Who is the tranny expert out there? Should my disc drum absolutely be press fit or not? How many discs should be inside the tranny and what thickness should they be?

Yes, it must be a tight fit. Either the drum, the main shaft or both are worn.
25 discs.

12 small disk (inside prongs), 13 Large disk
(outside prongs). drum ought to be a slight press fit.

That drum must be on tight, and it takes a puller to get it off.....if not, parts are worn beyond service.




Re-insert the correct number of discs back too,

Mine was a touch loose so I used loctite. I figured with loctite, the shat key and the set screw safety wired it would hold. So far it has, but of course, I can't see inside the bowels of the transmission to know if a future problem is lurking.

Mine was a tad loose too. No puller needed to get it out after initially breaking it loose, but it didn't rock back and forth either. Just a sliding fit. I put Loctite sleeve retainer on mine and put it back together. Been going for two years with no problem.

This is another one of those "Right way vs. good enough" decisions. If money is no object, you don't enjoy tinkering, you want to put the thing together and never have to even think about it again in your lifetime, then get parts that are to spec and do it the right way. If your on a tight budget, do enjoy tinkering, ain't afraid to have to pull it apart again a few years down the road and would rather be driving it now than than letting it sit until you can afford all the new parts, use some Loctite and/or prick the shaft a little with a center punch to upset some metal (Shadetree knurling job) and put it back together.

I fit in the second category. I once had someone tell me what it would cost to have an engine and tranny built professionally. I d@m near died at their estimate. I had paid less for the whole truck and it was still running, was just tired. I bought a rebuildable engine, bought the parts, had the machine work done locally and put it together myself for a third of what that guy told me. Drove it to breakfast that morning. Swapped the engines that day, and test drove it that evening. Had about 8 hours of downtime. Still runs fine. Might quit today, but for the moment, runs fine.

You just have to decide. Are you building a Montana 500 car or something to put around town in and have some fun?

Come on guys, how much does it cost for another disc drum?

Don't know. Never had to buy one.

Richard,

Sorry if that sounded rude. That was not my intention. I should have included a ;-).

Hal

No offense taken, Hal.

What's the hazard if it isn't press fit? I don't think mine is.

rdr

I had a loose one years ago and the back and forth movement enlarged the set screw hole. It eventually allowed the disc drum to move rearward enough to allow the front disc to jam up between the disc drum and brake drum. Locked up in high gear requiring a complete tear down to fix it. Ruined the trans shaft and a couple of discs. Really had us baffled for a while.

I have pull down and rebuilt several veteran T trans, have found that once the puller has cracked the old tight fit, they have never been any more than a light tap to reassemble.

Kerry, perhaps I have been lucky but that has not been my experience. ;^) Only occasionally have I found them to be a light tap fit. Most of the time it takes some pretty good pounding with a hammer and pipe. (I install the disc drum after the flywheel and trans shaft are assembled onto the crankshaft and use a pipe with an ID larger than the trans shaft)

Mine only pressed on the last 3/8" or so on the shaft.
It was reccomended to use some permanent locktite on the shaft and dude.....that sucker aint coming off now! Use the locktite FOR INSTALLING VALVE SEATS. I wanna say it's the Loctite 640 or something?

Be sure you change those three washers behind the drum, I'd think it'd be best to have fresh in spec ones back there. Coat the inside of the inner drum with a thin coat of locktite and the shaft then quickly slide and tap on. Quickly set the .002" clearance between the washers too.

A good tip is to coat the washers with oil and the upper one (that contacts the inner drum) with vaseline or grease. What's gonna happen is some locktite will drip on it and cause it to snag. This provides a barrier to prevent that.

Add a little bead up top between the shaft and drum and let it seep into any voids. particularly around the key way.

Patrick, did you have time to set the .017 to .027 clearance between the washers and disc drum before things set up?

Yep, thats what I was saying by "Quickly set the .002" clearance between the washers too.". Don't know why I said .002" but I picked the mid part of the clearance range and set it at that. You have about a minute before it becaomes immovable then you still need to give it 24hrs before you apply and torque to it.

*becomes
*any torque to it.

If you use locktite on it, how will you ever be able to pull it next time you work on the transmission?
Norm

Norm,

Heat.

Ditto.....

...Heat

You shouldn't have to work on it again if you do it right.

The clutch hub is supposed to be tight on the trans main shaft. If it is not something is wrong. You should have to use a puller to remove it. That being said, you can install the hub with Loctite with good results. Green " Sleeve Retainer" Loctite is best for this.
Fordially, Erik

I'm in the process of rebuilding a 26 trans.
Does anyone know the size of triple gear shafts? Also are the bushings supposed to float in the gears as well as turn on the shafts? Any info is appreciated. Thanks

Bushings should be a press fit into the gears and rotate on the pins.

I don't know the size of the pins but they are about .003" larger in diameter than the originals. I think Dan McEachern carries different sizes. Sometimes the increase in diameter is enough so you don't need to replace the TG bushings. Strive for an honest .004-.005" clearance. Don't measure with feeler guages. Risky going less than .0035" if you're using new bushings, but you can go a tiny bit more. Original bushings can go a bit less.
As Hal mentioned, the bushings must be a press fit on the gears.