Crazy gear reducing idea or not (HG)

[choppa]

How about this idea:

Talked to a fellow who said he knows of someone who reduced the speed of his Oliver HG crawler by using a set of different sized sprockets and chain rollers.
What he described was a sprocket installed on the output shaft leaving the clutch case (bell housing /engine side).
Another larger diameter gear mounted on the transaxle output shaft side.
These are coupled together via a short perpendicular roller chain over to a jack shaft which is mounted on the inside frame rail. Shaft runs parallel to engine/transaxle shafts. This jack shaft has two gears: One in line with the gear on the output shaft of the engine, one in line with the gear on the output shaft of the transaxle….I suppose the shaft and gears could be supported simply using pillow block mounted bearings.
To reduce speed, the gear on the output of the engine side should be smaller than the output shaft leaving the transaxle.. seems like a good idea…of course, the gears you choose leaves you with lower gearing all around… you won’t have the higher factory speeds any longer. But then again, is this so bad? I think with the high speed of 3rd gear as it is, how much use does it get anyway?… reducing all the speeds I suppose that one would use 3rd gear more often as it would be slower now. Thoughts?

 

[JDemaris]

Yeah, I've seen several attempts at it. All terrible. A guy even wrote and was selling plans a few years back. Calls himself the "Connecticutt Yankee." I think I paid $10 for his manual, 10-15 years ago.

One important first question. Where do plan to find any sprockets and/or hub adapters to fit the Cletrac/Ford 1 3/16" splined shafts? I did a few searches years ago and found absolutely nothing available. Standard spline sizes run 1 1 /8" and 1 1/4". NO 1 3/16" which seems to be a Clark trans/Cletrac/ and 1900s-1930 Ford size only.

The Model A Ford three-speed trans is a perfect fit. It has the same odd-ball 1 3/16" splined shaft at the output. And - the Model A standard clutch disk is exactly the same size as the standard HG - so the Model A disk fits right in.
And - the old Ford three-speed has full, large ball-bearing support in front and in back. That is rare. Most auto transmissions give no support in front, since that is left up to the pilot bearing at the end of the engine crankshaft. The old Ford Model A trans is extremely rugged, even by today's standards. Personally, I think you'd have to have a screw-loose to waste time trying to contruct an open-chain reduction system (no personal insult inteneded). I thought aobut it for my own first Cletrac once.

 

[choppa]

no insult taken John! Its why I post here.. To get experienced input from the guys "who have been there"

I thank you for the time you took to reply.

Now. the absolutly only advantsage I seen to this approach I wrote was that the stock clutch linkage and all would not have to be modified in any way.

OH.. I knew I had a question on all this...

What would one expect to pay to do this retrofit using a Model "A" tranny? Less transmission cost to obtain, of course. Not havinga machine shop I suppose I need to pay one to mill and machine the plates, Then have a certified welder weld the cast housing to the steel plates.

I suppose that gets costly as well.
i think if I were to go this route I would also like to find another HG/OC clutch housing to have machined just in case I ruined mine..


thanks, Dave

 

[Derek Cartwright]

Dave, I'm currently working on a Model A tranny in my OC3. Thanks to John, and some of the other guys over at the Cletrac website the process has been relatively painless. I found my Model A transmission on Ebay for $80 or so, and most of the other parts from Napa. The Ford clutch disk, and u-joints I purchased new from a Model A parts house on the net. I made the decision to purchase many of the parts new, but If you could shop around you might save some money buying used, or rebuilt u-joints etc...I haven't stopped to calculate my total expenditure yet, but I think right now I'm in the mid-$300's. I plan to have a machine shop drill my plates, but with some welding experience I'm going to try to do the welding portion myself. In my opinion, the cost is worth it in terms of the versatility that the aux. tranny will add to the machine. Derek.

 

[JDemaris]

I spent much more time thinking and measuring, then actually doing the hands-on work. If I was to do one now, working from my own plans, I suspect it would go 10X faster.

I was first in a panic when I decided I needed a Model A trans. But,then soon found out they are all over the place and cheap. I found a dozen locally, just laying in fields. Many old Ford Model Ts and As got made into farm-equipment.
I even found one swamp that had over 20 complete Model As with trees growing through them. I had my pick at $100 each. They all had engines, trans. rears, front ends, radiators, etc.

My dead-friend Bob was convinced that using a Ford flathead V8 housing was the best way to go. It told him he'd die before he ever got it to work. I was only kidding, but oh well. He indeed DID die first.

If somebody actually wanted to produce aux kits, it could be done fairly fast. Doing only one, from scratch, can be very time consuming.

Using a Dodge Power Wagon throwout bearing holder, and an new reproduction Model A disk works very well. It's better then the original Trasco setup.

The worst part of the job - is to slice the original housing in half, get it milled, and . . . get bushings welded into it that hold the clutch-release shaft. I have one tool for that which is a God-send. It's an old Ford-reamer from the 1930s. I have no idea of what it was originally made for. But, works perfect. You weld in two steel bushing bought from Tractor Supply, and then line-bore, or "finish ream." This 7/8" reamer is three feet long and works perfect. Low tech, but where are you going to buy a new 7/8" reamer that is three feet long nowadays? I got it at a swap-meet for $10 in a Ford box.

 

[choppa]

thanks Derek... wonder if you could get more than one set machined for a little more, and split the cost with a fellow crawler owner looking for the same conversion.

would love to see pics and hear of your progress.

send me an email PLEASE TO:

[email protected]

Dave

 

[M Diesel]

(quoted from post at 08:16:09 12/13/10)
I have one tool for that which is a God-send. It's an old Ford-reamer from the 1930s. I have no idea of what it was originally made for. But, works perfect. You weld in two steel bushing bought from Tractor Supply, and then line-bore, or "finish ream." This 7/8" reamer is three feet long and works perfect. Low tech, but where are you going to buy a new 7/8" reamer that is three feet long nowadays? I got it at a swap-meet for $10 in a Ford box.

I'd say most likely for cam bearings etc. All of my old IH stuff has the cam bearings reamed to size. That had to be a pain in them old long 6 cylinders.

 

[smallercrawler]

Hi JD, FWIW several months ago, after seeing some info you provided on this conversion, I found a couple of spline shaft makers on the web that offered all sorts of oddball splines including a 1-3/16" x 8, 10, and 12? teeth shaft and bushing if memory serves. Unfortunately due to computer crash I don't have that info at hand but will post if I run across it, think I just searched spline shaft.
Also on 10-4-10 a gentleman in Cal. had a small homemade tractor for sale on this tractor sale forum, photo ad#402020. Interesting because it had a Ford Model A transmission and drive line, not sure if truck or car, think you said truck was what worked.

 

[JDemaris]

Nope. It the car transmission that fits. Model A car trans is a three speed. Model AA truck is a huge four speed and will not work.

 

[smallercrawler]

Thanks JD.