Tiptronic transmission
08-15-2013 | 05:44 PM
#3
Burning Brakes
Joined: Apr 2013
Posts: 998
Likes: 6
From: MTL, Qc Canada
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08-16-2013 | 07:33 AM
#10
Rennlist Member
Joined: May 2006
Posts: 3,045
Likes: 182
From: Paris
The ZF tiptronic transmission on the Porsche 993 has a Major Achille's heel or weak point, cost me months of research, testing and dismantling of three Tip boxes laying in my garage.
My box broke, and I wanted ZF to rebuild my original box. They accepted to exchange it, but not rebuild.
So I started researching
I have had several visits from the ZF techs here, for inter-insurance purposes, where I demonstrated to them how a certain situation could break the transmission, and it is breakable.
If you do a search, you would fall on loads of situations where the TIPs broke, but rarely in a 993 since there
are not many.
The main shaft through the pump at the bell housing has dual copper seals originally installed by liquid Nitrogen immersion of the shaft at -196* celsius, and the heating of the seals. (as the valve seats in cylinder heads)
How the Transmission is breakable:
You start engine in Park , the trans fluid in torque converter builds up heat very fast since turbine and stator are stationary, and flywheel-impeller are revving.
If you rev up the engine above 2000 rpm and keep it there, with cold transmission, the impeller wants to grab on the stator and turbine and turn them, but turbine is locked by input shaft.
Oil in convertor heats up pump around input shaft seals, whilst input shaft still cold, and difference in fluid pressures between converter and trans core, oil will seep between pump and input shaft seals and pressurizes the gear clutch packs one after the other eventually burning them one by one.
But If you start engine, and drive directly at high RPM, the heating in the box is uniform since gears and all functioning, thus not wearing the bore.
How this situation occurs in real life:
I booked for an emission test 3 blocks from where I live, and when I arrived to the facility, they were late scheduled, and asked me to park car on test bed, leave keys, and come pick up car in the afternoon.
The car sat for a few hours, and trans was cold.
The tester hopped in, hooked the testing probe to the exhaust tip, and revved the engine for 30 full seconds.
The 1st gear clutch pack (forward clutch) got burnt.
Two days later, I start the car, go in reverse then neutral. Before selecting a gear, the car in neutral advanced slowly. I blipped the throttle in Neutral, and the car leaped a few meters forward.
To be able to trigger the insurances, I had to demonstrate this to ZF here with a full functioning box,
and was able to initiate the failure.
Anyone in the same situation, could give instructions to emission tester.
If obliged to rev a cold Tiptronic box, without running gears or driving. Start engine in Park, select any gear while braking, and wait for one full minute for oil to pressurize and uniformly heat the box a tad, then rev.
My box broke, and I wanted ZF to rebuild my original box. They accepted to exchange it, but not rebuild.
So I started researching
I have had several visits from the ZF techs here, for inter-insurance purposes, where I demonstrated to them how a certain situation could break the transmission, and it is breakable.
If you do a search, you would fall on loads of situations where the TIPs broke, but rarely in a 993 since there
are not many.
The main shaft through the pump at the bell housing has dual copper seals originally installed by liquid Nitrogen immersion of the shaft at -196* celsius, and the heating of the seals. (as the valve seats in cylinder heads)
How the Transmission is breakable:
You start engine in Park , the trans fluid in torque converter builds up heat very fast since turbine and stator are stationary, and flywheel-impeller are revving.
If you rev up the engine above 2000 rpm and keep it there, with cold transmission, the impeller wants to grab on the stator and turbine and turn them, but turbine is locked by input shaft.
Oil in convertor heats up pump around input shaft seals, whilst input shaft still cold, and difference in fluid pressures between converter and trans core, oil will seep between pump and input shaft seals and pressurizes the gear clutch packs one after the other eventually burning them one by one.
But If you start engine, and drive directly at high RPM, the heating in the box is uniform since gears and all functioning, thus not wearing the bore.
How this situation occurs in real life:
I booked for an emission test 3 blocks from where I live, and when I arrived to the facility, they were late scheduled, and asked me to park car on test bed, leave keys, and come pick up car in the afternoon.
The car sat for a few hours, and trans was cold.
The tester hopped in, hooked the testing probe to the exhaust tip, and revved the engine for 30 full seconds.
The 1st gear clutch pack (forward clutch) got burnt.
Two days later, I start the car, go in reverse then neutral. Before selecting a gear, the car in neutral advanced slowly. I blipped the throttle in Neutral, and the car leaped a few meters forward.
To be able to trigger the insurances, I had to demonstrate this to ZF here with a full functioning box,
and was able to initiate the failure.
Anyone in the same situation, could give instructions to emission tester.
If obliged to rev a cold Tiptronic box, without running gears or driving. Start engine in Park, select any gear while braking, and wait for one full minute for oil to pressurize and uniformly heat the box a tad, then rev.
08-16-2013 | 08:14 AM
#11
Rennlist Member
Joined: Feb 2013
Posts: 981
Likes: 310
From: Dubai
Appreciating your efforts, but i totally disagree with you!
What you call a major Achilles heel or week point is IMHO simple misuse of the box. As with the engine, it should be warmed up properly before heavier workload is applied. Trying revving in idle mode seconds after starting a cold engine for emission testing is NOT a common operating mode, its more operators stupidity.
Should it be explained specifically in the manual, you guys in the US have different views on that but again IMHO the manual should cover in the first place 'normal' operation, the rest should be covered by common sense.
Nobody is secure for abuse or stupidity from third party side (like here described) but where is here the line to define?
Again, appreciate your efforts but a major flaw would be one which would be reached in operation mode easily and/or obviously could be avoided through manufacturing process.
(In case of the 993 as sample the corrosion issue at the window frame ...)
In general, its the first time in 20 years i heard about such problem with the Tiptronic, so seems it happens not very often...
Therefore, for me, the Tiptronic is one of the most robust parts of the car, would like if my 915 gearbox in the 3.2 were that sturdy.
What you call a major Achilles heel or week point is IMHO simple misuse of the box. As with the engine, it should be warmed up properly before heavier workload is applied. Trying revving in idle mode seconds after starting a cold engine for emission testing is NOT a common operating mode, its more operators stupidity.
Should it be explained specifically in the manual, you guys in the US have different views on that but again IMHO the manual should cover in the first place 'normal' operation, the rest should be covered by common sense.
Nobody is secure for abuse or stupidity from third party side (like here described) but where is here the line to define?
Again, appreciate your efforts but a major flaw would be one which would be reached in operation mode easily and/or obviously could be avoided through manufacturing process.
(In case of the 993 as sample the corrosion issue at the window frame ...)
In general, its the first time in 20 years i heard about such problem with the Tiptronic, so seems it happens not very often...
Therefore, for me, the Tiptronic is one of the most robust parts of the car, would like if my 915 gearbox in the 3.2 were that sturdy.
Last edited by Holger3.2; 08-16-2013 at 08:42 AM.
08-16-2013 | 08:18 AM
#12
Rennlist Member
Joined: Jul 2012
Posts: 703
Likes: 0
+1!
Appreciating your efforts, i totally disagree with you!
What you call a major Achilles heel is IMHO simple misuse of the box. As with the engine, it should be warmed up properly before heavier workload is applied. Trying revving in idle mode for emission testing is NOT a common operating mode.
Should it be explained specifically in the manual, you guys in the US have different views on that but again IMHO the manual should cover in the first place 'normal' operation, the rest should be covered by common sense.
Nobody is secure for abuse or stupidity from third party side (like here described) but where is here the line to define?
Again, appreciate your efforts but a major flaw would be one which would be reached in operation mode easily and obviously could be avoided through manufacturing process.
(In case of the 993 as sample the corrosion issue at the window frame ...)
In general, its the first time in 20 years i heard about such problem with the Tiptronic, so seems it happens not very often...
Therefore, for me, the Tiptronic is one of the most robust parts of the car, would like if my 915 gearbox ofthe 3.2 were that sturdy.
What you call a major Achilles heel is IMHO simple misuse of the box. As with the engine, it should be warmed up properly before heavier workload is applied. Trying revving in idle mode for emission testing is NOT a common operating mode.
Should it be explained specifically in the manual, you guys in the US have different views on that but again IMHO the manual should cover in the first place 'normal' operation, the rest should be covered by common sense.
Nobody is secure for abuse or stupidity from third party side (like here described) but where is here the line to define?
Again, appreciate your efforts but a major flaw would be one which would be reached in operation mode easily and obviously could be avoided through manufacturing process.
(In case of the 993 as sample the corrosion issue at the window frame ...)
In general, its the first time in 20 years i heard about such problem with the Tiptronic, so seems it happens not very often...
Therefore, for me, the Tiptronic is one of the most robust parts of the car, would like if my 915 gearbox ofthe 3.2 were that sturdy.
08-16-2013 | 09:26 AM
#13
Rennlist Member
Joined: May 2006
Posts: 3,045
Likes: 182
From: Paris
Appreciating your efforts, but i totally disagree with you!
What you call a major Achilles heel or week point is IMHO simple misuse of the box. As with the engine, it should be warmed up properly before heavier workload is applied. Trying revving in idle mode seconds after starting a cold engine for emission testing is NOT a common operating mode, its more operators stupidity.
Should it be explained specifically in the manual, you guys in the US have different views on that but again IMHO the manual should cover in the first place 'normal' operation, the rest should be covered by common sense.
Nobody is secure for abuse or stupidity from third party side (like here described) but where is here the line to define?
Again, appreciate your efforts but a major flaw would be one which would be reached in operation mode easily and/or obviously could be avoided through manufacturing process.
(In case of the 993 as sample the corrosion issue at the window frame ...)
In general, its the first time in 20 years i heard about such problem with the Tiptronic, so seems it happens not very often...
Therefore, for me, the Tiptronic is one of the most robust parts of the car, would like if my 915 gearbox in the 3.2 were that sturdy.
What you call a major Achilles heel or week point is IMHO simple misuse of the box. As with the engine, it should be warmed up properly before heavier workload is applied. Trying revving in idle mode seconds after starting a cold engine for emission testing is NOT a common operating mode, its more operators stupidity.
Should it be explained specifically in the manual, you guys in the US have different views on that but again IMHO the manual should cover in the first place 'normal' operation, the rest should be covered by common sense.
Nobody is secure for abuse or stupidity from third party side (like here described) but where is here the line to define?
Again, appreciate your efforts but a major flaw would be one which would be reached in operation mode easily and/or obviously could be avoided through manufacturing process.
(In case of the 993 as sample the corrosion issue at the window frame ...)
In general, its the first time in 20 years i heard about such problem with the Tiptronic, so seems it happens not very often...
Therefore, for me, the Tiptronic is one of the most robust parts of the car, would like if my 915 gearbox in the 3.2 were that sturdy.
Thank you, and I always encourage a situation that leads to debate.
If I understand correctly,
you call it unbreakable
I call it breakable if misused
If it is another point, I did not get it
thanks
here is the ZF TSB
.
08-16-2013 | 09:53 AM
#14
Rennlist Member
Joined: Feb 2013
Posts: 981
Likes: 310
From: Dubai
you called it "ZF Tip ... on Porsche 993 has a Major Achille's heel or weak point"
i said your unit was misused ...
i called it one of the most robust parts of a 993 ... never said unbreakable ...
and the ZF TSB above mention BMW, Volvo, Jaguar, Peugeot and Lincoln.
do I miss something here?
Back to narkose, should he worry or abandon his idea about buying a Tiptronic coz of your discovery?
i said your unit was misused ...
i called it one of the most robust parts of a 993 ... never said unbreakable ...
and the ZF TSB above mention BMW, Volvo, Jaguar, Peugeot and Lincoln.
do I miss something here?
Back to narkose, should he worry or abandon his idea about buying a Tiptronic coz of your discovery?
