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

Shop Now

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

Allis Chalmers Discussion Forum
:

Engine Rebuild

Welcome Guest, Log in or Register
Author 
CH

02-07-2004 15:43:11




Report to Moderator

How many shims on each Journal do you end up using? Does it vary greatly between Journals?
I'm having trouble getting my B125 crank right. It's ground .20 under. I have .02 bearings.




[Log in to Reply]   [No Email]
Butch

02-07-2004 20:54:59




Report to Moderator
 Re: Engine Rebuild in reply to CH, 02-07-2004 15:43:11  
In reading down through your posts here you have either a bearing shell problem or a problem in the cap-block for the center main. Have you measured those shells and compared them to the set in the rear? Stranger things have happened than one bearing shell being the wrong undersize than on the package. I have also have seem some real jury rigging to fix problems from the past, I assume this was a running engine but that does not mean that somebody had it rigged to turn before due to problems related to a replaced cap or bad line bore for the mains. If the shells measure up and are not dragging on the crank radius only from to much radius in the grinding job then it sounds to me like your in for a line bore job

[Log in to Reply]  [No Email]
CH

02-07-2004 21:09:27




Report to Moderator
 Re: Re: Engine Rebuild in reply to Butch, 02-07-2004 20:54:59  
I'm afraid you might be right although I didn't want to think that. All shells are .095. No the engine wasn't running. I bought a B and got a parts B thrown in. The parts tractor is the one I'm working on, couldn't see it go to waste. The problem with this engine was the manifold rotted out. and flooded the center 2 cylinders.

I'm going to start from scratch, checking the alignment of the journals first. Let you know.

[Log in to Reply]  [No Email]
wdTom

02-07-2004 19:05:26




Report to Moderator
 Re: Engine Rebuild in reply to CH, 02-07-2004 15:43:11  
The way to deal with shimming is this. Put all upper bearings in the block nice and dry behind each bearing shell. Lay the crank in with some lube. Now one bearing at a time. Put the shell in the cap and put it on finger tight with the cap screws. Measure the clearance on each side with a feeler gauge. Put in enough shims to equal .0015 less than this on each side. Both sides should be made equal as for shims unless you need to remove one to get things right. Now put a strip of plasti gauge on the crank and snug the bearing cap down. remove the cap and check. If it is too loose still remove a shim or two to reduce the clearance. Now here is the deal, you also have to remove an equal amount from the bearing shells to maintain that .1115 crush. You do this by carefully fileing each side of the bearing. Lay a file on a flat surface and move the bearing shell over it. To check how much you are removing I use a dial indicator and a flat surface, moving the bearing shell,with the two ends on the flat surface, under the indicator tells how much you are removing. Now put it all back together and check withk plasti gauge again. Keep it up until youget the correct clearance. It takes a while, don't figure on doing it all in a evening. Keep everything spotless. Put no oil behind the bearing shells. Make sure the crank turns after you do each bearing. I start with the thrust bearing, then the other mains and then the rods. It will get harder to turn as you do the rods because of the piston rings dragging but you should be able to turn it. When you put the bearing caps on for the last time put some oil or oil/STP mis on them, but not behind the shells, that should be clean and dry. If you file one too much, use a shell from another set. By the time you get to the last one you should be good enough to not do this. This trick won't work on mains if they are different. Don't rush.

[Log in to Reply]  [No Email]
steve

02-07-2004 17:47:25




Report to Moderator
 Re: Engine Rebuild in reply to CH, 02-07-2004 15:43:11  
CH there should be 3 shims on each bolt, or 6 per bearing (3 on ceah side =.006) from the factory. You should have about .0015 to .002 clearance to the crank. If you have 20 under crank and matching bearings, should still have about the same shims as original. Someguys use plastigauge, that seems to get close. I normally do 1 bearing at a time. take out a shim and see if it gets snug to roll. when snug, add 1 shim. should roll easy by hand. Then go to the next bearing, etc. afterward do the same for the rods. you will begin to notice that they are within 1 shim of each other. very uncommon to have 3 shims on 1 cap, and none on another. Also take two bearings halfs and hold together with masking tape. mike the ID and see that it is just slightly less than your journal. If it is greater or equal, you need to take a couple thousands off the end of the bearing half with file or coarse sand paper. Bearing halfs should just touch or .001 shug to each other with cap tight. dont have 3-4 thousands crush or it will bind. In the end, the piston rings hould be the only resistance you get when turning over engine.

[Log in to Reply]  [No Email]
CH

02-07-2004 18:41:55




Report to Moderator
 Re: Re: Engine Rebuild in reply to steve, 02-07-2004 17:47:25  
My crank measures 2.230, original spec is 2.250. I put a cap on with just bearings, no crank, and got 2.234 on all journals. It still seems like the middle journal is higher than the front or rear because with the middle bearing in, putting the front or back in makes the crank drag. with just the front and rear in with pretty normal shims, it spins freely.



[Log in to Reply]  [No Email]
CH

02-07-2004 17:18:51




Report to Moderator
 Re: Engine Rebuild in reply to CH, 02-07-2004 15:43:11  
Update. It seems the crank is teatering on the center bearing. I pulled the center bearing out of the block, the front needed 4 shims on each side, spins free. The rear needed 3 shims on each screw, crank spins free.

What do you think? I'm going to try to find a true 20" straight edge and lay it across the bare journals tommorrow to see if the middle is high for some reason. I did measure all the bearing halves, they're all the same.

[Log in to Reply]  [No Email]
Marty

02-08-2004 09:16:39




Report to Moderator
 Re: Re: Engine Rebuild in reply to CH, 02-07-2004 17:18:51  
Have you checked to make sure your crank is strait? I would get a couple of rolling V-Blocks and a dial indicator and check this out. Good luck.



[Log in to Reply]  [No Email]
Let me add this

02-07-2004 15:55:58




Report to Moderator
 Re: Engine Rebuild in reply to CH, 02-07-2004 15:43:11  
The parts book calls out 6 crank shims, I assume per journal. It calls for 8 rod shims. The service manual says the rods have 4 shims per side and you can remove 2 on each side without filing the bearings.

I really need someone that's done a 125 to help.

Thanks



[Log in to Reply]  [No Email]
CHALMERSBOB

02-07-2004 19:09:22




Report to Moderator
 Re: Re: Engine Rebuild in reply to Let me add this, 02-07-2004 15:55:58  
GET YOURSELF SOME GREEN PLASTICGAGE AND ADJUST ACCORDLING. BOOK STATES 2-3 THOUSANDS CLEARANCE
GET A MANUAL AND FOLLOW IT. GOOD LUCK BOB



[Log in to Reply]  [No Email]
CH

02-07-2004 19:35:15




Report to Moderator
 Re: Re: Re: Engine Rebuild in reply to CHALMERSBOB, 02-07-2004 19:09:22  
Hi Bob,

I have the manuals, plastigauge, micrometers, calipers and dial guages. Started doing it by the book. Four shims on each side of front bearing gave me .002. Moved on to center main. Three shims on each side gave .002 but when I put the cap on I could hardly turn the crank. If I pull the bearings out of the middle and do the rear, three shims on each side giving me .002, the crank spins free. if I have the middle in and take the caps off the front and rear, I can rock the crank. The middle seems high.

[Log in to Reply]  [No Email]
Dave R

02-07-2004 21:22:55




Report to Moderator
 Re: Re: Re: Re: Engine Rebuild in reply to CH, 02-07-2004 19:35:15  
If you put just the front and back bearings in at .002" clearance and the crank spins and just the the middle one in the same way and it doesn't bind but with all three in it binds, it seems to me you are right. The middle is high or low. You might want to call the shop that ground your crank and ask if he can line bore the journals. I,ve never had this done myself so I don,t know what it costs, but I know my neighbor does a lot of engine rebuilds for other people and he says he always has them line bored so he can do away with the shims completly as it is cheaper for his customers than charging them by the hour to shim them. Good luck, Dave.

[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