Big Dave

I got the center cover off, and the pump gear was loose on the shaft. The woodruff key AND the nut are still both missing, but I haven't really had a chance to look for them. I just pulled the cover off and snapped a few pictures.

The rear spacer on the shaft also appears to be missing. The gear and pump look like I can clean 'em up, re-install the belt and start it up, once I find/get another woodruff key, nut and spacer.

Big Dave

The center cover has a nice groove worn in it now from the loose gear.

Gretch

So the nut backed off and the key slid out?....Dave, you gotta put those nuts on with a little more torque than just "finger" tight.......

The metal filings would worry me.....I think I would at least consider replacing the gear. You got lucky, Hoss.....

goliver

I'd do the belt too. Who knows how many shavings got punched into the belt and weakend it a bit. Just cheap insurance.

AO

How's the oil pump shaft look? It looks like the back side of the gear has been worn down - perhaps the source of the shavings? You ARE going to replace the oil pump, right? Unless the belt looks brand-spanking new, I'd probably vote for a new belt too. Either case, I'll light another candle for you. Work in peace.

worf928

Yup. Since it's already off the car. And I would check the shaft for damage and/or eccentricity.

Once the belt is on the gear it's pretty easy to torque (or double-check the torque of) that bolt.

Bill Ball

Big Dave:

The missing rear spacer/washer explains what happened. My vague recollection is that the use of the spacer varies with the model year and the thickness of the pump gear involved. YOU MAY NOT HAVE HAD A SPACER. If the spacer were not used with a new gear that called for the spacer, the nut would bottom on the shaft shoulder and not seat againt the gear. The loose gear would vibrate and loosen the nut. When I replaced my original aluminum gear with the updated steel one, I believe the center width was different. I hope I am not getting this mixed up in my mind with a gear on another vehicle I own. The PET doesn't seem to support what I am saying here, and I've been having more and more Altzheimer moments lately. Somebody else fill in the details of the spacer usage if I am on the right trail.

Regardless if I am all wet about the difference in thickness of different pump gears, if you are missing the rear spacer then I believe it was left off by accident and it precipitated the nut falling off as I describe above.

Big Dave

The gear is actually in decent shape, notwithstanding the blurry pictures. The pump's shaft turns smoothly with no wobbles. The belt so far looks to be in perfect condition.

I found the nut laying below the pump, but the washer and woodruff key are still AWOL. I won't be able to look deeper until I get the lock and can remove the balancer.

If I have to replace the gear and anything else remotely expensive, I'm going to wait a week or two. Our check book is smoldering after our sewer lines gave up the ghost yesterday. Yuck and Ouch.

I think I'm going to hibernate next August. The past two have not been good to me.

Mark

Dave - for your hibernation - just check into a hotel I don't think you need to dig that big grave.

Big Dave

Mark...LOL...I considered it.

Notice the tree in that picture. Now you have an idea of the size of the branch that nearly crushed my garage last Fall.

m21sniper

"The center cover has a nice groove worn in it now from the loose gear."

Heh, weight savings.

perrys4

Those guys in the picture are nuts! No bracing to shore up the sides of that hole! Must not be in L.A. Glad to hear you got off easy. That doesnt happen with 928 ownership very often. Might want to consider buying a lottery ticket. Congrats.

Big Dave

I asked those guys about cave-ins. The guy in the hole said he'd been involved in a few of them. His secret was to immediately run to a corner (assuming he could). He also swore he could climb out unassisted if he needed to.

I'm just glad we can use our toilets again.

Bill Ball

Aha, I was right! Page 17-5 of the WSM says in reference to the rear shim, "Only use together with light alloy gear." (I posted a note about this a year and a half ago...memory fading fast) It appears the 78-9 cars had steel oil pump gears that then were aluminum only to have steel return in the last few years.

Anyway, Dave, if you did not replace the gear then you should have had the rear shim. If you happened to replace the gear and the old one was steel, but you managed to get an aluminum replacement, then you would not have had the shim, but you would have needed one.

Unless the gear came completely off the shaft, the rear shim would still be there...unless it was missing to begin with. The torque during installation and post-assembly pictures would not reveal this as the nut still stops on the shaft shoulder and everything looks OK.

Regardless, you have an aluminum gear, and you need that rear shim. Get the shim or get a steel replacement gear.

AO

Bill-
Do you know how scary it is that you knew this from memmory? VERY! But good call. Mystery solved!