456 Belt Service

I am in midst of disassembly for belt service and I have a question - is the crankshaft pulley nut a "normal thread" (left to loosen) or opposite? I also cannot find a torque spec in the manual - anyone know what this is??

I will be taking a lot of pictures (as I often do) while I work through the job; any specific requests for views or info, let me know.
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I got the car with no service records and 39,000 miles on the odometer (it is a 1995) so I do not know when the belts were done. I have owned the car for 5 months and have put 5,000 miles on the car and I figure that is pushing my luck far enough.

As for belt tensioning, I plan on using the manual procedure of loading the tensioner and tightening the lock-bolt, installing the belt, releasing the lockbolt, rolling the engine over a few turns, then tightening the lock-bolt. This lets the tensioner set the belt tension. This is per pages 61 - 64 of the workshop manual, volume I, section B.

The manual mentions a Staeger Meter for measuring tension as a check, and you're right these are expensive..

 

Here's the VIN:
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I am changing the tensioner bearings. I got the new set that includes the spring follower as well.

 

Thanks for the information.

I used a pretty hefty breaker bar with the car in 6th and the parking brake on - no joy in either direction.

I guess it's time to finally break down and get that impact gun I've always needed...

 

I was able to get the cam cover off on the passenger side so it looks like I will be able to proceed without taking the added step of taking the intake manifold off (again...). Was a little disappointed to find silicone on all the joining surfaces and o-rings of the cover - looks like the last person who did the job didn't feel like footing the bill for the gaskets...

Still haven't been able to get the crank pulley off; impact driver won't fit with the adapter so I will either have to use a pipe on my breaker bar or mill down the socket I have. More fun.

Hint for all the do-it-yourselfers out there: see those velocity stacks in the picture? If you take them off you will likely notice they have Locktite on them. Make sure you use this when you put them back on. I did not when I did this over the summer and I found three of them rattling around in the plenum...
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I have put penetrant on it and I will wait a week (this is why you do this over the winter). By then I think it will be as ready as it will ever be to come off.

As for the Locktite - I am sure it was used. As for red - boy I hope not. That is one mother of a bolt and it will "never" come off.

 

I was able to (finally) get the crank pulley bolt off. I needed a 250 ft-lb air driven impact gun to do the trick. By the way, it is threaded as a normal bolt, counter clockwise to loosen. I was able to then do the passenger side belt. I got a new tensioner bearing though the old one seemed in good shape; belt looked good as well. The belt went right on with no issues and I was able to bar the engine over to set the tension. A check of the cam settings showed they were spot on.

Looks like I have quite a few valves that are under tolerance for the clearance between the shim and the cam. All the ones out are exhaust valves. The shows the spec for the intakes as 0.20 - 0.25 mm and the exhaust as 0.3 - 0.35 mm. The exhausts all seem clustered at 0.20 mm.

Anyone seen this with their engine?

 

I didn't take any as I forgot my camera. I will take some on the driver's side when I do it.

With the valve clearance issues, I may have to take the passenger side apart again, as it may be easier to do the shims with the cam out than to use the special tool to hold the valve down and go that route.

As far as step by step, I got the engine to TDC using a dial indicator and did a check of where the marks were on the cams. They were close. I then removed a bearing block from each cam and placed a thin piece of cardboard in between the block and the cam. I then re-installed the caps, torquing them to 1/2 the recommended value to hold the cams in place while I fitted the belt.

Then I loosened the tensioner pulley nut and removed the nut from the tensioner spring to unload the belt. Just to be safe I marked the belt and its place on each pulley.

I then pulled the tensioner assy off the car and replaced the bearing and its associated slide assy. The slide has a drift pin that engages the spring preload bolt. Removing this pin allows the slide to be swapped with the new one. The bearing came off easily and went back on easy as well.

Then I re-installed the tensioner assy without the spring and with the tensioner pulley nut loose. After I removed the old belt, I transferred the marks to the new one, lined then up, and installed it. The fun part was now to get the nut back on tensioner assy with the spring in position. I requires a fair amount of force to get the spring compressed to allow the nut to be installed. Once the nut was on, the tensioner was applying pressure on the belt and I rotated the engine through four cycles to ensure all my marks lined up and the belt tension was set. Once this was done I locked down the tensioner pulley nut and called it good.

My next step will be to check where the cams are relative to the manual. Even though the marks look right I want to check just to be sure.

 

Little progress and some in reverse...

In light of the fact that the valve shim removal tools are $900, I deviced to make it easier on myself and just remove the cams to change the shims on the exhaust and intake cams. These means I will likelt replace the belt I just installed on the passenger side; lessons...

I put together a file for keeping track of the math here and I have attached it for anyone who may be interested. The file needed to be broken up so I created a passenger and driver side file along with the spreadsheet for raw data.



For any of you moderator types out there, Windows is now on 2007 for its flagship software package and all the file types get an x at the back (e.g. .pptx for powerpoint); it may be time to update as this site does not allow these files to be uploaded.
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Do have one picture of progress - I didn't like the black paint on the cam covers so I decided to strip and paint them. I liked the bare aluminum look though so I think I will be sticking with this:
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Looks like for the covers I will be painting them with the VHT krinkle paint referenced in the 348 section. Saw a picture of someone's 456:
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More pictures as I replaced the pasenger side belt:
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