H Crankshaft

I took my farmall H crankshaft to the local napa (they have a machine shop). The monkey pressing the button on the machine decided instead of informing me of a very small scratch on one of the main bearing surfaces, to just grind all the main bearing surfaces to .040 under. Found this out when I went to assemble with .030. No one makes .040 bearings. The monkey then decided to tell me to just shim up the bearings. Will this hokey fix work or what do I do? I already have almost $350 into this crank and bearings and don't want to invest to much more. HELP???!!!

If he ruined the crank, don't pay him. I would talk to the owner of the business and ask for a new crank. However there was a post a few days ago about a .040 under crank, but it may have been for an M. I believe D Slater made the comment, he will probably see this and respond.

Iv got .40 under actually .45 under on a M crank. there Federal Mogul so there out there or were out there at least for the M.


Andrew

The aftermarket bering companies only go to .020 or so I was told by this site, Napa, and the IH dealership. Clevite's website confirms this. The Owner (or zoo keeper as I will refer to him from now on), backs his monkey. He said that I wanted it cleaned up and didn't specify that there were no .040 bearings available. Even though I provided a .030 thrust bearing I guess they couldn't figure it out. What do you think about a .005 shim stock around the bearing halfs to the stop tangs, and some fancy flat file work?

Have him weld it up & grind back to a standard size. Or pay another machine shop to do it for him.

The correct way to fix this is to build up the journals, and turn them back down, OR have a custom set of mains made.

I would be a bit concerned with .040 off the mains that the case hardening would be thin or gone. Additionally, shims will have to be made with the tab to fit into the slot so the bearings don't spin.

At the end of the day, I would NOT pay them unless they made it right. I have been rebuilding all sorts of engines for 35+ years. Any machine shop I have worked with mic's the journals BEFORE they start, and then asks me how far I want to go. There are all sorts of ways to resurrect a crank with undersize journals, however, none are cheap to do it correctly.

In a few cases where a mistake was made, I found that splitting the cost of "making it right" often times was the path of least resistance if the shop won't step up and make it right. You have to put a price on your aggravation and time. At some point, you need to cut your losses.

I probably would get a new crank in this case and have them swap out the undersize bearings for standards and call it a day........then never do business with them again. The quality of a business is not that they don't make mistakes........the quality of a business is what they do WHEN they make mistakes.................because crap does happen.

IMHO. good luck.

I don't think a reputable machine shop would have
ground those journals that much without contacting the owner. I would tell them if they can't find the correct bearings that you want your money back. It was their mistake.
Some of the people that post on here have parts tractors so you can probably find another crankshaft. I wouldn't try to shim that as it won't last and the bearings will probably spin.
Hal

Most shops that grind cranks want to furnish the bearings for it, and if not a good shop will want to know exactly what bearings you have or plan to use before machining. If you told them you were using .030 bearings they messed up, but would just be your word or there's if nothing in writing. Some shops will think your a pain in the you know what when you tell them exactly what you want on machine work and then double check there work when its done. With most after they get to know what you expect they try to please. If not its time to move on.
I wouldn't want to use a .040 crank, but thats just my opinion. Sure wouldn't use shims and if thats what the machine shop said to do, ditch them. Wouldn't want to pay for a crank they turned unless they could funish the bearing size also.

(quoted from post at 23:47:04 03/08/10) The aftermarket bering companies only go to .020 or so I was told by this site, Napa, and the IH dealership. Clevite's website confirms this. The Owner (or zoo keeper as I will refer to him from now on), backs his monkey. He said that I wanted it cleaned up and didn't specify that there were no .040 bearings available. Even though I provided a .030 thrust bearing I guess they couldn't figure it out. What do you think about a .005 shim stock around the bearing halfs to the stop tangs, and some fancy flat file work?

Click to expand...

If you use the .005" shim stock and remove .008" from each end of each insert you should be very close to the correct bearing clearance. That adds up to a lot of extra work for a result that is only second best.

May be a little late for a reply, but here goes.

Do NOT do the shim stock thing. The little tangs on bearings only help locate them left and right in the rod or main. They do NOT keep bearing from spinning if something goes wrong.

The OD of the bearing shells put together is slightly large than the ID of the rod bore. This is called "Crush" and is what keeps the bearings in place.

(quoted from post at 23:04:20 03/10/10) May be a little late for a reply, but here goes.

Do NOT do the shim stock thing. The little tangs on bearings only help locate them left and right in the rod or main. They do NOT keep bearing from spinning if something goes wrong.

The OD of the bearing shells put together is slightly large than the ID of the rod bore. This is called "Crush" and is what keeps the bearings in place.

Click to expand...

The tangs on the bearings are absolutely necessary to keep the inserts from turning in the block. In fact, many IH engines have the tang opposite rather than matching so that both tangs act to keep the inserts from turning.

The crush is the reason you need to take about .008" off the end of each insert. If you have .010" smaller diameter, the circumference is .03159" smaller. 4 X .008" = .032" is within .001" of specs.

You also have to provide a hole in the upper shim to allow oil to get to the bearing.

As I posted before, this is certainly less than an ideal situation, but done correctly, it will work.