D7-17A Broken Spring

[Dick Tucker]

While I was working on the engine knock problem I noticed that I have one leaf of the springs that is broken about 6" from the track frame. What is the process of getting the spring out and installation of a replacement spring. Also is there any possibility that the broken spring can be welded back together.

[SJ]

You have to loosen the brackets that support it to the tractor and then raise the front of the tractor up to make room to get it out of the roller frames.No it,s not a good idea to weld it but the leafs are available at a Cat dealer so that,s the way to go. I don,t know if a spring shop would have leafs big enough for it but you could ask.

[Old Magnet]

Got yourself a nice "grunt" job there.
Spring needs to come out the side over the track truck frame.

Remove auxiliary spring.
Jack idler forward and block in position.
Remove idler push arm (outboard), jacking screw and nut plus guide assy.
Jack up the front of the tractor and bring spring assy out over the frame. You will have to rotate the spring to get clearance to bring it out.

I've heard of springs being welded...but I am not a believer and have seen welded leaves crack again in the weld heat effect zone.

Also might consider a suggestion the "old 3T lover" had a few days ago.....go to the D8 spring with fewer/thicker leaves....some tape measure work required

[Dick Tucker]

Old Magnet does this require the track to be broken apart? Also this machine has hydraulic track adjusters.

[skywagon70]

You may get a lot of use out of it by welding . dont worry about welding the crack just weld it to the next leaf if it is a main leaf. or to next in both directions if it is inside the stack
Sometimes the fine art of the cobble will save a lot of time and money.
If you have to hire it done put your money toward fixing it right.
I have finished logging seasons by welding when time was getting short and never had one turn loose with only one leaf broke.
Butch

[Old Magnet]

No, you don't need to split the track.....just get the idler forward so that you can get a wedge between the idler and the frame. When that is secure then back the adjuster off and remove the idler arm, push rod and forward flange at the adjuster.

[Dick Tucker]

Old Magnet my tractor has hydraulic track adjusters. How do you back them off with the idler pushed forward and wedged? In the past I had to put a piece of timber in the drive sproket and back the machine up with the relief valve opened on the track adjuster.

[Old Magnet]

By backing off I mean release the pressure by backing off the screw in the release valve (slowly at first) once the idler is blocked....or back off the relief valve depending on what type you have.

[Dick Tucker]

Skywaggon70 the spring that I have broken is the bottom spring in a stack of four. The break is at the location where all four springs are held together with a metal box around them. Should I cut the box off weld the bottom leaf to the next leaf and them weld the box back together? What type of rod did you use a low hydrogen rod like 7018?

[skywagon70]

Dick sorry not getting back sooner I thought this thread had ran it's course
By the box I assume you are talking about the clamp that keeps the spring leaves in line and also from putting the weight of the roller frames on only one leaf when the weight of the engine section of the tractor is supported on a stump rock etc or when applying down force on the blade with hydraulics
If you are a crackerjack inverted welder you could remove the clamp, weld the underside of the break.weld the two main leaves together then replace the clamp.
I would probably only weld the two leaves together for abt 6 inches on either side of the break and just leave the clamp in place.
It is easy to keep watch on it to see if the welds crack or a new break.develops
weather or not this will get you by largely depends on how you are using it If you are pioneering in rocks and stumps on a project where downtime will eat your lunch I would say replace the broken leaf
If you just use it to clear brush on the back 40 and time is not a prime consideration welding just may get you by a long time
Yes i used 7018 largely because it was what was at hand
Disclaimer!!!!! I tend to be a bit of a cobbler at times lol
Hope this helps you make a decision
Butch