I am a newbie re-assemblying a '26 transmission. The transmission clutch disc drum bearing was seized on the trans shaft and spinning inside the clutch drum. I bought a new bearing. I seems way too large to be pressed into the transmission clutch disc drum.
1) How much larger should the OD of the bearing be than the ID of the transmission clutch disc drum? (.002?)
2) How much larger should the ID of the bearing be than the OD of the transmission shaft? (.002?)
3) Can anyone recommend a reasonable machine shop in the Allentown, PA area to do the sizing for me and press the bearing into the clutch drum?
It needs to be a press fit between the bushing OD and the drum ID. press as in hydraulic or mechanical press. (vice or arbor press)
Thanks Mike. I read the thread. I understand the "factory" ID of the bearing should be .002 larger than the OD of the transmission shaft, but could be up to .008
How much larger should the OD of the bearing be than the ID of the transmission clutch disc drum?(It seems too big to be pressed in there)
Also, how much might I expect to be charged for sizing and pressing the bearing into the clutch disc drum? It will be my first visit to a machinist and I really don't want to get ripped off.
Correction: I was trying to figure out how to press the bushing into the clutch disc drum when it ACTUALLY goes in the clutch driving plate. It pressed in there with resizing. duh.
I told you I was a newbie!
Thanks again. I have to order a triple gear bearing. One was really sloppy!
Yes, oftentimes the bushings are to large OD for the press fit--this has caused many good steering spindles to split. I don't have a Machinist's Guide book, but I would think .002-.004 would be plenty for the press fit--I will, of course, defer to others who may have the actual interference fit numbers. It needs to press in enough to not spin in the clutch when the transmission warms up.
As to machine shop charges, gee, depends on a lot of factors--is he a buddy working in his own garage, or a bona-fide business? Does the guy like working on "oddball" stuff? Also, you might want to LIGHTLY run a hone in the clutch piece to make certain there are no burrs in there.
Dwight -- Check that triple gear pin for wear as well. It doesn't seem that they'd wear much with bronze bushings riding on them, but they do. The wear is typically on the inside-outside measurement of the pin, not side-to-side.
When you put it all back together, the triple gears need more clearance than other things -- about 4 thou, rather than the 2 you'd like to see elsewhere.
Thanks Mike. I will check the pins. I will make sure they are about .004. I just realized I need a pair of bearings for the new brake drum shaft. The catalog says one for each end. Do I press them in flush with each end?
I hope it is the last purchase. The spirit is willing but the wallet is getting weak!
Dwight, when I worked for a large work shop building engines and transmissions we had two ways of getting the bearing/bush ready to fit. There we had hot oil baths and freezer units depending on which way it had to go, for inside a housing put it in your home freezer then leave it for a day or so then have every thing ready (vice or press) then take it out and fit and press and it should go in much easier as the cold will shrink it (or depending were you are go and leave it in the snow but you could have trouble finding it again) for out side fitting it is the same idea with a small camp stove and a tin of engine oil (out side the shed just in case) and heat it up with the part in it till hot then the same process. I have used this to fit items with little trouble but made a good mess.. Ray
I would go for .001/.002 press fit on your bushing. Two thousandths would be considered a fairly heavy press fit. I would personally stay closer to .001. Check the I.D. of the bushing after pressing in place. It will have closed up some and may need boring/reaming to open it up to the clearance you want.
Thanks Ray and Jerry for the advice