main allowed oil to get on the disc.
I got the clutch and flywheel off the engine tonight and there is some bluing from me slipping the clutch to make a smoother exit from a stop light.
You can still see ALL the flycutter patterns from the machine shop resurfacing the flywheel when the motor was rebuilt.
I am thinking I just need to go ahead and have it resurfaced again, put in a new clutch disc and pressure plate. they all have less than 500 miles, probably closer to 200.
OR, can i have the pressure plate resurfaced?? i know its a new disc no matter what.

By the way, yes I am going to redo the main seals, I know what I did wrong there but I have a question about the rope seal prep.
 

Attachments

  • clutch 1.jpg
    clutch 1.jpg
    50.6 KB · Views: 129
  • clutch 2.jpg
    clutch 2.jpg
    45 KB · Views: 144
suggest if you have the rear axle out take the drive tube off and change the centre shaft bearing .We have a 46 woodie,the chatter was terrible, replaced the bearing it was bad. also send that clutch/pressure plate to Fort wayne clutch have them check and set it up. the new bearing kit is obtained from Florida Skip. Comes with good installation directions easy to put in Johnny
 
The pressure plate is a poor replacement for the original style. You want the style with the three adjustment bolts at the end of the three fingers and has the fly weights. If you look at the profile of the clutch plate the friction facing on each side should not be next to each other. Between the facing should be a thin spring plate. If you were to squeeze the facings together, as the pressure plate does, you can compress the spring plate and then release the pressure and the facings separate slightly maybe about 0.060" or so. The clutch plate also has the springs around the area for the transmission shaft. You can use 220 sand paper to cut any glazing on the fly wheel. I soak the White rope seals in oil overnight, put them in place and work a round pipe over them to push them in place add some more oil to the worked area and assemble after trimming. I believe there is another style of rope seal that is dark or black in color, I do not use them.
 
I had bad clutch chatter , also. Got a new clutch & pressure plate from Ft. Wayne . Had a local shop grind the flywheel . Smooth as silk now . Problem gone .
 
Johnny, rear end stayed in car, I pulled motor and trans as a unit

TerryOH
I think I got the pressure plate through either Bob Drake or MidWest Early Ford. Same way with the disc. Either way I don't know what I'm getting till it arrives. I did go look and neither of them shows the adjusters on their pressure plates. Mine does have the weights that apply more pressure as the rpm's go up. Honestly I don't think it was made in America either.
But you feel the bluing of the flywheel just needs to be cut with sandpaper?
 
Had the same problem with mine after rebuilt. The flycutter marks were very clear on the flywheel. As I had other things to do I decided to drive it carefully for a while to see what happened. After 1500 miles it is smooth as silk. Be very careful using sand paper on the flywheel.
 
If you do have to purchase a new clutch I suggest Ft. Wayne only.There clutches have a cushion in disk which helps to stop chatter.Mine is smooth as silk!
 
I an NOT suggesting sanding off all the glazing on the flywheel. If you use the sandpaper on a block and lightly go over the flywheel surface it will remove any burnt on material and add light sand scratches over any glazed area. Light sanding will remove hardly any material. I am not seeing your flywheel as blued from heat just slightly glazed. I agree with others the flywheel does not appear to need resurfaced and Ft. Wayne clutch is the place to get another pressure plate and clutch.
 
Also the three finger type are more sensitive to correct adjustment you may find one finger is low ,A diaphragm type is a good alternative such as a BMW but there is some set up drama , Ted
 
Ft Wayne Clutch would likely be able to adjust a pressure plate during assembly even if it is not the type with the adjustable fingers. The older cores are out there if you don't have one. I assume it is a standard 10-inch Long type if it is a 1942 model whether V8 or L6. Another thing that can affect clutch engagement is whether the engine & transmission are relatively solid in the frame. Bad motor & trans mounts allow a lot of movement from the old torque tube pushing on them. If there is much play there, the equalizer geometry gets off square and can create a problem with engagement. I don't think they had steady rods holding the engine after the L6 came on line.
 
Last edited:
Unless the flywheel clutch surface is badly scored or burned, we deglaze them with a Scotch Brite pad in a drill. When replacing the pressure place, install the bolts finger tight to start them, then go around and tighten the bolts a bit at a time. This reduces the warping of the assembly that is often part of the chatter.` We recommend replacing all the motor mounts during the job.
 
rotorwrench - I am gonna have to call Ft Wayne Clutch. I dont know if they use stock pics, but the pic for the 10 inch pressure plate looks like what I have now. the 9 and 9-1/2 inch pics show the adjusters.


TerryOH - yeah what I said didnt come out right. I meant clean (with naptha or brake clean etc) the flywheel and pressure plate to get rid of any contamination (clean them reallllly good) then lightly sand both just to "clean them up" a little more


flatheadmurre - Thats a thought I hadnt had yet, the pressure plate out of adjustment
 
always ck flywhell runout after u bolt it to crank some folks dont qualify the mount surface of the flywheel before they grind it and can make it worse.im far from perfect but i try to check every thing.
 
I got everything cleaned up, I am waiting for the clutch disc from Ft Wayne Clutch. I got the parts and pieces to reseal and re-gasket the case from VanPelt. very good people to deal with.
The dark spots on the clutch and flywheel cleaned up really easy. I don't think they were heat related they cleaned up so easily.
As you can see in the pic there is a small gouge in the pressure plate, this was under a dark spot, and the flywheel has a small gouge as well. I wonder if there was a piece of trash in the pressure plate that fell out as i was driving to have cause that. The picture makes it look a lot worse than it actually is. The flywheel was resurfaced and the pressure plate was new when I put it all together before.

Anyway, I have to get the input shaft old seal out and the new one in, and the get the clutch disc and it will be going back in, hopefully this weekend.
 

Attachments

  • flywheel cleaned up.jpg
    flywheel cleaned up.jpg
    40.3 KB · Views: 84
  • pressure plate cleaned up.jpg
    pressure plate cleaned up.jpg
    43.9 KB · Views: 78
Even if you got some kind foreign object moving along with the clutchdisc they aren´t moving togetter...so shouldn´t make a mark at one location.
My bet still is heat and that you got a hardspot there now.
I would have let Ft Wayne have a look at the pressureplate while it´s out and check/adjust it.
 
Murre. You have a point there. Plus won't hurt to have any issue identified and corrected BEFORE the can thing is all back in. Better safe than sorry for sure at this point in the process
 
Ford did not use the rods after 1941, and redesigned the rear mount to hold in the fore and aft direction rather than merely supporting the weight. It is a somewhat hidden failure point...the rubber is sandwiched between two steel parts and is not east to see even unless you took out the mount. Failure there is often failure of the glue holding the rubber to the steel parts. Front mounts...some repro ones have very soft, flabby rubber...NG.
Canadian '42's, heavily used in the war in North Africa, apparently had lots of rear mount failures in the desert and the Canadian Service bulletins cover a parts kit and drilling instructions for installing '41 rods to do the fore and aft steadying. Probably unnecessary if you put in a new rear mount and avoid participation in desert wars.
 
Hi, I had the same trouble, put in 2 new clutches one from Mac's and one from early Ford, like you I read some posts here on the forum and called Ft Wayne Clutch and driveline, they sent me one of their clutches, worked perfect right out of the box. I did wash the rust preventative off the pressure plate and my flywheel with lacquer thinner and sanded the flywheel, been working on that for over a year and had the ****** out at least 8 times and played with shims, even bought a different bellhousing, it was simply a junk chinese clutch that those establishments sell. Apparently this is very common. Ft wayne clutch #800 258 8243 price 170>50 for a 51 flathead with 9.5 "
 
You must log in or register to reply here.
Back
Top