Gaskets that go with a head gasket change

[yellowgeko]

Alright dude and dudettes,

i know it seems all i ask are questions but this place is just a gold mine of knowledge. and way friendlier than any other place i have been. so i am new to the jeeps but confident in my inexperienced ability to fix alot. i have searched around and cant seem to find an answer so any input would be awesome. my valve gasket needs to be re-replaced (tighten ted it to tight DOH!), rear main seal, head gasket and all oil pan seals. so if i replace the head gasket, do i need to buy an intake and exhaust gaskets as well? or are they reusable. this is a 94 country and the only thing the previous owner did was keep the oil changed. is this all the gasket that will need to be replaced or are there more? i would like to do this in one fatal swope, seeing as this is the first weekend i will have time off from uncle sam's usaf to get things done. i have had it for over a month and yet have had a free weekend to work on it. also i am going to replace the engine mounts becuase i think that are bad. i get relaly bad vibes in idle and when i drive they go away. i looked at them and they look all warped and the rubber is pulling out the front. i can stick my fingers between the top of the rubber and the metal.

any input wold be awesome.

one more question, i know this may be kinda hard to explain and i will get pics up later, but on the under carriage, the whole thing is rust free, thanks t othe many oil leaks that keep the rust off, but it looks as though the transmisison may be leaking with oil? is this possible. also would that cause the oil to fly to the brake axle and get it covered with oil as well?

this thing is the funnest piece of junk i have ever owned, and i seem compelled to empty my pockets for it.

thanks

[Trooper]

Technically only the head gasket. unbolt the header from the exhaust, 2 nuts. Move all the other **** and disconnect stuff and go at it. My bad, you need a valve cover gasket.

[XJ4MEPLZ]

Some people recomend replacing the head bolts. I would replace the exhaust/intake gasket also, should not be too much.

Check your transmission mount also. Just try moving the transmission up/down side to side to check for excessive play.

Since you have the coolant drained it would be a good idea to change the thermostat with a good quality unit.

[jeepgod]

For about a $100 you get all of those gaskets in a package together.......technically you do not have to remove the exhaust or the intake to remove the head but it is always worth replacing old gaskets for a little insurance. If you are gonna replace the head gasket, I would recommend replacing the headbolts too even though they say you can reuse them once. I would go with polyurethane engine mount bushings because there will be less mushrooming of the bushing and more life out of your exaust manifold.

[5-90]

Gaskets - minimum necessary:
- Cylinder Head Gasket
- Valve Cover Gasket
- Combination Manifold Gasket or Exhaust "donut" gasket (if you remove the head with the manifolds attached, have a hoist! I'm a big guy - 6'3", 275# - and it's difficult for me to do with muscle power. If you have a helper, make sure it's someone who can take instruction - or that you can take instruction, and make it perfectly clear which one of you is to be listened to so you don't break any fingers!)
- Renewal kits for the fuel rail connectors and/or a fuel injector O-ring kit (if you remove the fuel rail from the manifold, you'll need the latter. Either way, you'll need the former.)
- Thermostat gasket (removing the thermostat housing gives you a convenient handle for controlling the head.)

Fasteners:
- Head Screws. They're a modification of the "Torque To Yield" design used for Diesel engines, and are only good for two full torque cycles, per FSM. If there are paint marks on the screws, replace them. If you're not sure, replace them. They do fail, and usually right at the deck. If you know you can reuse the screws, mark them with a bright colour of paint after torquing them as a signal to the next man. I typically use bright yellow or bright red - it's universally a "caution" or "danger" colour
- Manifold screws. 3/8"-16x1-1/4". If these are carbon steel and they come out, they get replaced (if you're not sure, apply the "Flotation Test." Throw them into the nearest body of water - if they float, keep them.) If you can only get carbon steel screws, get SAE Grade 5 - they'll retain more strength longer than SAE8. However, if possible, get bronze screws (silicon bronze or aluminum bronze is best) and those can be reused safely.
- Thermostat housing screws. They're threaded 5/16"-18, but I don't recall the lengths offhand. Replace with carbon steel (SAE5 or SAE8) and coat with RTV or PTFE paste, or use CRES ("Stainless,") or use brass or bronze (won't rust.) These screws should be inspected when removed - if there's any corrosion or pitting, replace them (you may apply the "Floatation Test" as above, if you're not sure.)
- Exhaust collector stud nuts. These are usually threaded 3/8"-16. SAE5 or CRES as above, but brass will be much better (it won't seize.) I replace much of my exhaust hardware with brass or bronze.

HINTS:
- The driver's side front cylinder head screw passes into the coolant jacket - coat the threads with PTFE paste (you can use whatever you find at the hardware store, in the plumbing section. I usually use Harvey's Pipe Dope - it's what's available here.)
- Torque the cylinder head screws in stages, once the screws are all in place. Torque to 25/50/75/100 pound-feet in order, then torque all screws except the driver's side front to 110 pound-feet. Pattern is, standing on the driver's side and starting with the passenger side centre, a clockwise spiral:

12 08 04 01 05 09 13
<--- front of engine
11 07 03 02 06 10 14 (The one in red is the one that gets the PTFE paste and torqued to 100 pound-feet

Torque manifold screws and stud nuts to 19 pound-feet, starting with the top centre and working in a clockwise spiral:

12 08 04 01 05 09 13

- 11 07 03 02 06 10 -

Make sure to reuse the little bowl-shaped washers under the heads - they're there for a reason (I could explain why, if you like.)

Coat the thermostat housing screws with RTV or PTFE, if you can't get brass, bronze, or CRES.

Valve cover screws get torqued to 84 pound-inches/7 pound-feet, no particular sequence. LocTite #222, #242 or clear nail polish will all work here. Recheck torque in a week.

I think that's everything useful you'll need to know. I know that some of what I'd said doesn't agree with the manual - but that's why I'm rewriting the manuals on a number of these things. What I've suggested you do does work, I know this because it's how I do it.

[yellowgeko]

Wow thats a lot of appreciated information. This is going to be a bit more parts that are needed than i expected. i had no idea that the screws needed to be replaced. thanks a ton yall. all in all how long from past experience do you think that this should take? i mean i know everything never goes to plan, but i was think a good 6 to 10 hours tops to be apart and back together.

[5-90]

I've done a straight head gasket swap in an after-noon and an evening - call it seven hours or so (and that includes a fairly detailed inspection of everything, and cleaning it before it went back on.)

How long really depends on your experience and means - if you have anything to help you lift the head, that saves you time. If you have anyone to help you lift the head, that saves you less time - but still saves you time (what I said about a helper essentially boils down to "two sets of hands on one brain" - and if you can't get that, get a hoist!)

If you've got more mechanical experience; you'll be better able to handle things that crop up, you'll see what shortcuts you can get away with, and you can work more efficiently than you could if you don't. If you're inexperienced, figure 10-12 hours or so for the job (two after-noon/evening combinations should serve.) I've done in situ overhauls in the space of a couple of days' actual working - the rest of the time in between was spent inspecting parts, sourcing replacements, getting some work done that I wasn't set up for (pressed gudgeon pins are a pain,) and that sort of thing. But, I've been doing this since I was about eight years old, so I've got a bit more practise than most.