turbo cam belt change

[Guest]

hello,

my timing belt tensioner is starting to make a bit of a racket - so i wanna get it changed along with all the belts down there.

I am assuming that the turbo belt is identical to the the 2.0 EFI when i order it all?

Is there a procedure somewhere for changing it? im sure i remember reading somewhere that you needed some tool to tension it - something along the lines of x force measured to deflect the belt x distance?

[E_T_V]

I hyave a feeling there are two sorts of belt profile (square teeth or half moon - depending on age).

I can't remember which was on what, but check this before you buy the belt (otherwise yes it is the same as the EFI.

Belt tension you can set by feel. Thumb and forefinger moderate force neeted to twist belt to 45 degrees along longest belt run is the guide I use.

[Guest]

Dam. I already ordered the kit from my local parts place. Will have close look when it all arrives. Is it obviously different?

[E_T_V]

Yes. The teeth are a completely different. One is half moon shaped. the other is a trapezoid shape.. I think all turbos will be the latter.

[Russ]

All turbo's were half round it was only B&C plate EFi s that were the flat profile. The O series was redesigned in late 85. Flat profile belts were fitted to the engine's with the rounded cam cover and rear mounted alternator

[Simon]

20HA engine had the older flat tooth design. 20HB and onwards went to the newer rounded tooth profile.

Key:
1. Camshaft gear timing marks
2. Crankshaft pulley timing groove and pointer
3. Hexagon drive hole
4. Tensioner securing bolt
5. Tension gauge setting position (ignore if not using a tension gauge)
6. Tension hook (service tool 18G 1315, or make your own out of stiff wire eg welding rod and spring balance
7. Deflection mark

Procedure:
Disconnect battery and remove timing belt cover. Renew belt if necessary and fit the tensioner to the outer of the two tapped holes in the water pump boss. If a new belt has been fitted, equalise the belt tension by flexing both lengths inwards simultaneously at the tension gauge setting position. If the tensioner “overcentres” without achieving belt tension, resite the tensioner at the inner position.

Tension the belt initially by engaging an 8mm hex drive in the tensioner and rotate the tensioner anticlockwise and tighten the retaining bolt.

Mark the rear camshaft cover with parallel lines 8mm apart in line with the outside face of the timing belt as in the diagram at (7) Position 18G 1815 or a bent wire hook across the timing belt midway between the camshaft and water pump pulleys as shown and attach the spring balance. Pull at right angles to the timing belt, the force required to align the outside face of the timing belt with the outer mark (8mm) should be 49N, 5Kgf or 11Lbf

Adjust the tension as necessary, slacken the retaining bolt and turn the tensioner anticlockwise and retighten. Recheck the tension. Refit the belt cover and connect the battery.

[Guest]

Cool thanks for that. Ive ordered a spring balance so will give it a go

[E_T_V]

All turbo's were half round it was only B&C plate EFi s that were the flat profile. The O series was redesigned in late 85. Flat profile belts were fitted to the engine's with the rounded cam cover and rear mounted alternator

Thanks for setting me straight. I knew there were two sorts of belt just go the two the wrong way round! D'oh!

[Guest]

Does anyone happen to know what to torque the tensioner bolt to. Im fitting a new item

[Simon]

You have PM, I will check data this evening. I don't think it's done up very tight because it fits into an aluminium casting.

[Simon]

Looked in the Haynes Manual and there's no torque figure specific to the belt tensioner. All it mentions is 8mm bolts going into alloy castings being 18lbf. I'd say do it up to that figure and it you aren't happy then give it an extra tweak, but be careful not to strip the thread in the water pump.

[Guest]

cheers simon,

i was thinking of going a bit tighter with it being an M10 bolt

[Simon]

M10 into cast iron is 37lbft. Seems a better bet.

[Guest]

thats really weird! I have exactly the same copy of that article in with my workshop manual!

[Simon]

You got it in stereo now!