1999 V70 First timing belt install-mechanical tensioner

[paredown]

Watched the videos--Robert DIY and the FCP video--then go to work, only to find that the very clear instructions on these videos (and elsewhere on this forum--eg this thread https://www.matthewsvolvosite.com/forums ... php?t=8803 ) apply to the hydraulic tensioner cars. Not only that, my '99 seems to have some hard line running right along the bottom where you have to remove bottom guard and snake the new belt in. Total PITA.

OK--despite all this, I;
--got everything apart--(had to bend hard line down and out of the way to remove old belt)
-Replaced water pump
-installed new idler pulley
-Have new mechanical tensioner installed to 5 ft/lbs (per link on this thread) and not adjusted:
https://www.matthewsvolvosite.com/forums ... =1&t=56658

Unfortunately the mechanical tensioner addendum just says 'install the timing belt' before following the directions it gives for adjusting the tension range--and my problem is--when I try to route the timing belt, I cannot for the life of me figure out how to get it on--it seems to be too short.

So are you supposed to install the tensioner after the belt is routed?

I have been working with the belt tight to crankshaft pulley, up over tensioner and water pump on left, and holding it as tight as possible bringing it up around the idler and over intake cam pulley--and that leaves me with no possible way of getting the belt over the exhaust cam pulley...

Edit to add: checked the rib count on the belt and it seems to be the same as the one I took off...
-

[Ozark Lee]

On your mechanical tensioner there is a "window" at the top of the tensioner. The window is a couple of tabs that protrude from top of the tensioner at the 12:00 position. What you want to do is adjust the center the tensioner hub to a point where the indicator is centered in the window and then tighten the center nut. The tension will change somewhat after the engine runs so it may take two or three times to get it right. I'll look for a picture and post it for you.

Don't run the engine until the tensioner is set.

Here is a picture of what I am talking about.

...Lee

[paredown]

On your mechanical tensioner there is a "window" at the top of the tensioner. The window is a couple of tabs that protrude from top of the tensioner at the 12:00 position. What you want to do is adjust the center the tensioner hub to a point where the indicator is centered in the window and then tighten the center nut. The tension will change somewhat after the engine runs so it may take two or three times to get it right. I'll look for a picture and post it for you.

Don't run the engine until the tensioner is set.

Here is a picture of what I am talking about.

...Lee

Thanks for the quick response--this part I think I understand--but I can't seem to get the belt on to begin with...

Should the belt be routable with the tensioner in its default position? I sort of get how the hydraulic style work--route the belt and pull the pin, but with the mechanical one, are you supposed to be moving the lever at the top by hand to get the belt on first.

[rspi]

Does your car also have CVVT?

[paredown]

Does your car also have CVVT?

I think not--but how would I tell?

[rspi]

One of these on top of the motor by the exhaust cam sprocket.

[Ozark Lee]

The belt should thread on with the tensioner in its default, out of the box, state. It won't have a ton of slack but enough to get the belt on with no problem. Loosen the center bolt on the tensioner to zero torque - finger tight, that way the tensioner can't inadvertently tighten. Once the belt is on then you can snug the center bolt enough to tweak the tensioner to the center indicator position before you torque the center bolt down to specification.

Part of the problem on setting the tension, why it usually takes more than one shot to get it right, is that the tension changes as the center bolt gets torqued down. For that, you just have to play with it until it comes out right after the bolt is torqued and the engine has run.

...Lee

[paredown]

Nope--don't have one of those.

For those interested, this is the adjustment procedure that Ozark Lee mentions, and is in the pdf in the MV thread linked above:

Use the following procedure when adjusting the mechanical camshaft belt tensioner on 1998 Volvo S70/V70/C70 (B52X2/B52X4) vehicles with engine serial number 1266128-on.

Service Procedure:
1. Install the timing belt.

2. Ensure that the belt is tight between the crankshaft and the intake pulley; if not, reinstall it.

3. Tighten the center screw to 5 Nm (4 ft.-lb.).

4. Holding the center screw stationary, turn the eccentric (A) with a 6 mm Allen wrench counter-clockwise until the tension indicator passes the right side of the adjustment window (B). See Fig. 1.

Front view of adjuster

VolvoFig1gif_00000015776.gif (6.67 KiB) Viewed 5173 times

5. Turn the eccentric (A) back clockwise until the indicator (C) reaches the correct position based on the temperature of the engine (see Fig. 1).

6. Hold the eccentric secure and tighten the center screw to 20 Nm (15 ft.-lb.).
Note: When setting the final adjustment, the needle (C) must enter the adjustment window (B) from the right. If the needle exits the window to the left, it must be readjusted past the window so that it enters from the right. See Fig. 1.

7. Press on the timing belt and verify that the indicator moves in response to the pressure.

8. If the bolts holding either cam wheel had been loosened, tighten them at this time to 20 Nm (15 ft.-lb.).

9. Press the camshaft belt and check that the belt tensioner needle moves freely.

Needle Position at Different Temperatures:
Note: This adjustment is always carried out on a cold engine. A suitable temperature is approximately 20°C/68° F.

At higher temperatures, for example with engine at operating temperature or at higher ambient temperature, the indicator is farther to the right. See Fig. 2 which shows the needle position when adjusting the camshaft belt tensioner at different engine temperatures.

Ambient temperature scale

VolvoFig2gif_00000015777.gif (7.56 KiB) Viewed 5173 times

[paredown]

The belt should thread on with the tensioner in its default, out of the box, state. It won't have a ton of slack but enough to get the belt on with no problem. Loosen the center bolt on the tensioner to zero torque - finger tight, that way the tensioner can't inadvertently tighten. Once the belt is on then you can snug the center bolt enough to tweak the tensioner to the center indicator position before you torque the center bolt down to specification.

Part of the problem on setting the tension, why it usually takes more than one shot to get it right, is that the tension changes as the center bolt gets torqued down. For that, you just have to play with it until it comes out right after the bolt is torqued and the engine has run.

...Lee

Thanks again--I appreciate the clarification and the fact that I will have to start the car and readjust.

I'll start again in the morning--but unfortunately I was already messing around with the tensioner, trying to understand the eccentric, so I will need to figure out what the default state is (where there would be the most slack).

This thread on Swedespeed digresses a lot--but it sounds like he had a heck of a time with his as well:
http://forums.swedespeed.com/showthread ... 6127/page2

With my best attempts at threading the belt, I ended up with only enough slack for an exhaust cam about half the size of what is there, so clearly I did not have the tb threaded on properly.

I read on another forum about someone wedging the bottom of the belt on the crankshaft pulley with a small piece of hardwood to keep it from wanting to move while they pulled it tight on the intake side, so I will try that to see if I can get that a little tighter to start.

[Ozark Lee]

If it is off by that much then chances are that the belt is hung up at the notch below the crankshaft pulley. When installing the new belt it needs to be turned to a vertical orientation, ribbed side toward the block, to slide on below the harmonic balancer. Once it clears the notch the belt can be flipped back to the horizontal position.

The tensioner will be in the default state when it has nothing holding it back at the center locking bolt - when the bolt is loose.

...Lee