Farmall 806 Diesel - rear tires question

Hi all,

New to the board and am trying to figure
some things out with my inherited Farmall
806 diesel.

Mainly, the tires - I have the following
on the rears now, and have the below in
the barn but do not think they will fit.

Can anyone help me understand what tires I
can find which will fit the existing rims
I have?

Currently On Tractor:
16.9-38 on 15" Rim (14-38)

In barn:
15.5-38 on 14" Rim
&
18.4-38 on 16" Rim (15-38)

I also have a bunch of rims, but don't
know if will fit the tires (how tell)
and/or if any of these tires will fit the
existing rims or this tractor...

Any help is greatly appreciated. 😊
 
Any of the above will 'fit'/work.An 806 could have any number of tire/rim combinations and be 'correct'. However,IMHO,the tires/rims that are on it are perfect.
 
Delta red is correct. An 806-D is a little big for 15.5x38. The 16.9x38 is a really good size for the tractor. The 18.4x38 is another good sized tire for it too. The stock factory cast wheels on the rear should attach the rims with 12 cast iron clamps, kinda an odd shaped chunk of iron impossible to describe in less than 10,000 words. There should be two bevels, ridges 4 inches apart on the inside center part of the rims, with 4 bumps on each bevel. Those bumps are drive lugs that use a different iron chunk to clamp the rim to the wheel. There's detailed instructions in the operators manual for the 806 or ANY 1960's or newer large IH farm tractor describing exactly how to attach the rims to the wheels.
The 16.9x38 tires are supposed to be used on 15x38 rims, the 14x38 rims are an approved alternate. 18.4x38 tires should be mounted on 16x38 rims, and 15x38 are an approved alternate.

The guys in the tire room used to mount up a pair of rear tires every 5 minutes and clamp them to the cast wheel and send them on the conveyor to the assembly line. They had Huge mounting machines kinda like a Coats 10-10 but about 4-5 times as big. The cast wheels were set on a 4 sided merry-go-round and the tire & rim was set on the wheel with a hoist that two guys assembled the clamps and tightened them with impacts. Two crews did over 400 rear tires and just over 200 frt tires every day, fronts were all done on 1st shift.
 
Wow, thank you all for the info...

I have the manual and have read the section on tires, but honestly, it is greek to me 😕.

They mention so many different ways to set up the tires and I do not know if it means I need different rims for each set-up, or what.

But, it sounds like the 18.4-38 tires I have can be mounted onto the existing (15-38) rims which currently have the weathered 16.9-38 tires on them (15" rim)?

If yes, it also sounds like I will then need to attach the lugs into the correct bevel in the rim to properly set the distance from the axles, correct?

If I do this, should I also adjust the front axle as well to ensure the front and rear tires are in alignment?

Thanks again for everyone's input...

The family farm came to me a couple years ago and I have been trying to learn as much as I can about all the tractors and parts I have scattered around the place 😀.

Best,

Bob
 
In my opinion, your 806 is probably one of the best tractors that IH ever built. Decent power for it's size and a tough power train. Taken care of properly, it'll work for you for a long long time.
 
😀
That's great to hear!

My grandpa farmed for over 50 years from the late 30's to the late 80's and was apparently an IH dealer as well at some point, there is even a story (I am guessing old farmer tale) that he had some prototype equipment he was running for IH trials back in the day - you should see our barns, I have know idea what half the gears and parts are for 🙄.
 
The 18's will work fine. It is easier to do the tire work with thw rim on the tractor. You don't have it trying to move nor have to handle it for this job.
On my 806 it had the 18.4-34's on it when I looked at it. The deal was to get 18.4-38's when I bought it. Been glad they are on there in place of the 34's. I've owned the tractor for 42 years now.
 
I got to test a new field cultivator for IHC,put it into Barley stubble,the 4 guys from Chicago flew into Fargo,and drove out, it was a interesting day, but like a idiot i didn't take any pictures,but maybe didn't want me take any either!
 
The correct width rim for an 18.4x38 would be a 16" wide rim. You can squeeze them on to a 15" rim but it is not ideal. Not the end of the world either, functional, just not ideal. The sidewalls will be a little pinched, causing the tread to bulge a little in the middle, which reduces the amount of tire contact to the ground by a little. Does it matter? Probably not for what you plan on doing with the tractor, unless you are looking at serious competition pulling, then you want 18" wide rims with 18.4x38's.

The condition of what you have, and how much work you want to go to, will play a part in what you end up doing. I personally would not even waste my time with the 15.5's. They belong on an H or M or something from that era.

Are the 18.4x38 tires any good? Are the rims they're mounted on any good? Are you planning on buying new tires?

You'll be able to buy new 18.4x38's for less than 16.9x38's. Bias ply tires are fine. You're going to get told to buy made in usa tires, but if budget is a concern, I personally recommend tires made in India as a good secondary choice. Check with your local tire dealer, as they will have the best deals and will install the tires for a reasonable fee. $100-$150 per tire is not bad. If you've ever had to remove an old large tractor tire where it's been on the tractor for decades and the rubber is rock hard, you would not do it for that much.
 
Hi Cat Guy,

I watched a video of a gentleman changing rear tires on a tractor while mounted and it seems doable...

Any suggestions on the right type of bead grease?

And if you were moving from 15.5-38's to 18.4-38's would you change the bevel location?

Currently the wheel hub is 7 3/4 inches from the rear end casing, mounted concave? (facing out) and I believe on the first bevel (the first one of two if moving from the tractor out away from the axle hub...

Not sure of the tread width for the new tires or how to measure to follow the manual.

Lastly, would you adjust your front wheels by extending or narrowing the axle if switching the rears?

Thanks!
 
That's awesome!

Yeah, I dunno what my grandpa did, or if the story is even true, but kinda neat to think it might be.

Too bad you didn't get pics, but I bet the memories more than make up for it 😀
 
Yes, the 18.4x38 tires should fit right on the 15 inch rims. We could have built 806's for weeks, maybe months and never built any two alike just with differences in tires and wheels. The operators manual has to cover ALL those variations. Depending on what you plan to use the tractor for determines how you want to mount the rims on the wheels and wheels on the axles. I would mount the rims so the cast center is recessed into the rim, and then set the cast center so the rim and tire extends out even with the end of the axle bar. Remember you need a "Left" and a "Right" side tire/rim/wheel, the cast wheels typically dish "Out", the rims should be mirror images of each other, and tires should have the lugs pointing forward on top of the tire. Those axles are REALLY hard on fence posts, gates, barn doors, even your hips if you hit them walking past the tractor. A narrower tractor takes up less barn space, it's also tippier on side hills. If your going to do tillage work you may want to use dual rear wheels/tires. A narrower tire spacing means an easier to maneuver narrow tractor. Same advantage if you plan to mow & bale hay, as long as you stay off steep sidehills.
Condition of the available tires you have would be the most important deciding factor in which set to use. It's always a good idea to use same size on each rear wheel, same revolutions per mile, same brand and tread style is a nice idea too.
 
Hi,

The 18.4 tires are not mounted but in the
barn and seem in good shape, new (not used
but older) and the rubber is still soft.

The 16.9's on the tractor now are pretty
cracked but the rims are great looking.

I also have several sets of 20.8-38's and
a bunch of others, 13.6-38 etc, but don't
think they will fit, right?

For the tractor, the thought is to learn
how to run the discs, plows, seeders and
grain drills etc with the 806 and try to
get some acres of forage in.
 
I'd think if you grabbed a camera to take a picture of that new field cultivator that one of the four guys would have stopped you, probably taken your camera till they were ready to leave.
I never heard of it happening, but at FARMALL we were not allowed to bring cameras to work. There were only a couple people allowed to have one as picture taking was part of their job description. During the BIG Strike I snuck a camera in as there were lots of Eagles flying thru the Quad-Cities and there would be several sitting in the trees along the Sylvan Slough behind the plant.
Now days with everybody carrying a cell phone that takes pictures it's still frowned on. Guess it depends on how much you like your job whether you take pictures or not. I will say this, I wish I had pictures of lots of stuff I did on the farm. I have a few, tractor and pull type combine in the yard, tractor and mounted picker in the yard. Line-up of ALL Dad's tractors with duals still on two of them, even had the Cub Cadet in the line-up. But NOTHING like an action shot in a field doing anything.
 
IF it has 16.9x38's on it now then more then likely it was used in the ROW , and yes you can Squeeze the 18.4 on a narrow rim but you will not have the traction and ware the center of the tire out faster . Tire sizes depend on your row crop and what will fit between the rows . a 38 inch tire will give better ground clearance also increases ground speed over a 34 to get the same height of a 18.4x38 out of a 34 inch you would need a 20.8x34 but that makes for a wider foot print and if your doing old fashioned in furrow plowing with a 14-18 inch bottom plow the tire in the furrow will be riding up on the plowed ground . 806's will handle and 18.4 x38 but what you will find is that that 38 inch tire will cost you a gear in tillage work as in say your pulling 5x16's in low 4 on 18.4 34 and you swap out the 34. for 38 your now down in low 3 rd and into the T/A more . Since i am and old fart and been around the 806 since day one that they hit the ground here in the Buckeye with my old boss buying the FIRST one and my uncle buying the second one the next weekend one going to a dairy beef operation and the second going to a Tater operation i got to see how they worked on different operations and ground and soil types . Also i own and 806 well i have owned a bunch of them over the years some only being around for a couple days and this one has been around since 1998 . This one is on 18.4x34's . I have seen 806's on 15.5x38's come out of tater and veggy country along with the 16.9x38's . I will say this depending on your operation will tell you what size tire ya need and keep in mind here ya want no less then and 8 ply tire on a 806 and never use a rim that is to narrow . We like to use a wider rim to flatten the tread and keep a straight sidewall. My 16.9x38's on my Super M T/A set on a 16 inch wide rim and i have not used a 15.5x38 since the early 70's when i had a 460 and a put a new set of Firestone 15.5x38 All Traction field and roads on it that i got out of the Firestone test center for next to nothing
 
The tire tread setting will depend on what your row width is going to be. Another words you will want the tread width to be a 60inch for 30 inch rows and 72 if your planting 36 inch rows. Mine are set for 30 inch rows. I believe they are concave out so the edge of the casting is curved outward the rims are on the outside bevel. The front axle is set all the way in. The measure is from the center of the tire to center of tire. You will have to adjust your tierods to set the toe if you have to adjust the front width. They can be set so they are even with the outside of the rear tires. Though I would set them so they are as clost to even with the inside of the rear tires. For 2 reasons 1 it will be much easier to get up to things close like if you want a wagon spout to flow into and auger or elevator. 2 it will give you a better centering for row crop work on any side hills.
My rear tires are just a bit wide for center on 30 inch rows. I think they actually measure something like 64 inch center to center. I would have to turn the casting around on the axle shaft and maybe move the bevel if I wanted it to get down to the actual 60 inch center. I have sprayed and applied anhydrous at this setting for decades with it.
 
Wow, thank you for the detailed response - the manual now makes more sense after reading.

So the tread widths given in the manual show the range, depending on how set on the rims, cast and axle position.

As for row crops, this is an area we haven't decided on. Definitely am planning on a demo plot of several row crops, but also plan on planting demos of grains, clover and grasses.

On a side question - what type of tread spacing would one use if planting other crops with spacing ranging from as small as 3/4 inches up to 15?

Does it not matter at that point?
 
Murphy's tire soap. If you mount them tubeless after they are on the rim/wheel if they will not seal at the bead to inflate just put the Murphy's around the bead till it has filled the gap and inflate wipe off the excess and put back in the can/pail. I used part of an 8 pound container for a couple of 24 inch tires on the combine last winter then had most of what I used back in the can when done. You can also ad some water with a pinch of it and have a lube for prying the tires over the rim edge on or off.
 
On a side question - what type of tread spacing would one use if planting other crops with spacing ranging from as small as 3/4 inches up to 15?

Does it not matter at that point?

Since you cannot fit the tires down between rows that small, it does not matter.

Unless you plan on using the tractor in a row crop like corn, it does not matter.

If the tractor has a loader, it is a good idea to set the tread width so the tractor is no wider than the bucket.

If you are using the tractor for mowing hay, you may want it set out wide so you can straddle windrows instead of driving on them.

If you don't really know what you want, leave it alone and change it later when you figure out what you want.
 
(quoted from post at 03:59:56 07/06/20) Hi,

The 18.4 tires are not mounted but in the
barn and seem in good shape, new (not used
but older) and the rubber is still soft.

The 16.9's on the tractor now are pretty
cracked but the rims are great looking.

I also have several sets of 20.8-38's and
a bunch of others, 13.6-38 etc, but don't
think they will fit, right?

They will fit, but they are the wrong size for the tractor. 20.8 is too large, the tractor will not have enough power to turn them effectively. 13.6 is too small and the tractor will tear them up quickly.

Use the 18.4x38s if they are in good condition.
 

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