Author Topic: Help! Cam sprocket question... (Read 2578 times)

larry104 · « **on:** August 05, 2006, 08:07:24 pm »

The Bentley manual says the cam sprocket uses a woodruff key. It turns out the cam has a keyway, but the sprocket doesn't. Naturally, I didn't mark the sprocket and cam end, thinking that the two were keyed.

Here's what I'm thinking of doing: leave the cam sprocket loose; lock down the cam; set the crank to #1 TDC; install the lock pin in the pump sprocket, rotate the cam sprocket to align with the belt, then torque down the cam sprocket bolt.

Does this sound reasonable?

935racer · « **Reply #1 on:** August 05, 2006, 09:30:19 pm »

Hopefully you have the cam lock tool on the back side of the cam. As far as the key way, no you don't need it and most don't have them. Get the belt routed properly and than have the cam sprocket off the cam shaft and get the belt ready on it, than just push the sprocket and belt onto the camshaft and throw the bolt in FINGER TIGHT, tension the belt and RE CHECK your timing marks at least twice. IF all is good crank the cam bolt down to 33lbs and you are good to go. Turn the engine over by hand twice to make sure there is no interferance and than start her up!

larry104 · « **Reply #2 on:** August 05, 2006, 09:34:39 pm »

Quote from: 935racer

Hopefully you have the cam lock tool on the back side of the cam. As far as the key way, no you don't need it and most don't have them. Get the belt routed properly and than have the cam sprocket off the cam shaft and get the belt ready on it, than just push the sprocket and belt onto the camshaft and throw the bolt in FINGER TIGHT, tension the belt and RE CHECK your timing marks at least twice. IF all is good crank the cam bolt down to 33lbs and you are good to go. Turn the engine over by hand twice to make sure there is no interferance and than start her up!

Yes, the cam lock tool goes in the slot on the back side of the cam. :mrgreen: Thank you for the help. I appreciate it.

935racer · « **Reply #3 on:** August 05, 2006, 09:38:40 pm »

No worries bro, if its your first vw diesel T belt which it sounds like it might be just take your time, its not that difficult of a job just just go at a steady pace and keep your cool, and triple check everything. Having the cam sprocket off and than putting the belt on and than sliding them onto the cam is the fastest and easiest way of doing a T belt in my opinion.

If you run into any other issues just ask away.

larry104 · « **Reply #4 on:** August 07, 2006, 07:52:46 am »

Quote from: libbybapa

Make sure that the cam to sprocket mating surfaces are completely clean and dry. Use brake cleaner. No oil residue is allowed.

Don't torque the cam sprocket by holding the cam with the cam lock. If you do, you will eventually break the end of the cam. Tighten it to 20 ft-lbs or so, then hold the sprocket (pulley holder, screwdriver against head, etc.) to do final tightening.

33 ft-lbs is not enough IMO. Some cams slipped from the factory. I tighten to 20 with cam lock in place. I then remove cam lock and hold the pulley with a homemade pulley holder. I then tighten to 45 ft-lbs. Give the cam bolt a sharp tap with a hammer. Recheck the 45 ft-lbs torque. If the bolt moves, then tap again and recheck until it doesn't. Simply tightening to 33 without any tapping or higher torque will very likely slip.

Andrew

That's a good idea. Seating the cam gear makes sense. Thank you.