I have been trying to locate the 2 lifting eyes to remove the counterweight on my PC128UU-1. The service manual tells how to remove the counterweight, but does not give the bolt specs, or bolt part number. I researched and discovered it might possibly be a M42 x 3.0MM. I cannot find one online. I have called the local Komatsu dealer, and they can not tell me what the size is, and they can not even locate one in their data base. "Just bring it in, and I am sure we can remove it" they said. Yea, right.... Anyway, can anyone out there be of any help?? Thanks in advance.
Yep, I can help. Had the same issue a few years ago with a smallish Komatsu HEX, can't remember the model now but the threads were a big metric size. We found out the weight of the counterweight, chose two standard eyebolts (M24 maybe?) that were rated for the load and made two step down bushings to suit. In other words two short steel tubes with the big thread on the outside and M24 on the inside. If you don't have a lathe, your local machine shop should be able to turn them for you.
Re-reading this, are you saying you don't know what the thread is? Just measure it. Measure the inside of the hole with verniers, that will be your root dia. Measure the pitch, a six-inch ruler should be close enough on a coarse thread like this if you don't have a pitch gauge and do a google search for a table of metric threads. It should be pretty easy to work it out.
The two threaded holes where the lifting eyes go have a fair amount of corrosion in them. Before I ever screw any eyebolt in them, they need to be cleaned out with a tap. Rather than measure and estimate the diameter and pitch, I was hoping someone would know the exact dimensions. The taps cost about 80 bucks. Komatsu is no help what-so-ever. I thought about getting two long bolts and welding heavy rings on the ends. The counterweight only weighs about 5500 pounds. So, I guess I will attempt to measure the diameter and pitch.
I'll see if I can measure mine tomorrow. Would've been a hell of a lot easier to install the new lift pump, fuel lines and water separator if I had pulled mine.
Mcmaster carr sell these http://www.mcmaster.com/#eyebolts/=...load cap 13,880, p/n 3107T65, cost 87.00
Here you go. I dug out the tap we used. Can't find the eyebolts though.
Cmark is correct. Not sure why your dealer was unsure of size, the below screenshot is take from shop manual.
Thanks to all for the info. I ordered a M42x3.0 tap. I am still looking for eyebolts I can afford. I had one quote of $325 each. At that price I will pass. Does anyone know where I can locate regular M42x3.0 bolts, about 3.5 to 4.5 inches long (100mm)? I have sent numerous email to all the metric dealers I could find, with no luck. Thanks. chipz
M42x3 is a metric fine thread and not commonly available. You need to go to your local machine shop. It should be a simple matter for them to turn the thread and make something for you similar to what I described in post #2.
Couple 1-3/4 blank forged eyebolts with a shoulder would be perfect to have machined and threaded? http://www.grainger.com/product/KEN-FORGING-Eyebolt-3JWN4 http://www.toolsforshop.com/eyebolt-blank-w-shoulder-1-3-4x3-3-4-in-model-k2035-blank.html