Clutch issue

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Model T Ford Forum: Forum 2013: Clutch issue
Top of pagePrevious messageNext messageBottom of page Link to this message  By Stephen D Heatherly on Sunday, December 01, 2013 - 08:05 pm:

When I had the engine out of the coupe to do some engine and transmission work I installed a brand new set of stock Ford style steel clutch discs. The lug shoes and clutch disc drum were in great shape and the clutch spring, which is only a few years old and still good, was reused. The clutch fingers were adjusted so that there is exactly 13/16" from the bottom of the clutch shift to the driven plate shaft flange. When I shift into high the clutch grabs very hard. I backed each of the adjusting screws off a full turn. That seems to have slightly improved the situation but, the engagement is still not anywhere near smooth. I am sure the problem is not being caused by how I am driving the car. I have been driving T's for a few years now and have not had any issues with getting a smooth shift until now. I believe if I back the screws off a little more the clutch will slip just enough to allow a smooth engagement but, if I back the screws out anymore I can't install a cotter pin. What do you guys think?

Thanks,
Stephen


Top of pagePrevious messageNext messageBottom of page Link to this message  By Cameron Whitaker on Sunday, December 01, 2013 - 08:18 pm:

Did you make sure to install the clutch disks in the right order? That can cause an issue. I believe that you start with a hex, then it goes round, hex, round, hex, etc., until you end with a hex. Also, did you put the correct number of disks in there? There should be a total of 25, as far as I remember. Usually I just make sure to keep the MTFCA transmission book handy when I install new clutch disks!


Top of pagePrevious messageNext messageBottom of page Link to this message  By Stephen D Heatherly on Sunday, December 01, 2013 - 08:25 pm:

Yes, 25 discs were installed 13 large and 12 small in the right order. All I could see installing the plates wrong would do is cause the clutch to slip.

Stephen


Top of pagePrevious messageNext messageBottom of page Link to this message  By Richard Gould on Sunday, December 01, 2013 - 09:01 pm:

Some years clutch rings had different length pins. Did you reuse the same ring? It doesn't make sense the clutch screws are so far unscrewed as not to allow cotter pins. Another thought. Are the pins coming thru the holes in the driving plate?


Top of pagePrevious messageNext messageBottom of page Link to this message  By Stephen D Heatherly on Sunday, December 01, 2013 - 09:15 pm:

Richard, I reused the ring that I had in the car before. The pins are coming through holes in the driven plate.

Stephen


Top of pagePrevious messageNext messageBottom of page Link to this message  By Jack Daron - Brownsburg IN on Sunday, December 01, 2013 - 09:24 pm:

Only thing i can think of is there may be an issue with triple gear clearance and the number of washers in the tranny. I took one 26 apart once that only had two washers in it.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Stephen D Heatherly on Sunday, December 01, 2013 - 09:29 pm:

Jack, I installed all three washers when I put the transmission back together.

Stephen


Top of pagePrevious messageNext messageBottom of page Link to this message  By Jack Daron - Brownsburg IN on Sunday, December 01, 2013 - 09:43 pm:

I understand,but the issue is did you really need all of them? How much flywheel to gear face clearance did you have? The book calls for 10 thou,as I remember.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Jerry VanOoteghem on Monday, December 02, 2013 - 01:44 pm:

My T's, which all have original steel discs, all shift hard... if I let them. As a result, I never try to feather the clutch. I let the engine rpms wind down to match the car's speed then shift to high. 90% of the time it's a seamless shift.

Any play in your driveline, like worn clutch disc lugs, worn u-joint, sloppy ball socket, excessive ring & pinion backlash , etc., will make the situation worse.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Stephen D Heatherly on Monday, December 02, 2013 - 04:15 pm:

Jerry, I really doesn't seem to matter how I shift it it is always hard.

Stephen


Top of pagePrevious messageNext messageBottom of page Link to this message  By Jerry VanOoteghem on Monday, December 02, 2013 - 04:53 pm:

Stephen,

I would definitely look for a sloppy ball socket, (where the torque tube ball mounts). When you come out of low, the rolling resistance of the rear wheels pulls the ball back, when you shift to high, the driving force slams the ball forward with a thud. There are shims available to correct this. Also, be sure you don't have a gasket between the ball socket retainer ring and the forth main cup. This is not needed and adds to, or can create, the problem.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Stephen D Heatherly on Monday, December 02, 2013 - 05:01 pm:

Jerry, I already have a shim installed and there is no slop in the ball.

Stephen


Top of pagePrevious messageNext messageBottom of page Link to this message  By Jerry VanOoteghem on Monday, December 02, 2013 - 05:04 pm:

Darn it! No luck today. Sorry.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Stephen D Heatherly on Monday, December 02, 2013 - 05:48 pm:

I guess I will take out the adjusting screws and deepen the slots a little and see if backing the screws off a little more cures the problem.

Stephen


Top of pagePrevious messageNext messageBottom of page Link to this message  By Hal Davis-SE Georgia on Monday, December 02, 2013 - 07:40 pm:

Are you closing the throttle when you shift? If so, do you give the engine time to 'wind down' before letting out all the way? What I do, is effectively 'shift into neutral' and hold my foot there for a second or two until the rpm's come down.....THEN shift into high. From his description, I suspect this what Jerry does as well. Using that technique, I would think even a dog clutch would shift smoothly.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Stephen D Heatherly on Monday, December 02, 2013 - 09:06 pm:

Yes, I am closing the throttle with the pedal half way up in neutral then releasing into high. I think I was a little unclear in my first post so I will add a little more info. If I have the engine and drive shafts speeds matched perfectly with it in neutral before letting the pedal up into high it engages ok, but if not it jerks into high rather than slipping a little to allow a smooth shift like it should.

Stephen


Top of pagePrevious messageNext messageBottom of page Link to this message  By Mark Gregush Portland Oregon on Monday, December 02, 2013 - 11:11 pm:

Could your low band be to tight and is still trying to grab the low drum even in neutral. Could be that if the disk are new they just need to work a little to get settled into place.


Top of pagePrevious messageNext messageBottom of page Link to this message  By William Rowles on Tuesday, December 03, 2013 - 04:29 am:

My 1920 runabout has had a hard "grab" shifting to high since I bought it. Being a newbee to driving Model T's I thought the problem was me, so I have read, thought, and worked hard to improve shifting technique over a period of 3 years. My observations have been that in addition to engine speed reduction during the shift and quick release of the pedal from the pause in neutral, significant differences are noted with oil type and viscosity as well as oil level in the engine/transmission. Try a different oil and keep the sump as full as possible, and observe whether this makes an improvement in the hard-shifting you are experiencing.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Jerry VanOoteghem on Tuesday, December 03, 2013 - 01:15 pm:

Stephen,

"...slipping a little to allow a smooth shift like it should. "

None of my 4 T's do that. I've always been of the mindset that they shouldn't. However, as I've stated, my driving technique is such that I have smooth shifts anyway. It's really not something I even think about, it's just become 2nd nature to shift that way.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Dave Huson, Berthoud, Co. on Tuesday, December 03, 2013 - 02:02 pm:

Steven Heatherly:

You say that you are going to deepen the slots in your adjustment screws. Rather than do that I would grind a few thousands off the tabs on the push ring.

traini


Top of pagePrevious messageNext messageBottom of page Link to this message  By Stephen D Heatherly on Tuesday, December 03, 2013 - 04:19 pm:

Dave, is there any reason to grind off the pins rather than deepen the screw slots? I really don't want to pull the engine out again.

Stephen


Top of pagePrevious messageNext messageBottom of page Link to this message  By Dave Huson, Berthoud, Co. on Tuesday, December 03, 2013 - 06:53 pm:

Sephen Heatherly:

I have been trying to think in my minds eye if you can get to the push ring with out pulling the motor. I am not sure, I have never done it but if you can I would recommend it. The reason I say that if you cut the slot much deeper in the adjustment screws maybe you weaken them. Are you sure that the push ring stubs are In the three holes in the clutch disk. That would sure make your disks drag. I always take one of the adjustment screws all the way out and shine a light into the hole to make sure that at least that one stub is in the clutch plate hole. If one stub is in then the other two stubs will be in.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Steve Tomaso - Milton,WA on Tuesday, December 03, 2013 - 07:21 pm:

Couldn't one shorten the opposite end of the adjustment screw a little ? Not the slotted end - the end that pushes on the pins. Could be "done in the car" easy enough - one at a time.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Jack Daron - Brownsburg IN on Tuesday, December 03, 2013 - 07:50 pm:

If he would face the triple gear bushings correct,all the other problems will go away.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Stephen D Heatherly on Tuesday, December 03, 2013 - 10:11 pm:

Dave, I'm certain that the stubs are in the holes. With the brake drum positioned so that one of the pressure levers is to the side you can see the stub protruding well through the hole. The strange thing is that the clutch does not drag in neutral but, engages hard. Maybe the discs are a little rough and need to wear smoother.

Jack, I don't understand what the triple gear face has to do with the clutch at all.

Stephen


Top of pagePrevious messageNext messageBottom of page Link to this message  By Jack Daron - Brownsburg IN on Tuesday, December 03, 2013 - 10:44 pm:

Stephen,all you need to know is in the book. It starts with facing off the triple gear bushings,assembling the transmission and then the three(if needed washers),then the clutch pack. Adjustment of those three fingers is to remove play in the entire tranny when face bushings wear.You are adding more force and removing the space. Which is 0.010 or less. You have to much material which is forcing the clutch ring back and you don't have proper adjustment with the three clutch finger screws.I have seen some trannies only have one ,or two of the washers in them. You might be able to jack up yours and remove one of the washers to get going.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Adam Doleshal on Wednesday, December 04, 2013 - 11:26 am:

Stephen, You mentioned "The clutch fingers were adjusted so that there is exactly 13/16" from the bottom of the clutch shift to the driven plate shaft flange."

I'm surprised nobody brought this up yet, but the "by the book" measurement should be to adjust the three adjusters so that the clutch spring is compressed to 2". The three adjusters also need to have the exact same number of turns on them (be exactly the same length when tightened up).

Its also a good idea to check your spring before using it, even if it is a brand new one. Put the spring on a bathroom scale and compress it to exactly 2" and read how many pounds of push it has at 2". Original springs should be around 100 pounds and work fine down to 90. Repro springs are often around 130 pounds. If you used a repro spring in place of a worn original, you will likely feel the difference. The repro springs are okay, but bear in mind that every time your engine is idling in neutral, or operating in low or reverse that you have 135 pounds of thrust on the front face of the third main instead of the factory designed 100 pounds and that excessive idling in neutral may prematurely wear the third main thrust.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Richard Gould on Wednesday, December 04, 2013 - 11:38 am:

Sorry, I can't see how the thickness of the triple gear bushing flanges have anything to do with what Stephen is experiencing.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Mark Gregush Portland Oregon on Wednesday, December 04, 2013 - 12:06 pm:

The 13/16 is talked about in chapter 315 in the Ford Service book.
Because of wear on the parts and only one slot there will be some variation between the three fingers but it will be small.
There should be .015 to .022 clearance between the thrust washers and the clutch drum (by the book chapter 307).
I don't see any where he says anything about triple gears or bushings, he installed a new set of clutch disks.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Stephen D Heatherly on Wednesday, December 04, 2013 - 04:28 pm:

Adam, I was going by the measurement given in the Ford service manual. After adjusting to 13/16" I measured the spring also and it was compressed to exactly 2". The fingers are adjusted evenly. I measured from the clutch shift to the driven plate shaft flange right next to each finger and have the same measurement on all three.

Mark, when I adjusted the clutch I first turned each screw in until they barely touched the pins on the push ring. Then I ground a small amount off the bottom of the screws so that they would all touch at the same relative position. After that I turned them in half turns until I got the 13/16" adjustment. I do have the proper clearance between the thrust washers and the clutch drum.

Stephen


Top of pagePrevious messageNext messageBottom of page Link to this message  By Richard Gould on Wednesday, December 04, 2013 - 06:40 pm:

Looks to me like you've done everything right, Stephen. I bet its the new clutches causing the difference. I've heard that NOS Ford clutches have a fast engagement. The new ones are also probably thicker that the old ones you removed.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Dave Huson, Berthoud, Co. on Thursday, December 05, 2013 - 12:11 am:

Stephen Heatherly:

Don't ever let any one talk you into doing a facing on the triple gear bushing flange. Those flanges are the only thing that keep you from rubbing the triple gears on the fly wheel. When you hear a loud squeal from a T backing up, you are hearing the triple gears rubbing the flywheel.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Dave Huson, Berthoud, Co. on Thursday, December 05, 2013 - 12:16 am:

Stephen Heatherly:

Don't ever let any one talk you into doing a facing on the triple gear bushing flange. Those flanges are the only thing that keep you from rubbing the triple gears on the fly wheel. When you hear a loud squeal from a T backing up, you are hearing the triple gears rubbing the flywheel.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Hal Davis-SE Georgia on Thursday, December 05, 2013 - 07:27 am:

Some of the repro bushings have flanges thicker than Ford spec. You have to face some of that off or you will never get the thing together. My drums were binding on the triple gears until I got the proper flange thickness on the triple gear bushings.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Richard Gould on Thursday, December 05, 2013 - 11:34 am:

I believe the book calls for 6 thou clearance between the teeth of the triple gear and the surface of the flywheel. That seems like a mighty small amount of clearance so I typically set mine at twice that amount and don't have any issues with things fitting together. I've seen a lot of flywheels with circular marks from the teeth rubbing and that's got to be a noisy situation. The more clearance you have between the triple gears and the pins the more rock you have and the more clearance you need to avoid rubbing. Ford set the clearance at 2 thou so there was little rock. Now we set them at twice that amount.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Jack Daron - Brownsburg IN on Thursday, December 05, 2013 - 12:11 pm:

You guys need to revisit Paragraph 292 on page 79 of the shop manual. The book says0.006-0.010 face clearance. NUff said.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Dave Huson, Berthoud, Co. on Thursday, December 05, 2013 - 02:00 pm:

Jack Daron:

You may be right, you have had a lot of experience with Ts. However the flange is a real wear point so I would never chop of any of the flange. I must have about 30 or more triple gears and every one of them have no wear left on the flange. ALL THE FLANGES have been worn flat. I know I have seen the clearance listed, I think in the Green Bible (now black) But I never grind them down, and I can still set the clutch Disk Drum Screw.
Of coarse if you are installing a Watts Clutch you have to machine some off the push ring pins !!!!

train


Top of pagePrevious messageNext messageBottom of page Link to this message  By Stephen D Heatherly on Sunday, December 15, 2013 - 05:08 pm:

I think I discovered my problem. The clutch discs appear to be too think. If I look through the transmission opening I can see the adjustment screws flush with the bottoms of the pressure fingers so, the adjustment cannot be backed off any more. I'm sure I did not put in too many plates because I have all 25 of my old ones. When it gets a little warmer I will pull the engine and put my old discs back in.

Thanks,
Stephen


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