Yanmar 3pt hitch lifting specs for US models

[rScotty]

I ran across this page this morning and thought I'd post it.

Some history: Back in the 1970s, the various compact tractor companies were vigorously competing on specsmanship, and one way they did that was by advertising FEL and 3pt lifting specs - but conveniently without mentioning just where these were measured. i.e. not actually lying about it, just helping customers form their own false conclusions....

Yanmar was a guilty as the rest. But dealers and their mechanics needed to also know the correct numbers. So Yanmar provided this sheet to its dealers, and also at about that time they were one of the first to change their advertising to include information presented in this more usable format.
rScotty

 

[California]

rScotty thank you!

I had only seen the advertised lift numbers (at end of 3-point arms) and wondered why the YM240 struggled to lift the Yanmar backhoe that had been an option for it back in the day. Now I see YM240's 24 inches out rating is only 661 lbs. That chart explains a lot.

I read somewhere this backhoe is 750 lbs, and that's what its previous owner told me, also. No wonder the tractor's relief squeals if I drive over a bump.

 

[clemsonfor]

If it's really that heavy was it really an option for the 240 or for larger tractors? Seems like they wouldn't recommend that or waranty a tractor that they outfitted over it's rated capacity?

 

[California]

If it's really that heavy was it really an option for the 240 or for larger tractors? Seems like they wouldn't recommend that or waranty a tractor that they outfitted over it's rated capacity?

Here's the spec on shipping weight, 785 lbs: last pic in this post is the YBH600 Manual. That photo on the manual cover sure looks like a YM240. What other models existed in 1978?

And here's someone who has that hoe on a YM155, he says it hasn't caused problems. But my YM186D has the same rated lift capacity as YM155 and the YM186D can't lift it. There's also a link in my post #9 in that thread to a 8/81 price list that says the YBH600 is for tractors 19 to 35 hp (which would include YM240 sold at that time) and weight 650 lbs + 35 for the 10" bucket. Add 5.5 gallons of Hy-Gard, and its over 700 lbs to be lifted.

 

[California]

rScotty in an old post of yours
https://www.tractorbynet.com/forums/yanmar/209956-backhoe-identification.html#post2404092
you said you used the YBH600 on your YM165.

My YM186D is rated same lift capacity as YM165 per that chart above. But it can't lift that hoe. It strains and squeals, even if I lift the hoe with its own hydraulics then raise them to shift all the load onto the tractor's 3-point.

Any advice on what I need to do, and how you accomplished using that hoe on your YM165? The only thing that has occurred to me is to remove the safety restrainer under the arms temporarily and test again. As I recall I loosened the restrainer bolts when I tried lifting it but that didn't help.

If I could carry that hoe with the YM186D, I could slim down to just that one tractor.

 

[rScotty]

rScotty in an old post of yours
https://www.tractorbynet.com/forums/yanmar/209956-backhoe-identification.html#post2404092
you said you used the YBH600 on your YM165.

My YM186D is rated same lift capacity as YM165 per that chart above. But it can't lift that hoe. It strains and squeals, even if I lift the hoe with its own hydraulics then raise them to shift all the load onto the tractor's 3-point.

Any advice on what I need to do, and how you accomplished using that hoe on your YM165? The only thing that has occurred to me is to remove the safety restrainer under the arms temporarily and test again. As I recall I loosened the restrainer bolts when I tried lifting it but that didn't help.

If I could carry that hoe with the YM186D, I could slim down to just that one tractor.

Hmm.... Yes, our YM165D had no problem lifting the YBH600 hoe. I don't even recall it being borderline. It just lifted it with ease. I'd had that YM165D since new, and it had the best of care so the hydraulics were 100%. And its loader ran off an accessory hyd. pump so that small loss wasn't there. Another plus was the FEL weight probably helped balance the weight of the hoe.

But we didn't use that hoe very often on the YM165D, That tractor - even with the front loader - just isn't heavy enough. Anytime we were digging and hit a tough spot the hoe would just throw the tractor around. So the YM165D had no trouble lifting the hoe, or powering it, or withstanding the hoe stresses....but that tractor+loader just wasn't heavy enough to work the hoe. It was like trying to go for a pleasure ride on a horse that likes to buck.

So we put the YBH600 hoe on our farm tractor, a JD530 that weighs about 5 times as much and has a category 2 hitch. That made a much better backhoe out of it, but it would still bounce the big farm tractor around a surprising amount. When we got the new Kubota TLB, I gave the YBH600 hoe to a friend to uses it on his MF35 farm tractor.

Looking back at the spec sheet, the YM165 is penciled in by me. That's probably because when the YM165D first came out, the dealer and I went over it in detail trying to find any parts he needed to stock that were different from the YM155D. We wondered what made the red tractors 165s instead of a green 155 if everything mechanical was all the same? We couldn't get an answer to that question from Yanmar.

Ultimately we couldn't find anything except I think an injector part number and of course the YM165 used the improved camshaft from the later model YM155s. So we finally concluded that the combination of injector and cam gave one extra HP (16 hp vs 15). And we figured that all the other specs were the same too.....
We could have been wrong. Maybe the lift specs 155 to 165 really are different. After all, the YN186 and the YM187 have very different 3pt specs. The YM187 lifts over 1000 lbs at the hitch points.

rScotty

What's the safety restrainer strap? I'll have to look that up. Could it be the problem?

 

[California]

Dang. Now I need to go look for a YM187. Or maybe put on YM165 3-point hydraulics and lifting components.

Hmm - I wonder if putting shorter arms on the YM186D would improve its lift capacity enough.

That safety restrainer on the YBH600 backhoe is a mandatory safety upgrade described in the 1979 Kubota manual I have for that hoe. (Same hoe was sold as Kubota or Yanmar, the specs and appearance are identical).


There's a photo in this old post. Then another photo farther down with more description. It is essentially a bar that goes below the 3-point arms. Its purpose is so the hoe can't pitch forward if the top link or its mount breaks. But the restrainer can also bind up the lifting geometry.

 

[rScotty]

Dang. Now I need to go look for a YM187. Or maybe put on YM165 3-point hydraulics and lifting components.

Hmm - I wonder if putting shorter arms on the YM186D would improve its lift capacity enough.

That safety restrainer on the YBH600 backhoe is a mandatory safety upgrade described in the 1979 Kubota manual I have for that hoe. (Same hoe was sold as Kubota or Yanmar, the specs and appearance are identical).


There's a photo in this old post. Then another photo farther down with more description. It is essentially a bar that goes below the 3-point arms. Its purpose is so the hoe can't pitch forward if the top link or its mount breaks. But the restrainer can also bind up the lifting geometry.

Yes, if nothing else changes, shorter arms should improve the lift ability. You can compare the specs at the hitch ends vs 24" behind the hitch ends to get an idea of what you would gain by shorter arms. It would be an interesting experiment.

Are you sure about the reason for that safety restraining bar? BTW, mine had it too.

It looks to me that is a preventer to stop the lift of the hoe when the hoe is used on a tractor with automatic draft contol. The YM165 didn't have that feature, but our YM336d did, and of course most farm tractors have automatic draft control. Draft control actuates when there is compressive stress on the top link. The original purpose was to automatically lift the 3pt arms an successive small increments when plowing. That way the plow lifts a little to glide over tough spots.... tree roots, big rocks...that sort of thing. When the tough spot is past, the arms return to their former position.

The danger with using 3pt hoes on tractors with draft control without disabling the draft control is that in some digging positions i.e. pushing down with the bucket - it will compress the top link causing the draft control to lift the 3pt arms, trapping the operator between the backhoe controls and the seat. There were a number of fatalities through the years. It was a common enough farm accident that a few decades ago 3pt backhoes were required to incorporate a safe way to prevent that from happening.
I believe that is what your photo is showing.
rScotty

 

[California]

Are you sure about the reason for that safety restraining bar?

It looks to me that is a preventer to stop the lift of the hoe when the hoe is used on a tractor with automatic draft contol. The YM165 didn't have that feature, but our YM336d did, and of course most farm tractors have automatic draft control. Draft control actuates when there is compressive stress on the top link. The original purpose was to automatically lift the 3pt arms in successive small increments when plowing. That way the plow lifts a little to glide over tough spots....

The danger with using 3pt hoes on tractors with draft control without disabling the draft control is that in some digging positions i.e. pushing down with the bucket - it will compress the top link causing the draft control to lift the 3pt arms, trapping the operator between the backhoe controls and the seat. There were a number of fatalities through the years.

You're right, the manual says it is to limit upward motion, they say to avoid crushing against the ROPS. That thread I cited was discussing pitching forward into the excavation (and crashing against the controls, operating them) if the top link separated, so I assumed that was the designer's emphasis.

Attached: page from backhoe install manual discussing the restrainer.

 

[bmaverick]

nice thread. learned a bunch guys!