January 28, 2006
I spent a few hours today removing the engine front covers, camshaft and lifters after picking up a larger 2-jaw pulley puller. The front pulley and damper are integrated into one, and it appears that the damper is made of rubber layers sandwiched together, so I needed a puller with extra-deep jaws to avoid mangling the damper. I don't know if these can be rebuilt, or even if they need rebuilding, so I'm going to clean it up and examine it and ask Nick Seybold and the guys at my machine shop about it. I think at the low RPM at which these engines operate and with balanced internals, it isn't especially critical. The good news is that it came off without incident just tightening the puller by hand was enough to coax the pulley off the crank snout. I was pleased to see that it was keyed so slippage is a non-issue (many modern engines are simply a press fit, even performance engines such as the Corvette LS1).
Once the pulley was off, I was able to remove the front cover and get access to the timing chain. Everything inside looked to be in good order, but exceptionally dirty like the rest of the engine. I made note of the retainer/seal on the crank snout that fits against the crank timing gear for reassembly.
Again I was glad that I decided to do a full restoration and engine rebuild before driving this car any serious distance as the timing chain was seriously stretched. Check out the photos below:
Pulling the timing chain was like pulling the front pulley. I could slide the crank gear off with my bare hand, but the camshaft gear was tight. I removed the center bolt and used my puller to gently slide it off. I had to rig a base for the puller's center screw because it was too large to fit in the center hole of the camshaft gear. All I would have accomplished there was damaging the gear. So I ran a 3/8" x 6" bolt into the hole (the camshaft has 7/16" threads so there was no damage), then put a 1/2" socket on the bolt head and used that as my puller surface. It worked surprisingly well and the gear slid off easily, again with nothing more than hand-tightening of the puller. No brute force required.
Once the timing chain and gears were out of the way, I could remove the camshaft thrust plate and the front engine cover which acts as the front motor mounts.
Then I threaded a long bolt into the camshaft and started easing it out, using the long bolt as a handle. I instantly realized that I hadn't removed the lifters and the cam wasn't going to come out until I did. So I used the long handle of my magnet retriever to push the lifters back into their bores to give the camshaft some clearance. With those out of the way, the camshaft slid out easily. The shop manual warns that cam bearings are very difficult to remove and install and if they are within spec, to leave them alone. I'll have to ask my machinist about that, but just in case they can't be replaced, I used a lot of extra care to avoid damaging the bearings with one of the camshaft lobes. And that's a loooooong camshaft to remove!
The only other item I noticed was that several of the lifters seemed to be pitted. I don't know if this was due to bad oil or because of sitting for so long before I purchased it. Perhaps they can be machined and polished or maybe I'll have to acquire a new set. We'll find out in the next week or so.
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