You should be able to remove the sprockets several ways:

1) use an impact gun
2) wrap the sprocket with a length of old timing belt, grip the belt with large pump pliers to stop the sprocket from turning
3) insert a large screwdriver or bar into the sprocket and brace on the head area

For installation methods, use #2 or #3 above.

Frank

Thanks Frank, that's very helpful.

One question I'd like to also ask here: I'm not getting any blue smoke out the tailpipe, should I replace any head components while it's out? I've heard valve guides are problematic on these engines but don't have any symptoms right now (200k on engine, never been opened up as far as I know).

I made up a cam sprocket,and crankshaft holding tool with a piece of 3/8" bar stock 2" wide and 18" long.I drilled the bar stock for 3/8" allen bolts 1 1/2" long.Using nuts to hold allen bolts tight on bar stock with the heads of allen bolts sticking out about an inch was able to use two of the slots in camshaft sprocket and torque them to 70lbs.On the other end left threaded portion of bolts out and using the holes in harmonic balance pulley to torque crank bolt down to 120lbs torque.Valves are hydraulic adjusted.Can take a picture of my jerry riged tool tommorow if needed.I also replaced my crank seal and not being able to find a suitable driver used the crank sprocket reversed with the old seal as the spacer and pushed it in with crank bolt and harmonic balancer worked slick will have to remember that one as I have blown two front seals in -20 degree weather on startup..

If you're not having any issues, I wouldn't replace the valve guides or stem seals. They'll decide when they want to be replaced. <img src="/forums/images/graemlins/lol.gif" alt="" />

Frank

A visual inspection should spot cracked valve seals. Same goes with sunken guides. Unless your just fixing the vehicle to get it running, I would recommend freshening the heads while they are off.

At the very least check the intakes for deposits and crud. Loose guides, crud and deteriorated valve seats all have a big impact on power. At that millage it's likely they need service. Sure you can still use them, since they were working, but with fresh heads you have a very good chance of finding some missing HP.

Kevin

Kevin's right - I forgot you were removing the heads in addition to removing the cam sprockets. Look closely at the exhaust valve guides to see if any have dropped. Valve guide seals aren't very expensive and might save trouble later. If you remove the valves and they don't show signs of burning, make certain they go back in the same location.

Frank

Thanks for the two cents Kevin. I am probably going to have the shop do a complete valve job with new guides. I'll know more of course once I can see the condition of the heads.

Thanks again Frank. I'm going to lean toward having a valve job done at the machine shop...do you know if the valve guides come with a head gasket kit or would I need to purchase separately? I plan on a FelPro gasket set and it says it comes with "valve seals" but not valve guides.

Also, any advice on whether to replace the head bolts too?

Valve guides do not come with any gasket sets that I know of - certainly not with OE gasket sets, so you'll have to purchase those separately. I haven't seen many bad valve guides, though. If you have any that are bad, they'll likely be on the exhaust side.

Valve stem seals do come with a complete engine gasket kit, but some of the head gasket kits may have them and some may not.

You should not need to replace the head bolts unless you want to. I would measure them carefully - they should measure just a few thousandths over 4.00". If any are longer than that, they should be replaced. You should use a bottoming tap on the block hole threads (M12x1.25, IIRC) and then measure the clamping range of the bolts as compared to the thickness of the head plus washer plus gasket compressed thickness. The OE gasket compressed thickness can be figured at .050" - not sure about the Felpro gasket. To be safe, (slowly) grind the bolts to just under 4.000" and clean them on a wire wheel brush.

On installation, oil the bolt threads, under the bolt head and the washer with 30w engine oil and torque to 80 lb-ft in stages and in the circular sequence shown in the FSM.

Frank

I've seen some pages out there that show a crankshaft holding tool to lock the crank when removing the crank bolt. I've got a manual trans, so I assume I can put it in 5th gear and hold the brakes while loosening/torquing the crank bolt. Will this work, or do I need to somehow lock the crank with a tool?