1951 coupe three speed manual vibration

[Grayble 123]

A couple months ago I purchased my first shoebox. Never had a flathead before or anything this old for that matter. When bought the car I knew it had a shutter when the clutch is releasing. I replaced the flywheel,pilot bearing, throw out bearing , clutch disc and resurfaced the flywheel. No change. Still a heavy vibration letting out the clutch. My question is through process of elimination. Is my next step replacing motor and transmission mounts? If you’re wondering it has overdrive that doesn’t work. Regulator has a cracked top. Found that out when we removed the transmission.

[tubman]

Originally Posted by Grayble 123

A couple months ago I purchased my first shoebox. Never had a flathead before or anything this old for that matter. When bought the car I knew it had a shutter when the clutch is releasing. I replaced the flywheel,pilot bearing, throw out bearing , clutch disc and resurfaced the flywheel. No change. Still a heavy vibration letting out the clutch. My question is through process of elimination. Is my next step replacing motor and transmission mounts? If you’re wondering it has overdrive that doesn’t work. Regulator has a cracked top. Found that out when we removed the transmission.

Yep.

Also, OD components are readily available, albeit sometimes expensive. I replaced the wiring harness, kickdown switch, and lock-out cable on my car because they were available and reasonably priced. I am not clear about what you call the "regulator"; could you be more specific? It could be the relay on the firewall, the governor or the solenoid (both on the transmission).

[Grayble 123]

I guess what I called regulator is the overdrive governor.

[pistonbroke]

Check and or replace your motor/transmission mounts. Get that OD working and you will be in heaven. Tim

[rjlester]

If it's the governor that is cracked and you can remove it, you can test it's operation using a drill and an ohmmeter.

Connect one probe of the ohmmeter to the wire and the other probe to one of the screws holding the plastic lid (ground). Attach the drill to the end of the gear/shaft. Spin the shaft and you should see the ohmmeter make a connection (zero ohms or very close to it) at a particular RPM. If it doesn't, you can remove the 3 (or 4) flathead screws holding the lid on, and you can clean the contacts inside. Be careful taking it apart and work on a clean bench as there are some small parts inside. I have cleaned three of these units and all of them worked better after cleaning the contacts with 400 grit sandpaper. I put 8000 miles on mine since summer of 2021 when I cleaned it and it still works great.

Hope you get it working, the OD on these will put a smile on your face.

[Grayble 123]

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Mounts should be here in a couple days. Thanks for the instructions on the overdrive. The car drives and rides great. That will help a lot. Exactly why I joined the group.

[Grayble 123]

I replaced my transmission mount and motor mounts. One mount on the right side had a bolt that wouldn’t tighten to the block. By the way, are the threads on the block supposed to be 3/8 16? The threads mounted through the crossmember are 3/8 24. Still vibrating obviously letting out on the clutch. Question is how can I rule out transmission issue?

[rotorwrench]

Did you do anything with the pressure plate? Some have adjustable fingers and some didn't. The springs may have a problem or two.

The older cars with torque tubes would chatter if the mounts were sloppy but the open drive cars after 1948 were not as susceptible to chatter. A warped pressure plate can cause problems. The resurfaced flywheel and new disk is 2/3 of the equation.

A person may need to place the car on jackstands in the back and see how easy the rear axle rotates. Any problems with brakes can increase the torque it takes to rotate back there.

If the OD is locked out by pulling the cable handle, it will function close to a non overdrive transmission. If there is a problem with the planetary, it should still function if locked out.

[Grayble 123]

Only thing I’ve done with the flywheel is resurface it for the clutch swap. There wasn’t any adjustable fingers. But the clutch pedal has been adjusted to about 1 1/4 inches. When the clutch disk was replaced the springs were good. I will get the rear end in the air and check for drag. The OD is not functioning. The governor has a cracked top. Highway speed is about 60 MPH.

[rotorwrench]

I was referring to the springs in the pressure plate or clutch cover as Ford called it. The Long type 9.5 inch clutch was used for many years but could have the same problems as any other spring plate type clutch. With some modifications, it can be replaced with a mid 70s GM type diaphragm clutch or the OEM pressure plate can be overhauled by a reputable company like Fort Wayne Clutch.

Governors for the Borg Warner R10 ODs are out there. I've seen them on flea pay. It governs when the system becomes operational at around 25 MPH on most Ford products so equipped. There are still usable parts out there for these 259 series transmissions. There may even be some NOS parts.

[pistonbroke]

Are you driving with the OD handle pulled out? that is the locked out of OD position. It shouldn't make a difference but in your case we are looking at everything. The next thing I would look at would be the rear end. With the car up and the rear axle not bearing any weight is it tight to the springs? Next is it easy to turn the driveshaft and how much backlash or slop as some call it do you have? Has some one removed a leaf or two to soften the ride and lower the car? This can cause spring wrap and clutch chatter . One last ? when you get this chatter or vibration is there any noise with it? Tim

[38 coupe]

It sounds like you are describing clutch chatter. Please verify if the shudder only happens when releasing the clutch. If the shudder continues while driving with the clutch released then there are different problems to solve.


If you are fighting clutch chatter that typically narrows down the problem areas to the clutch and motor mounts. You have attempted to address these already, which means a fix didn't take. I would suspect the new clutch, I know several people including myself who have had bad luck with new clutches for Flathead Fords in the last decade or so. I solved my problem by installing an old rebuilt pressure plate and old rebuilt clutch disk. I hope your problem is simpler.

[Grayble 123]

In reference to the pressure plate. There isn’t any adjustment the the springs on the pressure plate. Bought the 9 1/2” kit for shoebox central. I forgot to mention everything was replaced in the clutch assembly except the hub for the throw out bearing. Couldn’t find one at the time. One of the ears on the hub was a little worn. I drive with the OD cable pushed in. To be honest knowing the governor being damaged I assumed none of it worked. Yes the car has been lowered. There is a metal block underneath the rear springs. As far as noise, only the vibration. It only “vibration “ is in the process of releasing the clutch in low gear and a little in reverse. Otherwise it’s a smooth in second and third gears.

[38 coupe]

Ok, what you are experiencing is commonly called "clutch chatter".


I suspect your clutch chatter is due to your new clutch not being any better than what it replaced. I went through three clutch jobs on my 53 before giving up on new parts and sourcing good old parts.

[rjlester]

Originally Posted by Grayble 123

I drive with the OD cable pushed in. To be honest knowing the governor being damaged I assumed none of it worked.

I wonder, maybe your overdrive is actually working? If you let off the throttle over 30mph or so, do you have engine braking, or does it freewheel like you are in neutral? If it freewheels, it's NOT working.

Also, if you are going say, 50mph and you completely let off the accelerator, do you feel it "shift" into OD? Another test is to floor it once you are in OD (over 30mph) and you should feel it kick down if it is working.

[Grayble 123]

Where can I source NOS? Where can I get a good modern replacement? Letting off the throttle at higher speed nothing happens. The car slows down. No free wheeling. Kinda like the transmission is slowing you down. Back fires a little.

[38 coupe]

I get NOS parts several places, based on luck and research. The three places I use most are here on the Ford Barn, at swap meets, and on that auction site. It helps substantially to have the Ford part number when searching that auction site, you sometime find a part listed by part number without an application that is quite affordable.At the moment the clutch disk I would be interested in if I was you would be this one: https://www.ebay.com/itm/28504095046...Bk9SR9Tu8s_vYg
That clutch disk is listed as the correct diameter, looks to have the correct transmission splines, has old style friction material, and has visible "Marcel" spring between the two friction halves (important to reduce chatter).

[Grayble 123]

Thank you.

[rotorwrench]

If the unit is not locked out, the OD slows a lot like an automatic transmission due to the sprag unit in the tailshaft. When locked out, you get noticeable engine braking as with a standard non OD manual transmission. These are electric overdrives so the electrical system has to function for it to shift into overdrive at any speed above 25 MPH.

There can be mechanical issued depending on the condition of the parts. The planetary system can fail after a lot of mileage. A person knows when it does since it basically locks up the whole transmission. It pays to check them out any time they start to make funny noises or anytime they are disassembled for any reason.

Some of the new reproduction stuff can be faulty right out of the box. My 51 Mercury 10-inch Borg & Beck clutches are not reproduced so I have to have them overhauled but they always function properly after a good overhaul. I don't trust the new stuff anyway unless it's a diaphragm type.

[deuce lover]

Try Fred at Southside Obsolete in MN. Has a huge selection of NOS Parts.