multi-disc drag?

[iverson]

the multi-disc clutch in our 28 works great the only question I have is when it gets warm after a long ride I get a little drag not bad but cant get it in gear with out a little grinding its full of 600w car idles slow it doesn't grind at all when eng. and gear oil is cold. anyone know if this is normal?

[jb-ob]

First check your clutch adjustment, 3/4 " on a multi.

Until the new linings in my multi clutch pack seated, I needed 1/2 " of play.

To be completely accurate, use a feeler gauge between the throw out bearing and the clutch fingers to have .048-.050 clearance. (Murray Fahnestock. 'Know Your Model A')

JB

[Joe K]

Originally Posted by iverson

the multi-disc clutch in our 28 works great the only question I have is when it gets warm after a long ride I get a little drag not bad but cant get it in gear with out a little grinding its full of 600w car idles slow it doesn't grind at all when eng. and gear oil is cold. anyone know if this is normal?

What you're describing doesn't sound like a clutch problem but rather a transmission problem.

As in your transmission oil is heating up and acting less viscous to "pull" the gears around in advance of mating.

And to be truthful, it sounds pretty normal.

And one of the reasons Model A drivers typically "double clutch" to prevent gear clash.

Most modern drivers don't really know what is meant by "double clutch."

When going from first to second, you stop at the mid point of the "H" and let out the clutch. This brings half the moving parts of the tranny into alignment/motion. Then press the clutch in and complete the move to second.

Without clashing.

Similarly in second to third.

Some transmission don't need it except from 1st to 2nd. Others only from 2nd to 3rd. And some of the very lucky don't need it at all until the transmission is really warm.

And the REALLY lucky don't need it EVER - or own a Mitchell Transmission.

Joe K

[Tom Wesenberg]

On cars without a synchro first, I normally shift to third or second, then to first when the car is stopped.

[iverson]

jb I never measured the play but the throw out bearing has play that I am sure. I will look into that maybe a little less play will open up the clearance between the discs a little more and help. Joe the drag is not a lot I think you are right when oil is cold and thick no drag it goes into gear with out any grinding fine but after 10 mile ride it drags I dont have a problem with the shifting once its in gear but if I put it nutral at a stoplight it grinds its not that bad but I dont think it was doing it last summer clutch works very good smooth no chatter no slip its a nice working clutch. thanks guys

[iverson]

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Tom it grinds no matter what gear you put it in no matter how long you hold down the clutch its not a lot but its a noticable grind. when cold it goes into any gear fine trans is very quiet no wineing it shifts perfect its a 2 owner car that has not had any abuse I topped up the 600w last fall and no puddles under it so I think its still full I will check it again

[Pinesdune]

one other point, if your pilot bearing is getting marginal, it could bind up with the end of the input shaft once she's warm/hot from being run for a bit causing things to spin though the clutch is released , no way to check it or grease it without tearing it apart tho

[iverson]

good point Pinesdune. I never thought of pilot bearing getting tight or dry. first thing I will do when I get time is recheck the 600w then adjust clutch take out most of the play and see if that helps thanks

[iverson]

I have been thinking about this problem and the only thing that changed since last year is I put on a original funnel top radiator it seems to working ok but it is much lighter then the one I took off before the motometer never even got into the red now it heats up to the middle and tests at 170.I ran it tonight but only a few miles looks like rain. I am thinking when I run it over ten miles I noticed the drag problem after car sat for a half hour or so to eat maybe heat sink? I took off inspection cover not a lot of play but I think there is enough play and wear in linkage to get some adjustment I will try that if it don't work I will put the old heavy aftermarket radiator back in and try that thanks for all the advice I hate to have to take out clutch if not needed

[Tom Wesenberg]

I haven't known of any aftermarket radiators being heavier than the original one.
In fact the AA repro was only 2/3rds the weight of the original.

[iverson]

still have the problem I adjusted clutch about 2 turns any more and the thro out bearing will make contact. it still drags after a 15 mile ride. it never did this last summer the only thing different is a used funnel top radd and new shaft in waterpump. I never checked the temp before but the motometer barely showed anything now red goes up half ways radd tests 170 with a thermometer trans is full of 600w any suggestions?

[Joe K]

Do you mean drag as in "slippage?" Or do you mean drag as in "not fully disengaged?"

You may be seeing the first signs of "dust build up" in your multi-disk clutch. The multi-disk is a robust and forgiving beast, but it does have a tendency to build up clutch disk dust in the inner axial grooves - dust which one by one tends to hang up the disks - until the clutch becomes unreliable as in slipping - or possibly your case - not disengaging. Or both.

The remedy is a full disassembly and cleaning, and possibly some rework of the axial grooves. The clutch disks tend to wear grooves in the grooves where the teeth repeatedly land. These "bumps" can be laboriously filed out by hand - which makes the grooves slightly larger - but still functional.

I have seen someone who had to retire a multi-disk clutch because the grooves were thought TOO worn. He converted to single plate.

Be careful on that disassembly. You NEED to have the proper tools to do it as the clutch pac is spring loaded and you can get a face-full of clutch disks if you're not careful. You need the proper tools, or a proper understanding of the forces involved and alternate ways to give force/retention and keep in control during "let down" of the spring.

Joe K

[iverson]

Joe thank you for the safty warnings I will be careful when the time comes to take things apart our clutch dont slip it does not fully dissengage but only after a 15 mile drive. thats what seems wierd to me why only after it gets hot? most likley it is worn to the point that it will only get worse and its just showing up now. it looks like the best plan is to start looking for spare parts. I can get by with it if it dont get any worse I dont want to get into any big repairs during the summer its my 99 year old uncles car and we go for coffie when ever the weather is good

[Joe K]

The KRW tools would be "the way to go." Scientifically designed for a specific job and used/blessed by the Ford Service organization.

However, now pricey due to the "collectables" attraction of things KRW and Model A.

Some Model A clubs have sets of the tools for lending.

BUT - it is possible to do the disassemble using "other" tools. Some way to keep the assembly together once the bolts are removed is paramount. I have used a 21" Royersford "Excelsior" drill press (Flat belt driven Iron Beast that when the quill was retracted stuck up between the floor joists in the ceiling of my shop.) But I think you can use a pair of stout steel plates and a short length of 3/4 or 1" all-thread and get to the same condition.

If you have a 12 Ton harbor freight shop press, this like the drill press might work if you think to control possible "squirm" of that spring.

One simply CAN'T have too many tools, of course.

Joe K

[Fullraceflathead]

If its dust caked up in there I'd try a Air hose at 125psi first before tearing it all apart.
Obviously you need a face shield and DO NOT BREATH any of the dust.

[iverson]

Full race thank you! I think you are on to something! tryed your idea and blew out a lot of dust when cold. than started the motor and clutch draged like it does when hot after a few trys it freed up guessing air drove some dust to other places. I went for a 20 mile ride and it still drags but seems less getting dark but will try again when I get time

[Joe K]

The disks are wont to "get set in their places." Using air probably will upset these places, but driving more may make the "dragging" less as each finds its old or makes for itself a new place.

Another remedy I've heard of is to use a pressure washer and wash the clutch out with soap and high pressure water. It won't work worth a dern directly afterwards, (wet equals slippery for a clutch) but after the clutch dries out it may be better yet.

A few cycles of this and you MAY have a new clutch! Or a reason to have a new clutch?

Good luck with this. Keep this baby original if at all possible. Not that many multi-disks left.

Joe K

[Farrell In Vancouver]

TWO cents worth and nothing more, I also drive a multi and I have experienced your issue.
You can try another trick with and aerosol Brake-Kleen rinse. Pick up four large cans and rinse around the clutch pack using a can for every 25% of the flywheel splines. Keep rotating the the flywheel as you progress as there are only a couple of vent holes to get the rinse out. I found elevating the front of the car enough to get the housing on a back slant helped as well. I also tried this while engaging disengaging the clutch but it was difficult to do alone. You will be amazed at what gets flushed out so put something under the clutch to prevent a spot on the floor. Another issue I found with the multi-shifting is that they are sensitive to rpm. Keep your idle speed low to help slow the gears down faster.

[iverson]

Thanks Joe K and Farrell For more good advice! I had a chance to blow out clutch some more tonight more dust then blocked clutch pedal down and got a lot more. Starting to rain so no chance to give it a good try now I will report back tommorow

[iverson]

KGBnut I think JoeK covers it pretty good. My understanding is the 28 and 29s both have the funnel shaped top inlet and round tubes but the 29has a diferint shape to the top tank where the anti rattle welting for hood goes the tank is relieved and the bottom tank is completely different the fan shroud won't fit on the 29 because of the shape of the bottom tank. the pictures are a 29 or maybe the shape changed when the fan shroud was eliminated? That's my best guess

[iverson]

I tryed to post this on the other thread about funnel top radiators sorry

[d.j. moordigian]

Originally Posted by iverson

Thanks Joe K and Farrell For more good advice! I had a chance to blow out clutch some more tonight more dust then blocked clutch pedal down and got a lot more. Starting to rain so no chance to give it a good try now I will report back tommorow

Looking at you'r last photo got me thinking. Can you tell me the date on the
gas tank and also the engine number, please. Your floor mat is in question.

Also,..on your problem. I think it's the pilot bearing....for what it's worth..

Thanks,
Dudley

[iverson]

Dudley the tank date is 6-21-28 eng no A216238 body no chi320. not much left of the front mat but I can get you pics of the rear one its mostly there but falling apart. the pilot bearing is quiet I dont know if blowing the dust out is going to get in it and cause problems

[d.j. moordigian]

Originally Posted by iverson

Dudley the tank date is 6-21-28 eng no A216238 body no chi320. not much left of the front mat but I can get you pics of the rear one its mostly there but falling apart. the pilot bearing is quiet I dont know if blowing the dust out is going to get in it and cause problems

That would be great!

Thank you..

[iverson]

Not much chance to drive today rain here is some floor mat pics

[iverson]

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More May pics

[Charles Reese]

“Be careful on that disassembly. You NEED to have the proper tools to do it as the clutch pac is spring loaded and you can get a face-full of clutch disks if you're not careful. You need the proper tools, or a proper understanding of the forces involved and alternate ways to give force/retention and keep in control during "let down" of the spring.”

“The KRW tools would be "the way to go." Scientifically designed for a specific job and used/blessed by the Ford Service organization. However, now pricey due to the "collectables" attraction of things KRW and Model A.”



I cannot emphasis too strongly the wisdom of the previous FB’ers. I am fortunate to have one of the original KRW multidisc clutch tools. I will be happy to share with anyone in need of its use. One need only cover the shipping to/from. However, due to its ‘street value’ we will have to negotiate some fiscal arrangement by which I am assured of its timely return and good condition.

[iverson]

Charles thank you for the info. and the kind offer. I still have hope of fixing ours with out taking it apart. looking at your info the flywheel and a press might work to take clutch apart safely and align disks?

[Tom Wesenberg]

I've done a couple multidisc packs by using a 12" piece of threaded rod and some large washers.
I aligned the teeth by using a pair of screwdriver shafts.
Notice that one clutch disc has a small chisel mark in one tooth, and this one is closest to the tranny.

[iverson]

first chance to go for a 20 mile ride tonight and it looks like full race flatheads idea of blowing out the clutch worked perfect! no drag! the outside temp is in the 50"s so I will need a warmer day to find out for sure but the water temp got up to 170 and no drag so I am very optimistic! thanks everyone for all your help!