Rocker arm stud replacement

[tdskip]

Hi guys - so I finally worked up the courage to pull the rocker arm in the 71 TR6. This is the one that had a lot of sludge build up, and the #1 valve rocker arms oil weep holes were blocked with gunk and thus not lubricating the front of the valve and head assembly.

Turns out pull the rocker assembly was easy! Not sure why it took so long to jump in a do it, but anyway, the oil weep holes are now clear.

So here is where I need some help - when I took the assembly off I noticed the rear most #6 stud was partially stripped (I didn't do it - really!). You could only get the nut finger tight where as all the others took the torque specified in the manual. I ordered a replacement Part #76 from the diagram below. Any tips or tricks on getting the old stud out? Ditto on fitting the new stud?

Thanks in advance!

 

[tdskip]

#14 in this picture, slightly easier to read.

 

[Brosky]

Tom,

Double nut it at the bottom where the threads are still good. If not, go to Sears and buy a stud puller to fit that size (5/16")? and use that to remove it.

 

[tdskip]

Tom,

Double nut it at the bottom where the threads are still good.

Oh, like, that seems obvious now that you say it. LOL.

Chances are about .00001% that I would have ever thought of that on my own. You guys rock.

Thanks Paul!

PS - I'm going to be crushed if the oil doesn't flow through the front assembly now.

PPS - Will be first time adjusting the valves, another thing I've had a mental block on.

 

[TR3driver]

If the nuts won't work, just grab it with vise-grips. You're replacing it anyway, so any damage is irrelevant. Use the double nuts to install the new one, slightly more than finger-tight.

Did you clean the inside of the shaft as well ? Make sure the holes in the rear pedestal are clear, plus the passage through the head? If so, it should lube fine.

If the flat washers on top of the rocker pedestals are chewed up or missing, I'd suggest replacing them with hardened washers. Definitely don't leave them out.

Also check all the other studs by spinning a new nut down them with the rocker shaft removed. If it doesn't turn easily to the bottom of the threads, replace that stud as well. They do lead a hard life, and a binding nut may be a sign that the threads are distorted. Having one break is an unpleasant experience (so I'm told)

 

[DougF]

If it is really stuck and vise grips don't work, heat the stud to as hot as you can. Don't worry about expansion, that should break the grip of what's holding it. Trying to heat the head could be harmful to the cast iron and would use a lot of gas.

Are your rockers in good condition? Grooves on the pads where they make connection with the valves are indicators. Also, any wear on the bottom of the shaft from the rockers means replacement or rebuild. Wear in these locations make it difficult to set the valves and have a great effect on the smoothness of the engine.

 

[tdskip]

Good morning Randall!

Did you clean the inside of the shaft as well ? Make sure the holes in the rear pedestal are clear, plus the passage through the head? If so, it should lube fine.

Yes - I did. Cautiously optimistic, and clearly excited, that I've fixed the flow problem.

If the flat washers on top of the rockers are chewed up or missing, I'd suggest replacing them with hardened washers. Definitely don't leave them out.

Good to know - the existing washers look good. They cleaned up well and are still smooth and perfectly shaped.

Also check all the other studs by spinning a new nut down them with the rocker shaft removed. If it doesn't turn easily to the bottom of the threads, replace that stud as well.

I'll double check - all the other threads seemed find and came on/off smoothly.

Thanks

 

[tdskip]

So I got the rocker arms back and snug, did a valve adjustment which was pretty easy and kind of fun to do finally. And she starts!

Quick follow-up question - how long should it take for oil to start weeping out of the rocker arms?

Thanks guys.

 

[Brosky]

<div class="ubbcode-block"><div class="ubbcode-header">Quote:]how long should it take for oil to start weeping out of the rocker arms?[/QUOTE]

Uh, Tom, how long did your engine run without it weeping out of them?

Did you happen to clean out the one hole that is in front of the last rocker stud, in the rear of the head? That is the oil supply hole for the entire rocker arm shaft and you can have a perfectly clean rocker assembly, but if that hole isn't wide open, you will not get much oil at all to the arms.

 

[tdskip]

Uh, Tom, how long did your engine run without it weeping out of them?

About a minute, but I put oil on the rest of the shaft etc before starting it up so it was "artifically" lubricated the whole time, so I do not think any damage was done.

I think I'm going to have to pull the assembly apart and check it. The rear most rocker pedestal was clear of gunk prior to being re-installed but something is obviously wrong.

 

[DrEntropy]

Mebbe not. It won't actually "gush" but rather dribble.

 

[Brosky]

And it could be considered a "slow" dribble at that, but check that supply hole anyhow.

 

[tdskip]

Just pulled the assembly again and confirmed that the oil passage from the block to the rear rocker pedestal is clear. I blew some cleaner through the rocker shaft and oil weep holes and some nasty gunk came out, so hopefully that did the trick.

And the best part - I get to practice my new-found valve adjustment skills. Again. (and will then not touch any of this for a long, long time if it is working).

 

[SidescreenTR]

Hmm, I know I'm getting older and my memory's not what it used to be...but I would swear that the one and only time I started the engine on my first '3A (in 1960-something) with the valve cover off, I had to wash the oil off of the underside of the bonnet...and the inner wings...and well, everywhere! I mean a LOT of oil! Sprayed everywhere! No?

 

[TR3driver]

Possible, but not normal, IMO. Starting the engine with the rocker cover off is part of my normal maintenance routine; it both gives me a double-check that I didn't do something stupid when adjusting the valves and allows me to check that all the rockers get oil eventually.

The only time it sprayed the bonnet was after I had installed one of the external oiler lines. Way too much oil, even after I installed a restrictor in the line. The external oil line eventually wound up back in the parts bin, in case I ever want to destroy a motor again.

 

[SidescreenTR]

Well, I suppose I could be remembering the time the timing chain tensioner rubbed a hole in the cover. THAT was fun!

 

[tdskip]

Well - no dice.

The oil feed hole in the block appears clear, I swept the hole with a clean think screw driver and no gunk came out.

So I then reinstalled the rocker shaft and set the valves clearance, and no dice. There does not appear to be any oil spray or dribbles from the rocker weep holes.

Is there any special alignment of the rear-most pedestal so the oil flows up property? It appears that it should just line up when the pedestal is tighten
down on the stud.

 

[tdskip]

FYI - I have 75 oil pressure at idle on her.

 

[TR3driver]

I forget, does the TR6 have a plug on the side/back of the head for the oil drilling, the way a TR3/4 does ? If so, you could try removing the plug to see if you get oil there. If not, I'm afraid it's time to pull the head.

On the "rebuilt" 56 engine I bought, the passage inside the cylinder block was blocked. At the time, I thought perhaps the rear cam bearing had been installed wrong, but later I came to believe it was just hard oil deposits (varnish) blocking the passage. At least when I tried to drill through the cam bearing (with a long drill), I didn't get any bearing material, just hard black crunchies. And after that it oiled fine.

 

[Brosky]

There is a plug or screw in the rear of the rocker arm assembly. Good call Randall, I "assumed" that Tom knew about it and checked it. My mistake for doing that!!

And they are known for falling out.