My "new" 1872
 

I've started fixing the 1872. I was hoping it wouldn't need much and would be ready to work. Unfortunately, there's a lot of things that need fixing. It was running and driving, but the oil smells like gas, so that's going to get changed. The PO must have been a bit lazy when it came to draining oil:

Here's the adjustable carb I rebuilt to replace that POS Walbro:

The engine needs a bit of cleaning, and I need to add an inline shutoff valve and replace the grommet for the tank shutoff...it leaks badly at the moment.

All of the tie rod ends need replacing, and will be replaced with heim joints, and the steering cylinder rod ends are also shot.

This tractor will be getting an iron rearend, as a result of what I discovered when I looked under the tractor:

Ok....how come I can't see your pictures Matt??? what you hiding?

Nice project Matt, I'm glad to hear we share similar feelings towards walbro carbs. I guess you may have read about my recent encounter. Looks like it's time to get the pressure washer out.

Keep us posted.....Wayne

red X's for me to.

Guess were not members of a country club. lol! :bs:

Ok, I fixed it.

Let's see, where should I start...can't adjust it. Every one I've had has caused the engine to idle weird. The 1811 I used to own, and mowed with for years, surged at times and wouldn't idle right. Right before I sold it, I put an adjustable carb on it, and that was the best it ever ran. The M18 in my 782 still has the Walbro on it, and it runs too rich. Consequently, the only time it runs right is in the winter. It runs terrible in hot weather. I also don't like the plastic float and non-replaceable seat. I have also had a hard time getting carb kits for them. I order a kit that is supposed to be for the Walbro carb, and I get one for the adjustable Kohler carb.

I see now! Hope you get it all figured out!

Matt,
Everything that you mention is similar to my experience when I first brought home my 1872. I also have a cast iron rear end (from a 1650) that I plan to use when I get the time to do the swap. Sure would appreciate pics and descriptions when you're ready to tackle that job.

Russ

I got real lucky. My 1872 is in excellent condition. Like every Cub that I have owned, it needed a good cleaning at the car wash, but at least nothing needed replaced when I bought it.
I'm anxious to see Matts when it is done, It will be right! :biggrin2.gif:

Matt, regarding the hiem joints. Are you ordering them from mcmaster? That's about the best place i could find. Also, are our supers and gt's all "lefty loosy, righty tighty" regarding the joints? I saw that was an option when ordering and I can't remember off the top of my head? I need to replace all the ones on my super too, even the steering cylinder.

Yep, they're all right-hand thread. I'll be ordering from McMaster-Carr tonight, probably.

Just like Scott I ordered mine from Summit racing since I was ordering something else from them as well. nice joints good price. you will need the 1/2x5/8 cone spacers for the outer ends that Scott noted. $2 each.

I'm not seeing what I'm going to need those for. The OEM tie rod ends have no such spacer, and I'm replacing them with Heim joints with a stud.

Hmmm
 

Is there a more detailed walkthrough of this steering upgrade besides the one on cubfaq? The one there is pretty light on details.

Go to page 3 "steering upgrade courtesy of summit racing" thread

I finally got a bit more done tonight...my parts came in, so I've got all the gaskets and seals I need for the CI rear conversion. I replaced the really leaky grommet in the fuel tank, and I drained the oil. I got most of the tie rod ends replaced with heim joints...I failed to realize that the 3/8" ones on the tie rods can't have studs because they screw into the pivoting arm on the axle. I guess I'll have to put in another McMaster-Carr order. Tomorrow I'll put on the adjustable carb and refill the crankcase with Rotella, and perhaps drive it around a bit and wash the rear in preparation for disassembly.

That Walbro carb is a major POS!

I had an 1872 and if it sat for more than 2 months there was water in the carb. Only one drop of water would keep it from flowing fuel. I bet in the 5-6 years I owned it I had that carb off 10 times. Even replaced it with a new one and the exact same problem cropped up immediately.

Sold it mainly because of that problem. Didn't want to ^%%@# with it!

Quite a work-horse though!

I put on the adjustable carb, changed the oil, put in the inline shutoff, fixed the leaky grommet on the tank, put it all back together and...it no longer has spark:angry: It ran two weeks ago when my dad picked it up. It appears that the primary coil in the mag is open. My spare mag also has an open primary:angry:

I've FINALLY got the flywheel shroud off...man, what a PITA to remove without pulling the engine. And of course, now I see the muffler shield needs welding, the engine had 1 tight bolt holding it in, and there were no locknuts on the engine end of the driveshaft. Now I've got to order a mag before I can wash the rear and split this thing and start getting the CI rear together...

Sounds like you have plenty to do to that thing! It's a good thing that it found a new home with someone that has the ability and willingness to refurbish it!
I did end up getting another Kohler carburetor for mine. I cleaned it and rebuilt it, and put it on yesterday. It runs and idles great!

It lives!:)

It turned out that the mag was fine, but the air gap was too large. The fuel pump was bad, so it got replaced, but it still wouldn't run above idle. I couldn't figure out what was wrong since the carb was rebuilt and everything. I finally discovered that there are two different carb elbows for the KT17 and M18, and two different atmospheric vent locations for the carbs. I replaced the Walbro with an adjustable carb, but the atmospheric vent didn't match the elbow, so the vent was essentially plugged. I put a different elbow on with the right vent hole, and it started right up. It runs and drives nice (PS is GREAT) but the trunion needs welding and it shakes because the rear coupler is bad. Now I just need to get the CI rear in it, and it'll be all set.

Keep us posted Matt. I enjoy reading how you fix these things!

Great job, Matt! Thanks for the update. :ThumbsUp:

Back to work on this again. Since I finally got it running and driving again, I have now started the CI rear conversion. The first picture is the donor rear.

In the second picture, it's cleaned, and most of the loose paint stripped off.

I put match marks on the bearing retainers so that they wind up going back in the same way they came out. (Pictures 3 and 4)

There's definitely some gunk in here: (5)

Here's the bare transaxle, cleaned: (6)

Here's the coarse-spline 'guts' (7). I hope that I can use the pinion shaft from the aluminum rear, because the ring gear is shot on this one...there's a crack in one of the teeth. Tomorrow's project is to pull the rear that's in the 1872 and disassemble it.


Question for the experts: The IH manual has all these instructions about shimming the rear bearing cup for the pinion shaft, and I assume this is to get the proper pinion depth/orientation for the spiral-cut gears in the IH rears. The aluminum rear has straight-cut ring and pinion gears, and there are no such instructions in the CCC manual for the aluminum rears...it just tells you to put it together and set the backlash, with no mention of setting the depth. My thought is that it doesn't make much of a difference with the straight cut gears. If I use the straight cut ring and pinion, do I just follow the CCC manual?

Here's the rest of the pics.

Thanks for the update, Matt. Your 1872 will be right when you are done with it! :beerchug:

When I said 'backlash' in my post last night, I meant to say 'preload'.


Not quite...he used the CI rear's pinion shaft and put the matching ring gear on the carrier. I will be using the pinion shaft and ring gear from the aluminum rear in the CI case. If I was putting the same pinion shaft back in, I wouldn't have to change anything, but because I'm changing that, I have to figure out how to set the backlash, as the CCC manual for the aluminum rears has no instructions...it just says how to set the preload.

Today I removed the aluminum rear from the 1872. All 4 axle tube bolts that held the rear to the frame were twisted off inside, so the PO just jammed some short 7/16" bolts in there to hold it in...

The carrier looks like new, and there was no junk in the case. The axles look like new, as well. Everything's in good shape.

The best news is that the pinion shafts appear to be of the same dimensions between the CI and aluminum rears. I'll do some checking tomorrow, but it looks like that'll go right in.

I'll then spend the better part of tomorrow trying to get the right contact pattern. Hooray for trial and error:bash2:

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.

Should be the same as any other cub rear end. The manual for my 122 has the same contact pattern as the one's we built at Dana for off highway use (some of these was 22ft long without any tires mounted on them. I wouldn't over think it try what you know and go from there. You are the expert after all :biggrin2.gif:

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

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.

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

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...

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.

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.

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!

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?

Looks real good Matt! Very nice pattern.

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