Lizard928

WOW, I have never seen gears that bad!

Big Dave I think was the first to recoat the gears and he had them slip a little I think. But I could be wrong on that.

I have been recoating them as well, but I inspect the gears first and determine if they are good enough for recoating. The coating I use is MUCH harder, but reduces friction..... as to date I have not seen any wear on any of the ones I have coated.

DanielD

I think I'll take the old gears, have them mounted and framed. Finally hang them on the wall in the garage. Then I can tell folks I have over a grand invested in my garage art....

DanielD

Well, I've received all the parts from Roger (thangs roger!) and continued the disassembly process last night. The oil pump gear is totally shot; worse than the cam gears. The crankshaft gear has the same weat pattern on it as the rest of the gears. As the crankshaft gear is harder, it is in much better shape but getting replaced as part of this job. I'll put some old/new side by side pictures up later. And the saga continues....

DanielD

By the way, the crankshaft gear was a pip to get off...

oaros

Colin, do you coat with DFL-1?

Lizard928

Oliver,

I have not used DFL-1 before. But I just looked it up and it would not be an appropriate coating.
It is not resistant to many things, and I feel would wear rapidly because of this.
As well, it does not have any hardness ratings.

The coating I use is an extremely durable coating that is very hard, reduces friction though, as well as reduces heat transfer. I have seen zero wear on all the sets currently in use.
I am racking up more miles (and trying to find good cores), before I may consider offering them....

oaros

Thanks Colin!

Are you considering testing this coating in on the European continent - the UK? Could give addtional performance insights!

Kidding aside, I'll keep an eye out for developments.

DanielD

As I was installing the water pump one of the bolts stripped out. That made a simple thing tedious. Put in a stud and back on track now. Won't finish today.

Anyone have any tips for removing and installing the new cam gears? I'm planning on marking the new ones in the same place as the installed gears and do the swap. I'll set them up with the PK32Vr once I have that completed. In other words, I plan on turning the crank around to TDC once I have the new gears and belt on an then fine tune the cam timing with the porken tool.

Lizard928

Just put them on with the gear slightly clock wise of center.

This will make it much easier to adjust them with the 32Ver once you are ready for that.

DanielD

I've swapped the cam gears out with the new gears and centered them on the cams. I'm planning on timing them with the porken tool. On the passenger side, while I was setting the V notch to the new gear, the cam spun about 5 teeth counter-clockwise; I was at 0 TDC.... It was one tooth off when I decided to "tweak" it. I guess some spring pressure in there forced the cam to turn.

I've reset the cam gear to the V notch but am wondering if I have trashed my engine????

Lizard928

You have done no damage, continue on.

DanielD

When the cam gear spins can I turn the cam counter clockwise?

Lizard928

sometimes it is easier to leave the cam loose, and turn the crank.

Turn it CCW that way, then tighten down the 3 retaining bolts.

Do a couple full rotations, and try again.
Be glad you dont have high lift cams, and stiffer springs. It is much more tricky then!

DanielD

On the road again...

I thought I would go over the road I went down to get here with a chronological timeline... I kept this adventure to the weekends and many times couldn't do it on the weekends; so it took a while.

December 2010: Coming home from work in the 928 and stopped at the redlight. Accelerated normally with traffic; passing through 25-30 mph I see the dreaded "Toothed Belt Service" annunciated on the digital dash. OMG~CAR IS DYING, CALL OUT THE NATIONAL GUARD!!! Reset the dash warning, all is well. Continued to drive car home, no additional warnings. WHEW!, dodged a bullet...

The car was doing well for a few months.... Continue driving, no warnings... I average about 180/200 miles per week; 928 is a daily driver.

March 2011: Coming home from work, stop at the same cursed red light. Accelerated normally with traffic; passing through 25-30 mph the dreaded "Toothed Belt Service" annunciates again. CRAP! Reset the digital dash, no further warning. Drove the car the additional 2 miles to the house. Parked in the garage. Will not drive it again until fully checked out.

March 2011: Driving the old rice rocket, a V6 Honda Accord with 189,000 miles on it. I want my 928 back on the road but have no funding available. WAAAHHH...

April 2011: Read tons of Rennlist threads on the timing belt water pump maintenance activity. I find it takes a long time and can cost tons of money. CRAPOLA... Still driving the Honda.

May 2011: 928 still in the garage. Order the timing belt and water pump along with the associated bits and pieces from Roger. As always, they arrive within the week. Don't want to tear the car apart as I'm going out of town so I don't. Go to Europe and have fun. Go to Porsche museum in Stuttgart. See the 1995 midnight blue 928 GTS on display, "The Perfect Car" says the audio guide. Yes, they're right... I want my car back.... WAAAAHHH...

June 2011: As many of you, I pull up Dwayne's article on the maintenance procedure and begin to tear the car apart. Man it's hot as Hades... I find that in 143,000 miles an engine can get pretty filthy. I turn a greasy black over the weekend and destroy "my good clothes" says my wife. Start reading about cam gear wear and see that mine "match". Yep, that's cam gear wear. Check around a bit more, put up a few posts to get my concerns addressed and yes I need new cam gears too. Wait a while as the funds are not available.

July 2011: Order the updated cam gears from Roger and the timing tool. Continue to disassemble, clean, disassemble, clean. Get the car down to the nitty gritty and see that the cam seals are leaking so this was a good idea to go here. Replaced the crank and cam seals, all the gears, and rebuild things. All is going well in happy valley.

August 2011: While adjusting the initial cam timing the right cam springs spin the camshaft in reverse about 5 teeth... Post the "is my car dead?" question on Rennlist. Lizard says, "continue on Grasshopper"... So I do.

Get everything cleaned and put back together. Hey, it looks great now if nothing else. My brother comes over yesterday to sit and watch while I finish up. He's probably there to see the explosion when I attempt to start it I think. He sits and chats and hands me tools for about 4 hours...

Well, its time. I cover the driver's seat with a blanket and sit down. Insert and turn the key to start. Immediately she fires up!!! Yeah, success is sweet...!!! Take it out and drive it around about 50 miles for a shakedown cruise.
No drips, no leaks and it is so quiet now. I didn't realize the difference you hear at idle with the hood up when you swap out a bunch of worn out gears. It's amazing folks.

I do have one issue. There is a slight miss under hard acceleration and the gas mileage has dropped from 19 to about 16mpg. Any ideas on these two?

Many thanks to you guys here that helped me get through this. In North Mississippi I think I'm the only one with a 928. I've seen 3 others locally in the few years that I've owned this car. I couldn't do it without you folks.

Lizard928

With regards to your bad fuel economy (should be 22mpg on hwy), check/replace,

O2 sensor,
Spark plugs (BOSCH COPPER WR7DC+ or WR5DC+ ONLY),
Ignition and coil leads,
MAF sensor,
Caps and rotors.

test and replace in that order.