Timing Belt Replacement Tips

Timing Belt Replacement Tips

The reason the timing belt won't ride correctly, the tensioner pivot bearing are worn out. There are two plastic bearings on the pivot bolt, that is one of many things you should replace when doing the timing belt. Better to replace a few more things and not have to go back in for 60,000 miles. Is the crank seal good for another 60,000 miles? All the belt rollers and the pump. Some of those parts might be fine NOW but what about 4 years down the road? The 928 is such a labor intensive car to work on it is well worth the extra part once in a while so you don't have to go back.

I made the mistake of telling my mechanic how well the car was running (89 S4 Auto, 86K mi). Needless to say, I got a tensioner warning (and a heart murmur) on the way home (not to mention a flat tire). The belt had been replaced at 66K, but not the idlers. We decided to take the whole thing apart to check stuff, and that was a good thing. All three idlers were worn, two badly and one starting to disintegrate, leaving a mark on the belt (which, at 20K mi, was fine). So, the moral of the story is: listen to the Devek people, and replace the idlers with the belt (and the tensioner dust boot).

>I'm in the middle of a timing belt replacement and can not
>seem to get the waterpump pulley bolt to budge
> I'm to the point where I think something is going to break
>I have two questions. Is this bolt reverse threaded?


>And if not do they make a special tool to hold the fly wheel?
>Will I break a flywheel tooth by using screw driver instead?
>I am using a very heavy duty 3/4 drive breaker bar and am
>very nervous about pulling on it any harder.

Stop. Buy the tool from 928 Specialists, Devek, or 928 International. About $16.00 and well worth it.

John Veninger
1990 928GT

Been sloggin away on the T-belt install. This engine is god-awful filthy dirty! Thick black gick all over it. I have a solvent/air sprayer but it is still a lot of work. Steam would have been better.

Just for the heck of it I stuck a 10 mm box wrench in just above the oil pan's "chin" at the front of the engine to check the tightness of the oil pan belts. To my utter amazement, they were finger loose! Had to go under and tighten all the way around except where the crossmember denies access. Some of the bolts were so loose that I could spin the washer with my finger! Yet this engine did not use any oil on the dipstick at all in 2000 miles. Maybe the mounts are so old that the engine just rests on the crossbar and that is holding the pan on?

I had mentioned the improved "guide" below the crank sprocket that came on the MY83 AFTER my 83 was built. This thing does a different duty than the original static shoe type of guide. The static guide shows no evidence of ever being touched by the belt. The roller ends up putting just a bit of pressure on the belt where it is coming off of the crank sprocket. Since this is the slackest point of the belt, there may have been a vibration (a guitar-string kind of "twang") at this point at some engine speeds. I am guessing here, but I bet that is why they added this roller. You are supposed to replace the back plastic belt cover when changing to the roller type of guide, but I a pretty sure I can make the minor mod necessary to use the ole cover (and save $47). I can cut and weld this ABS plastic.

Also, someone suggested I change the crank seal while I am in that part of town and I found that there is a little bit of dribble at this seal when I got the back cover off. So thank you for that suggestion.

Out of curiosity (again) I pulled the oil level warning detector. Couldn't figure out how it works. It either has a reed switch and the float has a magnet, or there is a hall-effect transistor inside that little teeny tube. It shows 2.8 ohms one polarity and 3 ohms the other when the float is in the down position. Infinity when up (darn, now I remember I did not run the meter way up scale with the open indication. It could have some 100K resistance of something. Oh well, it works. Not a cheap little part either.

Also changing the water pump. My rebuilt pump has a metal impellor and was rebuilt in Germany according to what it says on the box. Some of the 6 mm screws holding the pump on came out very reluctantly. I had to go forward and back a few times for fear of pulling a thread or breaking a bolt. I have since gotten a M6 X 1.0 tap and retapped all the holes (also on the thermostat cover). All the screws were wire-brushed and then given a coating of NeverSeez from a pint can that I have had about 40 years! Boys, did I get my money's worth there! The NeverSeez is especially good for all bolts on exhaust systems. It not only helps you get the bolts off later, it also assures that when you torque the bolts in, your torque reading is related to tension in the bolt rather than friction in the threads.

Anyone who has stayed awake this long thru this ramble has my thanks and sympathy!

83s AT

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