3.0 tdi transmission shudder on full torque

[Sloppy_1]

got a 3.0 tdi and on full torque load only is shudders weirdly,

dont think its clutch slip, infact im certain its not plus had a new clutch with in 5k

read it could be inner cv's, front shafts were average so replaced them with good used ones still the same,

feels like prop diff area,

dropped diff oil and it was dark but completely swarf free, ran magnet through it,

prop looks spot on not play at all.

only does it under the highest torque load rest of the time its perfectly smooth no vibration, and its easy to drive around infact you only notice it hard driving on wide open roads.

any ideas?

 

[joinerman]

Engine mounts, Gearbox mount ?

 

[VeVeX]

Worn inner cv's will cause a rotational type of vibration under heavy load.

 

[Sloppy_1]

yea i will have to check the engine mounts and gearbox, in encindled not to think it is them but certainly worth checking,

its the stangest think its literally for a few seconds of peak torque then it goes...

ive checked all cv's and prop but i might drop the prop and give it a proper once over.

 

[Sloppy_1]

https://www.audi-sport.net/xf/threads/3-0tdi-quattro-vibration-shuddering-after-remap.91422/

here is the answer i believe...

 

[desertstorm]

That will be a clutch/ DMF issue. Did you have the DMF replaced when the clutch was changed ? .

 

[Sloppy_1]

That will be a clutch/ DMF issue. Did you have the DMF replaced when the clutch was changed ? .

it had a new clutch and dmf 10k ago, its just a poor mapping,

reading around its extremely common for the manual 3.0 and 2.7 in lots of vag stuff to have this issue the std flywheel just dont have the extra capacity and or the maps torque limits are to high early on and not smooth enough.

If you read the link i posted some poor chap replaced it all (whole clutch and flyhweel) with new and it only lasted a few weeks... another a few months (with new DMF and clutch that was in a5 manual), just crap maps designed for the auto versions where the torque converter would normal eliminate this happening, and the box would force a change.

 

[desertstorm]

So the noise is coming from the DMF/clutch as the map has exceeded the clutch capacity. The 240mm clutches fitted to the B7 3.0 TDI AFAIK are just a slightly revamped version of what is fitted to the high power manual petrol cars. Flattening down the torque peak doesn't really make that much difference to the performance .
One of the reasons I stretched the budget a bit when I bought my B8. After having a Passat 1.9 TDI running 210bhp that struggled with a 2.5v6 clutch .
The B8 has a twin plate clutch good for 800Nm, I run mine at 750Nm and it's on 135K miles now, with the last 60K being tuned.

 

[Sloppy_1]

So the noise is coming from the DMF/clutch as the map has exceeded the clutch capacity. The 240mm clutches fitted to the B7 3.0 TDI AFAIK are just a slightly revamped version of what is fitted to the high power manual petrol cars. Flattening down the torque peak doesn't really make that much difference to the performance .
One of the reasons I stretched the budget a bit when I bought my B8. After having a Passat 1.9 TDI running 210bhp that struggled with a 2.5v6 clutch .
The B8 has a twin plate clutch good for 800Nm, I run mine at 750Nm and it's on 135K miles now, with the last 60K being tuned.

yes well documented that its the dmf and proved by many to by swapping it noise goes then soon returns...

i completely agree a flatter torque curve would likely be of no issue what so ever (and likely undetectable when driving) its just low skill /testing from the mappers unfortunately on the 3.0 manual cars,

if i drive it 'like a petrol' and go up though the gear to high revs before each change its perfect with no issue, its when you catch it low ish revs foot to floor and the torque builds like a rocket and you feel the issue.

I will send you my map and you can flatten the torque curve! thats really what wants doing.