I've got a vibration in my forty one ford. It's got a rebuilt 8cm mercury flathead And the stock rebuilt transmission and old stock rearend. New Fort Wayne clutch that works beautifully and smooth. Between 2220-2800 RPM just about cruising speeds It has a bad vibration in the driveline and if I push the clutch in and keep the gas where it is and then let it back out. I can find a spot where the car doesn't vibrate all and keep driving. When revving the engine stationary, sometimes it will vibrate and sometimes it will not. IVe taken all the belts off to eliminate that and no difference. Almost seems like the clutch and fly will are out of balance with each other. I did not get these balanced when I added a part. When I got the Rebuilt trans,I figured I should inspect it just because and found that the thrust washers were missing And maybe I missed something else in there. Like the front bearing, but it seemed new. Any thoughts anybody?
They forgot the thrust washers?! What kind of end clearance did they have? Measure in tenths instead of thousandths. With work like that, my first suspect would be the transmission. Each of the flywheel, pressure plate, and everything rearward of there should be balanced individually. We hope that parts are good ( new and old), but plenty of opportunities for “not quite”.
First, thanks for the full description and pictures! Really helps to wrap the noggin around the issue. The thing that jumped out was driveline angle due to the lowering. I doubt this is really causing it, but I'd check things. With your description of it being able to be 'reset' not to vibrate using the clutch, I'd suspect it's in this area. Pilot bushing/bearing wear, clutch uneven, front input shaft bearing (front or rear), and check bellhousing and trans mount bolts.
Yes, that's the weird thing, as I can basically reset it as you said and make the car not vibrate. Everything was new as far as the pilot bushing. And the clutch and the throw out bearing. And I'm pretty sure I may have replaced the front bearing in the trans.
Needle bearings between the main and input or surfaces? Just a WAG... If you have a helper, have them push in the clutch and see what moves when side load is applied to the disc?
I had a vibration problem with my 58 Impala that I could solve by pushing the clutch in and letting it back out. What I found was the pilot bushing in the crank had split and part of it was gone. I always step on the clutch pedal before starting the engine. The weight of the clutch disc would cause the disc and the trans input shaft to get off center causing the vibration. With the engine running the disc would end back on center when you pushed the clutch in. Don't know if that is your problem. I really don't understand your description about pushing the clutch in and keeping the throttle steady.
As far as keeping the throttle steady. I'M going down the road at 50 miles an hour and I do not remove my foot from the gas pedal. Keeping it the same RPM and I just push the clutch in and out a couple times. I'm thinking the pilot bushing may be bad even though I replaced it. Can't remember if I put a bearing or bushing in it. Maybe I have some pictures.
Well, it sounds like it's either or both of the pilot bushing,Or the input shaft bearing . Either way, something's gotta come apart.
It could also be imbalance additive. In other words, if the flywheel/pressure plate have a slight imbalance, and the clutch disk also does, when the imbalances end up in alignment they could cause a vibration. Pushing the clutch in a couple times would realign the imbalances such that they could be cancelling each other.
It's been a while, but I finally got this apart today. When I got the motor out, I could see that the clutch was off to one side and not centered. I grabbed the input shaft of the transmission. And it was loose in eighth of an inch both ways! The pilot bearing wasn't wasted but not tight as I could put a spare input shaft in it and move it around pretty good. I've got 2 new pilot bearings. And the old one measures larger than the new, which is good, but 1 is open face. I'm thinking I may swap the trans As I have a rebuilt one here on the bench, That I rebuilt. I'm gonna try and find Somebody here Local to balance the flywheel and clutch assembly while I have it apart.
So I'm in the Lancaster Antelope valley area. And I cannot find a machine shop within 80 miles that will balance the flywheel. Anybody know of somebody that does this?
That’s odd, you’d think a shop that can balance a rotating assembly, could balance your flywheel/etc. There was a thread a few years back a member fashioned up some stuff to balance brake drums, I wish I’d saved the link. This was all static balancing and reminded me of a bubble balancer for wheels/tires.
I did balance my flywheels myself. Push a mandrel through the bearing, rest the assembly on knife edges or big discs that have small bearings (motorcycle wheel static balancer works very good). Counter the heavy side with a magnet and add weight until the flywheel stops in every position. Weight the magnet plus the added weight and remove the same amount from the heavy point. Once the flywheel is balanced, mount the pressure plate and do it again. On my flatheads, blown and normally aspirated I have no vibes at all.
Taking it to Valley Head service Tomorrow since I have to head down that way.. Got the other transmission in and just need to toss the motor back in once the flywheel is balanced.
Alex from Valley Head service Got the flywheel done. Flywheel itself Was 10 g off and when he put the pressure plate on it was 75g off.Said he'd never seen one that bad.
In 2017 I had the same problem in my 40 Ford. Your torque tube center bearing is most likely the cause of your vibration. It is encased in rubber. Over the years the rubber disentigrates causing your driveshaft to vibrate. OEM replacement bearings are available if you can find someone who has one. Aftermarket replacements are also avaialble from a fellow on Fordbarn.. There's lots of additional info. available on Fordbarn. Do a SEARCH on TORQUE TUBE CENTER BEARING REPLACEMENT and much info. like this appears. Feel vibration around 50mph - Page 2 - The Ford Barn and 1940 ford torque tube center bearing - Search When you remove your 41 rear end be sure to upgrade and replace all the seals and bearings when you have it apart as its a lot of work. I sent you a CONVERSATION mesaage.
Thanks for the heads up on the torque tube bearing. While I had the trans, out, I checked that and it didn't seem like it had too much play. And I'm also using a sealed cup u joint, so it doesn't have any slop in it Side to side, so it should keep that pretty centered.
All back together and drove it up-and-down the street a few times and 0 vibration. Revved it up in neutral a few times and nothing. Transmission Is shifting smoothly, I'll drive it home today and see how it goes.
That's great news. Well done. Perhaps I missed it, BUT, please tell us exactly what you did to eliminate the vibration.
the main shaft area where the Roller bearing rides was pretty worn out And so was the input shaft bearing allowing the input shaft to move about a 1/8 inch each way,making the pilot bearing sloppy allowing the clutch itself to move around every time you shifted. I had the flywheel and clutch balanced and were out a lot.10 grams on flywheel and pp 75 grams.
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