increasing lift capacity on jd 855

[kimodc]

Is there a way to increase the lift capacity (both FEL and 3 pt) on a jd 855? I have read about shim kits for the 790. Is there something similar for the 855? I am wanting to build pallet forks but am worried about having much lift capacity beyond the forks themselves.

Thanks,
Kim

 

[dfkrug]

My old 955 with the 70A loader had very strong lifting capacity...plenty for
such a small tractor. Unlike the budget tractors of that era (mid to late
90s), the 955 ran 2500psi hydraulics. Your 855 does, too, I am pretty sure.
I would not increase the pressure, but you SHOULD check it. Remember that
your cyl rods are only 1.00".

 

[dsmau]

My old 955 with the 70A loader had very strong lifting capacity...plenty for
such a small tractor. Unlike the budget tractors of that era (mid to late
90s), the 955 ran 2500psi hydraulics. Your 855 does, too, I am pretty sure.
I would not increase the pressure, but you SHOULD check it. Remember that
your cyl rods are only 1.00".

Unfortunately, the 855 shares the same pump as the 755 which has significantly less GPM (5.6 instead of 7.2) and PSI (2050 instead of 2500).
The good news is that it seems to be pretty easy to swap the pump on the 855 with the one from a 955. I think some people have done it but I am not sure where they took their replacement pump. As always, it is very expensive to buy from JD. I am interested in replacing mine just to have faster response when operating the loader. Can anyone with a 955 give the part numbers off their hydraulic pump so I can do some research? Or a picture? Or someone has one for sale?
DSM

 

[dfkrug]

Can anyone with a 955 give the part numbers off their hydraulic pump so I can do some research?

The easiest thing to do is go to JD Parts.com and look at the parts diagrams
to get the part nos. You are right that these x55 tractors have very
accessible implement pumps, which hang off the back of the tractor. I
expect a new pump will be $500 or so from JD. Now I see why you want
to adjust the relief valve.

 

[dsmau]

It is really expensive on JDParts:
AM876999 PUMP ASSEMBLY, HYDRAULIC 1,108.50 CAD
This is probably 1000 in US dollars. Too much for replacing a pump that works fine but just a little slow. I will keep my eyes open for a used one.
DSM

 

[kennyd]

Buy a gauge, a short piece of hose and a QD nipple and test what you have first for $30 or so...then you will have more info to make an informed decision.

 

[Kevin M]

That's a good point Kenny, look in the back of TractorHouse there's lot of salvage yards that break these down, might look into this myself ??

 

[J_J]

A larger pump will not do anything except increase the GPM. A pump with a higher pressure capability will help some. A 2 in cyl with a 500 psi increase will give about 1575 lbs lbs of increased force. A 3 in cyl with a 500 psi increase will give about a 3535 lbs increase of force. Can your tractor handle the increase force?

cyl bore-----shaft-----------psi-------lbs

2------- ---1----------2500 = 7854 lbs
2----------1-----------3000 = 9425 lbs
3----------1-----------2500 = 17,671 lbs
3----------1-----------3000 = 21,206 lbs
3----------1.5---------2500 = 17,671 lbs
3----------1.5---------3000-=21,206 lbs

 

[Kevin M]

That's also a good point , but the 7, 8, and 955 all share the same 70 loader. The pump upgrade should be OK though ??

 

[jenkinsph]

That's also a good point , but the 7, 8, and 955 all share the same 70 loader. The pump upgrade should be OK though ??

What is the diference in the front axles and wheels between the 855 and 955?
I can see the increase in gpm much more readily than an increase in pressures. Now if the axle and tire load ratings are the same you should be okay.