My Tractor Forum banner

So you want to rebuild a T head bottom end

10K views 13 replies 7 participants last post by  aweiss44 
#1 ·
#2 ·
That's great stuff, Roger. I'm hoping we can have a dialog about home rebuilding L model bottom ends and it can be made a sticky. :) Until very recently I've seen anything to do with flywheels as beyond the scope of the average enthusiast, requiring an expensive trueing stand, etc.. :Stop:
 
#3 ·
Wow, very informative, Roger!

As it happens, I've been thinking I might try to rebuild the leftover bottom end from the L8 from ****. I will for sure check back to that sequence!
 
#4 ·
An amateur question, is there no gasket between crankcase halves?
 
#5 · (Edited)
Nope, there is no gasket.

The halves were machined well enough to only require some Permatex number 3 or what is now called Permatex Aviation.

Permatex Aviation Form-A-Gasket® No. 3 Sealant, available at most auto parts stores.

The bolts holding the engine to the chassis clamped the halves together, and the Permatex was applied to the halves just before final assembly.

Careful how you pry the halves apart, you do not wish to mess up the sealing edges.

Roger,
 
#7 · (Edited)
Max,

Added later... Sorry, I meant 'copy and paste' in this procedure.

In this thread or tall tale or lies, when you click on the link to the photos and your computer takes you to the photos, then just right click on your browser address bar, it should highlight the address of the photos, while right clicking, select copy and save/paste that address somewhere on your computer that you can find.

You can even save/paste addresses to 'Notepad' on your computer, you gotta give the address some sort of name that you can remember when you save the file. Later you open Notepad again and look for that special name/address you were trying to remember.

There are many more fancy ways of saving all kinds of internet stuff, but that is one simple way.

Oh, Permatex number 3 is a little thicker than gasket shellac, seals the cracks a little better, does not harden, nor does it mix with oil.

Roger,
 
#8 ·
I sure wish there were such a detailed layout for going into a 400,800,8000, and G transmission. I will have to do that this coming Summer. I like how the basics and tips are there and then illustrated with pictures and graphics on the pictures. Great layout Roger.
 
#9 ·
Sorry Al,

I did own a great Onan powered 816 with hydraulics, but I never tore it down for a rebuild.

I have played with a few two wheelers.

I wish you the best on your project, all you need is a good camera, photo editing software and maybe good word processing software.

Roger,
 
#10 ·
Sorry Al,

I did own a great Onan powered 816 with hydraulics, but I never tore it down for a rebuild.
Too bad Roger. Us rider guys would profit if you had. Marc's posts help a lot, but I would like to see the splitting/opening of the trans layed out the way you did this.

I have played with a few two wheelers.
More than a few from what i have read

I wish you the best on your project, all you need is a good camera, photo editing software and maybe good word processing software.
I'm probably not the one to be posting much help. I have been fooling around with some free downloadable editing software in an effort to explain my questions better. I post my rookie questions hoping someone else out there is interested and will learn in seeing my questions answered. MTF is a great place to learn.
 
#11 ·
Another basic question, when Harley flywheels are trued, it involves a dead blow hammer of some kind. Any hammering needed to true Gravely wheels?
 
#12 ·
Roger, thank you for such a great series of pics and explanation to go with them. Thank you even more for sharing them with us.

This thread is now stuck guys. :fing32:
 
#13 ·
Phil,

Remember now, you gotta pick up this torch somewhere in the future. I will be glad to just dump ‘stuff’ on you.

About aligning flywheels, we talked about the two alignment planes, and that everything works around the crank pin.

A crank pin has an oil inlet galley in the ‘front’ end; the oil comes from the drive pinion shaft, through the front flywheel, but I will tell more tall tales about that later.

The alignment of flywheels, flywheels have a center bore hole for either drive or timing pinion shafts and away from the center of a flywheel is the bore for a crank pin.

There is some special hoopla about dynamic and static balancing of flywheels to connecting rods, and I always trusted Gravelys engineers; hey, their work has lasted how many years?

But we were talking about the alignment of flywheels, so let us consider how the two flywheels are held together. The flywheels can only pivot on the crank pin, and if you stop and think about that, then ninety degrees away from the crank pin is where the ‘greatest degree’ of deviation could occur; but then we can throw some more poop into the equation, the two flywheels must be parallel to each other.

Using a Carl Sagen, “imagine if you will” that there was some piece of crud or whatever in the mating of a flywheel to the crank pin; that would ‘tilt’ the alignment of a timing pinion shafts how much? When timing pinion and drive pinion shafts share the same imaginary center line, then the flywheels are perfectly aligned.

Back to alignment, set the flywheel assembly, crank pin down on a clean surface; studying the assembly profile from one side, determine which flywheel ‘sticks’ out more than the other. Smack the offender with a soft hammer or a hammer with something soft in-between ninety degrees away from the crank pin on the offending wheel, until the two flywheels shadow each other perfectly. Or until a straight edge on the outside flywheel surfaces sits perfectly square on both wheel outside edges.

Roger,
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top