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Tranny head scratcher
Posted: Thu Mar 27, 2025 2:40 pm
by Daisy Mae
OK, so the obvious is staring me in the face regarding a total rebuild, but I'm scratching my head as to the cause for an odd condition...not that it matters, but curious nonetheless.
So, Daisy's engine is strong, and amazingly I get free starts more often than not, even cold, runs smooth and it exhibits great low end torque. The tranny on the other hand I knew has issues, more critically having 3/8" thrust play in the drum pack. The bands/drums appeared solid enough, so I rolled her out and took her for an inaugural spin just to get a feel for her before breaking her down further.
I had known the clutch pack was frozen, and had ultimately freed it up with a long soak with acetone/atf. But, it's still not fully free given it still has a lot of drag in neutral, so much so I can't start it wheels on ground, won't catch past a 3-5 second cough. A wheel up however, it will often free start. Once running, engaging the rear brake will lock 'em up but bring the rpms down under load, but it will idle fine. I assumed the more it ran the more likely the disc's would free up more, but, no.
Linkages set appropriately with noted action internally.
During my inaugural drive, when releasing the pedal there's a delayed engagement, with obvious slipping as I can even advance the throttle with little response...and yet give her 3-5 seconds to think about it and the clutch will eventually chug and suddenly engage, and all is good. But, repeated with each change between 1st & 2nd.
The head scratcher.... why would the clutch pack be stuck sufficiently to be dragging in neutral, yet not sufficient to immediately fully engage?? Seems incongruent, but, obviously worn discs or more likely I'm thinking embedded disc flanges in the drum lands. In the end, just more signs telling me to tear apart. But still curious as to the mechanics causing that...i figure embedded discs.
I'm close to having gathered everything to rebuild my rear axle/driveshaft....so...out will come the engine/tranny too at the same time for some decisions.
Once back together though, the entire chassis will be rebuilt, and it will be time to really enjoy her as a driver!!
I had a love/hate relationship with my TT, but the shits & giggles factor with Daisy is off the charts!!
Re: Tranny head scratcher
Posted: Thu Mar 27, 2025 2:45 pm
by TXGOAT2
Are you certain that it's the clutch, and not a band adjustment or linkage adjustment, or worn pedal cams?
Re: Tranny head scratcher
Posted: Thu Mar 27, 2025 2:50 pm
by varmint
Pat said it before I could...
pack that sticks and...
low band that is loose.
Re: Tranny head scratcher
Posted: Thu Mar 27, 2025 2:53 pm
by Daisy Mae
Pedals to cams are tight, bands are all in spec re sufficient clearance off the drum, and engaged with good clearance to the floor, and, solid lock up of the drum, with positive release.
With initial start of the engine, and the rear off the ground, I confirmed each separate band operation/action.
All pedal/band action is good.... the only issue I have is the dragging clutch pack, and delayed engagement.
Re: Tranny head scratcher
Posted: Thu Mar 27, 2025 2:58 pm
by Daisy Mae
So a loose low band, would not that also translate to a pedal buried below the floorboard to engage, and/or, if loose, how translates to delayed clutch engagement... confused
Re: Tranny head scratcher
Posted: Thu Mar 27, 2025 3:02 pm
by Daisy Mae
Thanks for the clues...
Will need a rebuild regardless with the amount of play in the drum pack thrust, but, will definitely check out the linkages
Re: Tranny head scratcher
Posted: Thu Mar 27, 2025 3:15 pm
by John kuehn
Tighten the low band about 1/2 turn at a time. As stated in other posts it may be worn pedal cams not letting you get the right adjustment for the low speed band.
Re: Tranny head scratcher
Posted: Thu Mar 27, 2025 3:38 pm
by speedytinc
"(The drum pack moves 3/8")"
A proper thrust is .022"
Your clutch hub is supposed to be a press fit. It currently is floating fore & aft. Meaning the setscrew is sheared Or fell out.
In extreme cases like you describe, the key will shear giving no clutch or only a little for now untill the surfaces wear down completely.
Stop messing with it/driving it, only more damage will result.
Expect to replace the center shaft, clutch hub, some disks?, the set screw & wood ruff key.
Dont be surprised to find one or more of the 3 steel thrust washers welded to the brake drum hub.
The brake drum may or may not NEED replacing, but now's the time to get one with the replaceable shoes.
Re: Tranny head scratcher
Posted: Thu Mar 27, 2025 4:59 pm
by Daisy Mae
Thanks John, the 3/8" play I knew was a bad sign, but yes, that one trip around the block was sufficient to put her back under anesthesia.
Tear down commencing
Re: Tranny head scratcher
Posted: Thu Mar 27, 2025 6:29 pm
by Wayne Sheldon
The first thought that came to my mind was a mix of early and later clutch parts. There was a change in the brake drum in the mid 1910s. The early design required a special first disc in the clutch and/or a spacer to prevent a couple clutch discs slipping off the end, which in turn caused a few inner and outer discs to bind together. The discs often become warped such that the binding might not seize the clutch completely with only a small area near the center binding. Such a failure can leave the clutch operational, but working very poorly.
John K mentioned "Your clutch hub is supposed to be a press fit. It currently is floating fore & aft. Meaning the setscrew is sheared Or fell out."
I had that set screw shear on one of my speedsters years ago. It had been working fine for thousands of miles, and while on a major tour, the clutch began acting up. I drove gently and completed the tour. A couple days later, I removed the top transmission cover and then when pushing and pulling the clutch pedal saw the entire drum set moving forward and backward abut a half inch!
After tearing things down enough to replace the set screw, I found no signs of any damage caused to any other pieces. The hardest part of that repair was getting the sheared set screw tip out of the hole in the drum's shaft. It had made a very clean break (probably improperly hardened?), and did not want to be removed from the hole in the shaft.
As John K indicated, with that set screw not doing its job, the clutch pack can float fore and aft on the key. The clutch pack is an important piece in centering the transmission, providing the rear thrust position.
Re: Tranny head scratcher
Posted: Thu Mar 27, 2025 6:38 pm
by Ed Baudoux
You're going to find that the ears of your clutch discs are eating into the hub and the drum.
Re: Tranny head scratcher
Posted: Thu Mar 27, 2025 7:41 pm
by Daisy Mae
Wayne,
That is exactly what I had noted with my initial poking around...
Depressing the pedal in/out moved the entire drum assembly fore/aft approx 3/8"
I figured it was a worn bronze thrust face, didn't think about the sheared pin...but the symptoms sure point to a lot of cancer in various spots...worn bushings, sheared pin, embedded clutch discs....shot tranny. Heck, I think I finally discovered the real reason it was put to sleep in 1935.
As much as I was floating on cloud 9 regards the engine, the tranny brought me back to earth realizing I'm still dealing with a 111 yr old car. That, and every chassis assembly has shown lots of wear here and there to deal with, I shouldn't have been too surprised. I was close to pulling the rear to tackle that next, but, at this point I'll be pulling it and the engine too.
Good thing is Daisy will certainly be good to go for another long life! When done.
Re: Tranny head scratcher
Posted: Thu Mar 27, 2025 8:19 pm
by Norman Kling
It is possible that nothing is wrong with the band adjustment or the clutch. It is important to have the engine running at approximately the speed it would with the clutch out in high. The pedal should be one inch to one and a half inches above the floorboard when you push down to low gear. Stomp it down but not too hard. Just give it some gas and push down. Do not try to slip it in. The neutral should be free enough that when you are parked on level ground in neutral, and push the car the engine does not turn nor if you crank the engine the car does not roll. You need to give it some gas while you shift into low. Then when you set the pedal out into high, you move the throttle lever up and after the shift into high, you adjust the throttle to gain the speed you want to run. If you have the engine running too fast when you first go into high, you might slip the clutch for a few seconds.
Norm
Re: Tranny head scratcher
Posted: Fri Mar 28, 2025 12:36 am
by Daisy Mae
Norman, thanks for your feedback/suggestions. But the issue is definitely not an operational one, it's mechanical.
I'm not new to T's, having owned one or another for 45 yrs, restored my TT down to every bolt with the exception of pouring babbit, and am experienced driving them & coordinating pedals to throttle to timing to mixture. This is an entirely new thing experienced, where I already see obvious issues with the tranny, but where one attribute with the high speed clutch pack I couldn't fathom the duplicity of already knowing I had sticky plates causing neutral drag but not understanding how sticky plates also equated to delayed high speed engagement with the pedal released...when seemingly all else appeared good (cams, linkages, engagement, pedal position, positive locking of band on low speed drum (low speed ain't an issue) and clutch finger/ring pressure plate release/ engagement all appearing/working as it should). That's what was making me scratch my head. My presumption would have been sticky plates would equate to more immediate, not delayed, high speed engagement.
And I still don't understand how a loose low speed band equates to delayed high speed clutch engagement. I have zero problems with low speed operation and neither do I see dragging band/tension on the drum. It's the odd slipping of the clutch pack when pedal released, taking 3-5 seconds to shudder & grab. And that with me using first only part throttle up to say 10mph, throttled down to off idle to shift....only to coast along with unchanged speed until the long delayed shudder... one time even experimenting with the slipping condition by throttling her up a bit to no reaction, other than eliciting a stronger shudder once she decided to finally squeeze her keagles... i know the feeling of positive engagement, or even high or low throttle vs speed affects on clutch engagement....this ain't that... it was a head scratcher in my experience.
But as mentioned, mute at this point, I'll discover it with the tear down. I just couldn't balance the two seemingly disparate issues in my mind, where the only thing that made sense to me was embedded plates in the drum, or, the lateral play in the drum assembly affecting the condition...but not knowing for sure.....
Re: Tranny head scratcher
Posted: Fri Mar 28, 2025 11:21 am
by TXGOAT2
Teflon or graphite in the oil might make a clutch do that, or something like STP.... or gear lube...
Re: Tranny head scratcher
Posted: Fri Mar 28, 2025 11:54 am
by Jerry VanOoteghem
...the only thing that made sense to me was embedded plates in the drum...
That's my bet.
And I still don't understand how a loose low speed band equates to delayed high speed clutch engagement.
Bands, band adjustment, pedal cams, etc., have zero to do with your issue. It's all about the high speed clutch.
Re: Tranny head scratcher
Posted: Fri Mar 28, 2025 2:12 pm
by RGould1910
Had similar problem caused by a clutch disc getting wedged in between the disc drum and brake drum. Whatever it is should become obvious when you inspect it.
Re: Tranny head scratcher
Posted: Fri Mar 28, 2025 5:04 pm
by Norman Kling
It could be, as posted above, worn drum or hub. The discs will then stick and not press together as they should. Also Watts discs or jackrabbit discs tend to wear out over time and could cause a problem. Your spring might be weak. Many things to inspect when you pull out the clutch.
Norm
Re: Tranny head scratcher
Posted: Sat Mar 29, 2025 8:44 pm
by Daisy Mae
The mystery deepens....
The prior owner told me the car hadn't ran since 1935. I took that to mean it was original condition from that period. He further stated they were never able to get it started, and told me they figured it was a bad mag.
They had initiated a restoration in '68, but stopped when the dad went blind.
What I found interesting though in my earlier inspections was how spotless the internals were in the engine/tranny, eg, no sludge. Certainly not what I expected to see from something from 1935, or anything similar to any A or T I've worked on, usually being sticky tar sludge everywhere.
So I found out today they HAD rebuilt the engine in 68, but he couldn't recall if the tranny was rebuilt too or not, being a kid at the time, only that they could never start it.
Checking simple stuff first, one of the first things I discovered
was no continuity through the switch, and found both leads disintegrated at the posts. After going thru checking the engine, bearings, compression, plugs, timer, carb, wiring, the engine is great, starts very easily, offers up free starts, great low end torque, and smooth thru the rpm's. Certainly no visible, or operational signs of a worn engine. Oh ya...and runs great on mag!
The tranny appeared clean as well, the bands appeared good, considering how old if changed in the 60's, but I had noted the thrust play in the drums, and the sticky plates. Then of course the delayed clutch engagement with my first drive.
All this of course now adding to the mystery, given the engine/tranny presumably being rebuilt in the 60's, as compared to dealing with an old worn unit. But IF rebuilt, why the thrust issue?? Sticky plates I could understand, even if new, have sat for 55+ years. Unless, A) the engine was rebuilt but not the tranny, or B) the builder didn't build the tranny back correctly. Possibly, as some have stated, mixing early and later parts
I plan to start removing everything this week to pull it. Once I actually do some surgery it will be interesting as to what I may find.....
So, more to come....