Hydraulic cylinder replacement for a woods backhoe

[Lunker]

Hi -

New member here looking for help with finding a workable replacement for the dipper-stick cylinder for my Woods BH7500 backhoe.

Woods documentation calls for a 2 x 16.75 Double-acting hyd. cylinder - part number 37592
The cylinder I have has a closed length of 24.5" and an extended length of 42.5".. fyi - I have no idea if in fact this is the original cylinder. I purchased this hoe off of craigslist and am in the midst of refurbishing it..

Based on what Woods recommends I do not see an exact match for the cylinder at SurplusCenter but I do see some that are close:
Item# 9-7710-16 a little short - does that even matter? would I notice the difference? I'm new to the backhoe as well to the forum Surplus Center - 2X16X1.25 DA HYD CYL 1 PINS HVY DUTY CROSSTUBE

Item# 9-7710-18 a little long. If it is too long is there an easy way to deal with that? How would I know its too long (without using the hydraulics) Surplus Center - 2X18X1.25 DA HYD CYL 1 PINS HVY DUTY CROSSTUBE

Looking at this from another angle - how could I determine what the optimal cylinder length should be?

My hose fittings are all female 3/8 JIC if that matters.

Bottom line is since these cylinders are 1/2 the price of an OEM cylinder if one would work without issue it seems like a no brainer to get one. [Or comparable from any other supplier]. If on the other hand I need to stay OEM I'll just get the $270 Woods replacement.

Appreciate any guidance...

-Nick

 

[jfay]

Woods parts are more reasonable than most, about a third less than Kubota for the exact same part (Woods made Kubota backhoes). I would just go with the OEM part, you know it will work fine and fit right.

 

[J_J]

A longer stroke will make the bucket fold more.

Open the dipper and measure the pin holes. That would be the cyl length from pin hole to pin hole. Fold the dipper and measure the pin holes. That should be the stroke. Measure pin hole to pin hole for the extended length.

 

[Lunker]

Would I cut right up tight to the cross tube, shorten the rod as needed - and weld back to the cross tube? For cutting the tube - would a chop saw suffice? If this is easy enough to do I may give it a shot - otherwise buying OEM as jfay suggests may be the answer.

 

[KWentling]

Would I cut right up tight to the cross tube, shorten the rod as needed - and weld back to the cross tube? For cutting the tube - would a chop saw suffice? If this is easy enough to do I may give it a shot - otherwise buying OEM as jfay suggests may be the answer.

Chop saw would work OK. The problem I see is if you shorten the rod, (depending on how much it is shortened) when the cylinder is retracted the, the crosstube/weld is going to contact the gland and damage at least the wiper if not the gland itself. You could put a spacer in the base of the tube to contact the piston to alleviate that problem, but after all of that, is that going to give you the correct closed/extended length? Also, the crosstube needs to be very square or the pin will bind up as it moves through the rotation of the boom or whatever this attaches to. I think it would be wise to spend the money on an OEM.

Kim

 

[J_J]

If you are a good enough welder and protect the rod, it can be done. I would leave some space as to not damage the wiper seal.

Look at your cyl now in all positions, and decide if more or less would be any problem.

In a lever situation, a small change will induce a larger change at the other end.

In a 1 to 6 ratio, a 1in change on the small end will cause the other end to move 6 in. Can the machine handle the change.

Perhaps the cylinder can be rebuilt with a new rod and seals.

 

[kennyd]

What is wrong with the cylinder you have? If it's leaking it can be re-sealed, if it's bent then a hydraulic shop can make a new rod.

 

[gengine]

The dimensions that you gave, the 42.5" and the 24.5" is a 16" difference, therefore a 16" stroke. Sounds like the cylinder would work for ya. It's been my experience that its cheaper to have a hydraulic shop repair your cylinder than buying a new one. Especially if its only leaking. A longer stroke would make your dipper fold up more, but you don't want your buket crashing back into the rest of the backhoe. I think if you have to replace it, the .75" shorter than what is called for would be the safer way to go. That 3/4" difference over a 10' arm could mean a foot of travel at the bucket. Good luck!

 

[Lunker]

Actually I had purchased the seal kit for it - it was leaking quite a bit. The gland nut however is stripped - I spent a couple of hrs trying to get it off.. The reason it leaked so bad is because the rod itself is so dinged up the rough spots must have damaged the existing seal. Its also missing chrome in a lot of places. Since a new cylinder is not crazy $$ I just figured be done with it and get a new one..

-Nick

 

[Lunker]

gengine -

I wish I had a hydraulic shop local - but I live in a rural area - nothing close I am aware of.

I think you are correct about the 16" cylinder being the best choice -if I go aftermarket. Tomorrow I am going to take the spec's from this cylinder Hydraulic Cylinders 288-313 Detailed Information and see if it will work.

fyi - I am not trying to be cheap here but if an aftermarket cylinder is a valid substitute for OEM I may try it. The hoe has turned into a $$ pit - all new hoses, rebushed a bunch of pins, made a subframe, 'untwisted' the boom, etc. my wife is getting annoyed with my 'digger' as she call it

Thanks for the encouragement!

-Nick