charles 200TQ

Well, I said I didn't want to be on here this weekend but I made it!

I had a rough start on the timing belt change: During disassembly, I found that the front motor mount was toast so I thought I should find the mount and replace it since it would be so easy to do at this point. After calling everywhere, can't get it before monday. More time wasted... So I guess I'll put it back on and change it the PITA-method later.

But worst of all, everything was going smoothly until it came time to pull the camshaft sprockets. The Blau kit comes with this POS 2-arm sprocket puller, and the point was smashed to nothing so when I tightened the bolt to pull the sprocket, it walked all over the place and would start pulling at bad angles. So I got the passenger side pulled, and moved to the driver side. I sharpened the point a little on a grinder to get a better bite on the bolt head and prevent walking. After more difficulty, the sprocket popped off.

What I quickly notice, however, is that the diamond-shaped securing plate in front of the camshaft is no longer horizontal as it should be, but now is rotated almost 90 degrees clock-wise. Somehow the sprocket teeth jumped a few ribs on the belt.

I stopped for the night but I have worries. Tomorrow I intend to remove the valve cover to verify that the camshafts rotated with the sprocket, or in a worst-case scenario, the sprocket inside the head jumped some links on the cam-chain, which seems highly unlikely.

I just want to verify that I can rotate the camshaft sprocket counter-clockwise to the correct position. I attempted already but when I turned it, it just rotated right back to where it was.

After checking the camshaft timing marks, I intend to put the sprockets on loosely, and have the timing belt all on except on the cam-shaft sprockets. Then I'll rotate the sprocket to the correct position, and having the cam-sprocket locking tool in place should insure that the sprockets are in the correct positions. Then I'll slip the timing belt on to keep the sprocket from springing back to the wrong position and tighten the sprockets.

Any errors to this logic and plan that I am unaware of? I know that it spun and I know that it spun clock-wise. All that worries me is that the sprocket doesn't seem to want to turn counter-clockwise, and I know I can't spin the shaft 2 revolutions clockwise because then the valves will surely interfere. Any reason the camshaft sprocket can't rotate counter-clockwise?

Redneck Truck

4driver4 talked in someone else's post about the camshafts unloading, jumping, and scaring the **** out of you. Could this be what you've just experienced?

4Driver4

I think you're probably ok, but I don't think you have a clear understanding of how the sprocket and the cam shaft relate, and your plan for Sunday is off base.

First, the belt did not jump any teeth. However, the sprocket is not keyed onto the shaft. That's why the shaft can turn without the sprocket and belt turning.

Did the camshaft really turn, or did the diamond shaped plate just pop off the shaft and turn? That seems more likely.

90 degreess is a *lot*. That's more that a simple cam jump due to valve springs. You inadvertently turned that - a lot. However, since it is bank two, you are probably fine. Assuming that the locking pin is holding the crank shaft, remove the belt and cam sprockets, replace the diamond plate shaped things on the end of the camshafts (they only fit one way) and use the locking bar to rotate the cam back into position.

Do not worry about the chain under the valve cover. You couldn't make that jump if you wanted to. You'll get a better understanding of that when you do the cam adjuster seals.

Spend some time looking at some of the write ups before you go much further. You want to get timing right when you re-install the belt. Once you free the cam sprockets, timing is infinitely adjustable, and getting it right makes a huge difference in the way the car runs.

4Driver4

That's usually bank one (passenger) and usually about 15 degrees. Anything more than that and the cam didn't turn on its own. Either the little plate popped off and if just looks like the shaft turned, or he turned it with puller.

Personally, I'm not a fan of the pullers. If you loosen the bolt about two full turns and give it a sharp blow with a hammer as if you are trying to drive it back in, the sprocket pops right off.

AR15Texan

That was me that 4driver4 helped out. The passenger side did indeed jump because it is under compression. If you remove the camshafts to replace the seals you will more than likely need to "relax" the passenger side camshafts in order to get them out of the head. 4driver4 suggested that I rotate the camshafts in order to unload the valve springs. It worked just fine.

Remember to mark both sprockets and the chain so if anything moves while lifting the cams out you can easily realign. The "16 chain roller" count is not exactly 16 and it is difficult to line up due to the angle of the heads.

Sounds to me like you got the same kit I did from Blauparts concerning the 2-jaw puller. Lucky for me I have several OTC 2-jaw and 3-jaw pullers to use as theirs has a bent forcing screw. I know exactly what you mean about the screw "walking" off the bolt. By the way my puller was brand new and the tip flatten out on the first pulley. I don't think it is designed to "bite" into the hardened bolt head.

I spent the longest amount of time getting to the plug for the crankshaft pin and removing/installing the passenger side secondary air injection valve.

Good luck.

charles 200TQ

That was the first thing I did. I took off the sprocket and put the plate back into its keyed position and it has indeed rotated.

It did seem unlikely that the sprocket had jumped on the belt, but I thought it more unlikely that the shaft would spin because I was pulling on nothing that could turn the shaft except the sprocket. The point of the puller was bearing on the sprocket bolt, but it seemed crazy that that would rotate the shaft once the sprocket came loose.

Anyways, the only thing that concerned me was when I tried to rotate it back to position, the sprocket shaft wanted to spring right back to where it was. Again, it didn't seem likely to me, but I was just afraid that for some reason the sprocket only liked to be rotated one direction.

Thanks for the verification.

charles 200TQ

back with the camshaft sprocket holder tool, and when I have the tool holding the two sprockets, and the belt is not on yet. Looking at the camshafts on bank 2, it looks like the lower shaft mark lines up perfectly, but the upper camshaft notch is rotated a few degrees clockwise and definitely does not line up with the camshaft holder arrow.

It appears that the lifters are applying force on the upper camshaft and causing it to want to spring back to the off position. That's what appears to have gotten me where I am now. Once the sprocket was loose enough to rotate on the lower camshaft, that one set of lifters on the upper camshaft forced it to rotate over.

When I rotate the camshaft back, the chain seems to pick up a little slack, and that is why the upper camshaft mark does not appear to line up, because if it weren't fighting those lifters it would rotate the few degrees necessary and tighten up that slack.

I am going to go ahead and slip the belt on tighten everything up and then I'll turn the engine over (by hand) a couple revolutions to be sure that I have no interference issues and the cams come back around and line up with the correct marks.

The puller really had nothing to do with the rotation, it was the lifter's force on the upper camshaft lobes that caused it to rotate. Perhaps I wasn't at precisely TDC, but it seems strange to me that this would occur by being off by such a small amount.

4Driver4

I would stop worrying about the cams and the marks. They are only used for installing the chain correctly and have nothing to do with setting the belt up right. The locking bar is the only thing you have to worry about for the belt.

Don't bother reinstalling the belt. Just continue with the job.

Baudisattva

Hello, I have a 1993 Audi 90 S and the passenger side cam shaft moved clockwise maybe a 1/4 turn while breaking the sprocket loose with the puller ( CRUD ). You have said in other reply's to just use the holding tool to move it back into proper alignment. Do I move it back counter clockwise or do I move it all the way around clockwise till the lager holes on the diamond shape thingy's face each other again ? I have the Crank holding tool in place and was using the cam sprocket holding tool till I removed everything I needed to remove and then took it off to break the sprockets loose from the cam shafts and that's when the passenger side cam moved. The 12v site said to remove the holding tool after breaking loose the 24 mm bolts: step 18 and 19 12v Pages - Maintenance

Thanks for any help.

Randall

4Driver4

Move it back the way it came, but not until you have the new belt on and are ready to set the timing. Nothing bad will happen leaving it where it is.
If you try to rotate it all the way around, you will find that you cannot...and it is very likely that you will bend valves in your attempt.