A5 3.0 Tdi remapped, rear diff vibration over high torque

tom101

Active member
Joined
Jan 4, 2014
Location
Spain
TDI
Leon 150, A5 3.0
Hello, I need help with my car, it's an A5 3.0 tdi quattro '08 with 80K milles
I've remapped it with aprox. 300hp and 700nm (515fl).

My problem is that accelerating at low revs (between 2000-3000revs) in long gears (4th, 5th & 6th) there is an intense vibration/tremble around the rear diff. I'm not sure the vibration is in the rear diff or in the drive shaft.

Over 3000revs there is no problem at all, also in short gears there is not any vibration.
I'm pretty shure it's due to the high torque. But I have limited the remap to 600n/m and the vibration remains.

I have a friend with exactly the same car and remap 60k milles, and it has exactly the same vibration as me. So the problem it that the rear diff/drive shaft/ shaft bearing of this car can not allow this torque in low revs without trembling.


I like so much torque between 2k-3k revs, had anybody similar problems?
I would like to know any mods I could do to allow the rear transmission to hold high torque

thanks you very much
 
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aNUT

Vendor , w/Business number
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Nov 29, 2006
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Boulder, Colorado
TDI
'01 TT (ALH-ish), B7 Audi gasser, '05 Golf
Any time you have excessive vibration @ peak torque, the first things to investigate are the axles, mounts, and driveline. The AWD longitudinally mounted cars often have driveshaft stabilization issues. The driveshaft is supported by a rubber diaphragm, and it's been known to get soft or tear...there may be a stiffer one that's available. In North America we didn't get your car with TDI torque until very recently, so I haven't had to directly address any such complaints as all these cars are brand new.

You might also check for lash in the joints of diff itself.
 

mickyTDI

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Joined
Sep 21, 2003
Location
Longford, Ireland
I get this with my remapped Passat, it's only front wheel drive. At 2000 rpm in a highish gear when i floor it the whole car shudders, over 2000 it doesn't. Is your car auto? I'm wondering is it the clutch doing mini slips.
 

tom101

Active member
Joined
Jan 4, 2014
Location
Spain
TDI
Leon 150, A5 3.0
Any time you have excessive vibration @ peak torque, the first things to investigate are the axles, mounts, and driveline. The AWD longitudinally mounted cars often have driveshaft stabilization issues. The driveshaft is supported by a rubber diaphragm, and it's been known to get soft or tear...there may be a stiffer one that's available. In North America we didn't get your car with TDI torque until very recently, so I haven't had to directly address any such complaints as all these cars are brand new.
You might also check for lash in the joints of diff itself.
Thanks you, I also think this noise can be the driveshaft trembling up and down quite fast due to this soft rubber diaphragm.
Strangely the vibration is always the same, with the same frecuency. Speed does not affect it at all.And as I said before, only appears below 3000revs and long gears.


Have seek many dyno remapped tests of this model and always has a light and progresive gain until 3000 revs, so I think is a stock problem.
Mine is quite aggressive over 1900revs as I requested to the chiptuner, I always had it in 1.9pd

I actually think the real problem is that this car has not been sell so much in north america. Because I am looking for race parts like one piece driveshaft, reinforced support bearings, poliurethane silentblocks,..... and I don't find nothing at all :confused::confused::confused:

regards and sorry for my english
 

tom101

Active member
Joined
Jan 4, 2014
Location
Spain
TDI
Leon 150, A5 3.0
I get this with my remapped Passat, it's only front wheel drive. At 2000 rpm in a highish gear when i floor it the whole car shudders, over 2000 it doesn't. Is your car auto? I'm wondering is it the clutch doing mini slips.
I think that's normal, my seat 1.9pd does too due to peak torque, but it dissappears quick.

The vibration I describe is loud, is like having an helicopter attached to your real axle until you lift your foot
 

tom101

Active member
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Jan 4, 2014
Location
Spain
TDI
Leon 150, A5 3.0
well, I'm still not sure of if the noise comes from the driveshaft or the diff.

I've been looking for stronger driveshaft rubber, but didn't find anything to buy.

But I've found this way to reinforce this rubber fullfilling it with poriurethane window welt or similar.
I like it because is a fast and cheap way of test if reinforcing it, the noise gets reducer or not.

http://www.audizine.com/forum/showt...shaft-support-bearing-fix-using-3M-Windo-Weld

also have been looking for reinforced diff mounts and found this one,
the original ones are very soft too. The problem is that buying it from america delays so much and already have to pay additional tax, also this mount is realy hard and causes other diff noises as I have read in other forums.

I'm thinking about fullfill those rear diff mounts of poriurethane too in order to test, the original ones cost only 12$

http://www.apikol.com/index.php/products/audi/a4-4/audi-rear-diff-mount-b8.html
 

mojogoes

Top Post Dawg
Joined
May 1, 2003
Location
england
TDI
mk3 tdi golf
Hi!! Did your car have any signs of this same vibration what so ever before you had it remapped.................Its seems to me that if this was a fwd car it would have the same problems as what you describe but obviously shudder from the front end / gearbox etc as my mk3 golf would do if the tune had to much fueling and not enough advanced timing between 1800rpms and 3000rpms............You may have had a little shudder before tuning / a remap on paper but nothing that would cause you any alarm!!

So am I right in thinking that a tune / remap on this car would also need to in some way bypass the built in gearbox over torque system that regulates the amount of torque that the gearbox allows / sees , As it could be this which is in conflict with your tune and fighting against it?
 
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Jayg

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Oct 23, 2012
Location
Anchorage, AK
TDI
'12 Jetta 6MT-VW bought back as a lemon
This sounds like a rear differential mount in my experience.
 

mojogoes

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Joined
May 1, 2003
Location
england
TDI
mk3 tdi golf
Ah ha! yes also bad maintenance will show up any parts that need fixing after power upgrades lol.
 

ben0069

Well-known member
Joined
Oct 15, 2012
Location
wales
TDI
allroad 2.5 tdi v6
I am also getting this problem, exactly the same symptoms, last week I removed my prop shaft and have had a new centre bearing put on, I was informed that the 2 end joints were fine, car has covered 197,000 miles . I will be re- installing the prop shaft tomorrow(fri) and will post back to see if that was the cause.
Just to add, I didn't have this problem before I put a hybrid turbo on and bigger nozzles.
 
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mojogoes

Top Post Dawg
Joined
May 1, 2003
Location
england
TDI
mk3 tdi golf
Hi ben how much power are you running at present.............And did you have the car remapped / live tuned.
If the turbo and injectors/nozzles are a well known quantity then who is the chip company who wrote this file for that particular combo.
 
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ben0069

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Joined
Oct 15, 2012
Location
wales
TDI
allroad 2.5 tdi v6
prop shaft worse now than before I took it off!!! I should have saved a lot of time and expense by just getting a new one in the beginning!! more expensive times coming up, and I don't think it was the cause of the original vibration issue either, prop shaft vibration is more like a helicopter rotor being under the whole car and the faster you go the worse it gets the original vibration still looms between 2000 and 3000 revs.
could the engine be fuel starved ? would that account for this extreme shuddering? but then if I change down and floor it I get no vibration.:confused:
 

mojogoes

Top Post Dawg
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May 1, 2003
Location
england
TDI
mk3 tdi golf
No!! this is a sign of over fueling and not under fueling...........it was known back in the day and even accrued in cars who ve pump were a little to advanced and then after nozzle or a standard chip/map was added they would shudder exactly in the rev range you mention....................if you +hammered the pump you could also get it to do the same thing......Can you put it back to the standard tune to rule this out.
 

ben0069

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Joined
Oct 15, 2012
Location
wales
TDI
allroad 2.5 tdi v6
Thanks for that reply, it seems plausible, I will have to look into it.
 

ben0069

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Joined
Oct 15, 2012
Location
wales
TDI
allroad 2.5 tdi v6
Thinking back I must amend one of my earlier comments that I didn't have the problem before the turbo and nozzles, it was actually after the re map that this problem appeared. Which was done by.... which isn't a particularly good map after all and was bloody expensive.
 

mojogoes

Top Post Dawg
Joined
May 1, 2003
Location
england
TDI
mk3 tdi golf
So I take it that you fit your nozzles and turbo before having the tune done........my thoughts at this point are! Is this a well known tuning path i.e is there a known file for this tune or did you use a slightly different turbo or nozzle size / setup................which on the face of it would then probably warrant a live tune.
 
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ben0069

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Oct 15, 2012
Location
wales
TDI
allroad 2.5 tdi v6
yes it was a custom/live tune or supposed to be anyway!
 

mojogoes

Top Post Dawg
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May 1, 2003
Location
england
TDI
mk3 tdi golf
Well! I mean if I was a 100% sure that your gearbox mount/s and drive shaft/s were all in good working condition then I would definitely be looking at my tune..................Sometimes when something is staring you in the face its hard to see it!!

Pm me who tuned it for you if you like?

I'm not saying this has happened in this case but some of the tuners buy a file from a "certain tuners forums"which is somewhere close and then mess with the fuel quantity timing and boost to get it somewhere close to being it near cock on?
 
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tom101

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Joined
Jan 4, 2014
Location
Spain
TDI
Leon 150, A5 3.0
thanks you for your help

a friend and me have the same car (a5 3.0tdi) one with 60k miles and the other with 80k. Both are in with very good health and no noises before the strong remap + downpipe.

My car was last week in an official Audi shop where is working a friend. I asked them to change rear diff mounts, but they tested and checked all of them and they said all are ok. They couldn't find the problem.

After remap and the high torque the vibration appears in both cars because something in the rear axle does not allow that torque. I hope to guess what.

I'm thinking about fullfill the diff mounts or the center bearing diaphragm with poriurethane to get them harder. It's easy and fast.

Ben, what did you do with your rear diff that didn't work out?
 
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mojogoes

Top Post Dawg
Joined
May 1, 2003
Location
england
TDI
mk3 tdi golf
So tom do you think that the harder rubber poly bushes will cure all your vibration problem...........or do you think that you could possibly still have some of these vibrations after changing with harder bushes?
 

ben0069

Well-known member
Joined
Oct 15, 2012
Location
wales
TDI
allroad 2.5 tdi v6
Have checked bushings around the rear diff they are soft and torn, am waiting for new poly bushes to put in, I'm still waiting to hear from the company that put the new bearing on the prop shaft to know if they balanced it or not????
 

adamss24

Veteran Member
Joined
Nov 2, 2005
Location
Great Britain
TDI
audi a4 2.5 tdi 98 quatrro 6speed
Have checked bushings around the rear diff they are soft and torn, am waiting for new poly bushes to put in, I'm still waiting to hear from the company that put the new bearing on the prop shaft to know if they balanced it or not????
I will be very surprised if that's the cause of your problem, i suspect like mojogoes suggested that the tune is not up to scratch and it's asking for too much fuel/timing low down... Do you tow heavy loads with your allroad ? Mine does not do any of this however i had a few 200k miles that done that whilst too much torque/fuel was requested in order to spool large turbos. Smoother maps with gradual fuel/torque increases were the only solution as turbo spikes can bend rods and lift heads ! Let us know how it turns out after the new bushes are pressed in the diff mount...
 

tom101

Active member
Joined
Jan 4, 2014
Location
Spain
TDI
Leon 150, A5 3.0
I have in my rear axle a high displacement vibration over high torque, I think that may be the rear diff or may be the drive shaft. So I hope reinforcing the shaft diaphragm or the diff bushings cause any change in the vibration
 

ryanp

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Jun 22, 2008
Location
Barnsley, South Yorkshire, UK
TDI
Arosa CR - 550hp - 9.7 @ 150mph 1/4 Mile, Citigo 4x4 CR TDi - 340hp, Caddy 2.0 CR 4x4 TDI - 300+hp, Golf Mk2 Van 1.9 TDI - was 290hp, Mk5 Ibiza 2.0 FR TDi - 270hp, BMW 135d - 360hp, BMW 330d - 335hp, BMW 335d - 380hp + a few more ........
Our 3.0 is the same, would be nice to know if anyone fixes it as we can have 600+ Ft lb at 2200rpm but the vibrations are just crazy!!!
 

Elf458

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Joined
May 26, 2014
Location
England
TDI
Audi A4 B7 3.0TDI
Sorry to bring up an old thread...

Me and one other are having a pretty unsuccessful time trying to resolve this same issue. Was there any progress or does anyone have any light they can shed on the situation?

We both have b7 A4's 3.0 tdi quattro. One remapped and one not.

Thanks a million in advance!!
 

raffshore

Well-known member
Joined
May 29, 2006
Hello, I need help with my car, it's an A5 3.0 tdi quattro '08 with 80K milles
I've remapped it with aprox. 300hp and 700nm (515fl).

My problem is that accelerating at low revs (between 2000-3000revs) in long gears (4th, 5th & 6th) there is an intense vibration/tremble around the rear diff. I'm not sure the vibration is in the rear diff or in the drive shaft.

Over 3000revs there is no problem at all, also in short gears there is not any vibration.
I'm pretty shure it's due to the high torque. But I have limited the remap to 600n/m and the vibration remains.

I have a friend with exactly the same car and remap 60k milles, and it has exactly the same vibration as me. So the problem it that the rear diff/drive shaft/ shaft bearing of this car can not allow this torque in low revs without trembling.


I like so much torque between 2k-3k revs, had anybody similar problems?
I would like to know any mods I could do to allow the rear transmission to hold high torque

thanks you very much
Before my hybrid turbo I had some shudder in 6 and 7th gear when pulling from low revs. Now with the new turbo, it spools a little later and it's all gone so on my car (A6 4G quattro 3.0tdi) I think it came from the dual mass flywheel.
 

Elf458

New member
Joined
May 26, 2014
Location
England
TDI
Audi A4 B7 3.0TDI
Thanks Raffshore. Interesting to know!

The A4s we both are having this issue with have both had new clutches and flywheels so thats peculiar.

Did you run it with the different turbo for long? Did it ever reoccur? Also what was the spec of the turbo? I wonder how much later the turbo spooled and if this is more of a design issue... still guessing but good to know someone has got around the issue.

Thank you!
 

raffshore

Well-known member
Joined
May 29, 2006
Thanks Raffshore. Interesting to know!
The A4s we both are having this issue with have both had new clutches and flywheels so thats peculiar.
Did you run it with the different turbo for long? Did it ever reoccur? Also what was the spec of the turbo? I wonder how much later the turbo spooled and if this is more of a design issue... still guessing but good to know someone has got around the issue.
Thank you!
My engine code is CLAA, 204 hp stock, this engine has a 2056 turbo

first upgrade was a 2260 from the 245hp engine together with DPF and EGR delete. I drove it for 25.000 km like this. It occurred every time when I would pull from 1500 rpm in 7th gear around 2000 rpm and sometimes in 6th.
I never dynoed it but I should have had around 310hp and 720nm.

spool is maybe 200 rpm later compared to 2056
 
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