Re-torquing heads (1 Viewer)

[keving]

I will be doing a valve adjustment this weekend on my 85 BJ60.

While I have the valve cover off, would it be worth while to re-torque the heads? Re-torquing diesel heads has always been common practice with me on anything from old 220 and 350 cummins motors to my IH idis in my Ford diesels. As the head bolts stretch over time and they almost ALWAYS take another half turn or so when I re-torque them. Prevents head gasket failures.
Should I do this with my 3B? if so, what is the torque sequence and specs?

 

[VTCDN]

keving, IF , and IF your spelling the truth of ""Re-torquing diesel heads has always been common practice with me on "" then You would know spec's . 3B don't do TTY bolts, BuT !!!


Re-torque / Re-clamps back to spec , with clean outs , chase threads / re lubes plus WOULD NEVER HURT A SINGLE TORQUE / CLAMP SYSTEM.

VT

 

[keving]

I am NEW to 3B's, thats whay I am asking if it was worth while to do a re-torque on a 3B. And beign new to 3B's, I don't know the torque specs on them nor did I know if they were TTY bolts or not. Im just trying to learn...and again, thats why im "asking".

And yes, I have re-torqued many diesel heads, in fact the early IH 6.9's were factory advised to have the heads re-torqued at 30,000miles after leaving the factory. And lo and behold the owners who didn't retorque them are looking at head gasket replacement at 200,000miles or so. Some heads bolts will stretch with mileage.

 

[amaurer]

I don't think this would hurt a 3B... but I doubt its necessary.

There isn't really a rash of HG failures reported here at any mileage, unless it was preceded with an overheating event or a truck of unknown history.

As VTCDN says, 3Bs aren't TTY so you can tighten them up if you like. But I wouldn't waste my time - pulling the rocker cover and shaft just takes sooooooo long.

EDIT: I just learned something new from the FSM; some very late 3Bs appear to be TTY after all. if you have an extremely late engine, like 1988 check if the bolts are 12 sided - they're TTY. If they're 6-sided then they're standard.

Will post pages.

 

[amaurer]

Here's what I've got for virtually every 3B I've seen:

And this oddball is what I just found for some subsection of very late model 3Bs:

 

[gerg]

While your there re-torque the head. Pulling the rocker cover take less than 5 minutes and as long to put back in. Other than time, there is no drawback to doing it.

g

 

[lostmarbles]

... Pulling the rocker cover take less than 5 minutes and as long to put back in. ....
g

But as Amaurer said .... pulling (and re-installing) the rocker shaft is what makes it a PITA (and the reason why I wouldn't bother).

You need to pull that to get at "hidden bolts".

Here's what I mean by "hidden" on my B engine:

 

[gerg]

Its just 10 bolts, how hard can it be? Anyhow, it gives you a good opportunity to inspect wear on the faces of the rockers (they commonly wear at the contact point with the valve). Just make sure that when removing the rocker assembly that if a push rod sticks to it that it doesn’t lift up the lifter below it. I remember checking my push rods for bends and lifted a lifter out of its barrel and it fell sideways. It’s easy to fix, you just have to remove the access cover on the side of the motor and put it back in its spot. Now that actually is a pain in the ass. I can almost guarantee that your head bolts are loose.g

 

[keving]

Ok thanks for the info. My bolts are 6 sided, I guess they are standard. And if it is not required for a 3B I will leave them alone. Thank-you gentlemen

 

[goldchaser]

Fark 10 bolts!
Late at night im just finishing up torquing the head down on my 12ht.
Grrr-26 of the suckers,arms about to drop off.

 

[gerg]

There are 10 bolts on a 3B's rocker arm assembly. It has 18 head bolts. Im glad to head you did yours. Do yours to 120ft-lbs and see how you like it. I broke 3 sockets before I was done. Everyone should do it. Its like a right of passage. You may now call yourself a man.

 

[amaurer]

Pfft heads are easy. Now bearing caps, those are hard... basically the same thing only on your back holding the wrench over your head!

 

[fjbj40]

with oil dripping in your face

Daryl

Pfft heads are easy. Now bearing caps, those are hard... basically the same thing only on your back holding the wrench over your head!

 

[canucksafari]

But as Amaurer said .... pulling (and re-installing) the rocker shaft is what makes it a PITA (and the reason why I wouldn't bother).

You need to pull that to get at "hidden bolts".

Here's what I mean by "hidden" on my B engine:

View attachment 543579

Is there any room to get a crow foot socket into the hidden bolts? If so, then I found this formula you can use this formula for calculating the torque with a crowsfoot. E- Effective length of extension - measured along the centerline of the torque wrench. L Lever length of the wrench - center of grip to center of drive. T(W) - Torque set on the wrench. T(E)- Torque applied by the extension to the fastener. T(W) = T(E)* L/L+E
T(E) = T(W)* (L+E)/L

 

[77cruiser77]

If a crow foot socket could get in there I think it'd snap if you were about to apply 120ft-lbs of torque to it. either do it right and remove the assembly or don't do it at all. Interesting formula though

 

[amaurer]

I'm no mechanic but any time I touch a fastener with an open-end wrench or a crows foot the fastener suffers. At 90 ftlbs I'd be sure to round it off entirely.

:shrug:

 

[canucksafari]

If a crow foot socket could get in there I think it'd snap if you were about to apply 120ft-lbs of torque to it. either do it right and remove the assembly or don't do it at all. Interesting formula though

It all depends on the quality of the tool. Snap-on crowsfoot sockets range from a working max torque of 200ftlbs for the 6 point ($17) and 250ftlbs for the 12 point at $32. If the choice is removing the rocker shaft or spending a little extra money for a good tool, well you chose. I ended up buying a 17mm one to remove a rust welded nut off the top shock. I was putting way more than 120ftlbs on it and it didn't spread or strip the nut. Actually, the studs snapped but I got what I needed done. <Next time I will probably just use a nut splitter.>

 

[SuperHatch]

I'm no mechanic but any time I touch a fastener with an open-end wrench or a crows foot the fastener suffers. At 90 ftlbs I'd be sure to round it off entirely.

:shrug:

I was thinking the exact same thing...

 

[amaurer]

...max torque of 200ftlbs for the 6 point ($17) and 250ftlbs for the 12 point at $32...

I didn't know they made box-end crows feet... I could see how those would hold up better.

Come to think of it thats probably what I need to reach the AC idler tension screw on my BJ73, hmm...

 

[fjbj40]

you will not fit a crows foot in there, open or closed (closed are not called crows foot anyways). Even Snap-On...

From many years of working with crows feet I know that the crows foot would spread apart before you would reach the required torque for the head bolt.

Take the extra time and remove the rocker shaft assembly and do the job the right way.

Daryl

Is there any room to get a crow foot socket into the hidden bolts? If so, then I found this formula you can use this formula for calculating the torque with a crowsfoot. E- Effective length of extension - measured along the centerline of the torque wrench. L Lever length of the wrench - center of grip to center of drive. T(W) - Torque set on the wrench. T(E)- Torque applied by the extension to the fastener. T(W) = T(E)* L/L+E
T(E) = T(W)* (L+E)/L