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kc77 · Joined: 26 Nov 2003 Posts: 23 Location: Kansas City

Three weeks ago I replaced a spun-out (all the splines were ground off) drum on the rear right wheel of my '77 NA. I had been hearing noises which I thought were just normal tranny noises for a few months beforehand but I'm not sure if they had anything to do with the friction on the drum that went bad. Now, at highway speeds, every once in a while the whole car will jolt back, as if i lost power to the wheels for a split second. It happened once last week, once this week and twice today. What are my first options to check it before it gets worse? And does it have anything to do with the new drum? Is it slipping on the splines again?

thanks

-mark

Smoothie · Posted: Mon Aug 27, 2007 6:09 pm Post subject:

Maybe you are actually losing power.. When was the last time the ignition switch was replaced? Does the tach needle drop down when it happens?
_________________
"..it's made in Germany. You know the Germans always make good stuff."

'82 924T, US version, dark green metallic, 5 speed Audi 016G gearbox

RC · Joined: 25 Mar 2007 Posts: 2637 Location: Australia

Any "clunk" noises from your rear end, especially on corners or under acceleration?

Hope you have all your teeth!
On your diff gears.

Roger

isuras2 · Joined: 17 Jun 2005 Posts: 458 Location: Phoenix, AZ

I don't know if it is the same symptoms, but my car used to "cut out" or lose power intermittantly (like over bumps) that got worse and worse. It turned out to be the fuel pump relay.
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Rob
'80 931 (sold)
'80 924 NA (sold)
Former Omaha Crew

kc77 · Joined: 26 Nov 2003 Posts: 23 Location: Kansas City

it happens so fast i can't tell if the tach drops...I'll try to pay closer attention next time. it's more like a jolt than anything else. no "clunk" noises, although there's alot of whining under acceleration and cornering.

Benino · Posted: Tue Aug 28, 2007 1:26 am Post subject:

wow. those splines should never sheer off like that. The big axel nut that holds the drum on must have been loose for along time. Make sure you torque that thing down as hard as you can. It's supposed to be torqued to something crazy like 250 lb/ft. Don't quote me on that but I know it should be way way up there.

The other problem you are having I would guess is unrelated. I agree with what others have said and asked. Just wanted to add that a similar problem I was having was ignition related.
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1980 Porsche 924 N/A USA
1980 Porsche 924 turbo USA
1987 Porsche 944S USA

kc77 · Joined: 26 Nov 2003 Posts: 23 Location: Kansas City

yeah no kidding about the splines. this time I stood on the damn cheater bar to make sure it's torqued as much as possible.

I've also been having a tough time starting it the last few days - it will turn over but not start for no apparent reason (a jump doesn't help.) I'll let it sit for a few minutes then it'll start with no problems. (I replaced the starter last month).

Does this make sense with the ignition switch theory?

Smoothie · Posted: Tue Aug 28, 2007 6:49 am Post subject:

If the dash lights (oil, battery, etc.) do not come on with the switch at "ignition on" and/or there is no click from the starter solenoid when switched to "start", then yes, the starting problem is likely with the ignition switch too.
_________________
"..it's made in Germany. You know the Germans always make good stuff."

'82 924T, US version, dark green metallic, 5 speed Audi 016G gearbox

kc77 · Joined: 26 Nov 2003 Posts: 23 Location: Kansas City

Yeah, all the dash lights come on and the solenoid clicks. I even had the battery tested and it's ok.
What happens now is if I don't give it alot of gas on the first try at starting, it won't start for anything for an hour or so, unless I jump it.

This car has a mind of it's own.

Smoothie · Posted: Wed Aug 29, 2007 2:59 am Post subject:

Could be a charging problem, and that might be caused by a bad connection. First check-clean the battery post connections, then work your way around to everything else if that doesn't fix it.
While bench testing a 924 alternator here a few years ago, I found that the voltage jumped to over 20 volts if I disconnected the battery while the alternator was still being spun. So it's entirely possible that you have a flakey connection, and when it drops off even for a split second, alternator output jumps to over 20V which may in turn cause a problem for the ignition, which might account for your loosing power briefly while driving...?
Long story short - check-clean those connections, and including grounds.
_________________
"..it's made in Germany. You know the Germans always make good stuff."

'82 924T, US version, dark green metallic, 5 speed Audi 016G gearbox