Crankshaft end play
Printed From: Unofficial Allis
Category: Allis Chalmers
Forum Name: Farm Equipment
Forum Description: everything about Allis-Chalmers farm equipment
URL: https://www.allischalmers.com/forum/forum_posts.asp?TID=45812
Printed Date: 17 Apr 2025 at 3:40pm
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Topic: Crankshaft end play
Posted By: TMiller/NC
Subject: Crankshaft end play
Date Posted: 18 Feb 2012 at 3:26pm
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What is the maximum end play a B engine should have? Thanks, Tim |
Replies:
Posted By: CTuckerNWIL
Date Posted: 18 Feb 2012 at 3:31pm
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Something like .002-.006 of an inch is the allowable end play.
------------- http://www.ae-ta.com" rel="nofollow - http://www.ae-ta.com Lena 1935 WC12xxx, Willie 1951 CA6xx Dad bought new, 1954WD45 PS, 1960 D17 NF |
Posted By: MNLonnie
Date Posted: 18 Feb 2012 at 3:34pm
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My book says .001-.005 end thrust clearance. ------------- Waukesha B, B, IB, G, styled WF, D15, 615 backhoe, 2-Oliver OC3's, 4 Ford Model T's, 3 Model A Fords, AV8 Coupe, AV8 Roadster, 1933 Ford Wrecker |
Posted By: TMiller/NC
Date Posted: 18 Feb 2012 at 3:40pm
| Thanks for the replies. Next question is how to reduce the end play? Can the crankshaft gear be removed and a shim added? Need to remove .015. Thanks, Tim |
Posted By: steve(ill)
Date Posted: 18 Feb 2012 at 3:42pm
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I have pulled the gear off and machined off several thousands off the face to get the clearance right.
--- im trying to think back exactly what i did. I know the clearance was about .020 to start with. The gear musth bottom out against the journal and i machined off .015 to push it on further so the original bearing face moved closer in ? If i had machined the bearing face you would think the clearance would increase.. Been too long ago. ------------- Like them all, but love the "B"s. |
Posted By: TMiller/NC
Date Posted: 18 Feb 2012 at 3:47pm
| What holds the gear on and would I not need to counter bore the gear slightly to go on the crankshaft more making the side of gear closer to the front main bearing? Thanks, Tim |
Posted By: CTuckerNWIL
Date Posted: 18 Feb 2012 at 4:05pm
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I thought one of the main bearings was what was supposed to control crankshaft end play. If the throw out bearing is bad or you spend a lot of time with the clutch pushed in, the thrust bearing gets wore.
------------- http://www.ae-ta.com" rel="nofollow - http://www.ae-ta.com Lena 1935 WC12xxx, Willie 1951 CA6xx Dad bought new, 1954WD45 PS, 1960 D17 NF |
Posted By: TMiller/NC
Date Posted: 18 Feb 2012 at 4:27pm
| CTucker, I think, the front main bearing controls the movement front to rear, with the crankshaft having a thrust surface behind the bearing and the crankshaft gear on the front side. I'm thinking if I remove the gear and machine a counter bore in the inside of the gear it would allow the gear to move closer to the front main taking out some of the end motion. Am I right????????? Thanks, Tim |
Posted By: Gary(WI)
Date Posted: 18 Feb 2012 at 4:54pm
| Polk diesel in Madison wi removes gear then remachines crank surface and grinds crank nose the same amount moves crank ahead maybe 15-20 thousands does not seem to hurt Gary |
Posted By: TMiller/NC
Date Posted: 18 Feb 2012 at 5:02pm
| Can the gear be pulled off with a gear puller or does it have to be pressed off? Thanks, Tim |
Posted By: Dick L
Date Posted: 18 Feb 2012 at 6:06pm
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I have always pressed the gears off and never tried a gear puller. They come of kinda hard. You might be able to use a puller if you heat the gear some while pulling. You can counter bore the gear to get the end play back in spec. Before you do that make sure the crankshaft does not need repaired where the side of the thrust bearing rides on the crankshaft. Other wise you just wast your time on the gear because the crankshaft will chew up the thrust lip on the insert and you will be back where you started. If the crankshaft is smooth with a matching flat you will have a good repair.
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Posted By: TMiller/NC
Date Posted: 18 Feb 2012 at 6:24pm
| Thanks, DickL, I had the crankshaft main, rod journals ground to .020 under and the person who did the work said he cleaned up the thrust face. Me being dumb and not understanding the meaning of this, reassembled the engine and now I find the end motion. Thanks for the replies, Tim |
Posted By: steve(ill)
Date Posted: 18 Feb 2012 at 6:27pm
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Tim, i did exactly what you said. REmove the gear and counter bore so it slide in .015 toward the new bearing. I think i found that some aftermarket thrust bearings are thinner than the original factory unit. ------------- Like them all, but love the "B"s. |
Posted By: DrAllis
Date Posted: 18 Feb 2012 at 6:32pm
| I'll bet I'd not worry about it. |
Posted By: LouSWPA
Date Posted: 18 Feb 2012 at 6:38pm
I think if you do that you will change the timing ------------- I am still confident of this; I will see the goodness of the Lord in the land of the living. Wait for the Lord; be strong and take heart and wait for the Lord. Ps 27 |
TMiller/NC wrote:Posted By: TMiller/NC
Date Posted: 18 Feb 2012 at 6:55pm
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Dr Allis are you saying the end play isn't going to hurt anything? Does it make the engine have any unusual noises? Thanks, Tim
Oh yeah, will it effect the timing to counter bore the gear?
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Posted By: DrAllis
Date Posted: 18 Feb 2012 at 7:02pm
| Timing change will be miniscule. If you only knew, your endplay was very probably out of spec when you took the engine apart. Counterbore the gear if you want and if you ruin the gear in the removal process you can buy another gear to counterbore. If it was mine, I'd do nothing. |
Posted By: TMiller/NC
Date Posted: 18 Feb 2012 at 7:12pm
| Thank you to everyone for the replies and advice. It is surely nice to have such a wealth of information at a touch of the keyboard. Tim |
Posted By: Dick L
Date Posted: 18 Feb 2012 at 7:46pm
With it being ground and not rough, unless you put it the field 10 hours a day all summer long, doing nothing will probly let it go bad for your great great grand kids.
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Posted By: CTuckerNWIL
Date Posted: 18 Feb 2012 at 9:42pm
An intermittent knock started in my CA. It took me a while to find it. When I figured it out, there was .090 end play in the crank. I haven't ran the engine more than a couple minutes since then and don't have it apart but I think I'll have to fix my end play  ------------- http://www.ae-ta.com" rel="nofollow - http://www.ae-ta.com Lena 1935 WC12xxx, Willie 1951 CA6xx Dad bought new, 1954WD45 PS, 1960 D17 NF |
Posted By: LouSWPA
Date Posted: 18 Feb 2012 at 10:41pm
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I am working on a -45 crank right now, .014 end play. I was going to remove the gear, and "manufacture" a steel shim to go between the crank face and the bearing. I had already smoothed the journal face in neighbors lathe. Don't know if it would work or not, never will, because I discovered the mains are .040 under...without the shims ------------- I am still confident of this; I will see the goodness of the Lord in the land of the living. Wait for the Lord; be strong and take heart and wait for the Lord. Ps 27 |
Posted By: TMiller/NC
Date Posted: 19 Feb 2012 at 8:11am
| Lou, I need to tighten the end play .015 to get back in spec. The crankshaft is installed in the engine on the tractor, am still trying to decide whether to remove engine and press gear off. This tractor probably won't run more than a few hours a year at shows and a little joy riding out the street for a mile or so. From what DickL and Dr Allis are saying I'm leaning toward putting it back together and getting on with paint and joy riding. Thanks, Tim |
Posted By: Ken in Texas
Date Posted: 19 Feb 2012 at 8:33am
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Someone got it right when they mentioned new thrust bearing lips can be several thousands thiner than some of the older ones. I was lucky to be able to reuse my old front main and eliminate the need for crank machining to move the gear back to narrow the gap to spec for the newer bearing.
If you know ahead of time what thrust bearing you will be using, send it with the crank when you have it ground for a custom fit. It does involve pulling the gear. The cut is made to the crank not the gear.
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Posted By: LouSWPA
Date Posted: 19 Feb 2012 at 1:37pm
Frankly, for the use you are speaking of, I agree with Dr Allis and Dick. I was toying with the same thing, but, after discovering the main journals being so far out I think best to start with another crank. As for the timing issue, moving the gear will change the timing, AND with excessive end play, the valve timing will be constantly changing. But, as Dr Allis points out, probably not worth worrying about. ------------- I am still confident of this; I will see the goodness of the Lord in the land of the living. Wait for the Lord; be strong and take heart and wait for the Lord. Ps 27 |