1.6 diesel belt tension and torque specs

[murphus]

Hiya. Newbie here, just finishing up my first 1.6 timing belt replacement, a 1991 Jetta Eco Diesel, but without a manual because the Bentley I thought I won on eBay was never sent. Near as I can figure i got it too cheap and the seller backed out on the deal! But, thanks to good info found here and elsewhere i feel pretty confident i have it all figured out. New water pump, tensioner, belt. Belt's on, properly timed (used a cam lock plate, pin for the injection pump, crankshaft set on tdc, etc...) but i haven't found any solid recommendations for proper timing belt tension. Is there a consensus on best tension?

Also, can anyone give me torque specs for: camshaft pulley bolt, camshaft support nuts, idler pulley bolt? I have the camshaft pulley bolt torqued to 55ft/lb, same as a gas engine. I have the camshaft support bolts (removed the cam due to stupidly removing entire crank pulley before locating tdc) torqued to 14ft/lb, same as a gas engine. I don't have the idler pulley torqued; it's just tight. Crankshaft bolt was replaced, torqued to 66ft/lb then stretched another 1/2 turn (approx.; that's a bugger, probably only stretched it 1/3)

Thanks in advance for any help,
Richard in Kansas

[theman53]

There is a belt tensioning gauge, but I don't have one or know what the # is to set to. I used to tighten the snot out of the TB, but after listening to all on here I would say basically snug. You wouldn't want to be able to pull it off, but from the way I am doing it now it you can easily twist the belt...there are some saying 45 some 90 degree twist, but it is too subjective to me. Basically, the injection pump has bushings in it that are a pain to replace, so now I go to the softer tension side of the equation. I just twist the tensioner by hand until it meets the belt and tighten the tensioner. The nut will usually give it a little more and I call it good.

Listen to what others say though as you don't want it so loose it comes off. I also am not the foremost authority on it either

[Quantum TD]

If you don't have the tensioner gauge, then set it to 45 degrees of twist. That 90 degree number is for 8V gassers.

BUT, make sure the cam sprocket is loose (but camshaft locked in place), and the lock pin is out of the injection pump when you set the tension. If not, you'll only set the tension between the backside of the camshaft and the front-side of the injection pump. You'll also throw off your cam/crank timing.

A lot of people either forget or neglect to pop the cam sprocket free and pull the injection pump lock when they set the tension. Bad idea.


Once everything is where you want it, torque the camshaft bolt (be sure to counter-hold the sprocket) and the tensioner nut to 45 n/m (33 ft-lbs). On the cam sprocket, I usually go an extra 1/8 to 1/4 turn for good measure.

[theman53]

Yeah bentley says 33ft/lbs, but I think the general opinion is to go to 45 ft/lbs on the cam sprocket.