Lincoln "L" Technical Questions

My 1930 Model L phaeton was driven little for many years, and is now back on the road. Adjusting the clutch has proved problematic: it either slips or makes double-clutching (both up and won) essential, and even then causes gear grinding. I am trying to avoid complete disassembly for cleaning purposes, and think I read somewhere that there is an alternative, less "invasive" method. Just reviewed the service bulletins--nothing there. Can anyone offer an alternative? It may be time to disassemble, but that is not my preferred option. Thanks!

My brain tells me that I read in the service bulletins that you are supposed to fill the crank case with gasoline and run the car while operating the clutch. This would serve to clean the splines of the clutch discs. I don't know if I think it is a good idea, but I am pretty sure that was in the book. Maybe you could use something less explosive such as diesel or even a modern engine degreaser.

Sorry,
not the crank case, but the bell housing.

I was trying to post pictures of my clutch assembly since I have it out using my phone but it didnt work. I will try again when I get home.

clutch driven disc from my car

clutch assembly

clutch internal hub

My 1929 L is experiencing a clutch dragging (not fully releasing) issue that has become much worst lately. The engine was expertly overhauled with new pistons, valves, blocks and heads faced, new timing chain, etc, in 2004-5, by Paul Murray at Murray Motor Car in Monroe, Washington. The clutch was dismantled and cleaned, new linings installed, spline teeth were all checked and straightened or filed to slide smoothly in the driving ring. When initially driven, ~ 2006-7, clutch worked well. The car was driven very little at first, had to sort out ignition and carburetor issues. After getting that all in order, the car ran beautifully, except for one quirk - When cold, depressing the clutch pedal to the floor, the transmission could be put into gear easily, but after driving a few miles, the oil in the transmission thins a bit, and the gears would grind when engaging from idle, even with idle set very slow. It would go into gear easily, but not without a small amount of grinding.This condition has gotten worse with time, and now, in order to stop and start in city traffic I have to hold the clutch pedal down when stopped, or shut off the engine, then restart with it in gear before moving. The flywheel housing is clean inside, no sign of oil leaking from the crankcase or transmission. Brian Harlamoff's article in the latest F&B confirms what I was experiencing, but did not show the nature of the damage to parts. Form the photos Linus posted, it looks like what I suspected is happening: the plain steel driving discs are getting warped or otherwise distorted from the heat of this slipping action. I have driven the car very little since the beginning of this year, as dealing with city traffic requires a lot of stops and starts, and I don't want the issue to get worse, and want to be able to drive to wherever I can find someone to do the repairs.
It appears to me there is no good solution to this issue without removing the transmission and clutch and repairing/replacing the damaged discs. Where to find discs? This is a big job that I am not equipped to handle in my small garage.
Any tips on a competent service shop in this area (near Seattle, Washington)? Murray Motor Car owners have retires and closed their shop in Monroe...
Help Needed, Any and all comments are welcome

Alan, where are you at with this problem? I am not happy with my gear shifting performance either, and pulled it outside and did what it is recommended in the service manual. I was very unhappy pouring a gallon of gas into the clutch housing and starting the car, but did it. I then regreased the release bearing, etc. I tightened the clutch pedal play a bit. I did not appreciate any real change. This is becoming a struggle, particularly going from 2nd to 3rd. Maybe we all need new sets of pressure plates?
This is a job I am not looking forward to, so any other ideas most welcome.

Francis,
I do not know any sure cure. Paul Murray at the restoration shop, had dismantled the clutch, cleaned all the plates, and had new friction facings installed.   I reassembled the plates, straightened and filed edges of some plates, making sure that they would slide easily in the driving splines. When the car was returned from the shop in 2006,  the clutch worked quite well, still dragged a bit going from neutral into gear when hot. In recent years, we have driven it more frequently, and gone on a few longer (50-100 mi.) trips. It has gotten progressively worse as per my previous post. Linus Tremaine posted some photos of clutch plates obviously scarred and warped from heat.  I think this condition is the main problem, not gumming of the splines, which is addressed by the gasoline flush. The interior of my clutch housing is nice and clean, no sign of oil leak from rear of engine.
A possibility came to mind that the modern friction facings may have higher, or at least different, friction coefficient than the original asbestos based facings. Compressability also may be different, although I don't think that would make much difference. Harder surface, that does not wear into intimate contact with mating plate?  
I have resorted to holding the clutch pedal down while waiting for a stop light. If a long wait, shut off the engine, and restart in gear, or coast, if on a down slope. Not the way this is supposed to work...In the present shutdown, I have not used the car as much, but still drive it a little, every week or two.

Perhaps another forum correspondent has a contribution...This seems becoming a generic problem with Lincoln L.

I agree with your assessment. Maybe we should consider a project to investigate modern clutch disk facings? I would hate to pull this mess and not replace with something better. Lets see what others have to say. If someone has a set of discs they have on the shelf we might see what can be done with some new fabrication?

Ill chime in. I have issues with putting the car in 1st gear sometimes, especially on a hill. I have driven my car alot and all over. Dirt roads, steep hills in San Francisco, highways.. you name it. It behaves like any other non synchro gear box as far as I can tell. I have decided that its just the way it is. So, I adjust my habits to accommodate the car. I dont put it in neutral at stops, but get it into 1st as I am slowing down to stop. It doesnt grind that way. My 2nd to 3rd seems ok. sometimes I miss the shift, but i can always let out the clutch and change the RPM and then it will go.

In the service bulletin is makes it very clear that the discs should not be made perfectly flat. There is intentional "warpage" such that when engaging the clutch the discs start to touch each other unevenly. If they were perfectly smooth they would engage all at once and make an unpleasant shift.

Lincoln was not making junk when they made the model L. I dont think any modern material is better than what they used. I wish we could all drive eachothers cars and compare. I would not change something because I think it would be better. I would make sure its original and correct and then it should work.

also,
my car changes as it warms up. Make sure you have 600w in the gear box and not 90 weight. ( 600w is not "600 weight" but a type of oil. Its similar in viscosity to seam cylinder oil.)

All good points. I have been meaning to go to a heavier gear oil and you have motivated me to do it. What type have you been using? I think I just need more practice getting the RPM right, but going from 2nd to 3rd gives me trouble. I find myself putting it into 3rd real early and then lugging it up to speed. I know that is wrong.

i actually have steam cylinder oil in my transmission. You can just buy 600W in five gallong buckets though. Order it online or from a local oil supplier.

I am going to do this. Sounds like 3 1/2 pints is all you need. I can get a transfer pump to push it in.

Francis,

I have obtained 600W gear oil from Restoration Supply Co., in Escondido, CA .   www.restorationstuff.com
They carry Lubriplate products, Lubriplate product number is SPO-299, comes in plastic quart bottles.  This is a high quality industrial gear lubricant. There should be a source closer to you.

 I have heard there is an even heavier grade of gear oil - Lubriplate MAG-00 is a "semi-fluid grease" 1000W that I use in steering gear. Restoration Supply recommends this for old transmissions and rear ends that tend to leak.

Linus' remarks on shifting technique are exactly what I have used for some time. It's a bit of a bother, but quite successful. When shifting from 2nd to 3rd, I find it helpful to hesitate a second after releasing the clutch to shift out of 2nd, then hesitate a bit in neutral for the engine to slow down before shifting into 3rd. On level ground or slight downhill slope, I usually start out in second, up to 15-20 MPH, then shift up. Downhill, just coast a  bit, put into high. the timing of the shift depends on the speed of travel.
Reading in the Lincoln "Book of Instruction", I see a note on page 11, shifting to hesitate a moment in neutral when shifting from second to high, if shifted too quickly, "a clash of gears will result". 

Hope this is informative

Got it. Already switched to the Restoration Supply steering box fluid. This is high quality and worth the effort.

It is interesting that the main service manual (23-27) and the 29 specific manual provide a bit different directions for shifting. The 29 specific instructions state to go straight from 2nd to 3rd, whereas the earlier instructions are more or less a double clutch maneuver. I think my main problem is practice. Sometimes the double clutch will slide right in and other times I am totally stuck. I may also be winding out in 2nd too much. I am going to get out on a country road and sort this out.

Many thanks

Yes, It takes practice - I don't manage it right every time, either. I usually shift to 3rd between 15 and 20 MPH. VERY different from a modern stick shift car. This engine has so much low RPM torque, lugging a bit doesn't seem to bother it at all.
Good Luck
Carry on...
Al

Linus, I completely agree with you on the quality of Lincoln engineering and manufacturing, throughout the car.

I am still having clutch trouble - a few days ago, after driving some 15 miles mostly in stop-and-go traffic, It seemed the clutch would not disengage at all. I opened up the inspection cover, everything looked normal, except the release bearing was jammed against the clutch mechanism, mo free play in the pedal. Backed off the adjustment one notch, which freed the bearing. It turned freely, smoothly, no damage. Clutch drags very heavily, idle speed had to be increased so engine would not stop when car stops in gear.

I looked at the photos you posted of your clutch discs, burnished very severely.

My question now is, Have you re-installed that clutch? What did you do to it?, What kind of friction facing on the driven discs? How does the clutch work now?

One thought occurred to me just now: Modern clutch facings as used in single plate clutches, experience a much higher contact pressure per square inch than old car multiple disc clutch plates. Therefore, the modern facing material must be much harder in compression than the old-time facings. The friction coefficient is likely different, as well.

I wonder if other classic era cars have the same troubles with multiple disc clutches?

Ford model A had multiple disc clutch in '28 and '29, changed to single disc in '30-'31.

Your thoughts, please

Thanks, Al