Drive Train Rumble at Idle

[scam75]

Afternoon guys.

Posted this on TIPEC and thought I would drop it in here too.

Following on from thinking my torque tube may be on the way out I have a new development. Let me know what you think. I have to add this only happens when I've been out for a drive, not at start up when everything is cold.

When in neutral with clutch not depressed I am hearing a rumbling sound from either TT or gearbox. I have recently filled g/box with fresh oil, standard oil, not swepco or anything. The sound goes away when revved or when clutch depressed, also can only really be heard with the door open. Last night I noticed that the sound would go away maybe 9 times out of 10 with the gear selector pulled hard over to the right (driver side), not always, but as I say 90% of the time it went completely quiet with the gear selector pulled hard right. Pushing it left made no difference. Am I still thinking TT here or does this suggest it's the gearbox instead? If so would swepco be the next move?

Thanks all in advance

Stuart

 

[zcacogp]

Can't really help but the advice with 944 gearboxes is that they are almost always noisy.


Oli.

 

[scam75]

Yeah you're right Oli. Mine has been doing this for a year as well and not got any worse. It can't be right though as it doesn't happen when cold and it didn't used to happen! Someone will enlighten me........hopefully!!

Stuart

 

[alwigley]

Mine was making similar noises right up until the point it stuck in 3rd and never came back out ! Replacement box is eerily quiet in comparison....... One of these days I will pull the old box apart and find out what actually happened to it

 

[A5DSR]

Mines always had more of a slight rattle rather than a rumble. I wrote to Porsche about it years back when it was only a couple of years old and they said it is normal.
Still going strong and still rattles on idle. Disappears when the clutch is pressed.

I asked about filling with thicker oil. Not recommended.

 

[J4CKO]

How hard is it to change a Gearbox out ?

Driveshaft nuts, speedo drive, unbolt shift linkage, unbolt torque tube, unbolt and lower the cross brace thingy, doesnt look too bad.

 

[Catamax944]

The rumble you are describing is almost certain from the torque tube bearings , i had the same problem until i replaced the torque tube.
More recently the gearbox has started whining and i am seriously considering adapting the 01E 6 spd from the passat tdi in the near future , bolts on to the torque tube but needs modification to the shifter mechanism and the mounts.

 

[J4CKO]

01E

Wow, Passat gearbox will fit, I knew these had Audi 100/200 roots but didnt know that the Passat box was similar, how much work is it to adaps, do the ratios suit, a Passat Tdi only revs to 4500 rpm where a 944 will rev to what 6500 or more ?

 

[scam75]

ORIGINAL: Catamax944

The rumble you are describing is almost certain from the torque tube bearings , i had the same problem until i replaced the torque tube.
More recently the gearbox has started whining and i am seriously considering adapting the 01E 6 spd from the passat tdi in the near future , bolts on to the torque tube but needs modification to the shifter mechanism and the mounts.

That's what I thought. But why does it disappear when pulling the gear lever to the right? Is that not a curveball to this theory?

Cheers

Stuart

 

[scam75]

ORIGINAL: A5DSR

Mines always had more of a slight rattle rather than a rumble. I wrote to Porsche about it years back when it was only a couple of years old and they said it is normal.
Still going strong and still rattles on idle. Disappears when the clutch is pressed.

I asked about filling with thicker oil. Not recommended.

Very interesting but not totally convinced. Why does it go away when moving the gear lever to the right??

Argh

Stuart

 

[J4CKO]

could the linkage be loose, moving the gear lever to the right perhaps take up the slack ?

 

[Catamax944]

ORIGINAL: scam75



That's what I thought. But why does it disappear when pulling the gear lever to the right? Is that not a curveball to this theory?

Cheers

Stuart

Yes it does , a bit strange and i don't have an answer to that.

ORIGINAL: J4CKO

01E

Wow, Passat gearbox will fit, I knew these had Audi 100/200 roots but didnt know that the Passat box was similar, how much work is it to adaps, do the ratios suit, a Passat Tdi only revs to 4500 rpm where a 944 will rev to what 6500 or more ?

944 series cars have different variations of the 016 gearbox and the 968 has a early variation of the 01E gearbox ,both bolt on to the 944 torque tube even though the 968 has a different torque tube.
The 6spd passat tdi gearbox is the last evolution of the 01E style gearboxes which still shares the same bolt pattern to our gearboxes and like most 01E gearboxes is able to support a ridiculous amount of power and torque.
In theory it should work with the 968 gear linkage . Modifications have to be made to the casing in order to pass the linkage through it and design a mount that works with that casing.
The long gearing is good for almost any 944 engine.

 

[zcacogp]

It will be quieter when cold as the oil is colder and hence thicker. Warm = thinner oil = more rattle potential.

As you move the gearlever you will move the selector mechanism inside the box. It is possible that the selector is worn in the 'normal' position but less worn as you move off that position, so the rattle goes away.

I'd suggest (purely from guesswork, and happy to be told I am wrong) that these two symptoms indicate it's gearbox rather than torque-tube related. In which case, I refer you to the case of James v. Ramsden (1991).


Oli.

 

[Ex Skyline]

ORIGINAL: A5DSR

Mines always had more of a slight rattle rather than a rumble. I wrote to Porsche about it years back when it was only a couple of years old and they said it is normal.
Still going strong and still rattles on idle. Disappears when the clutch is pressed.

I asked about filling with thicker oil. Not recommended.

He may of gone on to add "Porsche main dealer's are about as much fcuking use as a chocolate teapot"! FFS![]