Timing belt has shrunk...?
 

Had the cylinder head off my '98 V70 T5, and put it back on again.

What's holding up completing the job is that when I came to fit the timing belt back over the camshaft sprockets, it won't fit, as though it needs to be about 1 cm / 0.5" longer... :confused_smile:

I'd arranged to ship the entire car over to my friendly Volvo indie so he could sort it, but he's just this week closed down, like most of Britain, due to the plague.

When I removed the timing belt from the camshaft sprockets I just pushed it to the side (I didn't remove it from the crankshaft) and left it undisturbed. It's as though I haven't bolted the cylinder head down completely (afaik, I have) and it's raised a little (on the exhaust side) - or the timing belt has mysteriously shrunk.

When I removed it, it was certainly under tension: it didn't exactly slip off. But it looks like I'd need to crowbar (or screwdriver) the belt back over the exhaust cog (I have loosened the tensioner, btw), and I'm not sure it should take that amount of leverage (?).

I was wondering whether the belt has managed to come away from the crankshaft sprockets and is sitting proud (tooth to tooth, notch to notch). One of the reasons I don't know for sure is the awkwardness of getting to that sprocket, or even seeing it, from above. What I can see looks ok.

I haven't turned the crank over since beginning the job. The crank sprocket's positioning marks are very difficult to see with 22 years of crud on them, and I'd like to be able to clean it up somehow to check before (if ever) I fire the thing up again.

I was thinking that I should remove the serpentine belt tensioner for a better view of the crank pulley, and for access, but haven't seen that mentioned in any diy explanations (although Robert DIY's video seems to have views only possible if that were done: https://www.youtube.com/watch?v=SpNgDfvRcVI).

Anyway, if anyone's got any bright ideas or similar experience, I'd be delighted to know about it.

You won't be able to fit the belt over the sprocket without removing it from the tensioner first. Feed the belt round the crank, upto the inlet sprocket and then the exhaust, down to the water pump and then to the idler and tensioner. This is the only way without pain.

Have a look here Click

Just a thought, did you line up all the timing marks before removing the belt?
If so, the crankshaft pulley should be in the right position, I would remove the c/shaft pulley so you can see the marks and refit belt properly.

As above. Jack the car up on the RHS, use axle stands, take the wheel off and remove the wheel arch liner. Then you'll find access to the crank pulley pretty good - after also removing the timing belt cover of course. All quite easy.

Thanks for the comments, chaps, much appreciated!

Turns out that removing the serpentine belt tensioner (not mentioned in any diy instructions I've seen) is necessary to see the marks on the crankshaft cog. I'll have to clean the block side to see the mark there clearly (I secured a wire brush onto a 500mm, 1/4" steel rod so I can use a drill to do this), but that is some progress.

What I can see is that the cog marks are clearly out by 2 or 3 teeth. Don't know why, I set the camshaft timing marks exactly before doing any dismantling [volvo again :shades_smile: ], and the engine hasn't been turned, but there you go...

I did use Tippex (correcting fluid) to mark the timing belt to the cam cogs, and the crankshaft pulley to the bodywork, so when I next get down to look through the wheel arch liner [Luxobarge :cool: ], I'll be able to see if anything's changed.

Turning the crankshaft to the right position may help... ...

I had seen that video, part 2 of the one I originally mentioned [cheers, 4x4].

One difference is that the tensioner in that video is the compress-and-pin type, whereas my wagon has the one where you slacken a bolt and set it to the ambient temperature before retightening. Don't know if that makes any practical difference. I'd tried looping the belt round the inlet and exhaust cam cogs first, but then got stuck on getting it round the pump. I'll have another go at leaving the tensioner till last [thanks, ITSv40], now I've got a clearer space to work in.

Anyway, thanks for the contributions, it's alway heartening to know there are people out there who know what you're going through.

P.S. "All quite easy" indeed... :mouth_closed:

Sorted.

And as has been my experience in so many situations, it came down to something pretty dumb.

Two things I didn't see mentioned anywhere:

1/ Removing the serpentine belt tensioner assembly so you can see down to the timing marks on the crankshaft/block*.

2/ The timing belt tensioner is the mechanical type (with a temperature setting), which I had loosened, and all that was needed was to push it aside to allow more slack to the belt...

So it was indeed "All quite easy". Ho hum.

Turns out that the crankshaft hadn't moved (once I got a view* of it), and the timing marks were bang on. I hadn't removed the belt from the crank so no need to remove the pulley, and as it turned out, found I was able to slip the belt onto the exhaust cog last of all (i.e. with the belt already on the tensioner).

It also helped that it wasn't near freezing out there (started this job in a heatwave at the end of last summer, kerb-side), so I was able to feel my fingers for longer than 2 minutes.

Anyway, as ever, great to get support here.

Next post will probably be when I need to make sure where some bits came from... I labelled my parts bags, but there are all these tubes dangling around :confused_smile: