VWise

I'm in the middle of replacing my head gasket, and I'm a little stuck -- well, at least my head is stuck. I can't pull the manifolds all the way off of it.

I removed all of the bolts without incident, but when I tried to pull off the last one I only got a nut-- there's still about an inch of threaded bolt sticking off of the head. Was the whole thing supposed to come off? I've tried going in with a wrench to unscrew the threaded rod part from the head, but it doesn't budge.

The one I'm talking about is #10 in the diagram below:

Cherockee

There are two studs, and no, they're not suppose to come out. They help you line it up when putting it back on.

5-90

From the factory, there are supposed to be two or three studs (#10 & #11, and sometimes #1 on your pic.)

However, since you're replacing the head - if you have help or a crane, I've found it easier to leave the manifolds on and pull the whole damned thing as an assembly, then service the manifold gasket on the bench.

REPLACEMENT OF MANIFOLD-TO-HEAD HARDWARE AND COLLECTOR FLANGE NUTS IS RECOMMENDED (but not in the FSM.) I typically use silicon bronze screws and brass nuts - everything is threaded 3/8"-16, the screws are 1.25" long, and you may cut new studs from 3/8"-16 threaded rod (cut 2"-2.25" overall length, and dress cut ends.)

I have detailed - extensively - what to use and why elsewhere on the board, so I shan't go into it all again. If you can't source Si-bronze or Al-bronze and are stuck using carbon steel, use SAE Grade 5 and NOT rpt NOT SAE Grade 8 (I've also explained my findings on that in detail, so pillage around and you'll find it. If the explanation isn't here, you should be able to find it on JeepForum, CherokeeTalk, or NAXJA.)

Manifold stud nuts and exhaust collector nuts should be replaced with brass parts, for similar reasons. Both will be threaded 3/8"-16 on the 6-242 engine.

The OEM studs should be replaced for similar reasons to the rest of the hardware - carbon steel, brass, or bronze threaded rod will all serve here.

If you want to use LocTite, I think the only version that will serve is #277 (check the number,) it's formulated for exhaust head. If you want to use never-seez, reduce install torque by HALF. (I have explained that extensively as well.)

And, although difficult, the head and manifolds CAN be removed/replaced as an assembly. I've detailed how to handle alignment of the assembly onto the block so you don't "scrub out" your head gasket elsewhere as well.

NOTE CAREFULLY whether or not there are paint marks on the cylinder head screw heads! If they are present, REPLACE THE SCREWS. If they are NOT present, MARK THE SCREW with some bright colour of paint (to make it obvious.) Per FSM, the screws are good for TWO "torque cycles" - NO MORE.

Note that the #11 cylinder head screw (driver's side front) extends into the water jacket. Therefore, apply a PTFE sealant of choice (any PTFE "pipe dope" will work, as will LocTite PST) before installation, not reduced install torque.

Although not specified by FSM, I prefer to torque in four stages: 25, 50, 75, and "final" lb-ft. This results in more even clamping of the head and a better head gasket seal.

I have also found that a light, even coat of RTV Copper on BOTH sides of the manifold gasket won't go amiss - don't use any other grade! Check torque on the manifold screws ANNUALLY. It is common for manifold screws to loosen on side-draught inline six engines, due to the length of the seal and the aluminum intake/iron exhaust combination (this has been detailed by me elsewhere as well.)

Retain & reuse the bowl-shaped washers under all of the fastener heads, or replace with 3/8" Belleville spring washers.

When removing/reinstalling studs, use the "double-nut" method.
- Run one nut onto the stud far enough to fit another.
- Run a second nut against the first.
- Torque the NUTS AGAINST EACH OTHER using a pair of open-end wrenches.
- To remove the stud, turn using the nut toward the INSIDE of the assembly
- To install the stud, turn using the nut toward the OUTSIDE of the assembly.
- Using a pair of wrenches, turn the nuts AWAY from each other and remove to finish component assembly.
- If possible, torque the stud to the same specification used for the screws & nuts, to improve retention & clamping force. A socket may be used on the "outer" nut to achieve this.

CCKen

5-90,

Can you post a link to this data please.

thanks

5-90

I would if I had one handy, but I don't. It should come up with a bit of searching - try looking for "Cylinder Head" or "Head Gasket" posts, throw in the words "threaded rod," and look for posts by me.