der Mond

I have heard many times about the G50 rattle and I'd like to know if that is what I hear when I accelerate from idle in first gear (or any gear, for that matter). It sounds like a rattle in the exhaust system that lasts a second or so at a certain low RPM. Can anyone enlighten me as to the specifics of the G50 rattle?

In Laffingwell's Porsche 911 Buyer's Guide there's a SC, I think, with wood grain dash panels. I was thinking something like that might be a nice touch on my black dash, either the lower panels or gauge cluster panel or both. I can't find anyone who sells them. Any ideas?

Marty916

The gearbox (G50) on my 87 Carrera had the same rattle, which I'm told is not uncommon with this gearbox. I'm not certain but I believe it has something to do with shaft bearing clearances. I understand that it doesn't effect reliability or function. My mechanic suggested running Redline lubricant and it did, in fact, make a significant difference in the rattle. It's basically gone and only manifests itself at very low rpm when lugging the motor (not that I do this often...) or starting off with extremely low revs. The later models had a multi-piece flywheel installed to mitigate the rattle which entailed a weight penalty and didn't completely cure the rattle. Unless your gearbox has significant wear(mileage) or an obvious fault, I would suggest changing the lubricant before proceeding further. There are other brands of lube that do the same thing but my only personal experience is with Redline, which I highly recommend. No info on your dash question. Sorry!

der Mond

Thanks - sounds like it is indeed the rattle I hear. I will just live with it since it's not getting worse. The tranny has Red Line 75W-90 in it per receipts. It shifts beautifully. You have answered my question as to what tranny oil to change into it this spring - I was going to give Mobil 1 a try. Thanks again.

AdamF

I think the G50 rattle is more or less a Getrag trait than just a G50 problem. I'm no Porshce expert, but I do work on BMWs and all the bimmers with getrag 'boxes and a few miles on them have a lot of input shaft noise as well. There's nothing you can do about it other than change the oil, unless you have ca$h for a rebuild. It does not affect reliability on the BMWs either.

JasonAndreas

The dual-mass flywheel used in the 964 completely cures the rattle (i just switched to a LWF) but the downside is it weighs 30 pounds.

danoberer

The rattle is a normal known phenomenon of the clutch springs when lugging at low rpm. No worries!

purrybonker

Clutches and trannies completely baffle me but, I used to have the rattle problem in my '87 as well. For reasons that make no sense to me, a new clutch has made the problem go completely away.

To further compound my confusion - I swapped the factory rubber centred clutch for an aftermarket spring centre clutch in making the transition. I fully expected the new clutch to be noiser than the old (springs vs. rubber) - but the exact opposite has turned out to be the case. I guess my assumptions about rubber being quieter than springs must ignore some basic principles of drivetrain noise that I simply don't understand.

Aw well - put in a new clutch if you're tired of the low RPM rattle. I used to particularily hate it in places like parkades where the noise would really "rattle" around.

Sounds soooo tacky...

der Mond

Thanks, fellas, I appreciate the info. It does sound tacky, but I'm at the point where I'm developing a project list and doing triage. As long as the tranny is strong and the engine I refer to as Zeus makes that godlike thunder, I'll live with it until clutch time....nice to know it's not critical