What is the basic timing belt replacement procedure?

[volvo 4 life]

I am going to remove the rear pulley on the cam and put the lock plate in so it stays at TDC. I have a new rear belt so I will just change both belts while I'm there. Tools needed would be the crank lock tool, cam lock plate, lock pin for IP, dial indicator, dial holder, and pulley holding tool right? I don't quite understand how it's possible to torque the pulleys on the cam because it isn't keyed. How do you keep the cam from moving while torquing the pulleys down? Even if you hold the pulleys with the sprocket holder it would seem the cam would still slip while trying to torque the pulleys down, especially the rear since it requires around 70 ft lbs of torque.

[v8volvo]

Originally Posted by volvo 4 life

How do you keep the cam from moving while torquing the pulleys down? Even if you hold the pulleys with the sprocket holder it would seem the cam would still slip while trying to torque the pulleys down, especially the rear since it requires around 70 ft lbs of torque.

The cam counterhold tool is your friend there, #9995199. This is actually the easiest one to find of all the diesel tools, you can still buy it from Volvo for around 30 bucks or used fairly frequently, because Volvo recycled it as a tool for cam pulleys on whiteblock gasser engines too and so it still has current applications. Or various members here have them available for loan, etc. It's actually pretty crucial to being able to do the job at all, let alone making it much easier. You use it for both the front and the rear pulleys, the cam doesn't move as long as you're careful.

Torquing (and loosening) the rear cam pulley bolt is also greatly aided by having the correct special offset wrench extension (can't remember the number but can look it up later...), especially in a 200 series where clearance to the firewall is even tighter, but you can survive without it as long as the last guy in there didn't go crazy tightening it.

BTW, you don't need the whole 70lbs on the rear bolt, I usually oil the threads of the bolt and underneath the head, and get the mating surfaces on the back of the cam and the inside of the pulley good and clean and dry, and go for more like 30lbs. If that pulley does slip the result is not catastrophic but I've never had one loosen up, and I like the lower torque because I want to be able to get it off again without a struggle the next time I'm in there.

By contrast, I usually prefer slightly a higher torque than spec on the front bolt, more like 45lbs rather than 33. Don't want that one to move...

[ngoma]

Originally Posted by volvo 4 life

How do you keep the cam from moving while torquing the pulleys down? Even if you hold the pulleys with the sprocket holder it would seem the cam would still slip while trying to torque the pulleys down, especially the rear since it requires around 70 ft lbs of torque.

Front pulley: Tapered fit is not apt to slip.

Rear pulley: Is a clamped fit, more apt to slip but doesn't seem to be a problem if you use this method. (v8volvo suggests cleaning up the rear pulley/camshaft mating surfaces, bolt, and washer, and lightly lubricating the bolt threads and under-bolt head contact surface [only] w/ synthetic motor oil, which permits equal [or better] clamping force with less bolt tightening torque.)