T Transmission question

[James Rogers]

I just dismantled a transmission for a customer and found lots of brass in the oil pan when I removed it . Upon further inspection, all the parts of the ****** were scored and dry looking. The triple gear bushings were destroyed and cone shaped from being run dry. The teeth on the drum gears were worn to a point where they contact the triple gears and considered unusable. Even the flywheel around the pins had score marks from the triple gears and the pins were gaulded . The engine has about 1500 miles and looks really good inside. I only had to make small adjustments to any of the bearings so I don't think the damage in the transmission was from low oil or there would have been some engine damage. There are no magnets on the flywheel but it does have paddles to distribute the oil in that area .

Any help or even a WAG will be considered help and appreciated.

 

[Model T Monte]

James, I`m just guessing but it was probably not rebuilt when the engine was. Probably the 4th main already had wear plus the brass in the triple gears. The big boys with more knoledge will probably give you an accurate cause of eccessive wear an shoot me down on this. Aint those T`s fun? Monte

 

[James Rogers]

James, I`m just guessing but it was probably not rebuilt when the engine was. Probably the 4th main already had wear plus the brass in the triple gears. The big boys with more knoledge will probably give you an accurate cause of eccessive wear an shoot me down on this. Aint those T`s fun? Monte

The transmission was rebuilt 2 years ago along with the engine. It also has the modern style fourth main and the brass in the gears was supposedly replaced then. I do suspect the bushings were reamed instead of being fitted with a hone which is a bad idea but don't think this is the only problem since all of the transmission parts look like they have been oil starved.
So far T's are fun and I like learning new things. I hope to be rebuilding T transmissions for sale soon.

 

[Jack Innes]

James, Could it be due to someone using modern sintered bronze bushings of questionable quality rather than solid brass or bronze bushings? There has been earlier discussion on the sintered type not standing up. This would be accelerated if the bushings were fitted too tight - the gauled pins might indicate that. Oil will not work if there is no room for it to get in.

 

[James Rogers]

I could believe that if the 3 washers in the brake drum under the clutch hub were not worn and scored. Looks like the ****** has been run low of oil but, the motor does not .

Keep the guesses coming, we'll hit it sooner or later.

 

[John Otis]

My only thought is that babbit will survive with a minimum of oil where brass or bronze bushes will not. I think that the car was run quite a bit with low or no oil. As a side note, many years ago we had an old Ford Falcon that we were bringing to the dump to get rid of. After several beers we got creative and decided to drain out all the oil and start it when we got to the dump. Well after we dragged it there we started it and took the battery out to save and put a hunk of junk on the gas pedal and waited. After about half an hour we just left it, still running at about 1/2 throttle. Damned thing probably ran out of gas before it seized up.

 

[James Rogers]

What would cause this?

 

[BRENT in 10-uh-C]

My opinion is being driven with a weak Jack Rabbit clutch spring. The little girl that had been driving this car has allowed the high-speed clutch to slip for a few miles (i.e.: next rest stop) before she told her Dad. In her defense though, this transmission (from day one) would always slip when a quick Lo-Hi shift was made. The only way you would get a positive engagement was immediately after the pressure plate screws had been turned in ½ round, --and then only for a few miles until it got to operating temps again. After that, it was back to slipping unless the throttle was totally pushed up, release the low pedal and count to five before advancing the throttle again.

I will also add that I believe this issue is totally seperate from the triple gear pin/bushing wear issue.

 

[James Rogers]

I agree now that we discussed this. I still would like to know what caused the pin/bushing problem. The only thing I can figure is the bushings were reamed not fitted. I don't like reamers much.

 

[John Otis]

I totally agree with Brent and I stand by my earlier post. A slipping clutch could easily develop enough heat to render the oil pretty useless in its ability to protect much including brass bushes. Babbit could survive very well with broken down boiling oil though, which may explain why the engine is still OK. I cant imagine an engine getting hot enough to do that much damage unless it was boiling and screaming like a teapot.

 

[Adam Doleshal]

James, What could have caused the triple gear bushing problem were defective pins that were available from several vendors about fifteen years ago. They were turned instead of ground and would chew up new bushings and trash the rest of the gears in a couple hundred miles if you kept driving it... Also, there are more than a few vendors making their own triple gear bushings, some are using 660 bronze, some use something better, some use something worse. I stock triple gear bushings made from the exact same mix as Ford Z bronze. Surface finish and correct centering is also the key to longevity. I set up all gears and drums in the lathe, bore the bushing out just enough to establish a correct center in relation to the rest of the drum, then finish to proper size on a Sunnen honing machine. I always hone with a roughing stone until I am within about .0002" of my desired diameter, then switch to a finishing stone for final sizing. I then use a micro finishing hone about 8 revolutions in each direction which gives a near mirror finish and removes any burrs from the oil grooves in the bushings.

Looking at your photos (they are pretty dark and I can't see much), I wouldn't be suprised if someone made that bushing out of plain brass...

 

[Kohnke Rebabbitting]

James, I have seen this many times. Who ever done the trany, did not get the clearances right. The way you described the scoring fits it to a T, NO PUN. Even if the parts were all good quality. When the triple gear bushings seize on the triple gear shafts, they start turning in the gear, and will wear fairly fast. They then will go tapered, and wear the gear teeth as sharp as a knife on the ends. Jack, John, and Adam, are right, on oil clearance, no clearance= scored bushings, they are not as forgiving as babbitt. I really don't think the oil amount was wrong, as what you have there, would have happened regardless. Now Brent is very correct on the clutch pack. You can't wait until the clutch is slipping that bad to adjust it. If the clutch was that bad, a 1/2 a turn was NOT NEAR ENOUGH anyway. It would have been closer to 1 1/2 to 3 turns depending. A builder I know, sent me a bunch of pictures of a T engine that they just got in, that had very few miles on it. The motor block was recently done by a well known Model T God = cracks in the block, pistons to tight, scored, cylinders bored at an angle to the crank, rods out of alignment, ((( this happens very often, as some shops have old wore out boring bars that sit on top of the block, and bore the cylinders at a slant, as the boring bars bottom is not true any more from from being slid around on its hand scraped surface of the bar. If the top of the block has been surfaced from previous top resurfacing, and is not true to the pan rail, a top mounting boring bar will not work anyway.))) hard seats were way below the surface of the block so when they surfaced it, they wouldn't loose the carbide teeth out of their surfacer head. They had the whole engine plastered full of that TIME SAVER , even was bad inside the rebuilt Trany. Now the Transmission was rebuilt by another very well known Model T God, = triple gear bushings all spun in the gears, but this was a little different deal, as they must have been bad the first time, as they tried to solder the new bushings in the triple gears. The flywheel was cracked on both sides of each triple gear pin about 2" long each. All drums were cracked, Tail shaft was cracked in the rivet holes, boys when these bad parts come up through a hogs head, they are not good for a guys foot connection to his leg bone. The flywheel magnet plates were also touching the magnet coil. That is only part of it, but I am tired of the two fingered typing, thanks Herm.

 

[PaulWI]

That last story is just wrong. That is why I do all my own assembly and only sub out the machining. Just because someone is a "professional" doesn't mean they know what they are doing.

 

[John Otis]

Same here. I always figured that I would take a lot more time fitting things and putting it all together than someone in an engine shop.