Spyerx

Did you have runout on balancer checked too?
Interesting!
Fwiw my stock pulls wobbles a bit too.

964Andrew

Yes, no runout on solid or rubber insulated pulleys.
Each time everything was perfectly straight before tightening to final spec. At some point I was tightening the hub in stages, increasing the torque and checking for runout at every stage. At low torque settings I was able to hammer it straight as per shop manual, but once the torque increased the hub just found it's old spot.

Thanks!
Andrew

spartansix

Hey Andrew,

What was your process/tools for removing and replacing the pulley?
It sounds like you've done this enough times that you must have figured out the best way to do it!

Thanks!

J richard

Did you ever measure the runout on the crank?
Are you installing the Allen bolts with the small washers? The thickness are very specific the pulley will not be tight without them.
Does the point of wobble correspond to the locating pin? I've seen them damages that keeps the hub from properly seating flat on the crank

apanossi

I recently went through this same problem. No matter what I did, the balancer would be out of spec with its runout. I must've taken it off, hammered on it, and replaced and retorqued it at least 7 to 8 times. I even ended up having the balancer rebuilt with new rubber. Each time no matter what I did, the runout was still out of spec. I also tried an alternative pulley and discovered the same runout problem. I concluded that it must be a crankshaft issue. Not wanting to spend any more money on this very expensive item but not wanting to leave a 10 pound wobbling mass at the rear of the engine, I ended up installing a Clewett serpentine belt. I didn't even bother measuring runout at this point. I have been driving with this system for over 2000 miles now with no issues or unusual vibrations. In fact, throttle response seems to be much more direct. And yes, I did end up reading whatever I could find on replacing the harmonic balancer along with the risks which does seem to make sense on paper. Mind you, my experience is strictly as an aggressive daily driver and not a track car. I will try to post a picture of the original wobbling balancer and the Clewett setup.

964Andrew

Crank was measured and polished, came back good. I don't have any small washers on the balancer, just the locking Allen bolts. When putting them back I used thread locker and tightened them in sequence. The wobble does not correspond the the pin location. The pin and the crank nose shows no signs of wear. I have even used brand new crank bolt - only $40 bucks at the dealer.

As per apanossi comment: Time to move on, 0.1 mm off the allowed runout is not a big deal.

Thanks!
Andrew

964Andrew

The process is very simple, should take no more than 30 - 45 minutes from beginning to when you have the pulley off.

Special tools (don't think why, just buy or rent these):
- Puller (9285/1): 000-721-928-51
- Pulley wrench (9290): 000-721-929-00

Preparation:
To get to the pulley, you will be removing: rear bumper, heat exchanger cross pipe, primary muffler or cup pipe, rear engine tin and engine carrier. You will need to put the car on jacks and support the engine from underneath while the engine carrier is removed. Get some blankets.

Step 1: There are several bolts or screws (depending who was messing with the bumper before you) that attach the bumper to brackets and body. On each side there are 3 screws attaching the bumper via a sandwiched support to the body of the car. Below there are 2 more on each side attaching the bumper top the bracket and the body. No need to remove the brackets itself.
Tip: remove the tail pipe for better access.

Step 2: Remove rear right taillight completely (don't let it dangle by the wires) and disconnect rear license plate wiring (2 pole square black plug in my case) Push the free end of the wiring back through the body, so it dangles below the bumper.

Step 3: Loosen the 1 or 2 or 3 belt pulleys connecting the balancer to the fan, alternator and/or AC. Remove the belts.

Step 4: Remove the 2 large allen bolts holding the bumper support to the body. One on each side, you might need a long ratchet for these. Place a large blanket or a rug under the bumper an pull and wiggle it towards you from the back of the car. It is an awkward and heavy piece, the blanket is there to prevent scratches if you were to drop it on the ground.

Step 5: Undo the compression clamps on the 3 rubber connectors for the heat exchanger cross pipe. Undo the 2 10mm bolts on the rear of the engine carrier holding the pipe and remove the cross pipe.

Step 6: Use a rope or a large zip-tie and tie the secondary muffler (on the right) to the body so it doesn't drop and bend the rear support bracket when you remove the primary muffler or cup pipe.

Step 7: Remove the 2 exhaust compression clamps attaching the primary muffler or cup pipe to the cat on the left and the secondary muffler on the right. Undo the 2 12mm bolts attaching it to the rear engine carrier. Remove the primary muffler or cup pipe.

Step 8: Loosen the distributor bolt (the one holding the distributor housing to the engine case (12mm I think). Note: you are only loosening it and not removing it. You need an extra 1/4inch space to remove the rear tin, so you want to push the distributor up just a tiny bit so it doesn't disconnect from the gears below or skips a tooth.

Step 9: Remove all 10 mm bolts bolding the rear tin (don't forget about the 2 in the middle between the engine carrier and the rear tin lip, use flat screwdriver to get to these. Also, depending if you still have the bottom engine heat shield covers, they are attached to the rear tin as well, no need to remove the shields , just undo the 10 mm bolts (I think there are 2 or 3 on each side below the engine tin).

Step 10: Push the distributor up and pull /wiggle on the tin. It will slide out.

Step 11: Place a floor jack under the engine, use a rubber hockey puck or a piece of wood to protect the centre mating surface of the engine case. Pump the jack just enough to contact the engine.

Step 12: Slowly undo the large hex bolts holding the engine carrier to the engine mounts. Watch how much the engine is dropping, you want preferably an 1/4 - 1/2 inch drop. Watch the engine mount rods at the base of the engine mount for the amount of engine drop. Pump the floor jack if necessary.

Step 13: Once the engine is stabilized on the floor jack and the large hex nuts are spinning freely - remove them.

Step 14: Undo the 4 17mm nuts on the back of the engine carrier (you might use a map gas to heat them in order to soften any thread locker that might have been used there). Undo the 10mm oil line clamp on the bottom of the engine carrier.

Step 15: Pull the bottom of the carrier towards you to free it from the 4 engine case bolts. Once this is completed, pull down on the carrier to free it from the long engine mount bolts.

Step 16: Use the 9290 tool to hold the balancer in place (I found that it is the most convenient to attach it on the pulley from the top of the engine. The long arm of the wrench comes out through the top of the engine bay.

Step 17: Place a wrench on the crank bolt and undo the bolt. It is on there very tight!!! Use the 9285/1 to pull the balancer of the crank afterwards.

After you are done with your repair or replacement, assemble in reverse order.

NOTE: Do not hold the engine supported only by a garage jack for long periods of time. As soon as I was done removing the pulley, I have put back the engine carrier and tightened all nuts by hand just in case. Also, I had a secondary axle stand under the engine if you floor jack failed.

Hope that helps!

Thanks!
Andrew

J richard

Unless you have the washers on the Allen bolts the balancer will not be tight. The Allen bolts have shoulders that will bottom without clamping the pulley tight.

964Andrew

I'm pretty sure the allen bolts are fully threaded on mine. There was no washers on the bolts when I disassembled the balancer and I'm quite sure the balancer was never before replaced, removed or disassembled since the car came out of factory. Just to make absolutely sure, you are talking about the 10 small allen bolts that are flanged on one side and have locking punch marks on the other?

Maybe the washers are something it was added later on to prevent a runout?

Thanks!
Andrew

C4inLA

Pet diagrams anyone ...

spartansix

Thanks! Your instructions are very helpful - I think I'll be checking runout and adjusting if necessary when I upgrade to a reinforced engine carrier.

964Andrew

Does not list parts of the balancer. Maybe TSB's?

Thanks!
Andrew

C4inLA

Yeah, I was afraid of that. Not that it helps anyone, I will check mine and see if I can determine if there are washers for my MY....

HalV

On page 14 of the Porsche AfterSales Training - Air Cooled Engine Repair manual it says never to disassemble the pulley so that may be why they don't list the parts for the balancer?

...The M14 x 1.5 central bolt (8) must be tightened to a torque of 235 Nm. Since the vibration damper and pulleys are balanced together, they should never be disassembled.

I'm pretty sure I read something similar in the service manual or a TSB as well.

apanossi

Here's a video of my wobbly harmonic before I switched to a Clewett system.
https://vimeo.com/182755540


And here it is with the Clewett installed. Still slightly wobbly.
https://vimeo.com/182757486