Bent bucket cyl on model 48 backhoe

[ptsg]

The mini excavators don’t have stabilizers, but have a blade that can serve the same purpose, so your comment makes a lot is sense. I think maybe their tracks are wide and stiff enough to handle the load.

Looks like you dug up a dinosaur turd.

I would've been happy if it was only one turd. Turned out it was three in total and the other two were the biggest ones. I had to break them in smaller pieces by hand.

I'm very surprised how these tires handle all the abuse. The tires come from a very light duty Citroen hatchback and mostly are from the year 2000 to 2005. I haven't had any blown tires and the only damage they get is from the tracks rubbing on the sidewalls.

 

[DanMc77]

I need some help from somebody with one of these model 48 backhoes. I need the length of the upper cylinder pin, #13 in the attached exploded diagram. I received the replacement cylinder and will need to make a new pin. JD used a 1 1/2" pin, but the new cylinder has a 1 1/4" bore in the body pivot, so I need to make a new pin and machine some bushings. I live in MA, but the machine is in NH at this time. I failed to measure the width of the dipper up by the pivot. The JD dealer doesn't have any info on the pin dimensions, so I'm left guessing. I could make the pin long, then cut it down shorter later, but if I had the exact width of the dipper, I could eliminate that step. Thanks!!!!!!!!!

Here's also the URL for the parts catalog page:

https://partscatalog.deere.com/jdrc/sidebyside/equipment/69939/referrer/navigation/pgId/270324131

 

[TractorGuy]

Have you looked at the cost for a new rod and kit? I would keep it original if those parts are available close to the new cylinder price.

For the poster with the leaking cylinder you should just reseal it.

That said I used 2x18 cross cylinders from Magister in all 4 locations on my JD 420 loader. I had to trim one end and shim the rod end with shaft collars. My fittings ended up on top and bottom instead of the sides but I was already replacing all the hoses.

This is my thread on the conversion for a 420 loader. Aftermarket Cylinders on 420 Loader

Check for USA cylinders too. Prices seem to fluctuate. A couple of weeks after I committed to use Magister the price of comparable Prince cylinders went down.

 

[DanMc77]

Have you looked at the cost for a new rod and kit? I would keep it original if those parts are available close to the new cylinder price.

For the poster with the leaking cylinder you should just reseal it.

That said I used 2x18 cross cylinders from Magister in all 4 locations on my JD 420 loader. I had to trim one end and shim the rod end with shaft collars. My fittings ended up on top and bottom instead of the sides but I was already replacing all the hoses.

This is my thread on the conversion for a 420 loader. Aftermarket Cylinders on 420 Loader

Check for USA cylinders too. Prices seem to fluctuate. A couple of weeks after I committed to use Magister the price of comparable Prince cylinders went down.

Yeah, I called JD on replacement parts. They said the replacement cylinder is $1500, and it's not available. They do have a replacement rod for $500. I'm not doing that when I could get a complete new cylinder from Magister for $177, including shipping. I just need to do some minor machining to make it work. I just went through the same thing with one of the stabilizer cylinders. I have no desire to "keep things original". In my case, I'm adapting things so the machine is compatible with common off-the-shelf parts, rather than getting screwed by JD. In the case of the stabilizer cylinder, I just needed to stretch the stabilizer arm 2" longer to make it compatible with a cylinder from Magister. In that case, I didn't have to make any changes to the cylinder, so if I drop another rock on the chrome rod, I can just pick up another cyl for a couple hundred bucks and I'm back in operation. I'm looking at options for a shield to protect the stabilizer cyl rods.

I still need to know how long to make this pin.

 

[Quebecguy]

On my 48 Backhoe the overall length of the pin looks to be 7 3/8" while the width of the dipper measures 7 1/16". If you want photos let me know.

 

[DanMc77]

On my 48 Backhoe the overall length of the pin looks to be 7 3/8" while the width of the dipper measures 7 1/16". If you want photos let me know.

FANTASTIC!!!!!!! THANK YOU SO MUCH!!!!!!!!!!!!!!!!

Photos wouldn't hurt, if you have the time to do that.

 

[Quebecguy]

When I measured again for the photos I found that the width of the dipper is more like 7 1/4" at the level of the pin. Higher up it is more like 7 1/16".

 

[TractorGuy]

Yeah if the rod is 500 bucks it doesn't make sense to keep it stock.

Look at the cross and pin eye options too. You might find something that requires less adapting.

As long as the bore isn't much bigger and the detracted length is close you should be able to make it work. If one end is narrow shaft collars make great spacers. In my case 1 on each side was just right.

 

[jthibodeau89]

For the poster with the leaking cylinder you should just reseal it.

I put new seals in it, but the rod is damaged. Loses a drop or two every time the damaged area goes through the seal.

 

[DanMc77]

Many thanks to QuebecGuy for the photos!!!! Yesterday I met up with my buddy who's a better welder than I am. We cut the rod on the new cylinder and welded on the eye from the bent one. The cut off end can be seen in the background, in front of the grinder.

When I bought this backhoe, it had been sitting outside for a number of years. You can see that there's some pitting in the original eye. I'll put a coat of paint on it before assembly.

We discussed options for bushing the 1 1/2" dipper bore to the new 1 1/4" pin size. McMaster Carr has some spring bushings that will be perfect: 1 1/4" shaft to 1 1/2" bore, 2" long. This will be easier than making them.

McMaster-Carr

McMaster-Carr is the complete source for your plant with over 595,000 products. 98% of products ordered ship from stock and deliver same or next day.

www.mcmaster.com

 

[ptsg]

Looking good. Those bushings are cool. First time I've seen those.

 

[Quebecguy]

Thanks for sharing the info on the bushings. Those might come in handy someday!

 

[jthibodeau89]

Great info on the bushings. They should work just fine. How does the width of the tube on the cylinder base compare to the gap between the the mounting plates on the dipper? The clearance should be on the order of 1mm in order to keep the pin in shear and minimize bending moment.

 

[Quebecguy]

How does the width of the tube on the cylinder base compare to the gap between the the mounting plates on the dipper? The clearance should be on the order of 1mm in order to keep the pin in shear and minimize bending moment.

On mine a 1/8" drill bit fits into the gap (or free play) easily. On the rod end a 3/32" drill bit fits in the gap. I don't know how many hours are on it - perhaps a couple of hundred but the backhoe has been working well since I bought it new in 2006.

 

[DanMc77]

Great info on the bushings. They should work just fine. How does the width of the tube on the cylinder base compare to the gap between the the mounting plates on the dipper? The clearance should be on the order of 1mm in order to keep the pin in shear and minimize bending moment.

At this point I don't have an exact measurement of the gap in the dipper. I haven't pulled the old cylinder body out yet, mostly because I wanted to keep the hoses connected until I'm ready to put the new cylinder in. Your comment of a tight tolerance is a helpful insight, so I'll have to be prepared with some shim washers to tighten it up if needed. Additionally, there could be some error in the alignment of the rod end tube that we had to weld on. I'm inclined to run the machine a little while, then pull the rod pin out and examine the wear patterns. It may be good if there's a little slop at the top, so I can adjust the angle of the cylinder a little, if there are uneven marks left in the pin.

 

[jthibodeau89]

Dan, shims won't help for shear. The gap betweem the solid metal of the mount and the cyl cross tube or rod cross tube is what determines bending vs shear.. If the total gap is over 1/8" (1.5mm/side), you may want to consider flanged bushings to close the gap on the base end. The rod end should be fine since you reused the rod cross tube.

 

[DanMc77]

jthibodeau89: Oh, now I see what you are referring to. I thought you were referring to a potential mis-alignment if the cylinder is skewed at an angle. We will see how it fits and go from there.​

 

[DanMc77]

New pin is done. Rather than drill a hole through the pin, weakening it, I'm using heavy snap rings to keep it in place. Plus, I have no way of knowing exactly where the retainer bolt is, since the machine is in NH. Pin is 4140 annealed. All of the pins that I have dealt with in this machine have been soft. There's 7 1/4+" between the snap rings. The bushings should arrive tomorrow.

 

[DanMc77]

Final status on this project.

I am in love with these spring shims. I ordered several of these of various lengths and ended up using the two longer sizes and cutting them down to length --> 2.13". The shims were tapped into the dipper bores, and then the new cylinder could be installed with the new 1 1/4" upper pin. The cylinder cross tube fit perfectly in the dipper with no adjustments to anything other than the shims.

Once it was installed, I noticed that there was a pretty significant gap on the rod end, as seen in one of the pics. The normal assembly has shim washers under the bolts for the retaining pins, and that helps to reduce this gap, but they are not enough to close this up. A couple shim washers were added to take up this space, so dirt has a little more difficulty getting in there.

Everything works perfectly again. Thanks to everybody that contributed their comments for this project!!!

 

[al20hp]

I just had the same thing happen to my bucket. Bent the dam rod!

I was reading your post .I think I am interested in going in the same direction. One quick question. Instead of putting bushings on the one end, why didn’t you replace that end of the new cylinder with the end from the original JD cylinder ?

Also, do you remember how much of the rod you had to cut off?

Thanks
Al

If I use the first one, the loader cylinder, that has 1 1/4" pins. Couldn't I use a 1 1/4" pin, then machine bushings to fit into the 1 1/2" bores in the dipper?

I've been happy with Magister. Mostly, I like their selection, and the prices are great too.