D7-17A Broken Spring

[Dick Tucker]

Skywagon70 the box that I was talking about on the spring leaves holds them together. The broken leaf is right at this box. Do you have to replace all four of the leaves that are held dogether by this box? The tractor that I am working on is a cable lift. If I weld the bottom broken leaf to the next one up do you think this will keep me from being able to replace the bottom broken leaf in the future? I can probably weld the bottom side of the crake but I did not know if this would help much. Welding the two leaves together on both sides for 6 inches would not be very difficult. How many weld passes do you recommend to weld the leaves together on each side?

[Dick Tucker]

Skywagon70 the box that I was talking about on the spring leaves holds them together. The broken leaf is right at this box. Do you have to replace all four of the leaves that are held dogether by this box? The tractor that I am working on is a cable lift. If I weld the bottom broken leaf to the next one up do you think this will keep me from being able to replace the bottom broken leaf in the future? I can probably weld the bottom side of the crack but I did not know if this would help much. Welding the two leaves together on both sides for 6 inches would not be very difficult. How many weld passes do you recommend to weld the leaves together on each side?

[skywagon70]

Dick
I would tend to just weld the 2 leaves together and not bother with the crack. the fact that you can easily weld the 2 leaves together is what makes this procedure somewhat attractive, it does induce different stresses as the leaves in an unbroken spring do slide on each other as they flex. welding will not allow that side to do this any longer and the 2 leaves will function as one
You can airarc the weld off to replace the broken leaf and not hurt the servicability of the other leaf much but i would try to find a servicable complete spring pack or better yet a hard bar because the removal and the replacement of a spring pack is no easy chore, and there is no use tempting fate with a leaf that has been compromised at all
I have also bridged a broken leaf with a short piece of spring the same width and thickness but with the box that would mean leaving it off or modifying it to fit over the thicker spring pack
If you do weld it keep watch on the ends of the welds for cracking every day or so
Butch

[skywagon70]

Dick I would tend to fill the v formed by the beveled edges of the leaves full of weld
Remember it may last a long time then again---------------
Butch

[Dick Tucker]

Skywagon70 thanks for the information I was already thinking about bridging the cracked spring on the bottom with another piece of material and not weld the broken leaf to the unbroken leaf since this would be a problem with the flexibility. I can make the box around the four leaves fit into the splice piece. This will give me time to either find a replacement leaf or as you mentioned a hard bar retrofit. Has a hard bar retrofit been done on a D7-17A that you know of?

[Old Yellow Cat]

I have a good spring for a D7-17A. The orginal owner replaced it with a Hard Bar. If you are interested, let me know how I can contact you.

[Dick Tucker]

Old Yellow Cat you can send me an email at dktucker@aep.com and let me know how much you want for the spring and where you are located. The leaf that is broken is the bottom leaf. Is the one you have available the whole set of four leaves that are held together by metal straps close to the ends at both track roller frames?

[Old Magnet]

A complete spring is seven leafs not four.
The heavy duty version has eight leafs.

The standard 7 leaf spring has three leafs (lower 3 clipped)
The heavy duty version has four leafs clipped

[Dick Tucker]

Old Magnet I have the heavy duty version. I have eight leafs with the bottom four leafs clipped together. Do you have any idea what the whole spring assembly of 8 leafs weights?

[Old Magnet]

I have no idea what it weighs.
You should be able to get a pretty good estimate by measuring the leafs and figuring at a weight of 0.2904 lbs/cu. in. or 490 lbs/cu. ft.