Backhoe rebuilding old ARPS 728 backhoe

meb9796 · Aug 4, 2013

I'm rebuilding a ARPS 728 backhoe attachment. I've got it torn down and I'm in the process of removing the old paint/rust, and I'm starting on the list of hardware I need to replace. I've attached a photo, but the pistons that control the left and right movement of the backhoe are mounted under the seat and bolted to the frame using 3 long threaded rods. Where they attach to the frame, there is a spring on the end of each bolts between two washers, held in place by a nut. My question is A) where do I find these springs (Mcmaster-Carr's inventory is too big for me to figure out which one I need and/or B) Could I get away with replacing these with something else (ie 2-3 lock washers, etc).

thanks in advance.

I'll post some pics when I get more of it down. Got the first coat of John Deere Green on about 1/3 of the pieces parts this morning.

2458n · Aug 4, 2013

I would think the springs are there to provide some,'' cushin''. I would check to see if there is the posibility of any movement before replacing with a hard type of fastening method. Are the springs completely collapsed?

meb9796 · Aug 5, 2013

About half of them were compressed or slightly deformed. All the threaded rods were bent, so I think this thing has seen some abuse. Was able to heat, straighten, and run a die down them, so they'll work again.

Brad_Blazer · Aug 5, 2013

Contact Ameriquip and see if they stock or have the specs for the spring p/n arp-8673. Otherwise measuring the spring and finding one that is close enough at McMaster isn't that hard.
http://www.amerequip.com/assets/documents/728-backhoe.pdf

meb9796 · Aug 18, 2013

I have that manual, and all the part numbers. I'm also having a problem finding the pin retainers that were broken off. I've been to Amerequip's website, but didn't see a listing so looked elsewhere. I'll send them an email to see what they say. Thanks for the idea.

meb9796 · May 16, 2014

Just to update, I finally found a replacement retaining pin in JD parts catalog (m118630). Ordered 10 of them from our local dealer and have finally start reassembling. I also found the spring I mentioned above by walking into my local tractor repair store and asked if they had one close to it. Got six and this pistons are on and rock solid. I'll add more photos the farther I get along.