Hey Steamroller, I will have to put a tape measure on my track ajuster bolts to be sure of size. Will get back to you on saturday.

SJ;
The bolts on the D4 are so rusted that there no threads left to work with,Getting the bolts off is going to be a real challege! I was thinking of torching the nut in half while it is still on the machine so everything does not fly everywere? I'm open for any advice on how or how not to do this the safe way.I think if I start to turn the nut that the spring will push it off the threads. I called the fastenal in my area they said that they can get allthread 1.50" galvanized for 175.00 for 6 feet,7.00 for each nut they said that it is grade 5 not grade 8.Will grade 5 work or is it too soft? also I am trying to get the blade supports off to make it a little easyer to work on.The 8 bolts are 1"x1/8 they are frozen on I tried a 1" impact nothing,I don't see any way too get any penatrating oil to the threads,Any thoughts on this problem? Thanks again STEAMROLLER

Did you try aftermarket source for the spring bolts??? Do a search for your part number on www.machinerytrader.com .
I bought spares a few years ago from www.heavyquip.com and they came in "Regal" wrapping. I don't recall them being very pricey and a lot less hassle.

I have had to use my 2500 ft-lb hydraulic impact wrench to get those blade support bolts off....1 in. air impact wouldn't even touch it. You do need and impact wrench to get them off.....heat and penetrant won't do any good there and the big cheater and socket applies to much bending resulting in broken bolts.

Do not take risks disassembling....get them to a press where you can release the tension safely.

I measured my old ajuster bolts I have 1 3/8". My bolts are worn but all 4 are the same. Hope this helps.