(800) 853-2651
SHOP NOW

806 with minor knock- OK to run for a while?

I

ironhoarder

Member
As I posted a few days ago, my 1963 806 suddenly developed a noticeable engine knock while basically idling and doing nothing in particular.

The engine was at a fairly low RPM and when putting it into gear (but before letting the clutch out), a new knock sound started in the engine. Not a catastrophic sound, just a bit of a knock.

The problem is that I need to finish taking in my hay and I have another 20 acres to cut and bale with this tractor.

An IHC mechanic friend suggested (without hearing it first hand) that it might just need rod bearings, and that is a very easy job.

So- what to do- just go ahead and do my hay and deal with it afterwards? Or take the time now to pull the pan and at least inspect the rod bearings (look for wiggle I guess)? Or just assume that it is gonna need a full rebuild- there is a bit of blow-by coming out the bottom of the engine- not terrible, but some.

The engine has definitely seen a lot of use, but seemed pretty decent when I bought this a month or so ago.
 
You risk throwing a rod out the side of the block running it with a knock, assuming it is rod bearings. Considering you need the tractor to finish your hay, I would drop the pan and check the rod bearings. Inspect for visible wear and if they look ok to the naked eye, check the bearing clearance with plastigauge. A new set of rod bearings may be all you need to get you by until you are able to go through the engine more throughly.
 
Has anyone considered the possibility, since it came on so suddenly, it could be a sticky injector?

No matter WHAT is causing the knock, continuing to run it will only run up the cost of eventually repairing it.
 
I have heard it speculated that it could be an "injector knock". Although, my farmer neighbor said he didn't think it sounded like that.

This is the first diesel engine I've ever had any trouble with, so I'm not familiar with the sound of an injector knock, or sticky injector.

How does one resolve a sticky injector? Perhaps a magic potion in the fuel like "Diesel 911" or whatever that stuff is called?
 
I had the same thing on my 806 a couple months ago . I found a push rod had broken at the top where it had been welded at the factory . Took the valve cover off dropped in a new push rod and back to work . Only problem I'm having is IH is dragging their feet on paying my warranty claim . I mean this tractor is a 1967 and only has about 18,000 hours , shouldn't it still be covered ?
 
What Cowman said.

Don't even think about running it until you find the problem.

That tractor is going on 50 years old. It is possible that it has never been opened up. Further, they had a real nasty habit of sending rods out thru the side of the block.

If that happens, you're gonna be kinda sick to your stomach. Go borrow a tractor if you've just got to be in the field.

Allan
 
Okay- I drained the oil and removed the pan today. Oil looked fine- black, but no bits of metal that I could see.

Alas, the big steering yoke needs to come off before I can remove the pan- and I don't have a 2" socket or big enough crescent- need to borrow.

Looking up in there, nothing looks obviously amiss, from what I can tell with the pan in the way.

Once I get the pan off entirely, what should I look for? I'll see if any of the rods are obviously loose, but assuming they all seem tight, then what?

I have a feeling that this tractor is going to my IHC buddy for repairs...
 
Some type of "snake oil" MAY help. However, if it really is an excessive "diesel knocK" caused by a sticky injector, or one with a bad tip, you may need to have the injectors checked, and cleaned and repaired as needed. While this won't be CHEAP, it's better than breaking a piston or doing other damage to the engine by continuing to run it.
 
Check the bottom of the oil pan and the bottom of the pan you drained the oil into CAREFULLY for metal filings.

If there are none, that MAY point to an injector as the source of the knock. Better have someone familiar with engines take a look. Don't just tear rod caps off at random, if there's no reason to. An "engine guy" can probably tell by feel (wiggling the rods) if a bearing is bad.

(WHATEVER you do, don't take any bearing caps off without being SURE they are match-marked, and that you understand the marking system, so you can get the cap back on the same way it came off. You will need a torque wrench, as well, to tighten up any caps that have been removed to "spec.".)

Of course, besides POSSIBLE injector problems, or worn bearings, something wrong in the wrist pin area, or even broken ring lands can cause noise.

Even the valve train can make a fair amount of noise, if something's loose.
 
Lets see here to pull the pan on a 806 wide ft. all ya need is a 3/4 socket a 3/4 wrench a hammer chisel a 9/16th. socket a couple extenchions and a few other odds and ends as you do not have to take off the steering arm just the support bracket off the yoke . Could have tha pan off in thirty min. with out any air tools. But what ever ya do DON'T run it . IF ya have to get your hay up Rent a tractor for a week it would cost alot less then and engine.
 
I have the pan itself off (9/16" bolts). I removed the bottom of the pivot yoke, revealing the ball at the end of the big steering arm. Can I just tap/push this arm down? I put a bit of force on it and it didn't budge. Must need a bit more force.
 
ironhoarder: Don't run it, don't even start it up until you get to bottom of problem. I don't know that 806 was ever prone to this problem, but the smaller 706 could break sleeves around the top. It would start off as a minor knock, that was the warning to shut it down.

The minor knock was sleeve moving up and down in the block, next move was piston sucking sleeve down with it, now the problem occurs when piston comes back up, things jamb up a bit when piston comes up.

I had this happen with my 560 with 282 diesel, same engine as 706. Tractor was on blower at silo, a young lad was changing wagons, 560 still running. He heard the knock, rather than shut it down he ran for help. When he got back with help, there were parts of two pistons plus parts of block scattered across the barnyard. KNOCKS are a warning, don't ignor them.
 
the problem is the fuel and the rotary injection system. what are you treating your low sulfur fuel with. this has been i concern of mine for a couple of years now with my 806. had the injector pump rebuilt about ten years ago. and the guy told me then that lower sulfer levels in fuel will be a problem with my tractor. was told to try k100 k100fueltreatment.com
 
You must log in or register to reply here.

Similar threads

L
New old guy needs help 300U knock
Replies
16
Views
547
300guy
3
D
850 Deere developed a knock
Replies
1
Views
208
wore out
wore out
W
Crank Area Knock
Replies
8
Views
290
J.Wondergem
J.Wondergem
S
1100 MF Engine Knock
Replies
6
Views
358
Southman
S
B
806 MCV Pressures and steering part 3
Replies
4
Views
310
Bluegill2
B
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