944 clakerty and knocking noise fro gearbox

[Bremar]

Hello all,
I took the 944 out for a drive 5 miles at most and when I got back in the drive it was making a clavckerty clack noise from the gearbox while idling in neutral. Also a clonking noise from the back of the car when I put my foot on and off the clutch. I’ve videoed it and put it on youtube.
I would really appreciate some help in diagnosing the problem and the remedy.
https://youtu.be/Q6_qdhNh3Yo

Thank you in advance.
Brett and sam.

 

[Bremar]

Hi Brett, Sam,
Although the sound seems to be coming from the gearbox, bear in mind that the engine, torque tube and transmission are all bolted together in a rigid assembly and noises are transmitted throughout. Also, the only bit you can get your ear next to with the car on the ground is the gearbox. I think you need to get the car up, preferably on a lift if possible for a proper inspection. The noise you describe and the circumstances make it sound typical of a failing clutch centre plate. If it still has its original rubber centered clutch plate, check the clutch bellhousing inspection cover for bits of rubber... Hope I'm right and your gearbox is OK...
Best,
Steve

 

[Bremar]

Thanks. I’m going to put it up on axel stands this afternoon to see what I can see. Realy did sound as if the rattling was coming from the very far end of the gearbox that tge camera was pointing at. ill get z sevond person to move the clutch pedal while I’m underneath and also look for rubber bits. Thanks again
brett and sam

 

[russmw]

While you're under there remove the rubber inspection cover under the gear box and with the car in gear pop your hand through the inspection hole and try to rotate the torque tube - It should be pretty much rock solid. Before I did the clutch on mine I could rotate it a noticeable amount (springs in the clutch plate had gone and the noise was resonating through the torque tube)

Good luck

 

[Briggy]

If it is the original rubber centred clutch, there may be other symptoms if it's failing. On my old 944, it would lurch when taking my foot off the clutch pedal. What I mean is, not matter how smoothly you operate the pedal, it's as though you've been really clumsy and the car lurches as the clutch engages.

 

[Bremar]

Hi,
I reversed the car up some low ramps and removed the rubber access grommet in the torque tube bell housing and tried to rotate the shaft, as mentioned above, to see if the rubber centre to the clutch had gone. I wasn't able to move it much so I guess the clutch is ok. The clutch is also quite smooth when changing gear. I haven’t yet lifted the front end to look inside the clutch housing for rubber particles.

https://youtu.be/VE3ij_1hLN0

 

[IanK]

When my rubber centered clutch died, the symptoms were a noticable backlash/play in the transmission when going on/off throttle. I had no clatter in idle either.

This doesn't seem the same but I don't claim to be an expert.

Ian

 

[scam75]

These 016 gearboxes do suffer from a bit of "chatter" in neutral quite often. I was once told it was the 5th gear idler. Try pulling the shifter towards you, then away from you, eg. left to right, right to left along the horizontal line of the H, if that makes sense, and see if it lessens or goes away (at full left or full right). If it does that's your issue.

If this is the case, fresh gearbox oil may make a difference, Swepco 201 is really thick stuff and should quieten things down a bit. I know some people aren't keen on Swepco (Pete!), but it's been spot on in my turbo box and has a huge service interval.

Cheers

Stuart

 

[Bremar]

Thanks Scam75 I think you’re probably right and following your reference I’ve Googled it and it does seem to be the issue.
I checked the clutch through the inspection hole. (Is there supposed to be a cover over that hole?) no rubber bits that I could see. Then this morning
before work, started the engine and the noise had gone. I’ve been for a 40 mile drive and when back on my driveway and getting out of the car I could hear the clatter again, not so loud tho. Tried moving of the gearstick as you suggested and there is a change in the clatter and at one point it disappeared.
I am reassured after reading stuff on line about "the 5the gear clatter” on Porsche 944’s that’s it probably not an issue more an annoyance.
Out of interest my car has the stronger an S2 gearbox with fresh MT-90 synthetic gear oil in it.
Thank you all fir the help.
Brett and Sam.