I am in the middle of a timing belt change and have been stopped cold. I can't fit the new timing belt because it is too tight going over the tensioner pulley. I would almost say it is too short but I tried refitting the old belt and it seemed to be too short as well.

What am I doing wrong?

The old tensioner is okay and I pinned it and loosely bolted it in place.

I changed the tensioner pulley and the idler pulley as well as the belt.

Whenever I look at a video or set of instructions the belt seems to slip on easily. Not so mine.

I got under the car and made sure the belt is running properly on the crankshaft gear--it is not hanging up on anything.

I draw the new belt up from the crankshaft, past the idler pulley and around the intake sprocket, trying to get it as tight as possible.

I then run it over the two sprockets and down to the water pump.

Up to the tensioner pulley. But here I cannot pull the belt over the pulley.

Should I need to lever it over the pulley? Or is there some crucial step I am not seeing?

frustratedly,

Bob

I would like to say that I successfully installed the belt myself but that would be a lie. A friend of mine who was a mechanic in an earlier life dropped around and installed it.

I asked him how he went about it and from what I could make of his explanation, the last part of the belt he slipped on was the long part that backs onto the idler pulley. He said something about moving the crankshaft as well but I could not fully understand that part of the explanation.

I want to thank everyone who sent ideas to me on Brickboard. Much appreciated.

muskox37

I will try to upload a picture showing what I think might be the best way to install a tight fitting 960 timing belt.

The picture does not show the final install. The belt should be wrapped around the water pump and up over the tensioner pulley.

I found there was always a bit of slack on the run of the belt up the right hand side from the crankshaft, past the idler pulley, and on to the intake sprocket. Even after I had tried to pull everything tight. I was trying to make the tensioner pulley the last one to pull the belt over but I never succeeded.

I now think the belt should be allowed to run straight up from the crankshaft pulley to the intake sprocket without engaging the idler pulley.

Then the belt should be drawn over all other sprockets, pulleys, etc.

Lastly the belt should be forced over the idler pulley.

But I am an amateur and something of an idiot mechanic.

Is this your 92 960? If so, as suggested, check out the 700/900 FAQ. Note there is a specific section on changing timing belts on 960’s in the link below. Maybe that will help. Never done one myself so I can't be much help...:)

https://www.brickboard.com/FAQ/700-900/EngineSealsBeltsVent.htm#960TimingBeltChange

--
Will I buy another Volvo??? We'll see....

I have had a read through that information and I am following Robert Spinner's video on timing belt change over for a 960.

I am now thinking that I should install the belt before I install the pinned tensioner. Just worried that I won't be able to install the tensioner once the belt is in place. Robert loosely bolted his tensioner in place before putting the belt on but he did say that others left the tensioner off.

muskox37

NMI

hello Dan,

Thank you for the information that you have found them tight. I have been finishing on the tensioner pulley but I will try again following your advice to finish on the cam pulley.

I could not get the tensioner installed with the belt in place. That idea did not work. I can't believe that I am three days into this struggle with no end date in sight.

muskox37

I was assuming a red block 240 engine, this is why I deleted the post.

I have no experience or knowledge on the 960 engines.

Dan

“...I then run it over the two sprockets and down to the water pump....”

Down to the water pump??

This write up from the 700/900 FAQ might help:

https://www.brickboard.com/FAQ/700-900/B230FTimingBeltAlignment.htm

Chris,

I am following RobertDIY's steps. He puts the belt on the crankshaft pulley first, then runs it up past the idler pulley on the RH side, over the two cam sprockets and then down on the LH side to the water pump and then up to the tensioner pulley.

I am thinking I should not have the pinned tensioner in place before I install the belt. I plan to try and install the belt first and then install the tensioner.

muskox37

Some timing belts are a little bit thicker than others especially non-OE belt.

When installing my Gates Racing Blue Kevlar last time, I really had to pull and struggled to hook that first few teeth of that last stretch to the cam sproket. Finger numbing experience I remember. Compared side by side the kevlar belt was a tad thicker than the old OE belt. Can't comment on Contitech or other makes as I had only used OE and Gates belts up till today. Try using clean rag cloth to help with the hooking, to make it less painful to the fingers. If the cloth got trapped on the cam sproket just spin the crank later a bit to release it.

Alternatively use OE belt. Its much easier to install.

Amarin.

Edit:
If you're installing the belt over tensioner pulley last (versus belt over cam sproket last), you might need a helper with big pliers to further compress the tensioner's spring.

I am installing an AC Delco belt that was manufactured in the U.K. But I took it off and tried to reinstall the original Volvo belt and had no luck with it as well. There are 143 rounded teeth on the belt.

I think my mistake is in trying to install the belt with the tensioner already in place. Today I will install the belt first and then try to install the tensioner. It is pinned, etc.

Did you install your tensioner before you installed the belt or after?

muskox37

I thought the engine was redblock B230. My mistake.

From your photos - Have you tried installing the belt by first removing the white plastic piece off the top of the tensioner? Looks like with that item in place the idler can't really go low down. Refit the piece after belt is installed and you've pulled out the pin/nail.

Here's Robert's video. Fast forward to 8.43mins.
https://www.youtube.com/watch?v=Nfit75Yg4u0

Amarin.

Dear muskox37,

Hope you're well. I just changed the timing belt on a '94 940, so the procedure is "fresh".

Presuming the timing belt has 123 rounded teeth, the belt should fit. Forgive me for asking, but have you compressed the tensioner's spring and inserted into the hole in tensioner's shaft, a thin steel rod (e.g., a finishing nail or a 3/32" drill bit) to keep tension off the belt? If this is not done, there's not enough slack to fit the belt onto camshaft's sprocket. If your car's distributor is at the back of the head - closest to the firewall - the alignment of the "idler" sprocket does not matter: only the crankshaft and the camshaft sprockets must align.

Presuming that the belt is seated on the crankshaft sprocket - and the tensioner's spring is compressed and held by the pin - the belt should fit round the "idler" sprocket and the camshaft sprocket.

The tensioner should not be bolted into place, until you're ready to close up. Just be sure the tensioner's "nub" - the round stub on the side that fits against the engine - is fully seated into the recess.

Hope this helps.

Yours faithfully,

Spook

Hello again Spook,

This is the second picture. Hope I can get it to upload.

Dan is suggesting I finish the belt installation on one of the camshaft sprockets instead of at the tensioner pulley. I will give that a try today.

You can see the tensioner pulley resting on top of the tensioner.

muskox37

Sorry I thought you were changing the belt on a 4 cylinder red block not a 960 engine which I know nothing about!
Dan

Hello Spook,

The belt has 143 rounded teeth. The car is a 1992 960 and I guess there are differences to a 940. I have compressed the tensioner's spring and inserted a finishing nail as directed by a RobertDIY video.

'The tensioner should not be bolted into place, until you're ready to close up."

Hmmmm. I bolted the tensioner in place loosely. I was worried that I would not be able to fit it with the belt installed. I have been trying to install the belt with the tensioner in place. Could this be my mistake? I will try installing it without the tensioner in place and then get back to you.

Once again, my thanks.

muskox37

Good day Spook,

As expected I could not install the tensioner with the timing belt in place. At the moment I am completely flummoxed. I will try to upload a couple of pictures. If you can see anything wrong please let me know.

I am trying to upload two pictures but don't know how to do that so I will have to make another entry to get the other picture up.

Hello Spook,

The belt has 143 rounded teeth. The car is a 1992 960 and I guess there are differences to a 940. I have compressed the tensioner's spring and inserted a finishing nail as directed by a RobertDIY video.

'The tensioner should not be bolted into place, until you're ready to close up."

Hmmmm. I bolted the tensioner in place loosely. I was worried that I would not be able to fit it with the belt installed. I have been trying to install the belt with the tensioner in place. Could this be my mistake? I will try installing it without the tensioner in place and then get back to you.

Once again, my thanks.

muskox37

>Presuming the timing belt has 123 rounded teeth

Not a big deal but just to make sure you don't confuse muskox37 the belt he is installing on his 92 240 would be square shouldered rather than rounded teeth wouldn't it?

Randy
--
Any twenty minute job is just a broken bolt away from a three day ordeal

Hi Randy,

All input welcome. But the car in question is a 1992 Volvo 960, not a 240.

My 240 is an 82!

Your broken bolt comment really hits home. I broke one of the idler bolts overtorquing it and I am into the second week of this job right now. I did manage to retrieve it without damage to the threads. What a relief!

Bob

Dear rstarkie,

Hope you're well. You're 100% right: a 1992 model takes the square-toothed belt! But I think that belt also has 123 teeth.

Good catch!

Yours faithfully,

Spook

Hello again Spook,

The belt on the '92 960 has 143 teeth. I checked it twice.

Regardless, now that I have the timing belt in place I did want to ask you about the serpentine belt tensioner. I can turn the pulley okay and it does not feel stiff but it does make a small noise when turned. If 'spun' it only goes about a quarter of a turn at most. Is this normal or should it run freely?

If it is okay I plan to install it tomorrow and I should be able to close up the engine and turn to the radiator.

muskox37

It's bad, should rotate freely and quietly. Also check idler pulleys.
Dan

Dear pageda,

Hope you're well. You're 100% right: a timing belt tensioner - that does not spin smoothly and quietly - is "junk".

Hope this helps.

Yours faithfully,

Spook

Good morning,

I just received the new serpentine belt tensioner pulley. It is a Dayco like the old one. And it cannot be spun at all. It is stiffer than the original. I have to hold the centre to get it to turn.

This is a surprise to me. I thought it would just spin on its axis. The timing belt tensioner pulleys were not as stiff.

It is identical in size and shape to the one I removed.

I suspect that most people replace the entire assembly rather than just the pulley and maybe that is why its 'spin' factor is largely unknown. It has a skookum bolt on it so I have tightened it to 30 plus foot pounds.

Back to work. Thanks again for your input, everybody.

muskox37

Good morning,

I ordered a new pulley from Rock Auto and then went to disconnect the old pulley from the tensioner. I started by squirting PB Blaster on the bolt ends and I left it for part of the day.

When I came back the pulley spun easily. The penetrating oil seemed to give it enough lubrication to restore its function. Hmmmm.

But it is still fairly noisy and I am getting the new pulley for about thirty Canadian, shipped.

So I will await its arrival before resuming operations.

Such is the life of a shadetree mechanic.

muskox37

It's not surprising that the pulley would spin freely with the application of penetrating oil but that will evaporate soon after and it has now diluted whatever lube/grease was in there. An application of oil might last longer but in the end a new bearing/pulley is in order. Cheap insurance. - Dave

Thanks for backing up my decision Dave. I agree 100 per cent.

muskox37

I have changed the idler and tensioner pulleys already. Guess I will have to see about getting a serpentine tensioner as well. Just as well I asked. Thank you Dan.

Serpentine belts often have both tensioner and idler pulleys also. I am not sure what the 960 has?
Dan

It has both. The idler pulley runs freely without noise. I am off to a local supplier to see if I can get a replacement. Might have to go to Volvo for this one.