My "new" 1872

[jbollis]

Originally Posted by Matt G.

Bill-

It'd actually be easier to do what you want to do...mine's getting a bit complicated because I'm dealing with a super. You could leave the pinion alone and change ring gears.

Matt,
So if one were to be using internals from say a 1211 aluminum rear to put into the cast iron rear. Then the carrier assembly is all that needs swapped, not the pinion ? If so,this is good news. Then as long as the shims are kept in the same places, it should be easy. I would still check the gear mesh to be sure, but it should ( set it self ) so to say, if the pinion gear does not need changed.

Does this sound right ?

Also were can I download/copy the manual for this ?


Thanks JOE

[Matt G.]

Methos-

Not quite that easy. I'm putting in different parts that came out, so I may have to re-shim the pinion to get it in the proper place. The IH rears had numbers stamped on the pinion shaft and case, and a process for shimming it, but I have to use the MTD manual trial-and-error process since I'm using the innards from an aluminum rear.

jbollis-

If you're building a rear for a standard GT (as in, NOT a super) and you're using a GT aluminum rear and a GT iron rear, you can leave the pinion shaft in there and just put the ring gear from the CI rear's carrier on the fine-spline carrier from the aluminum rear. You would still have to play with the carrier shims because you are putting a different carrier in the case. It can't fully set itself, because the side-to-side location of the carrier will change the contact pattern.

I was going to use the original pinion shaft, but I can't since the ring gear that goes with it has a crack in it. I don't know if this is just the aluminum rears in the super, or if it goes for all aluminum rears, but the driven reduction gear is 0.100" thicker than the same gear in the iron case, so I'm going to have to pick up some shims to get that where it belongs.

You can use this manual for the iron rears and this manual for the aluminum ones. They disassemble differently.

[jbollis]

Thanks , That sounds like what I was thinking for the carrier. I am building this for my 1872 super. I am starting from scratch, just a bare frame, so I do not have the rear end or hydro pump for it. So I am going to build the cast iron one and use a hydro pump from a regular gt (most likely either a 1211 or a 1282).

Thanks again JOE

[Matt G.]

Ok, anyone who's done something like this before, how's this look? Looking for opinions before I go any further. This looks pretty good to me, but I've never done this before, so...

[Matt G.]

Ok, here's a bit more info. I set up the dial indicator like so, and measuring it this way, I've got 9 thou backlash. Manual spec is 3-8 thou. I think I need to move some shims around, but now I don't have the right assortment to do what I think I need to do.

[Amigatec]

From what I see the pattern looks ok. Most of the gears I have setup were hypoid gears. Most rearends gears will make more noise in reverse, but most are hypoid.

[ol'George]

What works well for me over the years,
is to shoot cheap white spray rattle can on a clean ring gear.
(in the day we used white or red lead) but hard to come by today
Then restrict the ring gear while turning the pinion, then read the ring gear tooth contact.
This leaves a real nice clear pix of what is going on,as far as tooth contact.
the procedure gives a sharper immage by slightly preloading the gears.( only need to paint 5-6 teeth)
Guarantee it won't howel @ 60 MPH Ha,LOL!

[Matt G.]

Finally got back to this, as I spent the last week getting 6 tractors ready to leave today. They're gone, so now I can move on with this. I re-shimmed the carrier, and now I've got ~3.5 thou backlash (acceptable range 3-8 thou) and this:

How's this look?

[Methos]

Looks real good Matt! Very nice pattern.

[Elephants1772]

Originally Posted by Matt G.

as I spent the last week getting 6 tractors ready to leave today. They're gone

Does that mean you sold 6 cubs, or they were customers, that you repaired, I heard that you go threw a lot, but was wondering, if the "bizz" is restoration, or major fixation.

Thanks
Cody