Stabilizer cylinder replacement on JD Model 48 backhoe

DanMc77 · Jul 13, 2021

I'm creating this thread to document how a stabilizer cylinder was replaced on my model 48 backhoe using an aftermarket cylinder.

Why replace the cylinder? I was sloppy and nicked the chrome with one of the backhoe teeth. I was careful to immediately clean up the protrusion created by the nick, and that didn't seem to create a problem. However, I think it may be one of son-in-laws hit something with it and created a terrible scrape on the side of the chrome rod. I didn't notice it, and that scrape acted like a file to chew up the seal. In a short time, the cylinder was leaking profusely.

I chose to not bother with JD (they will want a small fortune) since I could pick up a brand new cylinder from Magister for $170 including shipping, and modifications were fairly simple to work through. The biggest issue was that the original cylinder is 22" retracted, but the closest aftermarket cylinder is 24" retracted. Additionally, the JD original is a 15" stroke, while aftermarket is 16". My goal was to be able to easily replace the cylinder, since this is very likely to happen again with multiple people running the machine, so I don't mind tweaking the machine to make it compatible with an aftermarket part. I preferred to use a cylinder with the Tang ends, but that was out of stock, and I had a time-crunch to get the machine running again. Here's the link for the cross-tube cylinder used:

2.5 bore x 16 stroke hydraulic cylinder, welded cross tube double acting cylinder | Magister Hydraulics

2.5" bore x 16" stroke cross tube hydraulic cylinder 3500 PSI. Heavy-duty hydraulics, 2-year warranty, free ground Continental US shipping. Magister cylinders manufactured using steel piston and steel threaded gland with wear rings for long life. Welded cross tube ends, honed cold-drawn tubing...

www.magisterhyd.com

To deal with that extra retracted length, the stabilizer arm was removed, and extended by 2". Bushings for the pins had to be made because the stock pin is 7/8", while the cylinder pin bores are 1". How does JD come up with such a strange pin size??? The cross tubes had to be trimmed a little bit to fit the width of the stabilizer arm.

Here are some pics of the installed cylinder.

If you look closely, you will see the two welds near the foot where the stabilizer tube was cut, and a 2" section of tube was welded in. Some fresh paint makes it look pretty. I need to paint the foot so it's pretty too (yeah, like that matters).

One final note: If you look closely at the photos, you will see that I had to remove one of the bolts that secures the backhoe to the tractor mount. This bolt interferes with the hydraulic elbow fitting. I'm not terribly worried since this is one of 7 bolts that hold that together. I picked up a shorter bolt that doesn't span the full width, but will still secure the two parts together. You'll have to study the photos to figure out what I'm talking about here. In the photos, the new bolt is not yet installed.

RocknRoll · Aug 1, 2021

Dan, Your posting and detailed information has been incredibly resourceful to me. I am in the same predicament with the exact same tractor / backhoe. I work with rocks and stone and have ignored the abuse on this extremely important component. I had them rebuilt from a pro shop once, for about the cost of new ones but a nick on one of the casings and who knows what on the rods with rocks, rocks, debris and gravel in and amongst them....the rebuild didn't last long.

In any event, I also discovered Magister and just ordered and received a new pair. I went with a "pin eye" 2.5 by 12.

Did this thinking I could live with a lesser retract and extension. Just use blocks for the extension. Just received shipment yesterday and found that darn bolt in the way. It seems to be holding the deck platform and backhoe frame or something. There does appear to be welds among those two plates. A little apprehensive about removing those bolts though.

Having seen your post, I am thinking about returning these items for the cross tube 2.5 x14 and I know, regardless, those bolts gotta go. Am I correct that the 14 inch stroke is closer to what we have on our JD specs? And then just live with a little less performance but more that I just ordered? Kinda wondering why you wouldn't have gone with the 14 rather than adding on to the stabilizer arms?

In as far as the cross tube mounts. How far did you have to refine them to fit the mount and what did you do to do that? Would there be anything wrong with just using my grinder to do that?

To even better fulfill this communication, I see that you have a camp in Conway, NH. I am in Freedom!!
Remarkable how close such like minds can be!

I'm not an avid forum goer but thanks for posting and look forward to your or any replies.

DanMc77 · Aug 2, 2021

I sent you a PM.

I wanted to go with the pin-eye, but Magister was out of stock and I needed the machine back up and running. Now that it's all done, I'm glad I went with the cross-tube because it's a better finished product. The cross tube creates a better pivot interface that will keep dirt and junk out.

As for the bolt: like I said in my post, there's a total of 7 bolts. The one that's in the way is just one. I found another shorter bolt to put in there and so I still have 7 bolts holding it together, it's just that this one grabs onto the plate and doesn't reach all the way to the other side. I'm 100% confident that this is fine.

On the cross-tubes, I put them into my milling machine and trimmed them down by about 1/4" to fit into the existing spans.

As for modifying the stabilizer arm, I wanted to end up with an easy replacement for the next time I drop a rock on the cylinder. The original is a 15" stroke. Nobody makes a 15" stroke cylinder. I didn't want to lose range of motion, so by adding 2" to the stabilizer arm, then I could use the inexpensive Magister replacement with very little effort to do the install. Trimming the cross tubes was not a big deal. And slicing the stabilizer arm, then welding in a 2" extension is easy also. So if I drop a rock on the other side, I'll do the same thing over there. I already have the 2" steel piece cut out and ready to be welded in when the time comes.