89 2.4 Timing Chain Released... How to get it back on?
About 30 minutes ago I slid the timing chain sprocket off the cam. I am pulling the head off to replace the head gasket. I tried to support the chain with a piece of wood-per the Haynes Manual. That didn't really work though because the wood is too long to wedge the chain in place. Kind of in precarious position (can't let the chain drop off the lower sprocket), I slid the chain back on the sprocket. Now it won't go back on.
I tried to slide the sprocket with the chain back on to the cam, but there is too much tension on the chain to clear the cam hub. The Haynes manual doesn't mention a tensioner and how to deal with that part. I now realize there is a tensioner down below pressing the chain guide in.
Is there a way to release the tension from above(through the head opening where the chain comes through) in order to slide the sprocket back on? I have tried to move the guide with a long screwdriver, but can't seem to move anything to get the slack I need to slide the chain and sprocket back on. I was trying to avoid having to remove the front cover. I think in order to get to all of that, I would need to remove the radiator, fan and a bunch of other stuff.
I can go ahead and pull the head off, but I know I'll have to deal with trying to get the sprocket slid back on when it goes back together. Thanks for any help.
I figured it out. Ended up using a long wood drill bit to push the tensioner downward. The chain retracted and allowed the sprocket to come up. Pulled the chain slightly forward and peered way down in there with a good flashlight. I found that it will retract in clicks (black piece). I retracted it all of the way back and slid the sprocket and chain back on. Seems like that is a vital piece of information that was left out of the Haynes manual.
Ended up trimming the wood piece down from 10" to about 9", maybe less, to get it to support the chain as planned for the head to slide off.
Head is now off. Had to do some heavy bumping with a block of wood and hammer. It did not want to come free.
Just as suspected, the gasket is blown between cylinders # 3 and 4. It had no compression, cylinders 3 and 4. The gasket was soon to go between cylinders # 1 and 2 also. Seems to me it was overtourqued previously and was squeezed out (metal of gasket portruding into cylinder). I don't know the torque specs for the head yet, but there had been some serious torque on the bolts that I took out. Head looks good. Cylinders look good. Valves look good. I think it had been reworked before. The chain looks fairly good to. The previous owner had told me it had been replaced.
I'll run the head by the machine shop tomorrow to have it checked out. I don't even think think the valves need any grinding.
This is what the manual say for the head bolts
1. Install cylinder head with gasket and tighten cylinder head bolts in numerical order.
2. Do not rotate crankshaft and camshaft separately, or valves will hit piston head.
3. Tightening procedure
4. Tighten all bolts to 22 ft.-lb
5. Tighten all bolts to 58 ft-lb
6. Loosen all bolts completely
7. Tighten all bolts to 22 ft-lb
8. Turn all bolts 80+5-0 degrees clockwise with an angle wrench, if an angle wrench is not available, Tighten all bolts to 54 to 61 ft-lb
Thanks Win lowe. This is good information. Interesting that the bolts only go to 54 to 61 ft. lbs. The ones I removed were way tighter than that. Had to have in excess of 100 lbs. Last head gasket I replaced was on a IH diesel tractor. The head was cast iron and had to have 3 guys to lift it back on. Big difference. This one actually seems more complicated in ways.
If you lack an angle wrench, you can make one easily enough.
Print this out and paste it onto some cardboard. Then poke a hole the right size for the whole thing to fit onto your socket or an extension.
Bammo, budget angle wrench. http://www.ducatimeccanica.com/Timing_Degree_Wheel.jpg
Thanks Win lowe. This is good information. Interesting that the bolts only go to 54 to 61 ft. lbs. The ones I removed were way tighter than that. Had to have in excess of 100 lbs. Last head gasket I replaced was on a IH diesel tractor. The head was cast iron and had to have 3 guys to lift it back on. Big difference. This one actually seems more complicated in ways.
You're welcome I got the manual from this forum when another member was kind enough to post a link for it. I cant find it now but copy and paste the following and you can download it RapidShare: 1-Click Webhosting
Thanks. An angle wrench would be a big help. Had to use some offsets to get to some of the bolts. Wasn't too bad though.
I will take a look at the manual. I will probably need it.
Stopped at the machine shop today with the head. The head will require some aluminum welding inbetween 2 pistons. A sliver is missing due to heat damage. Can't be planed out because it's too deep. He will also plane it some. Said he will pressure check the valves for leaks and will call. I think they look okay. He said he can do a valve job if I want.
I need to track down a good quality head gasket. I guess there is some type of "saver shim" that can be used on the bad spot. Not sure if I'll need it at this point. He didn't think so.
Not sure if I'll replace the bolts. Might just use thicker washers to make sure they don't bottom out in case they stretched.
Got a Felpro gasket set today for $46. Not too bad. I dropped the valve seals (out of the kit) off at the machine shop. He is going to go ahead and do a valve job too. Says the #4 valve/s are leaking pretty good. I am not going to need a saver shim.
He says no sealant (copper or otherwise) on a head gasket with graphite between an aluminum head and cast iron block. There will be movement and that's what it is supposed to do. The graphite helps in the movement due to the varying expansion rates of the aluminum and cast iron. Says both surfaces sb very smooth and no sealant or it will leak. Says go ahead with the old bolts. Not much torque is required and it will be okay.
He should have it done tomorrow. Maybe I'll get the head back on before it turns cold again.
I just about have this back together. Head is on. Sprocket and timing chain are on. That part was tricky. Exhuast manifold is on. Most of the bolts are in the intake manifold. I need to buy a metric nut that I lost when removing it. Does anyone know?: Is the torque spec critical on the intake manifold? I thought I would just pull them up snug and leave them at that.
Plugs are in. Need to bolt some pulleys back to the head and put the belts and upper radiator hose back on. Valve cover gasket needs to go on. That's about it. Hopefully it will run.
I have to say, this is exactly my problem. #3 and 4 cylinders no pressure, head gasket blown between the two. We got the wood block in but are having a heck of a time getting the timing chain and sprocket on the camshaft. You have answered all of my questions. Now I just have to go and get it done. I appreciate your play by play, it will be helpful. Hopefully we have as much success as you did.
The space between the cylinders (1 and 2 and then 3 and 4) is very narrow. From what I recall, that tensioner had to be fully retracted to slide the chain and sprocket back on. It is kind of a deal where you need 3 hands. I was holding a small flashlight in my mouth because I just couldn't see the tensioner without direct light on it. The first time I slid it back on, I was off one tooth on the cam, so had to slide it off, to get my marks lined up perfectly. I would retract the tensioner and it would push out (and lock or click) very easily if I slacked up on the chain at all. I would then have to again retract it with the long wood drill bit (abt 20" long, maybe more). Finally, it went on and everything lined up. For a period of time, I had the chain and sprocket wired up to the underside of the hood to keep it from falling off. I think I could have left it wired up and to the hood instead of the wood block. One thing is for sure, if you drop the chain, you are out of luck. The whole front would have to some apart to get everything back on correctly and in place. I think the tensioner will fall out if the chain is dropped.
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