Volvo Owners Club Forum - View Single Post - 850 Cars:

RollingThunder · Aug 20th, 2022, 10:54

Welcome to the forum.

An 850 timing belt isn't the easiest introduction to changing a timing belt, but it is straight forward if you're methodical and have good tools. Remember these are interference engines, so it is IMPERATIVE that you turn the engine over by hand, through at least two full cycles, to make sure that there is no contact between the valves and the pistons after you've fitted the new belt. Take the spark plugs out to make it easier to turn over, and so that you won't have any combustion chamber compression resistance when turning the engine over.

The other issues you may have - apart from keeping it all timed up, are

* removing the aux belt tensioner - weird square drive required, many make own their tool
* removing the torx headed bolt that secures the timing belt tensioner pulley - VERY restricted access and easy to chew up the torx head. Chewing up that bolt will REALLY ruin your day.
* removing and feeding the belt under the crank pulley - just awkward

Most Volvo owners refer to an American guy called RobertDIY on YouTube - he has a lot of very detailed videos which everyone finds useful. I still refer to his videos and I've owned Volvos since 1990

These are his timing belt videos
Part 1: https://www.youtube.com/watch?v=SpNg...nnel=RobertDIY
Part 2: https://www.youtube.com/watch?v=edKD...nnel=RobertDIY

I bought a few tools to make the job easier, and tbh I'd hate to try this job without them now (others may be available lol)

The serpentine belt tool - https://www.ipdusa.com/products/5830...lvo-IPD-105058

And the cam sprocket locking tool - I got mine from iPd but they don't list them anymore

Hope this helps

Oh, btw, if you lose the timing completely, you can get another tool that sets the camshaft timing correctly - it attaches to the gearbox end of the camshafts and aligns them using some notches, so it isn't the end of the world if the cams move, but it will add yet more time to the job. Mentioning which, don't undo the camshaft sprockets unless you intend to change the camshaft oil seals - they have slotted holes. I learned that lesson the hard way and had to buy the aforementioned camshaft aligning tool...

So, to repeat, this isn't the easiest timing belt around. Access is awkward at best. The Torx bolt brings beads of anxious sweat to anyone who has done one of these before. You MUST use a perfect torx bit on this or else you'll have many many hours of fun trying to extract it. And use a camshaft locking tool. Some may say it isn't necessary, but correcting accidental rotation properly means using the alignment tool.

Parts to buy? I fit only Volvo timing belts, but at a pinch I'd fit a Gates or Continental one. Nothing else. I also always replace the tensioner (sorry to contradict Clan, but thats what I do), I also replace all the idlers. Occasionally I've had to replace the aux belt tensioner as that was running with a nasty graunch. The idlers I buy as OEM INA branded parts and they've always been ok.

The waterpump is driven by the cambelt and you need to take the cambelt off to replace it, so its something else to consider. I'd check the pump before condemning it - the original ones were made to a much higher quality than OEM ones these days and I'd only replace it if it was actually leaking or sounded rough when rotating the pulley. Its another awkward part to replace as you need to (obviously) ensure the mating surface is spotless - and accessing that face to clean it is another test of patience

I've got a section on my website https://850R.co.uk which shows/lists the OEM manufacturers of some parts - mainly those removed when I did the timing belt on my 850R so it may be useful to you.

Good luck!

edit - just found a pic of the torx headed bolt for you. I rammed a piece of wood behind the bit to make sure the torx bit wouldn't slip and chew up the head

I used a spanner to turn the bit - access is too tight to use a rachet with the wood. This is on my 850R

Aug 20th, 2022, 10:54	#5
RollingThunder Grumpy Old Git Last Online: Apr 19th, 2024 09:16 Join Date: Dec 2004 Location: South Yorkshire	Welcome to the forum. An 850 timing belt isn't the easiest introduction to changing a timing belt, but it is straight forward if you're methodical and have good tools. Remember these are interference engines, so it is IMPERATIVE that you turn the engine over by hand, through at least two full cycles, to make sure that there is no contact between the valves and the pistons after you've fitted the new belt. Take the spark plugs out to make it easier to turn over, and so that you won't have any combustion chamber compression resistance when turning the engine over. The other issues you may have - apart from keeping it all timed up, are * removing the aux belt tensioner - weird square drive required, many make own their tool * removing the torx headed bolt that secures the timing belt tensioner pulley - VERY restricted access and easy to chew up the torx head. Chewing up that bolt will REALLY ruin your day. * removing and feeding the belt under the crank pulley - just awkward Most Volvo owners refer to an American guy called RobertDIY on YouTube - he has a lot of very detailed videos which everyone finds useful. I still refer to his videos and I've owned Volvos since 1990 These are his timing belt videos Part 1: https://www.youtube.com/watch?v=SpNg...nnel=RobertDIY Part 2: https://www.youtube.com/watch?v=edKD...nnel=RobertDIY I bought a few tools to make the job easier, and tbh I'd hate to try this job without them now (others may be available lol) The serpentine belt tool - https://www.ipdusa.com/products/5830...lvo-IPD-105058 And the cam sprocket locking tool - I got mine from iPd but they don't list them anymore Hope this helps Oh, btw, if you lose the timing completely, you can get another tool that sets the camshaft timing correctly - it attaches to the gearbox end of the camshafts and aligns them using some notches, so it isn't the end of the world if the cams move, but it will add yet more time to the job. Mentioning which, don't undo the camshaft sprockets unless you intend to change the camshaft oil seals - they have slotted holes. I learned that lesson the hard way and had to buy the aforementioned camshaft aligning tool... So, to repeat, this isn't the easiest timing belt around. Access is awkward at best. The Torx bolt brings beads of anxious sweat to anyone who has done one of these before. You MUST use a perfect torx bit on this or else you'll have many many hours of fun trying to extract it. And use a camshaft locking tool. Some may say it isn't necessary, but correcting accidental rotation properly means using the alignment tool. Parts to buy? I fit only Volvo timing belts, but at a pinch I'd fit a Gates or Continental one. Nothing else. I also always replace the tensioner (sorry to contradict Clan, but thats what I do), I also replace all the idlers. Occasionally I've had to replace the aux belt tensioner as that was running with a nasty graunch. The idlers I buy as OEM INA branded parts and they've always been ok. The waterpump is driven by the cambelt and you need to take the cambelt off to replace it, so its something else to consider. I'd check the pump before condemning it - the original ones were made to a much higher quality than OEM ones these days and I'd only replace it if it was actually leaking or sounded rough when rotating the pulley. Its another awkward part to replace as you need to (obviously) ensure the mating surface is spotless - and accessing that face to clean it is another test of patience I've got a section on my website https://850R.co.uk which shows/lists the OEM manufacturers of some parts - mainly those removed when I did the timing belt on my 850R so it may be useful to you. Good luck! edit - just found a pic of the torx headed bolt for you. I rammed a piece of wood behind the bit to make sure the torx bit wouldn't slip and chew up the head I used a spanner to turn the bit - access is too tight to use a rachet with the wood. This is on my 850R __________________ S40 2.4i '07 Japanese import '96 850R - https://www.volvoforums.org.uk/showthread.php?t=312484 Ex Danish Embassy '96 940 GLE LPT - https://www.volvoforums.org.uk/showthread.php?t=326071 Last edited by RollingThunder; Aug 20th, 2022 at 11:21.