Calvaire

Hi all,

I'm looking for some advice since I can't find a solution.

I recently purchased a 964 RS "basic" EU specs with 35,000Km and some races history.
The car from the beginning made some rattling noises coming from the clutch that were noticeable both from inside and outside the car. The noise appeared ONLY when the gears were in neutral and the clutch disengaged ( no pressure on the pedal). I brought the car to repair thinking that the problem could be easily solved by looking at the clutch cover or rebalancing the flywheel.

After some time , the mechanic calls me telling me that the primary and secondary bearings of the gear change need to be replaced since they're worned out. Than he also rebalances the flywheel and registers the clutch. He gives me tha car back and the noise is gone....for a while. In fact after some Km in the highway the noise builds up again when stopped. The noise is lower than before and mostly audible only from inside tha car.

I need to understand if the whole intervention has been necessary, or if I spent money (it was not cheap) for something that could have been done cheaper.

I would really appreciate your help.

Andrea

ASH.PALIN

Hi Andrea

I used to have a 964 with the RS clutch and was concerned about the noise when the car was in neutral and idling.........rattle rattle etc.
I took it to JZ machtech a well known specialist here in the UK expecting a release bearing problem or layshaft bearing and a big bill, but they said that the RS clutch is noisey and that it was no problem and normal and to any customer they do the conversion for, they always make them aware of this noise factor.
I am always suspicious of mechanics as my first porsche specialist was a shark!

Christer

yes, its the LWF - it rattles a little bit on idle and also when pulling away at low revs. This is nothing to worry about, and tell your mechanic to stop ripping you off.

tonytaylor

It does depend on how much rattling there is but "they all do that, sir".

Changing gearbox oil helps quieten down the transmission a bit, sometimes.
In an RS lightweight you'll have little in the way of soundproofing which makes a big difference. I had a LWF/RS clutch fitted prior to pulling all the soundproofing and the amount of extra noise is remarkable. I presume it has carpets.

964RS

I second that. BUT if you can hear a metallic singing sound when you don't accelerate/decelerate, then you might have a problem.

The first RS I ever drove scared the hell out of me when I heard the gearbox.

oldtimer

Just to confirm what others have said - RS transmission is very noisy at idle and low speed first and reverse gears, part of it is the LSD. If u not sure you need to either find another owner to compare or go somewhere where they know their RSs ( from their elbows)

Calvaire

Thank you all, very appreciated.

Yes I confirm the noise is only at idle and also below 2000 rpm when accelerating. then it disappears.

I will try to find somebody else with an RS to compare.

Another question ( maybe I have to post a new thread):

Are all RS "basic" EU specs, with 92 lt fuel tank? I recently filled from reservoire and made only 60+ liters..?

thank you!

oldtimer

mines an N program car made in 1992, last digits of VIN are NS491621, it has the big tank...some of the earlier cars may have had smaller tank, none of the later cars should have. Maybe yours is not original ?

Calvaire

I checked VIN numbers and it corresponded to an original RS (I don't have the numbers here at present) . I only fear that it has been replaced somehow in the past. Maybe because it used to race (and therefore replaced with an aluminium one) or maybe for some other reasons..

Are there visual differences under the bonnet for the two types of tanks?

Any picture?

Johan K

Andrea,

Congrats! You just purchased an awesome car!

These cars produce a fair amount of rattling and grinding noises due to the LWF and 20/100 LSD. You are probably OK.

My car has a VIN ending with 889 and has the standard C2 77 liter tank fitted from the factory. I guess the 77 liter tank was optional. Bear in mind that it weighs less than the 92 liter tank when full

Calvaire

This makes me feel better. I don't mind having 92 lt. I don't race the car so I don't need it.
Just to know original parts are there, you know...

Thank you too. I find the car amazing.

964RS

As far as I have been able to read the 92 liters gastank was standard on the LW RS.
Like Johan K said, congratulation to your new car!

/Anders

Calvaire

Do you know where I can check online original equipment/options for 911 models?

964RS

Try http://www.carreracupusa.org/ , then choose "Mazine articles" in the menu and then "Carrera Cup Confusion ver 3.0"

/A

Calvaire

Thank you. But I still have a doubt. How do you understand if an RS is a Lightweight or touring? (supposing the touring has been modified to look exectly as the lightwheight). the article states that they're in the same group (N-series). Is there a porsche database?