Questions re triple gear bushings & thrust washers

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Model T Ford Forum: Forum 2013: Questions re triple gear bushings & thrust washers
Top of pagePrevious messageNext messageBottom of page Link to this message  By Chris Bamford, Edmonton AB on Thursday, January 17, 2013 - 08:28 am:

Back in the fall, I had my '26 Touring running on stands while I adjusted the bands and clutch linkage. After a few minutes of this there was a groaning noise from within and the car stalled. I pulled the transmission inspection cover to find a hot smell and much smoke & fumes. Subsequent investigation revealed there was (I can be such an idiot sometimes) almost no oil in the engine and the radiator was largely blocked.

After cooling down and oiling up, the engine seemed to run smooth and quiet but maybe a bit down on power. I had to readjust the low band soon after which led me to suspect and find a cracked low speed drum.

I have acquired one of Dave Nolting's beautiful replacement drums and a set of Guinn wood bands to replace my Kevlar. Over the last couple days I have the engine out and transmission apart there are a number of problems within, and I am hoping to find out if they all stem from the low-oil running or if there was something else that must be corrected as well.

The engine and transmission were rebuilt in 2010, perhaps 3K miles ago. Triple gear bushings were given 0.004" clearance (on the diameter) and faced to stand about 0.008" proud of the gear. Three new thrust washers were installed but the play between the clutch and brakes drums seemed high at 0.035" so I added a 0.013" shim washer to bring the play to 0.022" (I may not be able to track oil levels but at least I can make notes).
_ _ _ _ _ _ _ _

Yesterday I found that:

All triple gear bushings spun freely on the pins and also in the gears.
All pins miked at 0.678" dia
One pin was blued with heat this bushing would spin but didn't want to slide off.
The thrust washer pack (three from the vendors plus my 0.013 homemade) is 0.133"
The triple bushings were now flush with the gears and all three gears had worn into the flywheel
_ _ _ _ _ _ _ _

My questions:

1. I would like to reuse all three pins (and not disassemble the flywheel with its perfectly-set magnets). Can I use that heat-blued one if I can successfully remove the bronze galling you see in the photo

2. Would the triple gears would wear into the flywheel just because of overheating the mechanism... or could this problem be related instead to my extra thrust washer, even though the clearance seemed OK.

3. The thrust washers look a bit overheated still OK to use?

4. Should the brake drum thrust surface be re-faced smooth?

5. All other comments and suggestions welcome!








Top of pagePrevious messageNext messageBottom of page Link to this message  By joe bell on Thursday, January 17, 2013 - 08:34 am:

When a triple gear pin has got that hot the heat treating has changed and the pin is now softer or harder, you take a real good chance of that pin breaking and making a real mess of other things. I know it is not what you want to hear but safe if always better. And you have it out right now, so much easier to fix it right when it is right there in front of you!


Top of pagePrevious messageNext messageBottom of page Link to this message  By Ricks - Surf City on Thursday, January 17, 2013 - 10:10 am:

After I removed a seized bushing last year, Chris, I found the pin badly galled. My fix was Dan MacEachern needle bearings using his new pins. The tranny is now the quietest it's ever been.

Are you coming back for this year's annual inspection tour? Orange County's was last Sat, and LB is this Sat.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Charlie B actually in Toms River N.J. on Thursday, January 17, 2013 - 10:46 am:

As you said: low oil & poor cooling = the pin gauling and discoloration. The thrust washers are out in my book.(cheap) The pins? Toss-up. Don't look overheated & the gauling might just be lack of lube. I'd can at least that 1 bushing though.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Steve Blancard on Thursday, January 17, 2013 - 11:33 am:

I just went through the same thing with one very frozen bushing and badly blued pin (actually still working on it). I just removed 2 magnets and pressed the pin out.

pin


Top of pagePrevious messageNext messageBottom of page Link to this message  By Paul Allen Vitko on Thursday, January 17, 2013 - 12:23 pm:

I would suggest you look at "What am I looking at" January 13 of this month. Buy a book called Audel Millwrights and Mechanics Guide, it lists reasons for plain bearing failure

From your pictures it appears to be lack of oil but look carefully at the pictures posted.

The Tulsa boys use timesaver-----so will I!


Top of pagePrevious messageNext messageBottom of page Link to this message  By Kohnke Rebabbitting on Thursday, January 17, 2013 - 01:13 pm:

The 4th picture down, shows the brake drum bushing. That bushing should be left out, as it is not needed.

When it is left out, that leaves a big gap for oil to get into the remaining bushing, not just the little hole, and you only need two bearings to support the main shaft.

One bushing in the brake drum, and one bushing in the drive plate.

We haven't used them since the 60's.

Triple gears always wear when the clearance is to great on the shaft, and the push is always in one spot, and when they have to much clearance, they will dig into the flywheel.

End play, on the main shaft, at the clutch pack, should be .015, after that there is a lot of unwanted, or needed slop.

When you run out, or low on oil, then nothing is safe.

Herm.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Chris Bamford, Edmonton AB on Thursday, January 17, 2013 - 05:48 pm:

Thank you everyone for your comments and suggestions.

Ralph, won't be seeing you guys at the Inspection Event we went to Hawaii instead this month. I've sent an inquiry to DMacE.

Thanks Paul, good reading and I too will use TimeSaver if going with bronze bushings.

Herman, that is an interesting suggestion. I guess there is no particular lateral load on that hub so taking out the rear-most bushing shouldn't hurt. Anyone else weigh in from experience or otherwise on this approach?

And a special thank-you to Dave from Chaffins who took the time to call me this morning and discuss the situation and, particularly, to ask if that was a flywheel crack in picture 1 at 2:00. Danged if it isn't much easier to see in the photo but there all the same, right through the pin hole. There's a second crack too, at 7:00 from the bolt hole to the bore. Crap.

Anyway, I found another flywheel locally that I'm picking up Saturday. This has turned out to be a bigger job than expected... that ever happen to you guys?


Top of pagePrevious messageNext messageBottom of page Link to this message  By Roger Karlsson, southern Sweden on Friday, January 18, 2013 - 04:39 am:

Chris, in a service bulletin Ford suggested you remove the rear bushing on a wide brake drum when rebushing a transmission. Here is an earlier discussion on the subject: http://www.mtfca.com/discus/messages/29/31393.html?1181962825


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