Thread: Rocker alignment against valves

Might pay to check that the rocker shaft bore or rocker shaft is not worn at those points or maybe bent pushrods, did you put the pushrods back in their original places.
Don't look right to me as the top of the valve stem has the shiny wear marks sticking out the side of the rocker pads. If they ran like that from new you would not have the wear mark as it is on top of the valve stem, it would be worn offset.
I know this is a longshot, but is it possible that the rocker arms (while off head) may have been rotated 180 degrees and the shaft fitted wrong way round, i.e. front to back, may not be possible but it is hard to diagnose from afar, Regards Frank.

Originally Posted by Tank

Might pay to check that the rocker shaft bore or rocker shaft is not worn at those points or maybe bent pushrods, did you put the pushrods back in their original places.
Don't look right to me as the top of the valve stem has the shiny wear marks sticking out the side of the rocker pads. If they ran like that from new you would not have the wear mark as it is on top of the valve stem, it would be worn offset.
I know this is a longshot, but is it possible that the rocker arms (while off head) may have been rotated 180 degrees and the shaft fitted wrong way round, i.e. front to back, may not be possible but it is hard to diagnose from afar, Regards Frank.

Thanks for the reply, Frank. I don't think it's due to wear in the shaft. The rocker arms in question sit nice and snug, but the alignment is just not quite right. Yes, I put the pushrods back in their original places (original as long as I have had the engine, that is) when I put the engine together. From memory, the mis-alignment has "always" been there.

I think the shiny top of the valve stem is because the steel looks the same across the entire surface, whether it is in contact with the rocker arm or not. Whenever I have checked valve clearance, there doesn't seem to be any uneven wear forming, but I am growing more cautious with my advancing age.

I will certainly be having a look at the whole shaft soon. It certainly went back onto the vehicle in exactly the configuration in whoch I found it in 2000. I could bush the rockers to get the pad into better position, but that could mean throwing the pushrod onto a different alignment.

Any more thoughts would be appreciated.

Cheers,

John

It seems to me that if you swapped the spacers at the ends around it would be closer.
Ie thick spacer for thin spacer, as the spring holds the rocker against the spacer.
Regards Philip A

I'd check with the workshop manual. I've not long had the heads off my 3.5v8 and while rebuilding and lapping, i found that the rockers simply weren't assembled right. The offset is supposed to be there (in the v8 EFI anyway), when I asked a mechanic about it, they said they're offset so the valves are slightly rotated each time they're depressed, to even wear on the seats. I assumed this would ring true for any engine with valves, but I'm definitely not as read up on Diesel as I probably should be.

Having said that, I'm not too sure they're supposed to be as far off as your photo shows.

Originally Posted by PhilipA

It seems to me that if you swapped the spacers at the ends around it would be closer.
Ie thick spacer for thin spacer, as the spring holds the rocker against the spacer.
Regards Philip A

Well spotted!! I think you have it. Truth to tell, I didn't look too hard at things when I took those photos. I was just finishing up for the day and it occurred to me that I may as well photograph the rockers and post a question on them....

Looking at it now - I reckon you've nailed it.

Thanks.

John

Originally Posted by Swarvey

I'd check with the workshop manual. I've not long had the heads off my 3.5v8 and while rebuilding and lapping, i found that the rockers simply weren't assembled right. The offset is supposed to be there (in the v8 EFI anyway), when I asked a mechanic about it, they said they're offset so the valves are slightly rotated each time they're depressed, to even wear on the seats. I assumed this would ring true for any engine with valves, but I'm definitely not as read up on Diesel as I probably should be.

Having said that, I'm not too sure they're supposed to be as far off as your photo shows.

That's an interesting point about offsetting, but it does seem rather a lot. The most I can see on any of the other valves is a tiny peek of shiny metal. Why should these two be so different?

I guess it's a lesson in always checking. In 2001 I refitted the rocker gear as it was, as it had no play. That's not to say that nobody had ever mucked around with it before. The engine appeared to have never had a rebuild, but I made an assumption on the rockers which i probably shouldn't have.

Thanks,

John

Originally Posted by Johnno1969

Well spotted!! I think you have it. Truth to tell, I didn't look too hard at things when I took those photos. I was just finishing up for the day and it occurred to me that I may as well photograph the rockers and post a question on them....

Looking at it now - I reckon you've nailed it.

Thanks.

John

Now I am not so sure. I had a really good look at the two photos... the spacer is the same on each. It is just that the one on number one inlet looks thinner until examined closely. It's actually the same.

Now I am not so sure. I had a really good look at the two photos... the
spacer is the same on each

The spacer next to no1 is definitely thicker than next to number 4 or my eyes are getting much worse than I thought.
Regards Philip A