440ic crankshaft-regrind or replace?

[yasmar]

Rebuilding my crawler motor...machine shop guy says you can't regrind the crank because it's too old, it'll weaken it.

Opinions?

Source for new ones? Lavoy?

[Lavoy]

I have reground somewhere close to 50 cranks, never had a failure. Seriously, I have no clue what your machine shop guy is talking about. As far as my opinion, I would go to a different machine shop. You are probably talking .010 or .020 undersize. That is a .005 or .010 cut, how in the world he thinks that will weaken a crank is beyond me.
Lavoy

[mini kahuna]

those old cranks were made with some REAL good material,they take grinding just fine,I even had a machinist tell me after grinding a 440 crank it was the nicest stuff he every ground on.

[tstiles]

my 440 ic crank is at the machine shop right now . never heard such thing as bein to old. i think my machinist said 40 thousands was max 4 undersized bearings,that he can get.

[Stan Disbrow]

Hi,

Perhaps the crank has been ground before and one more would put it too far undersize?

That's the only way I can see it becoming too weak.....

later!

Stan

[Ray III]

Crankshafts are surface hardened and cutting out too much removes your hardened journal.

But this is not an issue when cutting the small amount for an undersize bearing.

[yasmar]

continuing saga...learn today they can't grind it because they can't find the correct bearings. They want to MagnaFlex it and send it to have material welded on to be ground down to starting size.

Obviously, there must be bearings available...any one have apart number I can throw at these guys?

This crank has never been ground before.

Unfortunately I don't have too many machine shop options up here.

[Eric.MacLeod]

id pass on that shop.sounds like they are used to small block chevys and not john deere cranks. it will cost you more to let these guys experiment on your crankshaft than its worth. and they dont need bearings to turn your crank all they need to know is stock and then turn it 10 or 20 thousands down. ive dealt with shops before that dont want to loose my dollar so they say oh we can do it, yup cost a heck of alot more than it shouldve. now my machine shop that i use can do any work i need and alot cheaper than the idiots i had in the past.. Eric..

[Lavoy]

Standard, 10, 20, and 30 thousandths are readily available, some of them I stock. These guys must be total retards. If they can find standard bearings, the undersize bearings are on the exact same page of their parts book right under the listing for the standard bearings. If your guys can not figure out how to grind a crank, nor can they find bearings, I would not do business with them if they ground it for free. Anyone that incompetent would never do ANY work for me. Where you are at is not really that big of a deal, there are any number of people on this board that have competent shops to deal with, and shipping is easy. I have shipped multiple cranks, reground or otherwise all over the country. I would invest in a little freight money before I would let these clowns touch anyting of mine.
I don't know what it would cost to weld and regring a crank, but I would guess somewhere past what it would cost to ship your crankshaft to Russia and back.
Seriously, I would absolutely not do business with these guys. Get a price from them on all of this nonsense they want to do, and my guess is you can send the crank to me, and I can send it back to you cooked, magnafluxed, ground, and with the correct size bearings for what these clowns will want for their nonsense. The only possible catch is if you crank has been ground to maximum undersize, or has a defect too deep to clean at maximum undersize. Not that it is impossible, but in 20, 30, or more cranks I have done, I have NEVER had to go past .020 on any of them. I have had customers have to go to .040 on rods on very few occasions.
Lavoy

[mini kahuna]

I couldn't of said it better,we just had a allis crank ground,guy took off .10 the bearings and crank were back to me in a week.

find another machine shop

[Lu47Dan]

Lavoy +1
Find another shop to do the work, I drive about 20 miles to go to a shop that I trust. If the journals are standard and there are no big gouges in them then grinding them to the first undersize should not be a problem.
I found the shop I used while looking for a shop that could grind a crank for a Wisconsin TRA-10D, my two locale shops want to go .020 under right off the bat, the shop I use now, did it and it cleaned up at .010 under.
Machine shops may be scarce in your area but it is worth spending the time to find a good one.
Dan.