Question about Crank Timing Marks 99' S70 NA

Post by **850 LPT** » 18 Apr 2019, 16:29

Hi everybody,

I am starting the timing belt job on the 99' NA and I am one of the thousands of people who have struggled to find the marks on the crank and the notch on the valley (not sure if this is really what it's called)

I can make out the two little notches on the crank teeth, but the area where they are supposed to line up with something like another notch is too corroded to see anything.

My question is this:
If I line up the cam marks and I can see the marks on the crank teeth, can I not make my own marks behind the teeth and just make sure the crank stays where it is when the belt is off?
If everything stays where it is what could go wrong? Even if the crank moves I can rotate it back to my own marks.
Am I missing something in my thought process?

As always your help is greatly appreciated.

Dirk

Post by **erikv11** » 18 Apr 2019, 16:39

Hi Dirk!

Your thought process seems on target to me, however here are a couple variables that could disrupt using this approach:

- An old timing belt is usually a little stretched. This means that when the crank is on the mark, wit the old belt the cams are not exactly in the notches. However with the new belt, the match will be more exact. In other words, the positions will differ sloghtly between old and new belts. Better to use that factory marks than your own marks in that case.

- The timing on your car is likely spot on, but it is certainly possible it is a tooth off and you didn't notice it.

If one or both of these (or something else) is in play then once you get the belt off it could be hectic to get it all back together without a bona fide crank mark, especially if a cam turns this way or that, the crank is suddenly unexpectedly not exactly where you swear it was a few minutes ago, etc.

If you are sick of hunting for the mark then just go for it and maybe you will be fine, but I'd keep looking for that pesky ridged mark on the oil pump, it is there I promise ...

Post by **850 LPT** » 18 Apr 2019, 17:10

Thanks so much Erik,

I just found the ridge on the oil pump. Boy, it really is nicely hidden behind the belt. I used a thin glove with texture to it and rubbed the corrosion away as best I could. Then I used a small but strong flash light, and voila.

And then I turned the crank until the cam marks line up and noticed that the crank mark is slightly of, say by 1/2 tooth or so. I didn't think of the old belt being possibly stretched, so thanks for pointing that out. The old belt is due for sure, it has lots of fine cracks.

Enough for tonight, I will start fresh in the morning and pull the belt off, checking timing marks one more time to be sure.

Post by **jimmy57** » 18 Apr 2019, 18:43

5's after 97 or thereabouts have two notches and the oil pump will be in the middle. Earlier have one in the "valley" and later have two marks on the "hills". If you look straight down and find the ridge just behind the balancer side of crank gear you will also have a mark to make you assured you have found it.

Post by **abscate** » 18 Apr 2019, 18:48

Dirk, if you need a picture from my 1999 NA let me know. Home tomorrow

tardcart · Post by **tardcart** » 18 Apr 2019, 18:55

you got it just in time. You should probably do the water pump and rollers if this is the second belt. refer to old posts on what brand to use. dont worry too much about the exact position, it will all move a little as you put the belt on. just make sure in the end after rotating clockwise facing the belt that the marks line up. you have to set the cam cover back in place to check. usually the exhaust cam tries to be one tooth retarded. dont attempt to do the job with the balancer in place as some "experts" do. the belt is too stiff to bend it in there with out nicking it or making destructive bends too it. if its dry in there dont mess with any seals. You chance of botching that up is higher than any rewards of longevity. as a quick check the timing mark on the balancer should be aligned with the front of the timing belt.

Post by **abscate** » 18 Apr 2019, 19:00

Dirk , put it on the water pump last. It’s much easier than doing the tensioner, and easing the tensioner to get slack and putting on a different pulley is easy too. You can also tie the tensioner off with string.

+1000 on tads note about removing the balancer. I was a lot more comfortable putting the belt into the wide open slot. Getting the belt firmly into the crank sprocket the next jamminga shop towel in to hold it whilst threading works well too. Red tag it on a checklist so you don’t forget to remove it, it will come out when you rotate to check alignment anyway

Crack the big 30 mm harmonic balancer nut while the plugs are still in and the belt is on, car in gear!

Post by **850 LPT** » 18 Apr 2019, 19:55

Thank you guys for all the great tips, will check it all out in the am.

As for parts I bought only OEM stuff with an Aisin water pump, INA roller and INA tensioner. The belt itself is made by Conti in Hannover, Germany, my home town

I have actually visited the plant once when I was at technical college, that was pretty cool.

Good night everyone!

Post by **850 LPT** » 19 Apr 2019, 15:42

I got the new T belt installed today, but it took me a while. And what I thought would be the difficult part, was actually easy. I opted not to remove the pulley because I don't have an impact drill. But getting the belt around the backside of it was actually pretty easy. A little bit of fumbling but I got it on after 10 mins or so.

What took much longer was getting the belt installed with the timing marks lined up properly. I didn't expect to have problems with that, but what was bothering me was that it was so hard to see the marks in the cover. I ended up with the exhaust cam off by one tooth twice.

Then I had an idea (this was probably done before, I doubt I came up with something new). I extended the little notches out to the edge of the cover, where they can be easily seen. That made my life a lot easier, see below:

The only thing I'm not entirely comfortable with is the adjustment on the tensioner. I tried to have the little lever stand up straight since it was a 65 deg F day, but somehow I ended up with the hex. hole at about 7:30 or so. Tension seems fine but I don't know if I should try to adjust that again.
Also, that little lever moves around quite a bit when I rotate the engine, is that normal?

I'm running out of time, but hopefully tomorrow I can button this up and install the serp. belt, power steering reservoir and coolant reservoir. And then see if it runs

Post by **abscate** » 19 Apr 2019, 15:49

Remember you set the mechanical tensioner by going. Past the tension point and then back to the correct setting