Inside pics of early Elwood MFWD

Last winter while plowing snow, I noticed that my front wheel assist on my 660D was no longer working. I immediately parked it as i didn't want to cause any further damage.

I just got around to investigating the problem. I disconnected the front driveshaft and determined that the axle was OK. I removed the transfer case cover (for the first time) and that seemed to be OK. I tried shifting the IH tranny and found out that the 4th/5th slider gear rail would not move. I removed the IH shifter and found the all-too-common problem of non-aligned shifter rails while in neutral. The sliding gear was too far back and the shift lever could not grab it. Everything is back together and working well. Whew!!!

I learned a few things while working on the tractor. I had assumed that the Elwood sliding gear got its power from the top of the 4th/5th IH mainshaft sliding gear. That was correct. I didn't realize that all-wheel-drive was not available in 4th. The Elwood gear won't fully mesh when the 4th/5th slider is running in 4th. Elwood should have made that gear double width. I can't see any reason why that wouldn't work. There is enough room.

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Outside of transfer case. Dirty thing at top is 660D air cleaner. Black thing at right is a Fisher snowplow valve. Elwood sliding gear is below air cleaner.

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Shot from right side. It appears that the vertical triplex chain lifts oil out of the lower reaches of the chain box.

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Shot from left side. The Elwood sliding gear is over the 4th/5th slider. Belt pulley gear at left. Constant mesh gear to its right.

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Shot from left side. Elwood sliding gear is disengaged.

If the 660D 4th/5th slider tooth count is the same on M. SM, SMTA, 400, 450, 560 this transfer case will work on those tractors. Chain sprockets will have to be changed to account for different tire sizes, differential gearing, and the 660 planetary rear hubs. Not a big deal as it seems the sprockets are standard power transmission products.

Thanks for the pictures.

When the transmission is in fifth, do the gears mesh with the Elwood gear in the forward (disengaged) position? That would give four wheel drive in all but fourth.

Yes, fifth works. When engaging fifth, the IH slider
only has to travel about 1/4". There is full
Elwood gear mesh in that gear along with the other
gears except 4th. The Elwood gear is slightly
wider than the 4th/5th slider. Four wheel drive
4th gear will move the tractor if one moves the IH
shifter back slightly out of the detent. In that
case only partial contact with the countershaft
and Elwood sliding gear is possible. Not
recommended and difficult to do.

TA four wheel drive also works in R, 1, 2, 3, and
5. My TA planet gears have been welded to the
carrier so I am unable to do that.

Usually, I only run the tractor in 1st, 2nd, and
3rd. When I was plowing snow last winter, I put
it in 4th because I wanted to see how far I could
send the snow bank.

The shifter was previously repaired and built up
with brass. It will be difficult to make another
repair on that stick. I am also wondering if the
Elwood sliding gear pushed the IH gear backwards
while trying to shift into 4wd. Now that I know
what everything looks like, I be better able to
diagnose any future problems without turning a
wrench.

You would probably never need MFWD in 4th/5th anyhow. I would guess they never really worried about making sure 4th had 4wd.
Thanks for the pictures, that is some neat stuff.

I dug this picture out of the cave and was wondering if it is your tractor? David..............

Maybe I'm thinking wrong not seeing the parts first hand but looks like maybe if they made the elwood shifter gear wider and it was shifted out of front drive, then when transmission was shifted to 5 the 4th gear would mesh with elwood and put it back in 4 wheel drive. There would be no 2 wheel drive 5th gear. Never saw the inside of one but a M only used gears 1 through 3 also.
Did you notice if 4th gear on top shaft was 33 or 35 teeth? If it came with the 35 the gear box would mesh with 4th gear on a SMTA through 450, 560 also if it has the slow 4th. But as you said the planetary gears would through it off. I wonder if elwood used different gear ratios in the front axle when switching to tractors without planetary.

Nope, not my tractor. That might be the one that
sold at a PA auction during the spring. I think it
went for over $16,000.

Meanwhile, I have started converting a 400 to
MFWA. It won't be finished for awhile.<p<a href="http://s140.photobucket.com/albums/r16/Wardner/400%20hydro-creeper/?action=view&current=400141.jpg" target="_blank"></a>

Well, Dave, you may be right on a wider Elwood gear not allowing two wheel drive in fifth: only four wheel drive It's hard to tell now with everything buttoned up. That is something I didn't consider.

It would be interesting to view some original Elwood literature to see how an owner should operate the modified tractor. It is interesting that you mention M's only running with first thru third in 4wd. How common were the early Elwoods back in their day? One in a thoudand tractors or more like one in ten thousand? It also seems to me that most Elwoods were found on 660's.

I thought about counting the 4th gear teeth but it would have required moving the tractor with a come-a-long to get a good count. Too much trouble.

You said "But as you said the planetary gears would throw it off." I don't think I said that. I said the Elwood would work with with a TA. The IH main-shaft doesn't care if there is any prior reduction whether it's in the TA or transmission. However, I have always wondered why and when the TA was welded up. One of these days I will replace the welded TA with a good unit.

I have a feeling that all the Army surplus axles had the same gear ratios. Any ratio changing was performed with the four triplex chain sprockets.

Dave,

I just re-read the thread. When you mentioned "planetary" I was thinking TA and you were referring to rear hubs.

Anyway, as I stated before, I think all axles were the same as they were deuce and a half 6x6 front axles. Did the military really have high speed and low speed trucks? How would that work in a convoy?

You are probably right about the axles if they were military surplus. Since elwood was already furnishing the drop boxes it would be no trouble to change sprockets if there is room. Those type military axles were before my time, at least were I was in the military, worked on them from 69 to 71, the 2.5 and 5 ton used the drive shaft through the top type.
Thinking another reason fourth wasn't used is the 4th sliding gear could see a lot of wear if a lot of work was done in 4th. Gear driving it from bottom and it driving another gear. Think there would be a lot of side load on the main shaft piliot bearing to the right side general area of tractor also in 4 wheel 4th. Just thinking out loud, can't say for sure.

Wardner,

That looks like a slick way to drive a front axle that you are using on your 400. What kind of front axle are you going to use? Is that a standard 90 degree gear box as used on a rotary cutter?

On your Elwood setup, is there any way to adjust the chain slack on the two triple chains? Also, are the chains a 1 to 1 ratio or something different?

Harold H

I'll be using a Dana 60 with ARB air locker out of a Ford F350 4z4. I will need to add an "in or out" box between the right angle box and the Dana. I also intend to make the the rear drive lockable. It's a big job and it won't be done for awhile.

The right angle box is a IH PTO adaptor for mounting a belt pulley on the rear of an IH tractor. They were first used on 300-350 IPTO equipped utilities. They were also used for many years after that. Some were splined for 1000 rpm inputs. The bevel gears inside can be flipped for proper rotation.

Yep, there is chain adjustment. You can see the adjustment holes on the outside. That flange with the holes rotates an eccentric bearing carrier.

I didn't count the sprocket teeth. I suspect Elwood had many different ratios so that the transfer case would fit other "M" sized tractors, especially those without planetary rear hubs. The "W" and industrials used different differential ratios from the Farmalls.

Wardner,

I am just curious if you have worked ou the proper ratio from your brake shaft thru the 90 degree drive thru the Dana 60 axle to the wheels? That is a very interesting project you are doing.

Harold H

I did do the math and I hope it is OK.

Dana 60 axle code 41 = 3.55 ratio
Right angle ratio 31/16 = 1.93
Effective front axle ratio = 6.8
Bull gear ratio 70/13 = 5.38
13.6-38 tire rolling radius = 28.4"

Front tire rolling radius needs to be .78% of rear tire rolling radius or 22.3"

14.9x24 tire rolling radius = 22.5"

Before I buy tires and wheels, I will try to mount some available (to me from my stock) tires and wheels similar to the 14.9x24 on the Dana axle to see if I am in the ball park. I will mark the tires and roll the tractor on pavement. If I am not correct I will be able to extrapolate from that test the correct size.

Remedies would include changing the gear ratio of the Dana (lots of ratios), installing a planetary gear set between the right angle gear box and the Dana, or a different tire size.

I don't think this 4x4 adaptation will work very well unless the rear end is locked. There does not appear to be enough room to do it at the differential. But I don't know alot about tractor lockers. My plans are to install a splined shaft behind the bull gears using the fast hitch holes (tapped all the way through) to support the bearings. One bull pinion gear will be fixed to the shaft and the other will slide in and out of mesh. Shifting will be done with air or a linkage from the unused shifter hole.