Triple gear bushings

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Model T Ford Forum: Forum 2014: Triple gear bushings
Top of pagePrevious messageNext messageBottom of page Link to this message  By Dave Loving on Sunday, September 07, 2014 - 10:59 pm:

When I took the transmission off the flywheel, the triple gears fell off, but the bushings remained on the pins.
The OD of the bushings have been knurled. Would a bushing supplier knurl a bushing, or do you think when the transmission was rebuilt they took a used bushing and knurled it in hopes of getting a good press fit into the gears?
The engine/transmission was rebuilt by a professional Machine Shop.
Used triple gear


Top of pagePrevious messageNext messageBottom of page Link to this message  By Ted Dumas on Sunday, September 07, 2014 - 11:12 pm:

It could be the bushings were fitted too tight, they froze on the pin and rotated inside the gear. A "professional machine shop" or a "shade tree mechanic" may or may not know what they were doing.

You can likely fit new bushings and ream to a clearance of 0.004 if the pins are round and not tapered.

It could be the shop reamed the bushings to what they thought was too much clearance, then pressed them out and knurled the outside diameter so the inside diameter would shrink. They then did not allow enough clearance so they seized on the pin and rotated on the knurled surface instead.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Glen Chaffin on Monday, September 08, 2014 - 11:00 am:

Listen to Ted, A bushing will not seize on a pin unless it is too tight. There is a heated argument going on on the forum about this very subject right now. But people won't listen and still set there bushings up too tight. The result is always the same. Seized bushings. The gear is supposed to rotate on the pin not the bushing. We have rebuilt hundreds of transmissions using 0.004 clearance and never had a failure or seized bushing. Unfortunatelly, some on this forum like to argue with success.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Mark Gregush Portland Oregon on Monday, September 08, 2014 - 11:07 am:

Did you knock the pin out or did it fall out? If it fell out the hole in the flywheel at this point will be too big to hold another pin and you will need another flywheel and start fresh. If you pressed it out you may need to find the next size up at the big end to press back in. The pin is a press fit and when they are installed/removed enlarge the hole. Are the cracks in the gear or bushing?


Top of pagePrevious messageNext messageBottom of page Link to this message  By George_Cherry Hill NJ on Monday, September 08, 2014 - 11:39 am:

Dave

Good info in the replies so far.

Before I would offer any further advice, I need some further input. What exactly is the picture showing me? Something just does not look right. Looks to me like a pin and a gear with the bush missing, flywheel side facing up...but then what is that mushroom looking surface??


Top of pagePrevious messageNext messageBottom of page Link to this message  By Kohnke Rebabbitting on Monday, September 08, 2014 - 12:34 pm:

What is in the picture is a oil-lite Bushing that was offered in a set a few years ago.

When used, they all end up looking like that, and are very Brittle!

They were also made with out Grooves, they are junk.

It also looks like the pin and gear are both up side down in the picture showing the way they were running.

They would end up like that no matter how much clearance you gave them.

Herm.


Top of pagePrevious messageNext messageBottom of page Link to this message  By George_Cherry Hill NJ on Monday, September 08, 2014 - 12:57 pm:

Herm,

Thanks but look again...if that is the bush still in the gear...then someone is in the middle of drilling it out, or that specific sucker wallowed to a huge clearance!

In which case Dave should be starting from total ground zero on his rebuild as other things are going to be so far out of whack!

I have my glasses on and nose near the screen, still looks like a lot of air showing. Maybe I'm not seeing it right?


Top of pagePrevious messageNext messageBottom of page Link to this message  By Kohnke Rebabbitting on Monday, September 08, 2014 - 01:05 pm:

Dad had driven Model T's from the time he was 9, until he was 22 which he had a New 1925 touring.

They lived about 12 miles from Masnon, Iowa, and every Sat. morning, when he was 9 on up, with the roads they had drove in low gear there and back.

Also the Cop would crank the car when they left town.

Looking at the picture again, the bushing may not be oil-lite, as there were also a cheaper bronze, or Brass for a while, and had no oil grooves, but that was all I could get, so I waited.

You are right George, I posted right after the last one but I posted on the wrong Post!

I do not think it was drilled out, I think it just wore that far out.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Scott Owens on Monday, September 08, 2014 - 01:21 pm:

Looks like Glen has just done a rebuild and it will go for 20 years now. 40 years will give you an eye for detail. Scott


Top of pagePrevious messageNext messageBottom of page Link to this message  By Glen Chaffin on Monday, September 08, 2014 - 01:21 pm:

Never use oilite bushings. Another real bad idea by one of our so called experts. It's amazing how much trouble the experts cause. Stick with what Ford did when ever possible . It has lasted a hundred years. Even the 660 bushings made by Bob's lasted a lot longer than the oilite.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Dave Loving on Monday, September 08, 2014 - 02:07 pm:

Sorry, guys, I attached the wrong photo.
I took those gears out one year ago. Both that set and the set I removed last week were done by the same machine shop.
I do not believe the bearings in the photo are Oillite, brass perhaps. But without oil groves.
The current transmission problem is loose bushings in the gears. When I took the transmission off, the gears came off the pins, and the bushings stayed on the pins, the pins did not come out of the flywheel, and measure up OK. They look fine.
The clearance between the pins and the bushings was .010
The clearance between the bushing and gear was .040 !
My basic question was whether or not any bushing manufacturers Knurl the OD?
I apologize again for leading you astray with the wrong photo.

Regards,
Dave


Top of pagePrevious messageNext messageBottom of page Link to this message  By Steve Tomaso - Milton,WA on Monday, September 08, 2014 - 02:27 pm:

In my experience with triple gears that have had the bushings spun in is they are to be scrapped UNLESS you are or have an acquaintance that is a machinist to custom make & fit new bushings - you need to locate and/or purchase a replacement set of gears that will accept a new bushing that needs to be PRESSED in. Your opinion may differ !


Top of pagePrevious messageNext messageBottom of page Link to this message  By Dave Loving on Monday, September 08, 2014 - 02:40 pm:

Steve, I agree.
I am not putting the old gears back in.
Dave


Top of pagePrevious messageNext messageBottom of page Link to this message  By Glen Chaffin on Monday, September 08, 2014 - 03:11 pm:

Dave, No, triple gear bushings are never knurled. Sounds like your so called rebuilder used used worn out bushings. New bushings are always a press fit and don't need knurling. But the question is why did they seize on the pins. If they were used they should have been loose on the pins. However, the pins available today are standard size but the only pins available for many years in the past were 0.002-0.003 oversized so these are probably what they used which eat up the clerarance. One thing is for sure, only bushings with inadequate clearance will seize on the pins. So just buy new bushings from Snyder's or Chaffin's and ream them to 0.004 and you will not have anymore problems. However, you must also have adequate oiling. You should never remove your magnets from the flywheel without replacing them with at least four large oil slingers. This is a mistake that many make. You must sling oil back onto the drums or you are sure to have problems. Simply leaving the aluminum magnet supports on the flywheel will not provide adequate oil as they simply churn through the oil and do not sling oil. So be sure and install real slingers.


Top of pagePrevious messageNext messageBottom of page Link to this message  By George_Cherry Hill NJ on Monday, September 08, 2014 - 03:17 pm:

Okey doke...with that in mind, knurled were never standard issue, yet if you tear into enough of this you'll always come across a knurled one here or there used in some prior rebuild!

FWIW I did a blind test study of used pins and matching bushes about 2 years ago...I was up to about set 40 when I pulled the plug. I knew not from where they came each had unique zip tie arrangements when received. This was paired set #1. Look close at the picture below and what do you see? Knurled bands around the bush OD. I'd need to look elsewhere, but I think the chemistry of the pin was NOT OEM.

As to knurling,I am not sure why...I can accept that knurling is a poor-mans make-up for a ream job gone bad, but while the knurl now gives interference, the contact area is reduced by 30-50% if it is a deep or diamond knurl, d'uh! I can also relate and say that knurling was a bit of a signature for some...if you have never knurled before its not all that easy to get a good balanced knurl first time out the gate. I personally know the guy that built and blue-printed the engines on all of the Mopar national race winners. I knew him because he worked for me during the day, did his engine work nights and weekends. Tommy C. knurled a single row quadrille 20 thousenths deep on piston skirts on every engine he even built! He did his knurling during his day job and I let him. I asked him one day why he went with the quadrille pattern, why so shallow yet perfectly uniform, was it to be an oil keeper to help with piston slap on starting?

Nah he said, this style of knurling was his signature and anyone ever taking one of his engines apart would know that he built it!

OK, before you go further, the bush to the gear has a required ID prior to inserting with an insertion tool. You can search for the interference fit and if you come up blank seem me a private message and I'll send you the design fit. You say that the pins in the flywheel seem good and tight, but I'd still micrometer them in the 12-6 plane and 9-3 plane and post your results here. If they are original Ford issue, chances are they are still pretty round and still pretty close to size...if they were replaced at some point in their 87 year old life...chances are they are the dirtiest cheapest steel possible turned from yard scraps. These dirt ones always seem to lose size when there is a biter! Surface finish is critical, and you are going to have to determine what best to polish with.

As far as clearance between bush and pin...well...the other thread sort of beat that one to death with everyone actually agreeing as to 'size' (even me) but everyone debating what it should be called! Whatever you do, when done do the spin test as suggested. DO pay attention to the oil groove and make sure it is smooth with open ends...do face cut the new bush flanges to both square and have a fixed distance to a known gear surface.

BTW...the gear design hole should be a .999/1.000 ream at diameter. The bronze bush OD should be 1.0045/1.0055 and DO use an insert tool to keep the ID from shrinking crooked, then ream the bush to the desired diameter for that 3-4 thou clearance.

Get that far and come back with any questions.....



Top of pagePrevious messageNext messageBottom of page Link to this message  By Kohnke Rebabbitting on Monday, September 08, 2014 - 04:06 pm:

There are a lot of gears that have a over size bushing hole in them, and over the years I have learned to check the O.D. of the bushings as they are not always on, like most repro. parts.

I have also seen knurled bushings come out of gears, but when we find a O.D. off on the bushings, we send them back.

Herm.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Kohnke Rebabbitting on Monday, September 08, 2014 - 05:11 pm:

I just thought of something, I know the Wilson reamer's cut .003 thousandths over pin size. I got two N.O.S. many years ago, from Rollie Rebers, from MN. a friend of mine. They were all wrapped in greased Brown wax paper.

I also got a set from another guy , who is gone now, he dealt in all kinds of old tools, that was a used set in good shape, but had, and has a little rust in places but doesn't hurt anything. I have had them sharpened about 3 times.

As you see the shortest reamer is the one I am talking about. It still cuts .003 over, but it is getting short, and had to come in from the back side to clean up the other end the way it should be.

The reamer Jig I got from Dave Houston, many years ago.

Well, I got a set of N.O.S. triple gears out of a town about 40 miles south of me, when I was a kid.

That was when times were easier then. I found the stuff, and Dad paid for it. Man, worked great!

The gears come, as did all the N.O.S. Drums, Tail Shafts ect. that I have had over the years, all ready to go, bushing's were cut and reamed.

I measured the bushing thrust over the gear, and they are all about .008 thousandths, and all 3 of the K.R.Wilson reamer's fit the hole just like I had just reamed it myself.

And pictures.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Dave Loving on Monday, September 08, 2014 - 05:22 pm:

Let me clear up some misconceptions, I apologize for not making things more clear.
The Pins did not come out of the flywheel (The photo I posted was a mistake, that triple gear came out last year, same machine shop did both).
Last week when I removed the Transmission, the bushings remained on the pins, but were not seized, there was about .010 difference in dia. between the pins and the bushings.
The pins currently measure .675 and are round.
These are new pins installed in the flywheel about 3 yrs ago, the flywheel was not installed in the engine until last July after my other triple gears failed (see photo of one of those gears at the start of this thread).
I have a set of new triple gears reamed to .679 that spin freely when rotated.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Kohnke Rebabbitting on Monday, September 08, 2014 - 05:46 pm:

Wow, I have never seen pins that small as .675, unless wore, as Fords were .676-50 to .677, all the N.O.S. I have measured.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Ted Dumas on Monday, September 08, 2014 - 06:38 pm:

With the 0.004 clearance, you should be good to go. My rule for any Model T transmission bushing is better a touch too loose than a touch too tight. I assume that the bushings actually pressed into the gears without knurling or any other monkey motion.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Larry Smith on Tuesday, September 09, 2014 - 10:16 am:

Maybe the reason someone knurled the bushing is because it wasn't a press fit in the triple gear.


Top of pagePrevious messageNext messageBottom of page Link to this message  By George_Cherry Hill NJ on Tuesday, September 09, 2014 - 12:31 pm:

Hey Herm...

They do wear, if they are not Ford original material...

What do you think of this one? Of course it is used and was run hard and put away wet...but it wore to 0.018" total clearance before it stuck with a bite! (meaning it lost its ability to lube)

I found this one to be very curious but never revisited it. Look at hardness. Have to figure it started life normal and at Rc within +/- 2 of average. Something drew some hardness out and only a guess, but the heat of a long 'skip'/'dry spot'? The sample was stuck to the bush but it didn't weld itself together, it was stuck even with that broad clearance, but I was able to break the 'stick' with a near gorilla twist that almost needed Channel Locks! I don't know if the anneal spot on the pin was the point of 'stick' but 'something' drew the surface out there...
I don't know actual events, all of the tests I did were 'blind', I just have pix of 'as received' to identify them.




Top of pagePrevious messageNext messageBottom of page Link to this message  By Kohnke Rebabbitting on Tuesday, September 09, 2014 - 01:42 pm:

Good read George, easy to under stand. Wow.

Herm.


Top of pagePrevious messageNext messageBottom of page Link to this message  By George_Cherry Hill NJ on Tuesday, September 09, 2014 - 02:27 pm:

Herm,

I found the chemical composition for the pin using a vacuum mass spectrum analyzer that we use for Benz. (OBLF German Analyzer Unit)

I couldn't/can't do the bush as the baseline program on the analyzer is calibrated for Benz based on Fe primary, and if I have it recalibrated for some component of bronze as baseline, I lose continuity with Benz. NOT!

I sent a few of the trial bushes out at 200 a pop for each chemical wanted using the older chemical reduction methods via traceable way...wanted to prove whether Z or something else since history on the trial samples is not known...and that got old real quick in the ka-ching department.:-):-):-)

Unfortunately I don't think Sample # 3 Bushing was one of them.

Thanks for the complement...here is the crib sheet for the dimensional source location on the bush...forget it before...now you have a complete set

So...


Top of pagePrevious messageNext messageBottom of page Link to this message  By Ken Kopsky, Lytle TX on Tuesday, September 09, 2014 - 04:21 pm:

Who did the metal analysis? The carbon and chrome figures can't be right. That's barely above cold-rolled A36 steel quality. I don't see any Vanadium either. No wonder the hardness is all over the place. That H2 number is well below most mill state hardness numbers for steel I would expect to be used there.


Top of pagePrevious messageNext messageBottom of page Link to this message  By George_Cherry Hill NJ on Tuesday, September 09, 2014 - 04:53 pm:

Ken,

I pre-stated that if they wore by a lot, they were NOT Ford issue. My own personal experience is that OEM pins hardly wear at all in size, rarely go eggy.

With chemistry such as this, the only conclusion possible would be that the pin was an aftermarket pin of some 'other' metal.

The protocol called for every volunteer to go through the mass spectrum device and let the chemistry itself allude (on not) that it was an OEM pin!


Top of pagePrevious messageNext messageBottom of page Link to this message  By George_Cherry Hill NJ on Tuesday, September 09, 2014 - 05:11 pm:

Oh, BTW Ken you're right, Pin #3 was made out of junk steel! I'm actually curious as to how they managed to get a core hardness. But then again, I would have had to cut pins in half longwise and do another Rc check to see if it was real hardness.

The testing was done on the same analyzer and same protocol basis that day in day out does work for Mercedes Benz and does work for Brembo. I'm a Tier 1/most favored supplier status to both...don't even need 3rd party inspection as some do. I'd personally trust the lab numbers found!


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