What I found when i pulled my motor apart

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Model T Ford Forum: Forum 2013: What I found when i pulled my motor apart
Top of pagePrevious messageNext messageBottom of page Link to this message  By Mark Gregush Portland Oregon on Friday, July 05, 2013 - 11:51 am:

I pulled my engine apart yesterday to see why it was clicking at higher speeds and to replace the smokin Jack Rabbet clutch. Here is what I found.
The crankshaft flange thrust face is in good shape but the rear cap was wore enough to allow the flywheel to move. The keepers were in fact rubbing the coil ring. Some of the aluminum spacers have cracks which may have been there after I rebuild the flywheel and did not see at the time or my have formed over time. For the amount of miles left in the tour season I have three choices, leave them as is, redo the flywheel or remove magnets and the the coil ring and run on battery. I am planning on pulling the motor this fall for a well needed complete rebuild.
When I put the motor back together the last time with new rings I made sure that the ring gaps were evenly spaced. When I pulled the pistons out, at least 2 rings on each piston the gaps were lined up or very close.
The fiber Jack Rabbet disks were tight on the clutch drum and I had to pry some of them off. The notches were very elongated. This was a used set when I put them in but in use may have swelled up from absorbing oil and heat. I liked the turbo 400 disks when I had them in but my set is well worn (used when I got them) so will be putting Ford steel back in.
The 4th main is more worn then I would like, yes I understand it's importance, but for now I am going to turn it so the oil hole is to the side.
The crank shaft gear is not in the best of shape. I am going to take the nylon cam shaft gear off and put the steel gear back on for now before I wreck it. The nylon gear is new with only a couple of hundred miles on it.
To get through the rest of the tour season I am going to; build up the thrust on the rear main, put the steel camshaft gear back on, re-install the pistons with the rings in the correct spacing and grind the valves and decide how to proceed with the flywheel.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Jim Patrick on Friday, July 05, 2013 - 12:03 pm:

It seems like a worn 4th main cap would cause the magnets to move away from the coils, increasing the gap. What caused the magnets to move toward the coil ring? Would it not be more likely that the 3rd main bearing is worn, allowing the flywheel to move forward toward the coils? Would you be able to insert a spacer behind the 3rd bearing to re-establish the gap? How about removing several of the magneto coil shims? Jim Patrick


Top of pagePrevious messageNext messageBottom of page Link to this message  By Andre Valkenaers on Friday, July 05, 2013 - 12:09 pm:

Mark,
As your engine is apart, isn't it easier to change all the used parts by new and do directly the right thing to rebuild the engine???

Andre
Belgium


Top of pagePrevious messageNext messageBottom of page Link to this message  By Andre Valkenaers on Friday, July 05, 2013 - 12:11 pm:

Mark,
As your engine is apart, isn't it easier to change all the used parts by new and do directly the right thing to rebuild the engine???

Andre
Belgium


Top of pagePrevious messageNext messageBottom of page Link to this message  By Mark Gregush Portland Oregon on Friday, July 05, 2013 - 12:23 pm:

The rear main cap thrust is worn. Building up the thrust face on the cap with brass shim stock or babbett would fix that. When the car is in high the clutch spring is pushing the flywheel forward, when the clutch is neutral it is pulling it back increasing the gap. The rear cap has thrust at both ends. If I remove shims from under the coil ring that might buy me time but the car may not run on magneto because of the gap. Right now the mag is putting out about 5-7 at idle and 30 plus at about 20-25 MPH sitting.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Jim Patrick on Friday, July 05, 2013 - 12:33 pm:

Mark, I sent my 4th main cap along with the drive plate w/shaft to George King III (www.enginerestoration.com) in order for him to rebabbit the cap I.D. to the exact O.D. of the shaft. It came back perfect. Jim Patrick


Top of pagePrevious messageNext messageBottom of page Link to this message  By Mark Gregush Portland Oregon on Friday, July 05, 2013 - 12:35 pm:

Would it be the right thing, yes. Am I going to be without my T for the rest of the summer, not if I can help it. The guy that does my babbett is backed up anyway into next fall.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Kohnke Rebabbitting on Friday, July 05, 2013 - 12:35 pm:

When the ball cap wears, the transmission sags, while the top gap opens up, the bottom closes up.

It also lets the transmission bounce up, and down.

If you don't replace the ball cap, you could be looking at a broken crank flange, and yes a worn rear thrust does not help.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Mark Gregush Portland Oregon on Friday, July 05, 2013 - 12:37 pm:

Re the 4th main. The guy that does my babbett can do the same thing. I will have that done when I rebuild the motor.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Ed Baudoux on Friday, July 05, 2013 - 12:38 pm:

"When the car is in high the clutch spring is pushing the flywheel forward" No, it is not.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Mark Gregush Portland Oregon on Friday, July 05, 2013 - 12:44 pm:

I'll have to think on that one some more.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Stephen D Heatherly on Friday, July 05, 2013 - 12:58 pm:

When the high gear clutch is not engaged the spring pulls the flywheel backward away from the engine. When in high the spring does not push the flywheel forward, it just isn't pulling back on it anymore.

Stephen


Top of pagePrevious messageNext messageBottom of page Link to this message  By Jerry VanOoteghem on Friday, July 05, 2013 - 01:43 pm:

Unless I'm missing something, all you really need to do, to get going again, is replace/repair the rear main bearing & install a rebabbitted 4th main. (Oh, the clutch thing too.)

Not sure how turning the 4th main 90 degrees helps anything.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Jim Patrick on Friday, July 05, 2013 - 02:01 pm:

Mark, You mention that you plan on pulling the motor this fall for a well needed complete rebuild, but if the magnets are clicking against the coils, it means they are making contact, so your engine may not wait until fall. It may take just one bump in a pothole or over rough RR tracks at the wrong time to cause a magnet to catch a coil and totally demolish your engine. For the safety of your engine, your bank account and your sanity, you may want to forgo this touring season, before you are forced to do so because of a catastophic engine failure, while incurring major towing expenses just to get you and the car home before going through the trauma of opening her up to calculate what the delay cost you in extra repair costs. Money that could have been better used for a full babbit job, a magneto rebuild and other necessary expenses for a simple rebuild. Jim Patrick


Top of pagePrevious messageNext messageBottom of page Link to this message  By James A. Golden on Friday, July 05, 2013 - 02:43 pm:

The triple gear pins and gears are not mentioned, but if those clearances were a little too tight, those Watts clutch disks can be destroyed in as few as 50 miles, especially with an over heated engine that may have run through a long slow parade.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Andre Valkenaers on Friday, July 05, 2013 - 03:13 pm:

Mark,

Why don't you simply replace the 3rd main bearing by a rebuild one from the dealer a new ball bearing 4th main, new clutch and new piston rings.
In a week you are on the road again.

Good luck

Andre
Belgium


Top of pagePrevious messageNext messageBottom of page Link to this message  By Mark Gregush Portland Oregon on Friday, July 05, 2013 - 03:40 pm:

When the triple gear bushing and pins were replace they were setup on the loose side. I am going to pull the transmission apart and inspect them.
I have a NOS 3rd cap that I am checking to see if it will work. 4th main is an idea.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Jim Patrick on Friday, July 05, 2013 - 05:23 pm:

Is a ball or pin bearing for the 4th ball cap still discouraged? Awhile back it was determined that the babbited bearing is still the best bearing there is for this application for there is no modern bearing that can withstand the kind of abuse heaped upon it in this application. Especially a bearing most likely made in China. That having to support the weight of the heavy, rapidly revolving transmission on the lower portion only, can cause it to suddenly fail at anytime which it has done often enough to cause concern. I had purchased one of these modern brass, ball bearing equipped, ball cap and sleeve for my Model T, but when I came on the forum to asked a question about the instructions which said to cut out a 3/8" portion of the cap, I was discouraged by several respected members not to use it. To use the time tested babbited bearing, ball cap; so that is when I sent it off to have it rebabbited and am glad I did. Things may have changed by now, but in 2009, there were problems with the ball bearing type 4th ball cap. Jim Patrick


Top of pagePrevious messageNext messageBottom of page Link to this message  By Kohnke Rebabbitting on Friday, July 05, 2013 - 06:39 pm:

We have been making them for 40 years, and have never had a problem for fit, or had one fail, and you don't have to cut the drive shaft tube ball, but you do have to cut the tail shaft about .050, many need trueing any way.

Jim you have to consider your sources on who made the ball cap, and who installed it, and just opinion, compared to experience, and track record.

If some one says something is no good, ask your self Why?

Just like Babbitt, it stays in for some, and some it does not. Again, ask your self why.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Norman T. Kling on Saturday, July 06, 2013 - 10:42 am:

Most important problems you have are the clutch and the magnets hitting the magneto ring. You can adjust the magneto ring to proper clearance after you fix the rear main bearing. Actually the rear main bearing could be OK. Did you check for endplay? Normally the endplay would move the crankshaft away from the magneto coil, so it could be the coil is too close to the flywheel and shims need to be removed.

This problem is very important! You need to replace the brass screws holding the magnets to the flywheel. If the keepers have been scraping, the screws could very easily break off. Take some time to do the job right and you will be happy and your car will be happy. If you order the parts, and they are shipped promptly, you could be ready to run within a month. Better safe than sorry. This is a reason for having 3 model T's. One to drive, one to work on, and another for spare parts. Then you always have one or two ready for any tour or event.
Norm


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