Welcome! Please use the navigational links to explore our website.
PartsASAP LogoCompany Logo (800) 853-2651

Shop Now

   Allis Chalmers Case Farmall IH Ford 8N,9N,2N Ford
   Ferguson John Deere Massey Ferguson Minn. Moline Oliver

Attention Forum Users: On the 28th of December 2023 at 9:00am Central Time, we will be taking the forums down for maintenance while we prepare the new forums for your use. Please click here for more information.

John Deere Tractors Discussion Forum
:

JD Model D crankshaft spec

Welcome Guest, Log in or Register
Author 
Jon

07-20-2003 17:52:22




Report to Moderator

I am rebuilding an unstyled "D" s/n 143458.

1. The connecting rod 'throws' on the crankshaft are out-of-round. Does anyone know how much out- of-round is acceptable on these engines?
2. If the throws need to be ground, I will have to remove the counter-weight mounted on the crankshaft so that the machine shop can grind it. I assume that I can ground or mill off the weld that locks the nuts on the studs that support the counter-weight.

[Log in to Reply]   [No Email]
Paul from MI

07-20-2003 18:28:52




Report to Moderator
 Re: JD Model D crankshaft spec in reply to Jon, 07-20-2003 17:52:22  
Jon,
Kind of depends on your intended use, your own tolerance for "not quite perfection", and how much out of rounbd the journals are. I have a 1941 A thats got the original bearings. When I bought it 27 years ago I did a quick ring and vale job on it. The crank was out of round about .0025" at that time. Since money was tight, I just adjusted the rod bearing shims as good as I could get them and ran it. It's been 26 years, still running with no unusual noises, good oil pressure, not burning any oil, etc. This tractor doesn't see a lot of hard use but it's one that is used every few days for something or other.
Yeah, I wish the crank was in better shape, but it doesn't seem to hurt much within reason.

Paul

[Log in to Reply]  [No Email]
jon

07-20-2003 18:54:59




Report to Moderator
 Re: Re: JD Model D crankshaft spec in reply to Paul from MI, 07-20-2003 18:28:52  
Paul,
I'm picking up a new 3-4" micrometer tomorrow but I think they are out-of-round by 0.010" to 0.015 inches which is excessive - I believe. I've been told that excess clearance allows the lubricating oil film to break down and allows metal to metal contact. That's why I'd like to know what the industry accepts as maximum out-of-round for 3.500 inch diameter crank throws.

Regards,
Jon

[Log in to Reply]  [No Email]
Paul from MI

07-21-2003 18:36:40




Report to Moderator
 Re: Re: Re: JD Model D crankshaft spec in reply to jon, 07-20-2003 18:54:59  
Jon,
I'd be leary of anything more than .003 to .004". The original rod bearing specs allowed about .003" tolerance on the clearance, so I kind of figured I could allow that amount out-of -round if I kept the bearing clearance on the tight side. So far it's worked for me. If you are in the .010" to .015" range you definitely need to grind the crank. Good luck,
Paul



[Log in to Reply]  [No Email]
[Options]  [Printer Friendly]  [Posting Help]  [Return to Forum]   [Log in to Reply]

Hop to:


TRACTOR PARTS TRACTOR MANUALS
We sell tractor parts!  We have the parts you need to repair your tractor - the right parts. Our low prices and years of research make us your best choice when you need parts. Shop Online Today. [ About Us ]

Home  |  Forums


Copyright © 1997-2023 Yesterday's Tractor Co.

All Rights Reserved. Reproduction of any part of this website, including design and content, without written permission is strictly prohibited. Trade Marks and Trade Names contained and used in this Website are those of others, and are used in this Website in a descriptive sense to refer to the products of others. Use of this Web site constitutes acceptance of our User Agreement and Privacy Policy

TRADEMARK DISCLAIMER: Tradenames and Trademarks referred to within Yesterday's Tractor Co. products and within the Yesterday's Tractor Co. websites are the property of their respective trademark holders. None of these trademark holders are affiliated with Yesterday's Tractor Co., our products, or our website nor are we sponsored by them. John Deere and its logos are the registered trademarks of the John Deere Corporation. Agco, Agco Allis, White, Massey Ferguson and their logos are the registered trademarks of AGCO Corporation. Case, Case-IH, Farmall, International Harvester, New Holland and their logos are registered trademarks of CNH Global N.V.

Yesterday's Tractors - Antique Tractor Headquarters

Website Accessibility Policy