Sorry about this, but I just have to ask

[Dans240z]

Ugh! Taking off the front cover! I dropped the chain when I was changing the head awhile ago. I was praying that I didn't have to take it all apart, but Ed and some others set me straight. Atleast when it all comes back together, it's clean!

I don't think taking off the oil pan would work, way too much stuff in the way.

Have fun!

[Pir0San]

you wouldn't be able to access it from the oil pan, and even if you did, you probably skipped a link when the tensioner sprung. This could potentially cause you to get your valve timing incorrect, which would cause your valves to hit your pistons, killing your motor. If it's torn down to no head already, the front cover comes off easy as pie. While you're fixing the tensioner, you may want to consider a new timing chain, guides, and new tensioner as well.

Just an idea, I'd recommend tearing the front cover off, you might be able to get to it from the oil pan, but you don't want to do it wrong or kill it.

[Hrududu]

Does the oil pan have to come out to get the front engine cover off?

[Pir0San]

not out, but it does need to be loosened, and then it will give you enough clearance to do what you need. I would recommend taking the oil pan off though, because you're going to have to replace your oil pan gasket, it will break apart when you take the front cover off. I'd get a battery powered drill and a 10mm socket adaptor, and loosen all of the bolts you can with the drill, because it's a bitch to loosen them by hand. Then loosen all of the other bolts you couldn't reach with the drill by hand, and drop the oil pan down. After you get that down and get everything buttoned up under the front cover, put a new oil pan gasket on and bolt the pan back up.

Too bad you don't live anywhere near me, I'd lend a hand if you needed it.

[Hrududu]

Thanks Jeremy, I too wish you lived near me because I have no clue what I'm doing. I began this process on October 31st and I am still nowhere near done. I just don't have the tools, space, or knowledge to do this. The simple task of changing the head gasket has turned into a total pain in the arse I would rather not have to deal with. I would seriously saving up the $$ to tow it down to some shop and pay someone to finish this for me if I knew that was even a possibility. I just can't do it anymore. I spent too much time learning computer repair skills and not enough time learning mechanical stuff. The biggest problem is, there is no one around here who knows anything about these cars. In my entire life, I have only seen 3 or 4 other 240-280Z's here, and don't know a single person who has ever owned one or worked on one. It sucks when there is no one to give you a hand or some advice when you need it. The only help I am getting is from this site and this damn Haynes manual that doesn't tell crap.

[Ed]

Don't despair. Take a deep breath and do one thing at a time.

1. Turn the crank until piston # 1 is at top dead center (TDC).

2. Remove, crankshaft pulley, oil pump, water pump and the front cover.

Note. You will have to loosten the oil pan to remove the cover. You won't be able to remove the pan unless you undo the motor mounts and raise the engine.

3. Prep the head so you can place in on the block. Clean block surface with some carb cleaner and the head surface.

4. Make sure your allignment dowels are still in place.

5. Place the head gasket in place. And carefully put the head back on. Put the bolts in and torque according to you manual.

6. Make sure your crank has not moved by making sure piston # 1 is still at TDC.

7. Turn your camshaft so that both lobes of the #1 piston are pointing up.

8. Using your manual for referance reinstall your timing chain & tensioner.

9. Quit for the day.

10. Next day. DOUBLE CHECK that you have the engine timing set properly. Crank-cam timing.

11. Install the front cover. Tighten the oil pan & front cover. Don't forget the two little bolts that go from the front of the head to the top of the front cover.

12. Install the crankshaft pulley and make sure everything is still at TDC.

13. Look through your manual before you install the oil pump and the oil pump shaft. These have to be set in proper timing also.

14. Turn engine over by hand a couple of times to make sure everything is turning smoothly.

15. Adjust valves.

16. Smile your almost done.

17. The rest is cake.

Good luck and let us know if you have any trouble.

[Pir0San]

Ok, don't despair, I was in your boat once too. I agree with everything that Ed said, with the exception of the oil pan. I have been able to remove the oil pan with the engine still in the car, without really having to fight with it. As I said earlier, if you loosen all of the bolts and let it drop down from the motor, all you need to do is push it forward until it hits the crossmember, then pull the rear down while pulling the pan backwards, and it should clear the crossmember and transmission bellhousing with a little bit of work. It'll take you maybe 30 seconds of playing with it to drop it down correctly.

So, after you remove the oil pan, you now need to tear off the front cover of the motor. I know Ed just went over it (and by no means am I discrediting what Ed said), I'll go over it again. You said you had a Haynes manual, right? If so, in the top right hand corner of the front cover, it should have the numbers 28012 (206), and should be for the 1970-78 Z cars. If you do not have this specific manual, I'd go buy one from your local auto parts store, which shouldn't set you back more than $25.

So, to remove the front cover, you need to take the fan clutch off of the water pump (4 bolts that hold the fan onto the fan clutch, these are small bolts -10mm- so be careful not to lose them), loosen your alternator, take your belts off, and take the bolt out of the front of the motor that holds your alternator bracket on. After that, you need to unbolt the oil pump and distributor, and then unbolt all of the bolts that hold the front cover on. You also need to take off the crankshaft pulley on the front of the motor. This bolt is torqued down to 100ft/lbs, so you need to either allow the timing chain to bind so that the motor won't turn over, or you could be like me and use a pipe wrench to keep the pulley from spinning. I would tighten the pipe wrench on the pulley, and brace the pipe wrench against the frame on the Z. If you do it right, this will give you the leverage you need to break it free. If you can't figure out which ones are for the water pump and which ones are for the front cover, just unbolt them all and make sure to set all of these bolts aside so that you don't lose them. There is also a small 10mm bolt behind the oil pump that holds the front cover on, so make sure to unbolt that one as well. Chances are after you remove all of the bolts for the front cover and drop the oil pan, the front cover will still be stuck to the engine. You can either get a large screwdriver and try to break the front cover loose by using leverage against the block and the backside of the water pump housing, or you could even get a putty knife that can wedge between the front cover and the block. After that's all done, the front cover can be removed.

It might help you to remove the hood in order to do all of this work (or at least it helped me), so I'd suggest that. At this time, if you've done all of the above, your back will probably be hurting, so I'd grab a gasket scraper if you have one, go have a seat in the shade, and scrape all of the old gasket off of the front cover. After your break, you need to go back and scrape all of the gasket off of the block as well. Now is the time that you are going to need your haynes manual, so if you have it, pull it out now. Flip to page 32, and take a look at diagram 42.12. If you look closely, on your crankshaft and on the picture in the book, there is a key on the crankshaft that holds the crankshaft pulley in place. This notch also needs to be pointing up (in relation to the motor). When it is pointing up, the motor will be at top dead center (TDC). Now take a look at the book again, and look at the diagram 42.14d (the lower left hand of page 32). If you look, there is an arrow pointing at a notch/punch mark on your crankshaft sprocket. This notch is important, because it will help you to set your valve timing.

Now, take a look at figure 1.56 and figure 1.58. 1.56 shows how the chain should be set up on the motor. Your timing chain has two bright links in it (if you don't see them, then you need to clean your chain). One of the bright links needs to be on the punch on the crankshaft sprocket, and the other bright link needs to be on the number one punch mark on the camshaft sprocket, as described in figure 1.58. If you decided to replace your timing components (chain, tensioner, guides), you can set it at the 1 punch mark on your camshaft sprocket, but if you didn't (I'd recommend it if you haven't), then you need to compensate for stretch, which means instead of putting it on the 1 punch, you'd put it on 2.

Here's a pic

As you can see in the picture, the pink/red dots are the bright links on the chain, and they are set on the punch marks on both the crankshaft and camshaft sprocket. If your head is not at #1 tdc (where the cam lobes are pointing at 10 and 2 as seen here: ) then you need to set it as so. I think it's easier to do this with the head seperate from the block. I would set the head vertical, and have someone hold the head from spinning on it's back, and then set the camshaft that way. If you refer to the picture of the chain and head with the punchmarks above, it shows a seperate picture of how to set this. The camshaft sprocket should have the number 2 notch facing vertical, and should have the number 1 notch to the right of it, as seen in figure 1.58 in the Haynes manual. If you look through the hole in the camshaft sprocket (there should be 4 of them unless you have the sprocket as seen in the picture above) there should be a v notch on the sprocket itself and a dash on the camshaft locating plate. Set the notch as seen above, and your head is set up. Now, put the head gasket onto the motor, then set the head down on top of it and put in the 2 middle head bolts, but don't tighten them down fully, you just want it to set where it won't slide off. Make sure your head gasket is lined up with the head, and now set your chain on as seen in the picture above. One bright link needs to go on the punch on the cranshaft sprocket, and the other one needs to go on the number 1 punch mark on the camshaft sprocket. To do this, you might need to remove your chain guides in order to get the play you need to set the chain correctly. If when one of the punch marks is paired with a bright link and the other punch mark does not have a bright link on it, or anywhere close to it, you need to take the chain off and pair it with the opposite link until you get it right (one side of the bright links has more links in the chain than the other). After this is all set, you need to put your guides on, tighten them down, and then put your tensioner back into place. After this is all done, make sure all gasket faces are scraped thoroughly, apply Permatex (I use the black permatex) and reapply gaskets. After the gaskets are placed on both the motor and the front cover using permatex, put the front cover back onto the motor and bolt everything down. Don't torque the head down yet, otherwise you won't have the correct clearances to put the front cover back on. After the front cover is on, bolt the oil pan back on (with a new gasket, scrape all faces for the oil pan as well) and then torque the head down according to figure 1.61 on page 33. You need to torque the bolts down in 3 steps, the first torque setting is 29, 40, and then 60. After that's all said and done, you now need to put your oil pump back on. This is important, because if you get it wrong, the timing will be all fubared. If you look at page 22 in your Haynes manual, refer to figure 1.25, which shows how the oil pump and the distributor gear shaft should be set. There is a punch mark on the shaft, and a v shaped divot (so to speak) on the oil pump itself. These notches should be aligned, and then the shaft and oil pump should be slid back into the front cover of the motor. As I said before, make sure you do this right, because if you don't, your car won't run right, and you won't be able to adjust distributor advance correctly. After this is done, button everything up, put in fluids, attach lines, etc, and then the car should run.

Good luck!

[Hrududu]

Wow, you guys are great. Thanks for all the help, It really is needed. Luckily A neighbor of mine is pretty good with cars and said he will be able to come down on thursday or friday to give me a hand with this.

[260Zed]

Great write up by Jeremy! I vote to move it to tech articles.

[Pir0San]

Great write up by Jeremy! I vote to move it to tech articles.

Thanks! I've actually been a member of Zdriver.com for a few years now, so I'm used to detailed posts. I figured that the more detailed the post, the easier it would be to do the work we were describing. I've done this more times than I can count, so I'm pretty knowledgeable when it comes to the dismantling of the L series motor. I'd be honored for it to be a tech writeup!

[Pir0San]

Something I forgot to mention is that permatex should not be applied to the oil pan gasket, only to the front cover gasket and water pump gasket.

[ZSaint]

You are learning through the college of hard knocks. Your failures will become your instructor. You only take one (1) head off an L-engine before you learn the proper steps. Hope this is not going to be your last engine job. It gets easier as you learn. As a young mechanic, may I suggest you ASK people on this forum before you take things apart? We could have saved you a LOT of work. I guess now you will learn how to take the radiator and front balancer and pulley and cover and alternator off the L28 block. It willl be a painfully slow process this college of hard knocks! I remember doing this same thing at a race track many years ago. We spent the entire evening taking it all apart and putting it back together. Youth is a wonderful thing!:knockedou