(800) 853-2651
SHOP NOW

IH 466 breaking rockerarms??

A

Anonymous-0

Well-known Member
i have an IH diesel 466 in a tractor, bought used, it had a broken rockerarm. replaced it and broke in less than an hour. pulled head and had it checked out, could not find anything wrong. head was gone thru while it was off. got tractor running again, breaks another one in less than a days work!? always the same cylinder, same valve? any ideas what could cause this? what to check? need any more info just ask...thanks for replies and experiences....Ken
 
Is it breaking the intake valve rocker? A worn camshaft and lifter can allow the exhaust valve to close prematurely causing the intake valve to open with compression still in the cylinder. That will increase the pressure needed to open the valve.
 
no, it's breaking the exhaust valve rocker...everytime?? i looked at the cam lobes and lifter bottoms, looked fine...
 
We had a rash of this happening when these engines were released, there were two different suppliers of rocker arm and one was defective. I would doubt this is your problem unless you are putting in a used rocker arm that were from the problem manufacturer. Sure sounds like a cam lobe problem, did you check the lift. Also, the valve clearance specs were changed during production and sometimes it can be difficult to determine which cam you have to set proper clearance. Supposed to have a sticker installed but you know what happens to stickers on engines.
 
I bought one a few years ago, and had the same problem the guy told me it was getting hot and missing. the problem with mine was that the person before have adjusted the valves to tight and it broke 6 rocker arms. I would check that first because the clearances in those engines are very tight.
 
Had this happen with a 1456 found out that the camshaft key was very wore and was causing the valve timing to be off.
To check this remove the valve cover and rotate the engine until a exhaust valve is about half way open and then rotate the engine in the oppisite direction. The valve should travel the oppisite direction instantly with no hasatation. If there is any hasatation there is a problem.
To ratate the engine remove the inspection cover at the flywheel and you should be able to use a screwdriver or plybar on the ring gear.
Good luck chucky
 
Been thinking about that broken rocker arm some more. I would check the valve timing, number one cyl, intake valve should just get tight ready to start opening at 24 degrees BTDC plus or minus 3 degrees. One tooth off on cam gear will throw it off about 11 degrees. Then I would check valve to piston clearance on the offending rocker arm, no minimum specs here but must have some movement like maybe .025, and you will have to keep turning engine while checking this as it will not fall on TDC so check as piston is nearing top until you find the spot where miminum clearance is. You indicated you had head checked out , however, excessive valve protrusion or piston height could give you this problem also.
 
thanks for the suggestions guys, gives me some leads to check into.

talking to some local mechanics, wondering about connecting rod bearing or wristpin possibly..
 
got engine nearly torn down, found one lifter slightly concave with others losing their hard surfacing... and one cam lobe in poor shape.. that's all i can see wrong so far..

could not see any problems with cam and lifters previously, sure seems like things went to hell quickly?

got engine kit, cam and lifters coming, thanks for the help guys
 
You must log in or register to reply here.

Similar threads

A
IH 384 Diesel
Replies
11
Views
398
JimB2
J
O
IH 354 carb issue
Replies
12
Views
545
used red MN
U
A
injection problem
Replies
2
Views
197
Dieseltech
D
W
IH 434 Steering
Replies
9
Views
711
WPM
W
UncleTom
IH 656 head gasket failure.
Replies
10
Views
562
M. Doud
M
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.

Copyright © 1997-2024 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

Back
Top