Maximum gearbox torque before slipping

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blm70
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Location: Rainham, Kent

Maximum gearbox torque before slipping

Post by blm70 » Mon Feb 01, 2016 7:37 pm

Hi all - as per the title.

My gearbox was rebuilt a few months ago which included the TC. The company that carried out the work initially put the wrong filter in - it was the right one for the chassis no. but caused some cavitating and they swapped it for one with a different length funnel which cured the noise. Shortly after, my mechanic noticed a slight ATF leak and I took it back to the gearbox people who replaced the O-ring seals (they didn't replace them initially as they weren't leaking.) I asked them about the loss of fluid but they reassured me that they had checked it and there was plenty there so no damage would have been caused. It is still under warranty btw.

Since then it has been fine.

Just recently I had it remapped by MRC due to a new exhaust/pre-cat delete and they advised me that they had to reduce the torque to 782Nm (576 lb/ft) as it was slipping. Doug also said a standard 'box can handle up to 880Nm (650 lb/ft) with their mapping.

I've given it a thorough workout and can't sense any slippage plus it changes gears very smoothly with no thumping into gear or hunting etc. which I would expect from a recent rebuild.

Doug & Ben suggested a full gearbox service as then they can examine the ATF to check the condition of the 'box, TC and clutches. I have agreed to go ahead with this as Ben explained that after a fluid change they will adjust the map and carry out a test drive to check for any slipping.

However, I'm aware that this may not make any difference. The options then would be to a.) live with it or b.) drop £7k+ on a new 'box from Audi (if I entrust it to MRC) which whilst expensive would be worry-free i.e. a warranty would cover any issues. Would the warranty cover mapped 'boxes though, as I'm aware that even strengthened 'boxes from the U.S. aren't guaranteed to handle excessive torque?

Hopefully after the service it will be able to handle the torque, but if not, should I go back to the gearbox company and explain that it's slipping and ask them to rebuild it again? I know from previous conversations that they don't recommend mapping engines due to the additional stress it puts on the 'boxes...

Thoughts/comments welcome :)
Current:
TT Mk1, 225 Quattro Misano Red, AmD map

Former:
RS6 Avant 2004, MRC Stage 1+, Bilstein Coilovers, Milltek & s/s downpipes
Saab 9000 Aero 1997, GT3071, Siemens Dekka 630s, Forge 50mm i/c, 3" downpipe, Maptun stainless header, Konis, Quaife lsd, a/c deleted, 4.05 ratio 'box, custom map, 470hp & 440lb/ft.
Saab 9-3 Aero Estate 2.8 v6 2006, 3" stainless downpipe & remap, 302hp & 380lb/ft.
Rouse Sport 304R Sapphire Cosworth 1990 (stock), 260hp & 300lb/ft.

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Shoppinit
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Re: Maximum gearbox torque before slipping

Post by Shoppinit » Mon Feb 01, 2016 8:32 pm

Get a 517 trans valve body?
Daytona RS6 C5 Avant. Viper'd, Billies, Waggers, MTM box brain, C6 stoppers, xcarlink, R8 coolant cap (woohoo)
///M3 E46 | XC90 (V8, natch) | Passat GTE | RR Classic V8 flapper
"The major difference between a thing that might go wrong and a thing that cannot possibly go wrong is that when a thing that cannot possibly go wrong goes wrong it usually turns out to be impossible to get at and repair."

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SuprSi
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Re: Maximum gearbox torque before slipping

Post by SuprSi » Mon Feb 01, 2016 9:18 pm

You're not missing out on much torque wise, most stage 1's come out ~800nm anyway so he's not limited the torque by a massive amount. I'd personally just enjoy it if it's not slipping and is still in warranty, but maybe beefing it up would help it out in the long run.

Shopp: Out of interest, how much extra torque can the gb manage with the 517 valve body? Cheers
2003 C5 RS6 Avant Daytona Grey

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blm70
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Re: Maximum gearbox torque before slipping

Post by blm70 » Mon Feb 01, 2016 9:35 pm

Thanks both :)

I'll still get it serviced but I'm certainly not unhappy with the way it goes - the mapping is first-class with a really smooth curve..

Out of interest, can a 517 be ordered in the UK as all the articles I've read point directly to Americaland?
Current:
TT Mk1, 225 Quattro Misano Red, AmD map

Former:
RS6 Avant 2004, MRC Stage 1+, Bilstein Coilovers, Milltek & s/s downpipes
Saab 9000 Aero 1997, GT3071, Siemens Dekka 630s, Forge 50mm i/c, 3" downpipe, Maptun stainless header, Konis, Quaife lsd, a/c deleted, 4.05 ratio 'box, custom map, 470hp & 440lb/ft.
Saab 9-3 Aero Estate 2.8 v6 2006, 3" stainless downpipe & remap, 302hp & 380lb/ft.
Rouse Sport 304R Sapphire Cosworth 1990 (stock), 260hp & 300lb/ft.

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jockthedog
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Re: Maximum gearbox torque before slipping

Post by jockthedog » Mon Feb 01, 2016 10:22 pm

When your box was rebuilt did you get new clutch packs? Reshimmed clutches?
If neither then the clutches are not going to be 100% effective.

Any decent rebuild should replace ALL orings - which were leaking?
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blm70
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Location: Rainham, Kent

Re: Maximum gearbox torque before slipping

Post by blm70 » Mon Feb 01, 2016 10:37 pm

jockthedog wrote:When your box was rebuilt did you get new clutch packs? Reshimmed clutches?
If neither then the clutches are not going to be 100% effective.
Just dug out the receipt which says "Rebuild Automatic Gearbox and Rebuild Torque Converter". No idea if that includes clutch work but I will ask.
jockthedog wrote:Any decent rebuild should replace ALL orings - which were leaking?
I agree they should have been replaced as a matter of course, leaking or not. I don't know which ones were leaking although it doesn't leak now.

Be interesting to see what MRC find...
Current:
TT Mk1, 225 Quattro Misano Red, AmD map

Former:
RS6 Avant 2004, MRC Stage 1+, Bilstein Coilovers, Milltek & s/s downpipes
Saab 9000 Aero 1997, GT3071, Siemens Dekka 630s, Forge 50mm i/c, 3" downpipe, Maptun stainless header, Konis, Quaife lsd, a/c deleted, 4.05 ratio 'box, custom map, 470hp & 440lb/ft.
Saab 9-3 Aero Estate 2.8 v6 2006, 3" stainless downpipe & remap, 302hp & 380lb/ft.
Rouse Sport 304R Sapphire Cosworth 1990 (stock), 260hp & 300lb/ft.

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blm70
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Joined: Sun May 10, 2015 7:07 pm
Location: Rainham, Kent

Re: Maximum gearbox torque before slipping

Post by blm70 » Tue Feb 02, 2016 8:14 pm

jockthedog wrote:When your box was rebuilt did you get new clutch packs? Reshimmed clutches?
Phoned them today and they confirmed that they replace everything including the clutches, as otherwise they wouldn't be able to offer a 2 year warranty.
Current:
TT Mk1, 225 Quattro Misano Red, AmD map

Former:
RS6 Avant 2004, MRC Stage 1+, Bilstein Coilovers, Milltek & s/s downpipes
Saab 9000 Aero 1997, GT3071, Siemens Dekka 630s, Forge 50mm i/c, 3" downpipe, Maptun stainless header, Konis, Quaife lsd, a/c deleted, 4.05 ratio 'box, custom map, 470hp & 440lb/ft.
Saab 9-3 Aero Estate 2.8 v6 2006, 3" stainless downpipe & remap, 302hp & 380lb/ft.
Rouse Sport 304R Sapphire Cosworth 1990 (stock), 260hp & 300lb/ft.

User avatar
blm70
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Posts: 313
Joined: Sun May 10, 2015 7:07 pm
Location: Rainham, Kent

Re: Maximum gearbox torque before slipping

Post by blm70 » Mon Feb 15, 2016 5:21 pm

Just returned from MRC after having the gearbox flushed (twice), new ATF oil, strainer, gasket, O-ring & seal.

Apparently, the wrong ATF had been used plus the bottom of the sump was slightly dented.

Oh, the N75 needed replacing too as the boost was spiking. At least replacing it has fixed that issue though.

Back on the dyno and.... it's still slipping :thumbsdown: Doug mentioned that with the higher torque it 'jumps' so he's had to reduce it as before.

Discussing options, and the only way forward seems to be an exchange box from Audi Germany as Doug said they've never had one fail plus it comes with a 2 year warranty. He even said the uprated internals from the US aren't guaranteed, which I was surprised at.

Now this isn't a cheap option and I'm currently trying to negotiate the best price. Just had a quote from Martin @ Unit20 and I'm waiting to see if MRC can match it...
Current:
TT Mk1, 225 Quattro Misano Red, AmD map

Former:
RS6 Avant 2004, MRC Stage 1+, Bilstein Coilovers, Milltek & s/s downpipes
Saab 9000 Aero 1997, GT3071, Siemens Dekka 630s, Forge 50mm i/c, 3" downpipe, Maptun stainless header, Konis, Quaife lsd, a/c deleted, 4.05 ratio 'box, custom map, 470hp & 440lb/ft.
Saab 9-3 Aero Estate 2.8 v6 2006, 3" stainless downpipe & remap, 302hp & 380lb/ft.
Rouse Sport 304R Sapphire Cosworth 1990 (stock), 260hp & 300lb/ft.

stuartph
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Location: Essex

Re: Maximum gearbox torque before slipping

Post by stuartph » Mon Feb 15, 2016 8:33 pm

That's a shame your box is still slipping :audibash:

I had the wrong fluid in mine also , which mrc confirmed, not sure how they know , red fluid or green

Plenty of cars out there with rebuilt boxes that haven't been done properly

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blm70
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Re: Maximum gearbox torque before slipping

Post by blm70 » Mon Feb 15, 2016 10:56 pm

stuartph wrote:That's a shame your box is still slipping :audibash:
Yeah, not at all happy about it Stu but if I go back to JT Automatics and they agree to redo it (which would be the third time), I guarantee it'll still slip. They also don't seem to know what ATF fluid to use, plus they didn't look after my car whenever they had it e.g. when I first picked it up it was filthy inside and had no petrol left, despite it having just under half a tank when I dropped it off, then on another occasion they left it parked with one wheel touching the kerb.
stuartph wrote:I had the wrong fluid in mine also , which mrc confirmed, not sure how they know , red fluid or green
Witchcraft...
stuartph wrote:Plenty of cars out there with rebuilt boxes that haven't been done properly
Yep, got the t-shirt :roll:

Still, on reflection: it does actually work well enough and it is still pushing out over 25% more torque than standard. Glass half full etc..
Current:
TT Mk1, 225 Quattro Misano Red, AmD map

Former:
RS6 Avant 2004, MRC Stage 1+, Bilstein Coilovers, Milltek & s/s downpipes
Saab 9000 Aero 1997, GT3071, Siemens Dekka 630s, Forge 50mm i/c, 3" downpipe, Maptun stainless header, Konis, Quaife lsd, a/c deleted, 4.05 ratio 'box, custom map, 470hp & 440lb/ft.
Saab 9-3 Aero Estate 2.8 v6 2006, 3" stainless downpipe & remap, 302hp & 380lb/ft.
Rouse Sport 304R Sapphire Cosworth 1990 (stock), 260hp & 300lb/ft.

stuartph
1st Gear
Posts: 82
Joined: Tue Oct 29, 2013 4:04 pm
Location: Essex

Re: Maximum gearbox torque before slipping

Post by stuartph » Tue Feb 16, 2016 10:34 am

Your having fun with the car that's what matters :biggrin3:

I think an Audi box or from Chester trans is the only guaranteed way of knowing the box is correct for the rs6 , fluid , filter height , etc etc

So mrc or unit 20 that is the question

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blm70
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Location: Rainham, Kent

Re: Maximum gearbox torque before slipping

Post by blm70 » Tue Feb 16, 2016 7:24 pm

stuartph wrote:Your having fun with the car that's what matters :biggrin3:

I think an Audi box or from Chester trans is the only guaranteed way of knowing the box is correct for the rs6 , fluid , filter height , etc etc

So mrc or unit 20 that is the question

You're right - if I wasn't enjoying it I would have sold it already :mrgreen:

Just received a quote from MRC...
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Current:
TT Mk1, 225 Quattro Misano Red, AmD map

Former:
RS6 Avant 2004, MRC Stage 1+, Bilstein Coilovers, Milltek & s/s downpipes
Saab 9000 Aero 1997, GT3071, Siemens Dekka 630s, Forge 50mm i/c, 3" downpipe, Maptun stainless header, Konis, Quaife lsd, a/c deleted, 4.05 ratio 'box, custom map, 470hp & 440lb/ft.
Saab 9-3 Aero Estate 2.8 v6 2006, 3" stainless downpipe & remap, 302hp & 380lb/ft.
Rouse Sport 304R Sapphire Cosworth 1990 (stock), 260hp & 300lb/ft.

S4WON
Top Gear
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Re: Maximum gearbox torque before slipping

Post by S4WON » Tue Feb 16, 2016 7:53 pm

Ouch. Can almost buy a whole new C5 for that...

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blm70
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Posts: 313
Joined: Sun May 10, 2015 7:07 pm
Location: Rainham, Kent

Re: Maximum gearbox torque before slipping

Post by blm70 » Tue Feb 16, 2016 8:05 pm

S4WON wrote:Ouch. Can almost buy a whole new C5 for that...
But it might need a gearbox at some point. Plus everything else that's bound to go wrong...
Current:
TT Mk1, 225 Quattro Misano Red, AmD map

Former:
RS6 Avant 2004, MRC Stage 1+, Bilstein Coilovers, Milltek & s/s downpipes
Saab 9000 Aero 1997, GT3071, Siemens Dekka 630s, Forge 50mm i/c, 3" downpipe, Maptun stainless header, Konis, Quaife lsd, a/c deleted, 4.05 ratio 'box, custom map, 470hp & 440lb/ft.
Saab 9-3 Aero Estate 2.8 v6 2006, 3" stainless downpipe & remap, 302hp & 380lb/ft.
Rouse Sport 304R Sapphire Cosworth 1990 (stock), 260hp & 300lb/ft.

ahoooga
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Re: Maximum gearbox torque before slipping

Post by ahoooga » Tue Feb 16, 2016 9:21 pm

S4WON wrote:Ouch. Can almost buy a whole new C5 for that...
Probably, but will it have a decent gearbox though for that money ? :bigblink:

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