Ask Mr. Thinker

Dear Mr. Thinker,
I would like to get your advice on how to get following tractors in running shape. I have a "BO" crawler, serial number 336572. I would like to know if the transmission parts from a 1945 or 1946 "BR" are interchangeable.

I also have three 1951 "Bs." Two of these tractors had stuck pistons. I put a mix of diesel fuel/motor oil in the spark plug holes, left it about two days and rocked the flywheel back and forth until the pistons came loose. Do I need to take the pistons out and replace the rings before I try to crank them up?

One other question: Did John Deere make a pulley that I can fit on the flywheel so I can fit a pump to it and have live hydraulics? I also need an operator's manual for the "BO" crawler. Can you help me?
H.P., Alabama

Yes, the transmission parts on the "BO" and "BR" tractors, including the Lindeman "BO" crawler, are pretty much interchangeable from serial number 329000-up. You need to get a parts book to make sure. As to your "Bs," Mr. Thinker would normally recommend that you replace the rings before you even start on the rest of it, but, you sound like a young guy who maybe doesn't have a lot of money, so yes, it's worth a try. You're going to have to spend some money getting them running, anyway, so if they will make compression in both cylinders, go ahead and fire them. Once in a while, the rings won't be stuck or will come loose and will be just fine. Not often, but Mr. Thinker has seen it happen.

No, Deere didn't make a pulley for the flywheel to run a hydraulic pump, but they did make a "live" hydraulic pump kit, which placed the pump between the governor housing and distributor / magneto and this provided "live" hydraulics and worked really well. Hunt around or contact some of the advertisers in this magazine - you will find one. It's the best and easiest way to go.

An operator's manual for a "BO" crawler is no longer listed in the Deere Service Publications Catalog, but they used to have them so call 800-522- 7448 and be persistent. You might luck out. If not, try giving Jack Kreeger a call at 402-571-2824. Jack used to sell some reprinted material about the "BO" crawler. Good luck! MT

Dear Mr. Thinker,
I picked up a cylinder block with a 6-1/8 inch bore for a John Deere diesel tractor in Texas. The casting number on it is R20870R. My dealer and others say that this number is for some kind of bushing, but this is a block! Can you help in identifying it?
J.S., Minnesota

Mr. Thinker seems to recall that some late production 830 and 840 tractors used a cylinder block with this casting number. Usually, the casting number will translate into a part number, but not always - and such is the case here. A quick way to tell for sure is that a block for a 70 / 720 / 730 diesel will have a machined pad on the lower front corners of the block, whereas the 80 / 820 / 830 / 840 blocks do not. If all else fails, weigh the thing, since the 7 series blocks weigh about 175 pounds and the 8 series blocks weigh about 200. It's also possible that reading it wrong (easy to do) and that the actual number is R20920R, which is the part number the late 820 / 830 / 840 block. MT

Dear Mr. Thinker,
I have a 1936 model "A" tractor, serial number 431573. This tractor came on rubber tires from the factory and has the round spoke wheels. My question concerns the size of the rear tires - are they supposed to be 10-36 or 12-36? Naturally, the rims are bad. Is there anyone who repairs or replaces the rims? I've located some 10-36 wheels, but am afraid these are for a "B" tractor. This tractor has been in the family since it was new and I want to restore it to original condition.
A.S., Kansas

If your tractor has the original AA385R rear wheels, it should have a six inch rim which was suitable for the 9.00 x 36 rubber tires, the only rear tire size offered until November 1936, when wheels for 10-36 and 11.25 x 36 tires were offered for the first time. Finding 9.00 x 36 tires is going to be just a little tough, but try M.E. Miller, Wauseon, Ohio at 419-335-7010, extension 4 to see what is available.

Yes, there is someone who can rebuild your rims. Contact Nielsen Spoke Wheel Repair, 3921 230th St, Estherville, Iowa 51334, telephone 712-867-4796; they can fix you up. Good luck with your restoration, a "family' tractor is always something special! MT

Dear Mr. Thinker,
Did JD ever have plans to build a steam traction engine or a portable steam engine in the early part of this century? I've also heard that Deere built an experimental automobile about this time, too.

One other question: Do you ever get goose pimples sitting on that rock with no clothes on?
H.H., North Dakota

As to the first question - not that Mr. Thinker knows of. However, Deere DID experiment with a borrowed steam traction engine to develop a line of "New Deal" gang plows, with from two to six bottoms, in the late 1880s and published a brochure touting the advantages of steam plowing with the "New Deal" gang plows. That being said, there is absolutely NO evidence that Deere ever gave any thought to producing a steam engine and there is no record of any experimental machines. The upper management of Deere had to be dragged kicking and screaming into the gasoline tractor business, much less steam. Deere MIGHT have experimented with an automobile in the early part of this century, but what you are probably referring to is the short-lived Deere-Clark automobile, produced only in 1906. Deere president Charles Deere was in on this venture, but it is fairly certain that this venture had no connection with Deere and Company itself.

As to your other question, Mr. Thinker has gotten used to the goose bumps, but is spending a small fortune on Preparation H. Not all of his problems in that area are from sitting on the rock. MT

Dear Mr. Thinker,
I am currently restoring a 1939 and a 1946 "H" tractor. I am going to try to keep the 1939 tractor to original specifications, but am going to customize the 1946 tractor. I've built a three-point hitch for it and have installed wider rims. I plan to bore the block .090 and install aluminum pistons. What I would like to know is how thick are the cylinder walls going to be after boring?
H.R.B., Illinois

That's an impossible question to answer, as cylinder wall thickness varies from block to block. But you need not worry, the walls will be thick enough since Deere put plenty of "meat"in them. Send Mr. Thinker a photo of that three-point setup when you get it done. MT

Dear Mr. Thinker,
I am restoring an "MT," serial number 28818. 1 need to know which gas cap is correct for this tractor - is it the tall one or the short one? Am I right in assuming that the gas cap and the radiator cap should be cadmium plated and not painted? Did the hose from the air cleaner to the carburetor have clamps and, if so, what kind?
M.S., Indiana

As originally built, the "MT' used the "short" gas cap, although the "tall" one is a legitimate replacement part. You are right, the original gas and radiator cap were cadmium plated, but for safety's sake and the tendency of liability lawyers to litigate, you should give serious thought to painting the gas cap red.

Yes, the hose from the air cleaner to the carburetor used clamps (three) and the originals were of the two-wire style which are getting mighty hard to find. But be patient, you'll find some. Nice to hear from someone who's really paying attention to detail. MT

Dear Mr. Thinker,
Could you settle a bet? My buddy says that John Deere built tractors with hand clutches after the demise of the two cylinder tractors, I say that they didn't. Who's right?
K.S., Ohio

Hope you didn't bet the farm on this one, because you lose. Although it's not widely known, the 2020 grove and orchard tractors produced from the 1960s to the early 1970s had a hand operated clutch. MT

Dear Mr. Thinker,
My question is: Why do some diesels start fine without glow plugs while others, if the glow plugs don't work, you can forget it?
O.B., Florida

There are a lot of variables, but basically, it depends on combustion chamber design. Most (but not all) diesel engines that use glow plugs also use the precombustion chamber system in which fuel is injected into a prechamber and ignited there, then on to the work of pushing down on the piston. This design was thought to be less noisy and, when combined with glow plugs to warm the incoming air, easier to start in cold weather. This was the system used on 1010 / 2010 diesel tractors.

Direct injection, as used on the two cylinder diesel tractors and the 3010 / 4010, was a little more noisy and depended on higher cranking speeds (and ether, in cold weather) to warm the air sufficiently to ignite diesel fuel when injected directly into the cylinder. Refinements to the direct injection system have resulted in less noise and easier starting and direct injection is the preferred system for today's modern diesel engines. Has Mr. Thinker confused you sufficiently? MT

Dear Mr. Thinker,
I'm confused. I see ads from the carburetor rebuilding people - some of them say that glass beading carburetors is the greatest thing since sliced bread and some say that this process will destroy the carburetor. What's your opinion?
W.S. Kentucky

Mr. Thinker has to side with glass beading for a number of reasons. One, it gets the carburetor absolutely clean and unless excessive pressure is used, will NOT remove metal from the carburetor.

Two, it stress-relieves the carburetor through a process called shot-peening and prevents cracking. You might ask, how could a carburetor be stressed? Stop and think about it. It's bolted in position, which creates stress. Repeated hot / cold cycles. Water freezing in passages. That's stress.

Three, if this procedure is good enough for the FAA which requires, for example, that propellers on airplanes be periodically bead blasted to relieve stress - it's good enough for Mr. Thinker. Add to that the fact that firms such as John Deere, Caterpillar, Ford and General Motors also endorse the procedure and Mr. Thinker is convinced that the anti-glass bead folks are just blowing smoke.

For an in-depth explanation of this process, Mr. Thinker recommends the "How to Rebuild DLTX Series Carburetors, Part II,' produced and sold by Robert's Carburetor Repair, Box 624, Dept GM, Spencer, Iowa 51301, telephone 712-262-5311. This is an excellent video and goes into much more detail than Mr. Thinker has room for. Well worth the chips. MT

Dear Mr. Thinker,
We are dairy farmers and farm with nothing but the best - John Deere! We have two, three, four and six cylinder tractors. My question is about motor oil. Are the multi-weight oils (10W-30) as good at protecting engines as single-weight motor oils? I know that the multi-grade oils will do better at low temperatures than single-grade because they flow better, but will they adequately protect engines in hot weather? Does 1OW-30 break down or evaporate more than regular 30-weight?
K.H., Pennsylvania

You must not get off the farm very much. Let's see, Deere has only recommended and approved multi-weight oils since the mid 1950s, so yes, it's Mr. Thinker's opinion that multi-grade oils with today's additives are just as good, if not better, at giving complete engine protection in any kind of weather or operating conditions than single weight oils.

If you're really worried about it, you might consider something like 15W-40, which is what most over the road trucks use and those engines routinely go for 750,000-plus miles without problems and develop as much or more heat as any tractor engine. One of Mr. Thinker's more flaky associates used to torture Ford pickup trucks by pulling about three times the weight they were designed to pull; he used a quality 15W-40 oil and never had an engine problem or excessive oil consumption, even at 150,000 plus miles which is remarkable in light of the fact that this character drove like he had an 830 cylinder head tied to his right foot. Bottom line: If you use a quality multiweight oil, you'll not have any problems related to lubrication. MT

Dear Mr. Thinker,
I have one of the Deere hydraulic pumps that drives off the governor housing, which I want to install on a 1951 "A" tractor. I have the JD parts book and the hydraulic tech manual, but I cannot determine how to hook it up to the Powr-Trol, other than the suction hose seems to go in the plug hole in the bottom of the rockshaft housing and the pressure hose apparently goes to a plug somewhere in the Powr-Trol unit.

Opinions from "experts" range from "I don't know what you're talking about" to "major internal modifications needed" on the Powr-Trol unit! Can you help or refer me to a tech manual that will help?
R.G.C., Texas

Mr. Thinker has answered this question before and made a boo-boo when he did it, so he'll take another swing at it and get it right this time. Assuming that you know how to mount the pump, the rest of it is pretty simple. First, drain the Powr-Trol housing and the rockshaft housing. Remove the Powr-Trol unit. Remove the PowrTrol pump and remove the idler gear. Drill the drain hole at the bottom of the rockshaft housing below the pump to 15 / 16, tap with 3 / 4 x 14 pipe tap and install a 90 degree 3 / 4 inch union adapter in the bottom of the rockshaft housing, with the fitting pointed to the right of the tractor. Reinstall pump. Install a 1 / 2 inch street elbow where the drain plug was located in the Powr-Trol housing. The elbow should be pointed to the left and slightly forward. Reinstall the Powr-Trol housing, using the valve housing spacer with a gasket on either side. Now run and hook up oil lines to the pump, fill the system with oil (30 weight motor oil preferred) and you should have "live"power.

There are the basics and no major modifications are needed. For more information, see if you can find a copy of JD Service Bulletin No. 198 as it gives complete installation instructions and more detail than Mr. Thinker can go into here, due to limited space. Good luck! MT

Mr. Thinker is the collective identity of several "experts." He answers any kind of Deere related question. He can be a little grouchy and satirical, however, so be careful what you ask. He’s always informative, sometimes nasty, but never boring.

Send your questions to: Mr. Thinker, c/o Green Magazine, 2652 Davey Road, Bee, NE 68314