Jump to content

856 engine problem.


Recommended Posts

Is there a way to get the rocker shaft off the engine without removing the fuel tank?  Rocker broke on # 6. Exhaust rocker of course so can’t just slip it off the end. There’s not enough clearance under the tank to pull the back 3 rocker shaft/head bolts. Thanks!

Link to post
Share on other sites
5 minutes ago, CIHTECH said:

Split it would be my method, especially if it has a cab. 

Agreed.  You can have it split in 30 minutes with the hoods already off.

Link to post
Share on other sites

Splitting won’t help me out here as I don’t have stands for that tractor.  I guess I raise the tank a little.  There is some wiggle room as it has a Year A Round cab from a 66 series with the big hood notch.  

In any event it would be good to have this thing together and running again by mid morning tomorrow . . . mixer wagon tractor and my other tractors are on the stalk baling warpath away from home.

Link to post
Share on other sites

You can jack up the tank enough to get the rockers off.

Take a close look at the valve guide where the rocker broke.

Look thru the valve spring at the guide to see if it is higher than the rest.

Those engines had a tendency to have a loose guide move up in the head until it went into bind and the rocker was the weakest link.

Also check the push rod to make sure it is not bent.

You can replace the rocker and hope it don't happen again.

Something had to have happened that caused that to break.

Always seems to be #6 exhaust so must be due to the higher heat,

  • Like 1
Link to post
Share on other sites

I'd lift the fuel tank up enough also to get it off I've done that on other models that size and worked well 

Link to post
Share on other sites
1 hour ago, Gearclash said:

Is there a way to get the rocker shaft off the engine without removing the fuel tank?  Rocker broke on # 6. Exhaust rocker of course so can’t just slip it off the end. There’s not enough clearance under the tank to pull the back 3 rocker shaft/head bolts. Thanks!

Yes lift tank a bit. You can unbolt shield under tank slide it out. I never have split one to take head of lift tank a bit or take tank off is what some guys do

  • Like 1
Link to post
Share on other sites

Even with the heat shield out there is not enough room to pull the bolts.  Anyway, I think I have it beat.  I wiggled the roll pin out of the #5 block that holds the rocker shaft, then I could slide the shaft sideways through the blocks with bolts in them yet and R&R the offending rockers on #6.  Need to check everything over and button it up, and do a test run.  I have a theory on why the #6 exhaust rocker failed -- just a theory at this point.  Need to look at that guide --

Link to post
Share on other sites

Back together and running.  

I’m pretty sure the rocker just died of natural causes.  Don’t see any thing else amiss.  Then there is this tidbit.  I had the head off this tractor a couple years ago to replace a blown head gasket.  I remember that there was a rocker I didn’t like the looks of, it was loose on its bushing.  I wanted this thing together and without more expense and time loss, so I crimped the rocker on the bushing and put it back together.  Bad idea as that is the one that failed.  Live and learn.

D82B08BA-4A07-4D7C-9F81-2513D642338A.jpeg

BAD4D6BA-5D2B-48E3-90C1-2A1A9A1810F0.jpeg

Link to post
Share on other sites
2 hours ago, Gearclash said:

Even with the heat shield out there is not enough room to pull the bolts.  Anyway, I think I have it beat.  I wiggled the roll pin out of the #5 block that holds the rocker shaft, then I could slide the shaft sideways through the blocks with bolts in them yet and R&R the offending rockers on #6.  Need to check everything over and button it up, and do a test run.  I have a theory on why the #6 exhaust rocker failed -- just a theory at this point.  Need to look at that guide --

Yes there is pull the shield unbolt the brackets that hold tank on front. Raise it enough to stick a 2x4 under tank between starter. You can work bolts up and tip rocker stands over with bolts in them. Have done lots of 66 , 56 , 06  head work and inframe engine work. You can get bolt , rocker arms and head out with tank in place. If not it is only 2 pipes and 4 more bolts to just get tank up out of way

  • Like 1
Link to post
Share on other sites
51 minutes ago, Gearclash said:

I’m pretty sure the rocker just died of natural causes.

51 minutes ago, Gearclash said:

I wanted this thing together and without more expense and time loss, so I crimped the rocker on the bushing and put it back together.

I'm not sure I would label the failure "natural causes".  I think I would call it "death from complications from prior repair", lol. 

 

Link to post
Share on other sites
20 minutes ago, J-Mech said:

 

 

20 minutes ago, J-Mech said:

I'm not sure I would label the failure "natural causes".  I think I would call it "death from complications from prior repair", lol. 

Never fails, pay me now or pay me later.

  • Like 1
Link to post
Share on other sites
14 minutes ago, Nebraska1206 said:

856 Custom, that fuel tank is a little easier to deal with than what a regular 856 has

If my 856 is a custom I am not aware of it.  No badging as such.

Link to post
Share on other sites

So, would someone explain what was different about the 856 Custom? Only learned they made them in recent years.  I had never seen one, and have never read what the difference was? 

Link to post
Share on other sites
18 minutes ago, snoshoe said:

Fuel tank says it is.

Hmmm.  Interesting.  This tractor does have only one hydraulic outlet so that would make sense.  No Custom badging on it anywhere, although I am very doubtful about the originality of this tractor.  I know the block is a C4.  My uncle has a nice, very original 856 Custom that he bought new.

Tag on mine.  

25E17646-5DB1-440D-8E5C-BE48386311F2.jpeg

Link to post
Share on other sites
19 minutes ago, J-Mech said:

So, would someone explain what was different about the 856 Custom? Only learned they made them in recent years.  I had never seen one, and have never read what the difference was? 

The 7&856 customs were IH's quick response to JD's 4000. The fuel tank and battery covers are two noticeable differences. There were a number of deletions to bring the price down. They have been listed on here before. The 826 replaced the customs.

  • Thanks 1
Link to post
Share on other sites

Custom tanks mounted to the bell housing and the others mounted/had supports that bolted to the head. That was the giveaway on this tractor.

Link to post
Share on other sites
8 hours ago, snoshoe said:

The 7&856 customs were IH's quick response to JD's 4000. The fuel tank and battery covers are two noticeable differences. There were a number of deletions to bring the price down. They have been listed on here before. The 826 replaced the customs.

So basically the 826 was ih's cheaper cost model your saying? I always wondered why they produced the animal. 

Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...