While I have had my 94 Turbo wagon for a month now I was waiting for warmer weather and some $$. In the first week of ownership the timing belt broke. I was looking for tools to hold/position the cams and I happened upon this tutorial. Excellent write up. Thank you for the inexpensive tool idea.

 

Sorry to hear that your timing belt broke, did it do head damage?

 

I am not sure. I am tempted to just install a new belt and see if it turns over. But I should really remove the head and inspect it.

 

Why take the chance of doing more damage by replacing the belt "and see if it turns over"? There is no "half way" after the belt breaks! Do yourself a favor...take the head off and check it out, it's the only smart thing to do! Maybe you could see if the valves are damaged by just removing the intake manifold? Anyway, my 2 cents worth!

 

I know the proper thing is to pull off the head and inspect. Just being lazy I guess.

 

So Ive started using this tutorial to replace the Head gasket on my 97 850 GLT, but after I got to the point where I was pulling off the camshaft pulley, as i tightened the the puller the whole pulley turned. Is this going to mess up my timing and or should I try to tap the pulley back on to turn it back to where it was when everything was lined up.....?

 

Dear Mr. Ycartf,
You started this thread and I too am curious about the above question. That's my biggest fear about doing my timing belt and the front Camshaft seals, what if something moves a little, lets say an inch or two? Can you just return the part that moved back to the original spot and retain the timing? Inquiring minds want to know...Thanks!

 

Let me get this right, you were pulling off the camshaft pulley and as you tightened the puller - the pulley turned? Are you talking about the crankshaft pulley? I ask because there was not a puller used to remove the camshaft pulleys.

In regard to your question (and Rickford's question), if you move something (cam or crank) just a small amount and by hand, you should be fine. The camshafts and crankshafts are only meant to be moved in synch (in time) with each other to prevent collision of valves and pistons that would damage them while they are moving under force and thousands of times a minute. But if you rotate one of them just a small amount (and by hand) while removing them, it is a lot different than them impacting each other under the force and speed of the engine. I doubt that an inadvertent rotation of a few degrees (done manually) would cause any noticeable valve/piston damage. While every effort should be made to keep them (cams and crank) stationary during removal (and this can be accomplished by using the tools/methods I show), you are probably fine. I would just realign whatever got off, nice and gently, and by rotating it back in the direction it came from (ie you would not want to rotate something 350 degrees clockwise when you could just rotate it backwards 10 degrees counter-clockwise). Hope this helps.

 

Okay, just to be sure, if a camshaft (or crankshaft) gets moved (by hand) an inch or two in either direction, by accident or carelessness or whatever, and one camshaft (for example) is off the mark and the other one is on the mark, then you can just rotate it back to where it came from (not all the way around but just back in the opposite direction it moved from) you'll be back in time. Is that correct? Thanks in advance!!!

 

While I don't know absolutely for sure (from firsthand watching through a clear engine or anything), I would say yes. Whatever small amount of movement you may have accidentally gotten should not (in my understanding) have had enough torque and/or speed to have caused any real damage. But I'm not saying you should just independently spin a camshaft or crankshaft by choice (as can be done on our Toyota's for example).

Something else you can do -
If you accidentally rotated it forwards and you have doubts about rotating it backwards a small amount to get it back in time (rotating it forwards to realign the component should always be fine - forward being clockwise in the normal direction of operation), here is another thing you could consider/do. Measure how many teeth "off" you are on the component you moved and move the other components the same amount. Let's say (for example) the crank was accidentally bumped forward (clockwise) 4 teeth. All you would have to do is rotate the camshafts 4 teeth. Every one of these components rotate the same number of teeth at a time - or else the belt would fly apart.

So either way you want to realign it, don't worry, it is doubtful you've messed up your valves.

 

While I don't know absolutely for sure (from firsthand watching through a clear engine or anything), I would say yes. Whatever small amount of movement you may have accidentally gotten should not (in my understanding) have had enough torque and/or speed to have caused any real damage. But I'm not saying you should just independently spin a camshaft or crankshaft by choice (as can be done on our Toyota's for example).

Something else you can do -
If you accidentally rotated it forwards and you have doubts about rotating it backwards a small amount to get it back in time (rotating it forwards to realign the component should always be fine - forward being clockwise in the normal direction of operation), here is another thing you could consider/do. Measure how many teeth "off" you are on the component you moved and move the other components the same amount. Let's say (for example) the crank was accidentally bumped forward (clockwise) 4 teeth. All you would have to do is rotate the camshafts 4 teeth. Every one of these components rotate the same number of teeth at a time - or else the belt would fly apart.

So either way you want to realign it, don't worry, it is doubtful you've messed up your valves.

 

I just thought I would share this for anyone near Atlanta wanting an 850 Turbo that would be willing to repair the HG (can use this tutorial). It says the turbo only has 700 miles on it and they are asking $1000 OBO.

1995 Volvo 850 Turbo

Thanks, Tracy

 

Great write-up: thanks!

Question: in the "Cylinder Head Replacement" section (p8), it shows the camshaft aligning tool in place as the cam tower cover is installed, but on the "Timing Belt Replacemt" page (p9), the tool is no longer attached. I just finished installing the cam tower cover, but I'm reluctant to remove the camshaft aligning tool, because the pressure from some of the valve springs (I assume) seems to be trying to turn both the camshafts, so I'm wondering if it IS removed, might this cause valve-piston contact, and subsequent valve damage?

Thanks again!

 

Note that the crankshaft rotates TWICE as fast as the camshafts, so if this fix is even possible, the camshafts would have to be rotated HALF as many teeth forward as was the crankshaft.

The pistons have to go down/up/down/up for the intake/compression/power/exhaust cycle, whereas the intake and exhaust camshafts need only open the valves once per cycle.

 

Chax, there is no need for the alignment tool to remain on the camshafts after the cylinder head upper section has been secured (and is holding the valves into position).

Also, you're mistaken about rotating the camshafts half as many teeth as the crankshaft. If we were talking about "degrees" you would be correct, but we were talking about teeth. To say that you would rotate the camshaft a different number of teeth than the crankshaft would mean the belt would travel at two different speeds simultaneously (impossible). The camshafts have twice as many teeth as the crank ...... see?

 

I was wondering about that and how it could be if there is a belt going around gears. Actually its about gear circumference which equates to more teeth on the cam gears. Now I get it...Thanks! (Again)

 

how much did the head work cost?

 

The head work ended up costing me $175. That was for resurfacing/smoothing the head surface, performing a test for cracks and such (plus checking to see if it needed a valve job), performing a valve job (smoothing out all the ports), and installing the new valve stem seals that I had already bought and brought in with the head. Also, this was done in the summer of 2010 and in Southeast Alabama (where I know we have a lower cost of living than a lot of the USA). Hope this helps, and best of luck!

 

tutorial is not there anymore?