02' 4.6is Supercharged / 107k / Trans. Fail. Safe

[burninator]

Originally Posted by 740ilDuke

Damn...feels like its gone be awhile.

Sent to Vortech on 12/28

[740ilDuke]

It came from a 2003. I will try to get the number off the tag.

VIN: 5UXFB935X3LN80178

If that helps.

Originally Posted by RRPhil

I see 5HP24s at that mileage quite frequently and they’re in excellent condition (but others are completely ‘worn out’ at much lower mileages). When I check the thickness of the friction plates at 200k miles they’re often identical to brand new plates because the control system is so sensitive to any unplanned clutch slip that it immediately flags failsafe if there’s anything going on that could generate wear and damage. The long-term adaptions stored in the controller tweak the clutch control pressures over the years to maintain the shift times, again, protecting the clutches. Arguably at such a high mileage you should swap the controller with the transmission to preserve these settings.

Clearly, it’s a bit of a lottery fitting something at that mileage without knowing its duty-cycle history. If it’s been driven gently for the whole of its life the transmission could last indefinitely. If it’s been used for towing, frequent hill climbing, driven aggressively, etc. it may be much further through its fatigue life. Similarly, you have no way of knowing if the fluid has overheated in the past and therefore oxidised and massively reduced its protection/life.

Common failures at high mileages are the A-clutch drum snap ring groove (for transmissions built before November 2000), the B-clutch hub/C-clutch drum axial bearing failure, the F-brake piston seal (for transmissions built before August 2001) and wear in the torque converter lock-up clutch. Other than these well-known weaknesses the rest of the transmission is very durable. If the transmission has previously been rebuilt then the above issues may already have been addressed? Transmissions built after October 2001 have all the latest development fixes from the factory. If you want to know the date of manufacture of a particular transmission just let me have the serial number off the green plate riveted to the side of the casing.

Phil

[740ilDuke]

Hopefully it was the holidays that slowed their inspection/rebuild process down.

Originally Posted by burninator

Sent to Vortech on 12/28

[snik]

Originally Posted by RRPhil

I see 5HP24s at that mileage quite frequently and they’re in excellent condition (but others are completely ‘worn out’ at much lower mileages). When I check the thickness of the friction plates at 200k miles they’re often identical to brand new plates because the control system is so sensitive to any unplanned clutch slip that it immediately flags failsafe if there’s anything going on that could generate wear and damage. The long-term adaptions stored in the controller tweak the clutch control pressures over the years to maintain the shift times, again, protecting the clutches. Arguably at such a high mileage you should swap the controller with the transmission to preserve these settings.



Clearly, it’s a bit of a lottery fitting something at that mileage without knowing its duty-cycle history. If it’s been driven gently for the whole of its life the transmission could last indefinitely. If it’s been used for towing, frequent hill climbing, driven aggressively, etc. it may be much further through its fatigue life. Similarly, you have no way of knowing if the fluid has overheated in the past and therefore oxidised and massively reduced its protection/life.



Common failures at high mileages are the A-clutch drum snap ring groove (for transmissions built before November 2000), the B-clutch hub/C-clutch drum axial bearing failure, the F-brake piston seal (for transmissions built before August 2001) and wear in the torque converter lock-up clutch. Other than these well-known weaknesses the rest of the transmission is very durable. If the transmission has previously been rebuilt then the above issues may already have been addressed? Transmissions built after October 2001 have all the latest development fixes from the factory. If you want to know the date of manufacture of a particular transmission just let me have the serial number off the green plate riveted to the side of the casing.



Phil

That makes the 5HP sound awesome.
What's the main differences in failures and wear parts you've seen with the 6HP? Do they share any strengths or weaknesses with the 5HP, or is the 6HP totally different?


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[RRPhil]

Without doubt, the single biggest problem with the 6HP26 is faulty solenoids. These cause the vast majority of issues with this transmission. The other main issues are:

• Transmission refuses to shift higher than 3rd gear (E-clutch slipping due to hydraulic leakage caused by wear in lead-free rear stator bush)
  
• Clunky 2-1 rollout shifts (Latest mechatronic firmware updates not performed)
  
• Clutch packs destroy themselves following fluid change and adaption reset (ECU cannot find new adaptions in time to prevent clutch plates burning up, due to change in friction coefficient)
  
• Complete loss of drive (Failure of output shaft spline through fretting corrosion due to lack of lubrication at factory)

Mechanically though, I would say it is a more robust transmission than the 5HP24. Having said that, Audi put the 5HP24A behind their 6.0 litre W12 engine and even the 353kW/560Nm Audi RS6 Plus, so the 5-speed running gear is certainly capable of handling more power/torque than the 4.6iS E53 delivers.

Phil

[wpoll]

Originally Posted by RRPhil

Without doubt, the single biggest problem with the 6HP26 is faulty solenoids. These cause the vast majority of issues with this transmission. The other main issues are:

• Transmission refuses to shift higher than 3rd gear (E-clutch slipping due to hydraulic leakage caused by wear in lead-free rear stator bush)
• Clunky 2-1 rollout shifts (Latest mechatronic firmware updates not performed)
• Clutch packs destroy themselves following fluid change and adaption reset (ECU cannot find new adaptions in time to prevent clutch plates burning up, due to change in friction coefficient)
• Complete loss of drive (Failure of output shaft spline through fretting corrosion due to lack of lubrication at factory)

Mechanically though, I would say it is a more robust transmission than the 5HP24. Having said that, Audi put the 5HP24A behind their 6.0 litre W12 engine and even the 353kW/560Nm Audi RS6 Plus, so the 5-speed running gear is certainly capable of handling more power/torque than the 4.6iS E53 delivers.

Phil

Wow - thanks Phil!

I've always wondered about the mechatronic firmware and the 2-1 slam - assume you are referring to the EGS module firmware. Does' anyone know exactly WHAT the latest version is (and more to the point WHERE it is... ).

And interesting comment about the adaptations. I've always thought that damage was a possible outcome of adaptation resets (when not required) - interesting to hear this is the case.

So if the mechatronic firmware is updated, I'm assuming that process erases the adaptations, or are they stored in a separate register and are re-applied via the new firmware?

Interestingly, I had (have) a mild case of 2-1 slam on my 6HP-26X but when I recently replaced the ATC500 power divider fluid and performed the VTG oil wear adaptation reset via DIS, the 2-1 slam disappeared. Mostly. I can still induce the slam but the car rarely does it and it's now SO much more drivable, especially coming up to Give Way signs in hill suburbs.

I have no idea why - but I'll take the win!!

[snik]

Interesting stuff there. Thanks for sharing.


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[CleanIsFast]

Clunky 2-1 rollout shifts (Latest mechatronic firmware updates not performed)

This software must be different than what DINAN offered, because when I had my 4.6iS - I had DINAN transmission software installed and it did not cure the 2-1 clunk. New transmission oil service did not cure it either. Only sport mode was able to eliminate the 2-1 clunk for me.

I always believed it to be a temperature issue since it only happened at 'normal operating temp' or at least what was indicted. Or solenoid issue.

[740ilDuke]

Originally Posted by burninator

Sent to Vortech on 12/28

Any comms with Vortech?

[740ilDuke]

So, looks like it’ll be shipping out end of the week!

I’ve got a little inspecting to do, the drain line did look dry; this explains it too.
____________________________________
Scott,

The unit you sent in for inspection has been looked at and it will need to have a minor repair (bearings and seals), cost of the rebuild is $396.99 + return shipping.
The oil in the unit is fairly dirty and looks like you might have a drain issue, make sure your drain line
Is as straight to the top of the oil pan as possible. no kinks, bends or loops
Make sure the line is a no smaller than ½” diameter”




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