Topics

YM1401D Front to Rear Gear Ratio


OneAcre
 
Edited

Hello All...

I just joined, and this is my first post.

I have a 4wd Yanmar YM1401D with rice tires. Does anyone have the owners manual? I'm  trying to find the front to rear actual gear ratio in order to put together a less aggressive tire package from used automotive tires/rims.

The ratio is needed in order to apply the correct amount of front tire lead. I do realize that it can be calculated by driving in 4wd and counting revolutions, it just seems the actual ratio should be recorded somewhere.

I'm  also aware of the Hoyes kit. I have a fully equipped fab shop to do the rim rework and would prefer to save $ by doing it myself. Thanks in advance!

.....OneAcre


KC2GIU
 

OneAcre,

Thank you for joining!  Seriously.

As a community of like minded Yanmar machine owners, Green, Red, Yellow, Blue, and any other color in the crayola box, we tend to pull together and provide assistance.

In the past year, one of our members provide a location of where to find the " YANMAR YM1401 Service Manual.pdf "  We snagged it and now have it stored with 50+ other Yanmar tractor manuals here with our community. 

Come over to the website, login.  Next look to the bottom of the left column.  Click on WIKI.  The page will then load.  Now click on the:
Yanmar Tractor Owners RESOURCE Page.   Take a review of the valuable page.  The come back to the top of the page where you will find ...

FILES, PHOTOS, DOCUMENTS and RESOURCES can be located at the following link:
(link opens in new browser tab)

YANMAR BROCHURES - link

YANMAR SALES COVERS - link

YANMAR MEMBER PHOTOS - link

YANMAR SPECIFICATIONS - link

YANMAR ROPS DRAWINGS - link

YANMAR MANUALS - link
 
 
Yes, the YANMAR MANUALS is the one to enter and search for the titled YM1401 you are seeking. 

Our community also seeks out manuals we do not have.   If you find any in your searches, please send a message to the group owner at:
main+owner@yanmar-tractor-owners.groups.io

Again, thank you for joining.  We are here to help or to talk tractor, farm, homestead, or machine uses. 

Steve


Scotty
 

I've done the measurements for calculating lead/lag in several different ways and posted them several times. You might be able to find them in old postings. If not, we could start over. 

 Although it does seem that the actual ratio should be recorded by the factory I have not found them to be reliable. I also suspect that the ratios may have been changed by the factory during a model run. Maybe as different tires become available, or maybe for reasons of stress and geometry in gear manufacture. . 

When changing tires, you will want to contact the tire company to get the "loaded rolling circumference" of the specific tire that you are interested in using. This information is available from the manufacturers but is not alway provided in their simple specs. Note that a loaded tire is not circular, it is is oval. So rolling circumference is NOT arithmetically related to loaded or unloaded radius or diameter. The difference is more than the percentage of that you are looking to match. 

Ro get the actual gear ratios in my YM165D - a similar tractor - I jacked up one side of the tractor, put it in 4wd, and then rotated the forward tire until the rear had made one EXACTLY one revolution measured by a wire pointer clamped to the frame against a chalk mark on the tire. Then reversed the process by rotating the other tire to check. Do it several time. Slowly so as not to engage the differential. Done carefully, that will give the internal gear ratio front to back. 

I then put wet paint blobs on the tires and drove slowly down a straight paved road and measured the distance between paint spots laid down.  That gave me the real loaded circumference of my tires. 

From there it is just arithmetic and searching tire and rim manufacturers to find tires and rims that are satisfactorily close. 

You can get it too perfect. I believe that Yanmar and others are using the innate elasticity of the lead/lag system to keep the 2wd/4wd lever engaged. If you are successful in getting the lead/lag ratio close to zero, the tractor will work very well but I found I had to put a latch on the 4wd selection lever to prevent normal operating vibration and bumps from shifting the tractor into and out of 4wd. 
good luck,
rScotty


On Dec 6, 2020, at 4:56 PM, OneAcre <francisforge@...> wrote:

Hello All...

I just joined, and this is my first post.

I have a 4wd Yanmar YM1401D with rice tires. Does anyone have the owners manual? I'm  trying to find the front to rear actual gear ratio in order to put together a less aggressive tire package from used automotive tires/rims.

The ratio is needed in order to apply the correct amount of lag. I do realize that it can be calculated by driving in 4wd and counting revolutions, it just seems the actual ratio should be recorded somewhere.

I'm  also aware of the Hoyes kit. I have a fully equipped fab shop to do the rim rework and would prefer to save $ by doing it myself. Thanks in advance!

.....OneAcre


OneAcre
 
Edited

Scotty...

Thanks for the detailed response. I actually did find discussions on this topic where you weighed in. Your responses were probably the clearest. A couple tire companies have online lead lag calculators as well. Here's a link to one by Titan: https://www.titan-intl.com/resources/Lead-Lag-Calculator .

It seems after a fairly thorough search there aren't many options for tires that direct fit the little Yanmars. What is there is quite expensive. The goal is to create a second set of common size tires to be used for general property maintenance like lifting, pulling, raking, etc. I'll  keep the rice tires for heavier work like box scraping, running a chisel for cable laying, gravel spreading and loader work.

In the desert where I live mud isn't much of a problem so the extra flotation of turf tires isn't required. Also there isn't any grass on the 'stead. I'd like to keep the new setup close to stock in order to keep my compact tractor...well, compact. In my ramblings I found a few shops that do tire grooving. Back in the day before plentiful off road tires, I remember jeep enthusiasts doing this to improve traction. Depending on the tires I end up with (pre-mounted trailer tires come to mind... cheap and plentiful) it could be fun to try.


KC2GIU...

Thanks for the link. I missed the 1401 service manual. It's a nice addition to the ym169 service manual that Hoyes recommends for this tractor. Just need to brush up on my Japanese! Lol. I also found the ym165d parts manual Scotty says is similar. I was kind of hoping for an operating manual though.

I notice the ham call sign. Me too! K7BEF. Nice to meet you and thanks for the warm welcome to this group.

....OneAcre


KC2GIU
 

OneAcre,

Seems there is a huge connection of Amateur Radio people, tractors and farmers in life.  We have many here too. :)

rScotty is a huge wealth of info for our machines.  He has posting about the ratio on TBN and in our Yahoo archive stored on the FILES section on this site.

Additionally, on TBN, a YM1401D poster mentioned there is a set of John Deere rear rims that would accept semi-truck tires and the front wheels as Jeep or off-road tires.  The JD rear rims are a bolt pattern match up.  The funny thing is, Those are still Yanmar rims, just painted yellow for Deere.

I do know one thing with the 4WD, inflation pressure can tweak the overall load and usability to arrive at a near zero rotation ration of 1:1.  Almost like tuning an antenna to the SWR of a perfect match. :)  

There is a website that takes images and translates those to ENGLISH.  The YM1401D PDF pages can be saved as 1 page at a time, and then uploaded to:  https://translateimages.site  Click on the area to pick the languages you want, submit and them pick the Japan text to read in English.   Google tends to be wacky, but Bing is very close to have a clear understanding.  I've done a F235 manual all in English and the specification page and Electrical page for the YM2500/YM2610 manual.

On the F/FX/AF machines, the UFO-PTO computer controlled tillers are in Japanese.  Those things are high tech.  Draft control, tiller speed, and other automatic functions.  The https://translateimages.site really helped to solve for the first time how to use those machines with their tillers.  Yanmar has done a great job in this technology.

Steve


Scotty
 

For the Ham connection, I'm ex-K5EZK

our land is hilly and dry sand. No mud. I like turfs or industrial tires for the width & stability. As far as traction goes I'll take more width of rubber on the ground over more aggressive lugs every time. But this depends on your land. If I had mud I'd go the other way. 

As far as cost, you will need 4 "wheels complete with rims" (some are 2-piece)  as well as the tires. For the YM336D, I found a dealer with a half used up set of rear JD 1050 turf tires on the rims which fit the 336D perfectly. I was able to get them for $1100. He had fronts too, but the ratio was wrong for the YM336D. Then I simply had to measure my lead/lag ratio and find the proper front rims & tires that would work. Front rims are easy compared to rears. It turned out to be easy to find them in every variation of mounting, width, and diameter. For front tires  I ended up with some light aircraft tires at about $125 ea. to get the proper rolling circumference. To mount them I bought new rims to fit the tire and tractor for about $70 apiece. 

This was all 30 years ago, hence 30 year ago prices.  
That's the last one I did for myself because college got in the way.
rScotty


On Dec 7, 2020, at 8:10 AM, OneAcre <francisforge@...> wrote:

[Edited Message Follows]
[Reason: added comment about ym165d parts manual]

Scotty...

Thanks for the detailed response. I actually did find discussions on this topic where you weighed in. Your responses were probably the clearest. A couple tire companies have online lead lag calculators as well. Here's a link to one by Titan: https://www.titan-intl.com/resources/Lead-Lag-Calculator .

It seems after a fairly thorough search there aren't many options for tires that direct fit the little Yanmars. What is there is quite expensive. The goal is to create a second set of common size tires to be used for general property maintenance like lifting, pulling, raking, etc. I'll  keep the rice tires for heavier work like box scraping, running a chisel for cable laying, gravel spreading and loader work.

In the desert where I live mud isn't much of a problem so the extra flotation of turf tires isn't required. Also there isn't any grass on the 'stead. I'd like to keep the new setup close to stock in order to keep my compact tractor...well, compact. In my ramblings I found a few shops that do tire grooving. Back in the day before plentiful off road tires, I remember jeep enthusiasts doing this to improve traction. Depending on the tires I end up with (pre-mounted trailer tires come to mind... cheap and plentiful) it could be fun to try.


KC2GIU...

Thanks for the link. I missed the 1401 service manual. It's a nice addition to the ym169 service manual that Hoyes recommends for this tractor. Just need to brush up on my Japanese! Lol. I also found the ym165d parts manual Scotty says is similar. I was kind of hoping for an operating manual though.

I notice the ham call sign. Me too! K7BEF. Nice to meet you and thanks for the warm welcome to this group.

....OneAcre


OneAcre
 

Scotty/K5EZK.....

Nice to also meet you. My little acre is flat with very little sand. The PO spread type 2 fill everywhere.  I don't know how clear my avatar is, but it shows the little 1401 pulling up 12" concrete footings in 4-6 foot sections with the FEL and chains. There was deep sand in that area, I've got to say the performance of those rice tires for pulling was pretty impressive!

For the proposed less aggressive setup, after cutting out the centers and welding in new 3/8 plate hubs any tire rim combo will fit. Some of the areas I need to access have narrow gates, thus the need to keep the tires close to stock. My ricers are about 9-1/2" across the lugs in the back and 6" in the front.


KC2GIU...

Many hams I talk to are living in HOA communities and have difficulties getting any kind of antenna in the air.  It sure is nice to have the space and freedom to play radio and tractors!

Thanks to all for the help!...OneAcre


OneAcre
 

Update.....

Failing to find anything in print for the YM1401D front to rear gear ratio, I decided to take Scotty's advice and just measure it. This is the method I used.

The tractor was taken off road and placed in 4WD.  A plumb pencil line was marked through the center of the left front and rear rims. A yellow crayon mark was placed on the top of the tires for easy revolution counting while driving.

The tractor was then driven forward in a straight line exactly 10 revolutions of the rear tire while counting the number of revolutions made by the front tire.  A second plumb pencil line was marked through the center of the left front rim to determine the fraction of the last partial revolution. The foregoing was done 3 times to ensure accuracy.

The result was almost exactly 14.75 revolutions. Dividing by 10 gives my YM1401D a front to rear ratio of 1.475. Time for a trip to the boneyard for tires!

.....OneAcre


Scotty
 

Keep us posted on what you find out. I like to use "loaded circumference" from spec. tables, and often use that circumference along with the gear lead/lag ratio to change into a percentage of lead/lag. That makes it easier to visualize and is also the way that industry compares their lead/lag ratio. 

The closer you get to matching the internal front to back gear ratio to a perfect front to back tire ratio (using loaded circumference ), the easier it will become to shift into and out of 4wd. You've probably already noticed that lever can be difficult or easy to shift depending on the traction. So the difficulty moving that lever is a simple check that will let you know how much "wind-up" of the whole 4wd system that creating. You want the minimum resistance to shifting into and out of 4wd that is consistent with good steering.

As you approach zero lead/lag the shifting will become so easy that you will have to put a latch on the lever so that it doesn't shift itself when you hit a bump. 

I haven't found any problem with the steering even with zero lead/lag. Just don't go too far in the wrong direction. The front tires should be zero lead or slightly pulling the tractor, you don't want the rears pushing the front end sideways when you are trying to turn.  
rScotty

On Dec 17, 2020, at 9:32 PM, OneAcre <francisforge@...> wrote:

Update.....

Failing to find anything in print for the YM1401D front to rear gear ratio, I decided to take Scotty's advice and just measure it. This is the method I used.

The tractor was taken off road and placed in 4WD.  A plumb pencil line was marked through the center of the left front and rear rims. A yellow crayon mark was placed on the top of the tires for easy revolution counting while driving.

The tractor was then driven forward in a straight line exactly 10 revolutions of the rear tire while counting the number of revolutions made by the front tire.  A second plumb pencil line was marked through the center of the left front rim to determine the fraction of the last partial revolution. The foregoing was done 3 times to ensure accuracy.

The result was almost exactly 14.75 revolutions. Dividing by 10 gives my YM1401D a front to rear ratio of 1.475. Time for a trip to the boneyard for tires!

.....OneAcre


Winston Linda Maberry
 
Edited

For what it's worth the 220/226 repair manual calls for 1 to 4% front wheel pre-run percent with a wear limit of 0 and 6%.

Also the 276 repair manual calls for 0% with a wear limit of 0 and 6%.

Having followed these converstations for a long time my conclusion is better to have a little positive front tire lead and just make sure you don't have a rear tire lead. 


Scotty
 

I would agree with what Winston says. From my experience 0% works fine, and somewhere around 5% is about the limit for avoiding driveshaft windup problems if you have a loader, soft ground, or asphalt surface...anything that will not allow a front the tire to slip easily.  

How much windup the system can tolerate has a lot to do with the traction of the ground and especially how much of a load is in the loader bucket. You need to allow the front tire to slip if it needs to. That's maybe the most critical.... Without a loader and with a medium to heavy three point implement - i.e. normal farm tillage or rice paddy work - the system ought to be pretty safe from damaging itself whether in 2 or 4wd. 

If you go to shift OUT of 4wd - and the 4wd lever doesn't want to move - then there is too much windup stress in the system. Eventually operating that way will break something.
rScotty


On Dec 18, 2020, at 5:54 AM, Winston Linda Maberry <mabe1945@...> wrote:

[Edited Message Follows]

For what it's worth the 220/226 repair manual calls for 1 to 4% front wheel pre-run percent with a wear limit of 0 and 6%.

Also the 276 repair manual calls for 0% with a wear limit of 0 and 6%.

Having followed these converstations for a long time my conclusion is better to have a little positive front tire lead and just make sure you don't have a rear tire lead. 


Hal Hadaller
 

I broke my stub axle on right rear wheel. Overworked poor 1820D after hurricane Michael. 4WD is mandatory with loader. Also a box blade or weight on the rear. Otherwise loader is a wheelbarrow. Have had 1820D 20 years and this stub axel is only problem. However Kyoker 110 has been constant problem. Change cylinders from 1 3/4 to 2" ones so seals stay in now. But attachment to 2 8mm bolts on each side a joke. Gradually up'ed size to 5/8" so bolts don't break now but bolts in shear don't hold much and loctite plus lock washers, still get loose.

Great little tractor.

Hal - Panama City

On Dec 18, 2020, at 8:19 AM, Scotty <roger@...> wrote:
I would agree with what Winston says. From my experience 0% works fine, and somewhere around 5% is about the limit for avoiding driveshaft windup problems if you have a loader, soft ground, or asphalt surface...anything that will not allow a front the tire to slip easily.  

How much windup the system can tolerate has a lot to do with the traction of the ground and especially how much of a load is in the loader bucket. You need to allow the front tire to slip if it needs to. That's maybe the most critical.... Without a loader and with a medium to heavy three point implement - i.e. normal farm tillage or rice paddy work - the system ought to be pretty safe from damaging itself whether in 2 or 4wd. 

If you go to shift OUT of 4wd - and the 4wd lever doesn't want to move - then there is too much windup stress in the system. Eventually operating that way will break something.
rScotty


On Dec 18, 2020, at 5:54 AM, Winston Linda Maberry <mabe1945@...> wrote:

[Edited Message Follows]

For what it's worth the 220/226 repair manual calls for 1 to 4% front wheel pre-run percent with a wear limit of 0 and 6%.

Also the 276 repair manual calls for 0% with a wear limit of 0 and 6%.

Having followed these converstations for a long time my conclusion is better to have a little positive front tire lead and just make sure you don't have a rear tire lead. 


KC2GIU
 

Hal,
 
Other than lock-washers, is there room for nylock nuts?  The rear sway chains with the old brush mower would hammer on the lower arms, the chains would unwind or the lock-washer would give way.  Then out of no-where, the lower 3PT arms would go fully back and forth.  Took weeks finding parts and pieces in the tall pasture grass.  Now, it's nylock nuts 100% of the time.  I have a write up on TractorForum.com in the Yanmar section and one at Hoye's YMOwners.com forum to improve their standard product that is sold everywhere too. 

Back on the topic here.

Even with ALL the fine tuning for the front and rear, it is important to monitor tire pressure for all 4 wheels.  A good rim and good material tire will hold air for long periods of time.  Something to keep in mind.

Steve