4.2 Trans fluid & filter change
07-07-2012, 06:51 PM
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4.2 Trans fluid & filter change
I'm debating changing the trans fluid on my 4.2, I have no record of the fluid/filter ever being changed. I have put about 15k on the car in the last 2 years that I have owned it. (135k on the clock)
The trans shifts fine, the only things that I have noticed about it is sometimes it downshifts hard into 1st gear when coming to an abrupt stop, and when its really hot and idling in D while stopped at a light I can hear a low freq thumping sound coming from the trans. If I shift it into N the noise goes away immediately.
My wife and I are going to be taking a 1500 mile roadtrip in a couple weeks, and I feel in a bit of a catch 22 situation. I feel that I should change the fluid & filter for peace of mind, but I am also worried that changing the fluid could lead to trans failure as well. I've read more than a few posts on here of people who changed their fuild and shortly after the trans failed.
Thoughts?
The trans shifts fine, the only things that I have noticed about it is sometimes it downshifts hard into 1st gear when coming to an abrupt stop, and when its really hot and idling in D while stopped at a light I can hear a low freq thumping sound coming from the trans. If I shift it into N the noise goes away immediately.
My wife and I are going to be taking a 1500 mile roadtrip in a couple weeks, and I feel in a bit of a catch 22 situation. I feel that I should change the fluid & filter for peace of mind, but I am also worried that changing the fluid could lead to trans failure as well. I've read more than a few posts on here of people who changed their fuild and shortly after the trans failed.
Thoughts?
07-07-2012, 07:17 PM
#2
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A coin toss...
My instinct would be to change it, but only after your trip. But all debatable.
You might also search out Tozo M8 on the D2 A8 board--same 5HP24A in the A8 since they also shared the motor. He has rebuilt many of these and seems the definitive authority on 5HP24A maladies.
As a 2000, it's probably not an "if" but a "when" that the tranny will fail, before tons more miles that is. Actually, you have gone longer than many already probably. I was disappointed to hear that the trannies were "improved" and beefed up after 2000, which I translate to ZF knew they had an issue but kept their mouth shut a long time. As the original buyer, that shouldn't have happened as far as aftersale support/warranty.
As far as my own experience, I did do a fluid change on mine at about 65-70K miles in search of a fix to a "clunk." Buried deep in the archives is my later post that it turned out to be a wiring problem (deep in the harness) to a sensor on the tranny. Car ran for several years well after that was all finally fixed. The fluid was clearly well used and (the expected) metal bits from the clutch wear were in the pan. Later tranny just catastrophically failed when (most likely) the clutch basket just tore out and I lost the first several gears--happened on a standing start hard acceleration run to about 35MPH that I had done about 1,000 times over the years. Again, the clutch basket is documented as something they later strengthened.
There a lot more good posts specific to the 4.2 tranny on the D2 A8 board actually if you want to dive in deeper. Meanwhile though, I would say the fluid changed and that breakage years later were unrelated, especially since the failure issue has itself been "improved" by ZF. I went to a ZF authorized installer, so got the "new and improved" rebuilt one. I did try changing the fluid again once it blew, but of course that was too late to fix it given the later diagnosis. That time the fluid (at about 110K) was much cleaner than the first time. Obviously that fluid change didn't "cause" the issue either, since I was the driver when the underlying huge clunk let loose. So here, my net is yes there are lots of posts probably where the tranny was shot shortly after a fluid change, but then of course people often knew they had a likely problem that caused them to try a change. Kind of like having a heart attack after going to the hospital for possible chest pains. Doesn't mean you shouldn't go to the hospital to get some treatment to try to avoid the heart attack. Given the issues you mention, realistically your tranny is "at risk" of something bad happening either way.
You might also search out Tozo M8 on the D2 A8 board--same 5HP24A in the A8 since they also shared the motor. He has rebuilt many of these and seems the definitive authority on 5HP24A maladies.
As a 2000, it's probably not an "if" but a "when" that the tranny will fail, before tons more miles that is. Actually, you have gone longer than many already probably. I was disappointed to hear that the trannies were "improved" and beefed up after 2000, which I translate to ZF knew they had an issue but kept their mouth shut a long time. As the original buyer, that shouldn't have happened as far as aftersale support/warranty.
As far as my own experience, I did do a fluid change on mine at about 65-70K miles in search of a fix to a "clunk." Buried deep in the archives is my later post that it turned out to be a wiring problem (deep in the harness) to a sensor on the tranny. Car ran for several years well after that was all finally fixed. The fluid was clearly well used and (the expected) metal bits from the clutch wear were in the pan. Later tranny just catastrophically failed when (most likely) the clutch basket just tore out and I lost the first several gears--happened on a standing start hard acceleration run to about 35MPH that I had done about 1,000 times over the years. Again, the clutch basket is documented as something they later strengthened.
There a lot more good posts specific to the 4.2 tranny on the D2 A8 board actually if you want to dive in deeper. Meanwhile though, I would say the fluid changed and that breakage years later were unrelated, especially since the failure issue has itself been "improved" by ZF. I went to a ZF authorized installer, so got the "new and improved" rebuilt one. I did try changing the fluid again once it blew, but of course that was too late to fix it given the later diagnosis. That time the fluid (at about 110K) was much cleaner than the first time. Obviously that fluid change didn't "cause" the issue either, since I was the driver when the underlying huge clunk let loose. So here, my net is yes there are lots of posts probably where the tranny was shot shortly after a fluid change, but then of course people often knew they had a likely problem that caused them to try a change. Kind of like having a heart attack after going to the hospital for possible chest pains. Doesn't mean you shouldn't go to the hospital to get some treatment to try to avoid the heart attack. Given the issues you mention, realistically your tranny is "at risk" of something bad happening either way.
Last edited by MP4.2+6.0; 07-07-2012 at 07:22 PM.
07-08-2012, 03:34 AM
#3
07-08-2012, 04:51 PM
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why is this debatable.?
The tranny manufacturer (ZF) recommends changes before every 50k miles. Fresh fluid has specs closest to the design specs. Dirt and varnish clog transmissions. I fail to see the debate.
There is a debate on a full flush, if you have gone many, many miles without the proscribed service. In that case varnish could be dislodged, creating problems where none would otherwise exist.
And, of course, you must use the OEM fluid. Others are likely not compatible, and ZF is very clear on using that fluid only.
Do the service, do not flush, use esso fluid. Next.
G
The tranny manufacturer (ZF) recommends changes before every 50k miles. Fresh fluid has specs closest to the design specs. Dirt and varnish clog transmissions. I fail to see the debate.
There is a debate on a full flush, if you have gone many, many miles without the proscribed service. In that case varnish could be dislodged, creating problems where none would otherwise exist.
And, of course, you must use the OEM fluid. Others are likely not compatible, and ZF is very clear on using that fluid only.
Do the service, do not flush, use esso fluid. Next.
G
07-13-2012, 06:14 AM
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i believe that many dont appreciate the difference between a flush and a change of fluid. There has been some rational speculation that a complete flush on a tranny that has not had any service for ages, might dislodge varnish and other deposits and cause trouble.
I'm not saying that's necessarily true, but i understand the chain of events.
I prefer to do regular services (drain free fluid, clean pan, change filter) periodically and never get into that situation.
G
I'm not saying that's necessarily true, but i understand the chain of events.
I prefer to do regular services (drain free fluid, clean pan, change filter) periodically and never get into that situation.
G
07-13-2012, 02:18 PM
#6
I agree, and I think that the source of the dislodged particulate is probably the filter. When they flush, most shops just hook up the tool and go; they never drop the pan. Every time I've changed fluid, the filter has been loaded with crap. If you flush (and I'm not saying you should) you should really change the filter both before and after the flush.
07-13-2012, 09:51 PM
#7
AudiWorld Super User
Quite the opinions there
Debatable with the high mileage on the tranny now. Statistically, I think it's fragile. And as a 4.2, it's overdue for issues given the known early issues w/ the 5HP24A.
You might want to read the ZF site more closely. What you say is not the current or recent recommendation in general. For "severe operating conditions" it's 80-120km (50 to 75K miles) or 8 years. Their definition of severe operating conditions is not close to every day usage on American roads. Otherwise, "maintenance free" which of course has always been Audi's party line. http://www.zf.com/na/content/media/u..._11_en0700.pdf
Agreed on the OE spec fluid, whether from Audi, Esso, ZF or Pentosin. When done, also agreed on full drain and filter change vs. machine flush approach.
You might want to read the ZF site more closely. What you say is not the current or recent recommendation in general. For "severe operating conditions" it's 80-120km (50 to 75K miles) or 8 years. Their definition of severe operating conditions is not close to every day usage on American roads. Otherwise, "maintenance free" which of course has always been Audi's party line. http://www.zf.com/na/content/media/u..._11_en0700.pdf
Agreed on the OE spec fluid, whether from Audi, Esso, ZF or Pentosin. When done, also agreed on full drain and filter change vs. machine flush approach.
Last edited by MP4.2+6.0; 07-13-2012 at 10:03 PM.
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07-14-2012, 06:40 PM
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I didnt read your entire post befoe my earlier reply. I have not seen the revised recommendation, but last i did dig in it was either 50k miles or km (or maybe 80k km). In any event, it was for regular service. Now, the transmission has not changed; so why did the service recommendation? There are many reasons to change the stated interval, and many dont have our best interest in mind. For instance, many expensive services are pushed beyond 100k beacuse they are not calculated in several common LT cost of ownership indicators. Nice.
Now, i dont follow your logic here at all:
"Debatable with the high mileage on the tranny now. Statistically, I think it's fragile. And as a 4.2, it's overdue for issues given the known early issues w/ the 5HP24A."
Yep its fragile. That's not the issue. And isues have causes. The question is what contributes. Whether its fragile or not, clean, in-spec fluid will protect it and allow it to operate better than older out-of-spec fluid. So what's the downside? Ont he face of it, there is none. So i went one step further and indicated why the "old wives tale" (and that's what i believe it is) started - confusion between a flush and a service, made worse if a tranny is old and has never been serviced. I wont connect the dots but various things build up incrementally over time. That's not opinion either.
The issues, with the 5HP24a are several, but the most serious is the torque converter. There is debate over why that fails (see another thread) - but one camp essentially says "its inevitable and related to time". That would mean fluid changes have no effect on it either way. I dont agree. Heat and pressure clearly contribute to any mechanical failure. Absent a force, things dont fail even if they are faulty. And heat tends to both cause expansion stress and for many materials softens them. So i assert that heat and pressure (load) must play a role. Either way, i dont see the role of a fluid change in this equation.
These seem fairly self evident, though.
G
Now, i dont follow your logic here at all:
"Debatable with the high mileage on the tranny now. Statistically, I think it's fragile. And as a 4.2, it's overdue for issues given the known early issues w/ the 5HP24A."
Yep its fragile. That's not the issue. And isues have causes. The question is what contributes. Whether its fragile or not, clean, in-spec fluid will protect it and allow it to operate better than older out-of-spec fluid. So what's the downside? Ont he face of it, there is none. So i went one step further and indicated why the "old wives tale" (and that's what i believe it is) started - confusion between a flush and a service, made worse if a tranny is old and has never been serviced. I wont connect the dots but various things build up incrementally over time. That's not opinion either.
The issues, with the 5HP24a are several, but the most serious is the torque converter. There is debate over why that fails (see another thread) - but one camp essentially says "its inevitable and related to time". That would mean fluid changes have no effect on it either way. I dont agree. Heat and pressure clearly contribute to any mechanical failure. Absent a force, things dont fail even if they are faulty. And heat tends to both cause expansion stress and for many materials softens them. So i assert that heat and pressure (load) must play a role. Either way, i dont see the role of a fluid change in this equation.
These seem fairly self evident, though.
G
07-14-2012, 10:06 PM
#10
AudiWorld Super User
FWIW, having been inside mine...
I never had any torque converter issues. I know the 5 speeds do at times, and as I recall the ZF "updates" also addressed the torque converter.
At the first fluid change I did, I found the fluid discolored but also somewhat slimy (not just an oil feel; more like something like MOS2). The pan had the not unexpected tiny metallic bits, largely around the magnets. Both the pan and all the visible transmission innards like the bottom of the valve body had a silvery sort of slime that didn't just drain off w/ the fluid. Did not really find what I would call varnish, no more than a micro coating of typical tan brown color like you find inside a clean motor.
The issue was mine had the "clunk" on shifting--hard shudder through drivetrain and then SAFE mode. Fluid and filter change didn't really help. MAF change did a bit. Eventually though, it turned out to be the broken output speed sensor wire in the harness itself ; never saw it documented other than my own posts in past years. Had the valve body rebuilt by a ZF Audi specialist shortly before I found the ultimate wire issue. Meant I had the pan open again. Again, that silvery metallic slime, though not as much as the first time. And yes, each time fluid drain and filter change. Rebuilding valve body really got shfifting back nice and sharp; really like new.
Anyway, having seen the inside of the tranny three times, including up into the clutches which is possible when the valve body comes out, I can see there is a fair amount of none native stuff that ends up in that fluid and coating all the parts over time. Actually, knowing even the valve body, I pulled out individual solenoids and found some of the same slimy stuff deep in there too.
Yes, I would expect new fluid will have a renewed additive package that will increase the solvents. Again, at the mileage of the OP's tranny and the known history, it's unfortunately likely to fail before too long. I also considered (IIRC) that the OP didn't mention any prior fluid changes--and by now few owners are original like I still am and thus may not know the history. If it had a history of changes, like back at 50-75K miles, I would say sure change it again soon. All that is why I suggested it might at least sense to just leave it be until after the planned long trip.
Last on the ZF fluid change specs, yes you are correct as I recall it once said something different. But, it was changed a fair number of years back now. No, I don't trust Audi (or other manufacturer) recommendations either on "maintenance free" since they are incented to to promote low maintenance as a selling feature, and are even graded on it in things like total cost of ownership stats. On the other hand, ZF has less incentive to do that I think. Plus, their spec's and recommendations are published worldwide, and not doctored for local markets as some manufacturers may try.
At the first fluid change I did, I found the fluid discolored but also somewhat slimy (not just an oil feel; more like something like MOS2). The pan had the not unexpected tiny metallic bits, largely around the magnets. Both the pan and all the visible transmission innards like the bottom of the valve body had a silvery sort of slime that didn't just drain off w/ the fluid. Did not really find what I would call varnish, no more than a micro coating of typical tan brown color like you find inside a clean motor.
The issue was mine had the "clunk" on shifting--hard shudder through drivetrain and then SAFE mode. Fluid and filter change didn't really help. MAF change did a bit. Eventually though, it turned out to be the broken output speed sensor wire in the harness itself ; never saw it documented other than my own posts in past years. Had the valve body rebuilt by a ZF Audi specialist shortly before I found the ultimate wire issue. Meant I had the pan open again. Again, that silvery metallic slime, though not as much as the first time. And yes, each time fluid drain and filter change. Rebuilding valve body really got shfifting back nice and sharp; really like new.
Anyway, having seen the inside of the tranny three times, including up into the clutches which is possible when the valve body comes out, I can see there is a fair amount of none native stuff that ends up in that fluid and coating all the parts over time. Actually, knowing even the valve body, I pulled out individual solenoids and found some of the same slimy stuff deep in there too.
Yes, I would expect new fluid will have a renewed additive package that will increase the solvents. Again, at the mileage of the OP's tranny and the known history, it's unfortunately likely to fail before too long. I also considered (IIRC) that the OP didn't mention any prior fluid changes--and by now few owners are original like I still am and thus may not know the history. If it had a history of changes, like back at 50-75K miles, I would say sure change it again soon. All that is why I suggested it might at least sense to just leave it be until after the planned long trip.
Last on the ZF fluid change specs, yes you are correct as I recall it once said something different. But, it was changed a fair number of years back now. No, I don't trust Audi (or other manufacturer) recommendations either on "maintenance free" since they are incented to to promote low maintenance as a selling feature, and are even graded on it in things like total cost of ownership stats. On the other hand, ZF has less incentive to do that I think. Plus, their spec's and recommendations are published worldwide, and not doctored for local markets as some manufacturers may try.
Last edited by MP4.2+6.0; 07-14-2012 at 11:04 PM.