Ricardo Vega

Hello guys, been about a year since I've been on here and haven't been using my '87 928 S4 much since I moved further away from where I live to my new work place. I knew I was up for a WP/TB service on it anyways so started using a back up car. I've taken apart more than the parts needed to be removed during the WP/TB service. Since I did have the essentials off during this procedure I decided to remove other items such as power steering reservoir, steering pump, and the drivers side cam gear to clean off before putting it back together. But, now I'm at a point where I have removed drivers side cam gear and put back on and markings I put omit doesn't match up at all. Gear has moving from 12 o'clock position to 1 or 2 o'clock. I try to move backwards but there's a bit of hesitation. So before I do anything stupid I wanted to ask you guys how it can be aligned back again and if it's recommended that I get that I gear alignment tool from www.liftbars.com, the PK32V'r tool kit in other words. Thank you let me know. I'm not in a rush. Rather take my time to educate myself on what wisdom you guys have to say. RVII

jcorenman

Welcome!!

The cams are frisky and have a habit of rotating by themselves with spring pressure. As long as the engine is at the 45-deg position then the cams can be freely rotated without risk of any interference.

The cams and gears are keyed, and can only go together one way-- with an oversized keyway to allow the gears to rotate 5-10 deg each way for adjustment. If you have the gear in place roughly centered on the keyway, then have a look into the three slotted holes where the ignition rotor mounts-- the threaded holes should be in the middle of the slots. Install the washer and bolt, and tighten (48 ft-lbs) counter-holding the hex-shaped washer with a 30mm wrench. That gets the cam gear attached to the cam correctly.

Now (with engine at 45-deg) rotate that cam clockwise with the 30mm wrench on the hex-washer, until your 45-deg marks are in the right place. You will feel the springs pushing back as if the engine is possessed, pay no attention-- but make sure the engine is at 45-deg. String the belt, double-check, crank some tension on the belt and then rotate engine clockwise to 0-deg and check those marks. It is inevitable that you will be one tooth off on the first try. Hint: Start with the crank gear then the oil-pump gear, then driver-side cam gear and around the WP. At this point grab the 30mm wrench and rotate the driver-side gear counter-clockwise, pulling any loose slack towards the WP and the yet-to-be-strung pass-side gear. This last one is always the hardest, you can't leave any slack elsewhere.

And by the way, this thread...

MainePorsche

Excellent description Jim.
I thank you too for the pearls re the belt placement.

M. Requin

Just getting ready to install new cam sprockets- a very tidy explanation, thanks and Merry Christmas!

FredR

Ricardo,

You need to specify where the engine is crank angle at the moment before you do anything else.

Anyone playing with cam wheels and belts should lock the crank at 45 BTDC before doing anything else.

I certainly recommend the 32 VR tool and the bump stick tool. My cams were timed with clock gauges under my supervision and I found the 32VR aligned perfectly with the factory spec. Now cam timing and changes to it are a doddle.

When threading the cam belt you also need to ensure the tensioner is fully slackened off

Rgds

Fred

Ricardo Vega

Hey guys sorry that if forgot to mention that the crank is at the 45 mark and that I currently don't have the belt and water pump on it yet. I've started to put it together and the Drivers side gear was removed for me to clean off since it was soiled with belt dust. When I put the gear back on it does have the 5-10 degree play but even then it's still to far to the right to get close to its original position I marked on gear and back plate using a sharpie marker. I try to spin gear backwards but bounces back. So before I screw anything up how can I put it back before I start applying the pump and belt?
I've tried to add pics but I get an error code using app. Maybe on browser it might populate.
Thanks!!!

Ricardo Vega II

Ricardo Vega

This is how it's now. As you can see black marks don't align.

Ricardo Vega

This is how it started with crank at the 45 mark.

jcorenman

No problem. All you need to do is center the threaded hole in the slot (below), replace the bolt and washer and torque it as described above. That will get the sprocket back on, and adjusted roughly to the correct location-- fine-tuning with the PK gadget comes later, after the belt is in place and tensioned.

The cam gear then needs to go three teeth left (CCW) to make your marks line up, but that doesn't need to be done until you are ready to string the belt. So get some masking tape and write yourself a big reminder and stick it on the gear, then go work on the rest of the job. When it comes time to string the belt then rotate that gear three teeth to line up the marks before wrapping the belt around the gear.

The odd thing is this is the driver's side cam being frisky, usually it is the other one. But no matter, as long as the marks line up with the belt in place then all is good.

FredR

To turn the cam wheel you obviously need to tighten the nut. To turn the cam you do not use the holding nut- rather you must turn it using the big hex washer [27mm?]. When mine jumped a bit to get the cam to where i wanted it I rotated the cam in the usual direction given someone had posted about not reversing the cam wheel. I suspect this strictly does not apply when there is no belt in place [the tensioner being the main problem for reversal I believe] but either way I took no chances.

Regards

Fred

mark kibort

This is one of the reasons i do the belt attachement with the car at TDC, not 45 degrees. then, the passenger side pulley is the one that is 'frisky" ,and will move 4 teeth CCW. in your case , at 45degrees off to do the belt , pully job, the driver side is the "frisky" one and is going to be spring loaded 4 teeth off. (about 30 degrrees)

anways, you should never unbolt the cam pulley when the belt is off because if it moves , you may not know where it goes back. however, there is usually a little washer stain, like seen in the picture you can use to align the pulleys and tighten the cam NUT.

as was said, you will string the belt with some help of someone holding the wrench on the driver side pulley, to put it back to the "45degree mark" in your case, with the belt on and strung up, you want that side tensioned. taunt! then, you can work on alinging the passenger side and slip the belt over the teeth of the pullly and you are then done. re tension the tensioner, and you are good to do. chenck the marks. they should be close. (with in 1/4 tooth) this part cant be changed. later , if you want to reallly align the cams, you need the tool or pulllll the valve covers and do it the old fashion way. not worth it, if you can put the cams back to where they were based on the rotor holes vs the little cam pulley windows. eye ball that and you probably are fine.

giddyupp

Not sure - but the gear in the picture looks as though its coating is pretty worn - if so it really ought to be replaced.

mark kibort

i think we all will be burned up by the sun, before that pulley wears enough to be a problem. Illl buy that guy a pulley, fly out and replace it for him, if it wears out before another 100k miles! (providing he tensions the belt properly! )

Ricardo Vega

Thanks guys for all input. This is my first attempt on doing this job on a 928 S4. So far it's been fun. I should be getting to the camgear attachment like in the next few days, since X-mas is here. But I should be able to spin the gear and not damage anything? It's very difficult to rotate and a bit afraid of damaging anything on it.

the flyin' scotsman

With the crank set at 45 degrees BTDC you can spin either set of cams clockwise fully 360.

If you dont have the 32VR tool and bump stick you should buy or borrow and get the timing perfect.