knock in 45
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=68087
Printed Date: 06 Sep 2025 at 3:26pm
Software Version: Web Wiz Forums 11.10 - http://www.webwizforums.com
Topic: knock in 45
Posted By: LazyDFarms
Subject: knock in 45
Date Posted: 03 Apr 2013 at 10:09pm
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got a knock in my 45 but i can only really hear it under a load. sounds like its coming from frount of engine. havnt had time to tare into it. any ideas were to start. thamks for any help. ------------- I'VE DONE MORE WITH LESS!! |
Replies:
Posted By: CTuckerNWIL
Date Posted: 04 Apr 2013 at 5:57am
You might check to see that the front pulley isn't loose on the crank. Might also check for end-play in the crank while you at it. My CA had a knock I could never tell where it came from. when I went to check the front pulley, the crank slid forward about .06 
------------- 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: Brian F(IL)
Date Posted: 04 Apr 2013 at 7:59am
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A few years ago I had a "clunk/knock" that sounded like it was in the lower end of the crankshaft. Ultimately it crapped out. Found out upon engine removal that the four bolts holding the flywheel to the crank had broken over time.
Darn things only lasted 59 years...
 |
Posted By: SteveM C/IL
Date Posted: 04 Apr 2013 at 8:03am
| I second the frt pulley. There's a set screw on top of a set screw. |
Posted By: Rick
Date Posted: 04 Apr 2013 at 8:07am
| There's only a set screw on top of a set screw, if it has power steering from all of the ones I've torn apart. Normally, it will have one large set screw with a jamb nut. Rick |
Posted By: SteveM C/IL
Date Posted: 04 Apr 2013 at 8:12am
| Rick is correct about the fasteners. |
Posted By: Lonn
Date Posted: 04 Apr 2013 at 8:20am
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I'll third the front crank pulley. Also you should check to see the front angle iron under the engine is not loose. There is a specific preload to this iron that holds the front of the engine. I've seen that being loose with only one bolt holding it and it was striking the front pulley. Has to be shimmed correctly otherwise you can crack the clutch housing which I have also seen. ------------- -- --- .... .- -- -- .- -.. / .-- .- ... / .- / -- ..- .-. -.. . .-. .. -. --. / -.-. .... .. .-.. -.. / .-. .- .--. .. ... - Wink I am a Russian Bot |
Posted By: Matt MN
Date Posted: 04 Apr 2013 at 12:47pm
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Only Knocks under a load.. Cam Bearings ------------- Unless your are the lead horse the scenery never changes!! |
Posted By: Lonn
Date Posted: 04 Apr 2013 at 1:49pm
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Missed the under load part so ya might be bearings. I had a WD I bought with that kind of knock too. ------------- -- --- .... .- -- -- .- -.. / .-- .- ... / .- / -- ..- .-. -.. . .-. .. -. --. / -.-. .... .. .-.. -.. / .-. .- .--. .. ... - Wink I am a Russian Bot |
Posted By: Brian G. NY
Date Posted: 05 Apr 2013 at 8:54am
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Matt, I think you meant "main" bearings. Generally, a knock under load or while "lugging" will be a main bearing.
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Posted By: Rick
Date Posted: 05 Apr 2013 at 9:22am
| Here's something to think about. I had a WD45 a while back that had just had the engine rebuilt and ran perfect. I used it to do some light logging with and one day while pulling a log I heard a knocking sound. I used the tractor with this knocking sound for about a year, before other issues came about and I decided to part it out. After taking it apart, I noticed that the clutch input shaft was very badly worn where the pilot bearing rides and the pilot bearing was shot. I was sure this was the problem that caused the knocking sound. I pretty much confirmed that when my brother's D17 needed a clutch. We took the tractor apart and found the clutch input shaft was worn very badly...just like the one on the WD45 I had. This tractor was also used for logging and would really knock loud when under a load...especially when the tractor leaned a lot to the left or right, when pulling logs uphill. We replaced the torque tube (which was easier than disassembling the old one)with one that had a real good input shaft and that solved the knocking sound altogether. Point being...maybe it sounds like it's coming from the engine, but maybe it's NOT actually the engine at all. However, it could be a number of things. Just something I'm throwing out there. Rick |
Posted By: DonBC
Date Posted: 05 Apr 2013 at 11:44am
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A stethoscope can sometimes narrow down the problem. Even using a stick of wood like a broom handle will work. I once diagnosed a broken crankshaft on a Ford flathead V8 using a broom handle. The engine would run but had a knock. I at first thought a rod bearing but it didn't sound right. I said that I found it hard to believe but said I think it is a broken crankshaft and when they tore it down that's what it was. On the weekend I helped my son change the water pump on his Dodge Caravan. His water pump was seeping a little but he also had a distinct ratting sound when the engine was idling. We changed out the pump but he still had the rattle. I had spun the alternator, tensioner and idler pulley when the belt was off and they all spun smoothly. I suspected the bearings on the air conditioner clutch. I didn't have a stethoscope so I got a 2' length of 1" x 1" wood and listened by placing it on each item when the engine was running and it was loud and clear that it was the alternator that was making all the noise. ------------- Jack of all trades, master of none |
Posted By: DaveKamp
Date Posted: 05 Apr 2013 at 3:39pm
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On a WD, or WD-45, if I hear a knocking under load, the first thing I suspect is my left knee... ...but that's just me.  ------------- Ten Amendments, Ten Commandments, and one Golden Rule solve most every problem. Citrus hand-cleaner with Pumice does the rest. |
Posted By: Matt MN
Date Posted: 05 Apr 2013 at 4:01pm
No I meant Cam bearings, Main bearings will knock under no or light load, but cam bearings will knock under heavy load. What is the oil pressure doing when it starts to knock?? ------------- Unless your are the lead horse the scenery never changes!! |
Brian G. NY wrote:Posted By: Brian G. NY
Date Posted: 05 Apr 2013 at 4:25pm
| Wow, that's a new one for me! |
Posted By: LazyDFarms
Date Posted: 05 Apr 2013 at 7:29pm
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The oil pressure is normal, I can bearly make out the knock when its idling and can't hear it when I rev it up. Its not a canstant knock and I cant idenify it with the stethascope method. But put her in 4th, pull back on the hand clutch hard and she will knock so you can feel it in the steering wheel. By listening and I think I have good ears, but It sounds like number one and its almost to high for a main or a connecting rod. Wrist pin? What is the most common cylinder and what bearings are to go first. (under general farm use) Thanks Dennis
------------- I'VE DONE MORE WITH LESS!! |
Posted By: Eric B
Date Posted: 06 Apr 2013 at 1:00am
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If you suspect a knock coming from a con rod bearing or wrist pin you can take turns pulling off one spark plug wire at a time with the engine running to see if it makes a difference. ------------- Currently- WD,WC,3WF's,2 D14's B. Previously- I 600,TL745,200,FL9,FR12,H3,816 LBH. Earth has no sorrow that Heaven cannot heal! |