where did I likely screw up my trans rebuild; it leaks out the torque converter area
12-28-2017, 08:27 AM
#1
AudiWorld Member
Thread Starter
where did I likely screw up my trans rebuild; it leaks out the torque converter area
Blown A clutch drum in a 1997 A8 Quattro. Fixed; runs fine now. Drips out the bottom of the bellhousing area, when just sitting there in the garage.
I may just keep putting fluid in it to see how bad the leak is. At some point it may get expensive, not to mention cumbersome, what with the lack of a dipstick.
Any common places for amateurs to screw up?
I may just keep putting fluid in it to see how bad the leak is. At some point it may get expensive, not to mention cumbersome, what with the lack of a dipstick.
Any common places for amateurs to screw up?
12-28-2017, 12:23 PM
#2
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Dangit, I'm so sorry to read that.
One likely cause might be the reddish-brown seal with the spring inside, that goes around the input shaft area. As I recall, the oil pump is basically supposed to provide a hydraulic barrier between the bell-housing area and the inside of the transmission. So fluid is leaking either
- Out of the oil pump (massive failure, unlikely)
- Through the oil pump (crack, unlikely)
- Around the outside, as in between the oil pump and the case (slightly more likely though there is an O-ring there)
- By the inside shaft (most likely)
So the latter place is where I'd focus.
It's easy to put the torque converter in not-quite right and then when the transmission is mated to the engine, the torque converter crushes the oil pump. I haven't yet made that mistake as far as I know, but whoever worked on a ZF 5HP-24A car I subsequently bought .. they had done that. What they'd done trashed the oil pump and the torque converter and even caused the input shaft to shear off eventually. Anyway, if you need a replacement oil pump, I have one, and Nat at Eriksson sells rebuilt torque converters.
If my premise is good as to the shaft seal you might not have to tear down the whole transmission to fix the leak, just focus on the front area. Kinda the transmission equivalent of "yes, you have to pull the valve covers and that sucks, but it's not like you have to pull the heads."
I'm sure it's disheartening even so, but it could be worse.. I'm cheering you on.
~Tanya
One likely cause might be the reddish-brown seal with the spring inside, that goes around the input shaft area. As I recall, the oil pump is basically supposed to provide a hydraulic barrier between the bell-housing area and the inside of the transmission. So fluid is leaking either
- Out of the oil pump (massive failure, unlikely)
- Through the oil pump (crack, unlikely)
- Around the outside, as in between the oil pump and the case (slightly more likely though there is an O-ring there)
- By the inside shaft (most likely)
So the latter place is where I'd focus.
It's easy to put the torque converter in not-quite right and then when the transmission is mated to the engine, the torque converter crushes the oil pump. I haven't yet made that mistake as far as I know, but whoever worked on a ZF 5HP-24A car I subsequently bought .. they had done that. What they'd done trashed the oil pump and the torque converter and even caused the input shaft to shear off eventually. Anyway, if you need a replacement oil pump, I have one, and Nat at Eriksson sells rebuilt torque converters.
If my premise is good as to the shaft seal you might not have to tear down the whole transmission to fix the leak, just focus on the front area. Kinda the transmission equivalent of "yes, you have to pull the valve covers and that sucks, but it's not like you have to pull the heads."
I'm sure it's disheartening even so, but it could be worse.. I'm cheering you on.
~Tanya
12-28-2017, 01:20 PM
#3
AudiWorld Member
Thread Starter
I was very careful on the current ZF rebuild, pulling the converter off and back on a couple of times to make sure I got all 3 clicks to the same distance each time.
Thanks for the encouragement. Not sure when I'll get to it; it'll depend on how fast I'm losing fluid. And maybe the price of the fluid as well. I used Pentosin ATF1 on the rebuild and the recent top off. I have seen the Febi Bilstein fluid for $91 for 10 liters at https://www.ebay.com/itm/10-Liters-A...4201#vi-ilComp. Then I've seen people say that Mobil 1 and Castrol import trans fluids are also compatible to the Esso LT 71141 spec, but I'm still dubious.
12-29-2017, 09:33 AM
#5
AudiWorld Member
Thread Starter
But Maxlife is red!
I don't actually care about the color. You think there would be any issues mixing the Maxlife with the Pentosin honey-colored fluid?
12-29-2017, 10:55 AM
#6
I am no expert but I believe ability to mix has to be part of the spec. You can't drain it all, there is always going to be some mixing.
I also use Red Lubeguard, no idea if it helps but I have been using it for a long time.
I also use Red Lubeguard, no idea if it helps but I have been using it for a long time.
12-30-2017, 11:13 PM
#7
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I have three D2 A8s in my shop as I'm writing this, plus one in the back room and one outside, so corner-cutting and its benefits and problems tend to have an amplified effect on me.
Earlier this year, I bought a car with a ZF 5HP-24A transmission and I noticed it had red fluid. I contacted the ZF distributor in CT for guidance. He has been a tremendously helpful resource. Two years ago I knew nothing specific to this variant of ZF transmissions, and much of the good advice I got, I got from him. So, when he speaks, I listen.
He wasn't all too reassuring about the red fluid, and he liked my idea of diligently getting rid of it. My techs and I ended up opening up the transmission lines to the radiator, running the engine so that the red stuff spouted out one hose into a "discard" container while we added new "G 052 162 A2" fluid as fast as the red stuff was being expelled. We did that plus, as I recall, two entire sets of "G 052 162 A2" fluid changes to get rid of the red stuff to a huge extent.
I don't have the engineering insight to be able to say when it's prudent to cut corners and dilute the purity of the engineering of the original ZF quality. So, I tend to go with the official opinion for lack of knowing where else to draw the line. I dismantle a lot of these transmissions and I see the consequences of people cutting corners, and as time goes by, it makes me ever less keen on cutting corners because the consequences are so stark. It comes down to what one is trying to accomplish, I suppose. If the plan is to limp along for another year and then the D2 goes to the junkyard, then maybe cutting corners is fine. I like to work on the longer-life premise instead -- and often it becomes a self-fulfilling prophecy.
Above I've given one example of the implications of cutting corners by using red fluid, and that's that the ZF distributor (who doesn't sell me fluid and has my best interests at heart throughout a long and happy biz relationship) advised me to get rid of it.
My next corner-cutting story involved which brand of filter to buy. Do I have to buy the ZF one or could I cut corners and go with something else? The simple answer is that of course I could cut corners. I might just not like the consequences. So I focused on Gary Ferraro, who is highly skilled in rebuilds of the 5HP-24 variant of transmission. He used to cut corners as such and had enough come-backs that he could trace back to the non-ZF filters that he regretted it, so from then on, he just used original ZF filters.
The next corner-cutting story involves the effect of additives. I dismantled a D2 A8 ZF 5HP-24A that had failed, and whatever additive the previous owner had put in had literally eaten away all the black paint on the inside of the oil pan, and these shrivels of paint had gone all over the place. What a mess. I don't know what additive he used, but ever since that day I realized I couldn't justify to anyone why I'd add an additive to my transmissions, in violation of the ZF recommendation, so ... I don't ... for my cars anyway, and the used transmissions I sell.
It's hard to say whether cutting corners is prudent because many people who do this have just one such car and thus a sample size of 0001 and very little to compare it to, nor do they necessarily see the long-term effects. They might be real but indiscernible. For example, a friend of mine had a husband who liked eating two double bacon cheeseburgers every lunchtime. And for a while, he was just fine even so ... until he wasn't.
~T
Earlier this year, I bought a car with a ZF 5HP-24A transmission and I noticed it had red fluid. I contacted the ZF distributor in CT for guidance. He has been a tremendously helpful resource. Two years ago I knew nothing specific to this variant of ZF transmissions, and much of the good advice I got, I got from him. So, when he speaks, I listen.
He wasn't all too reassuring about the red fluid, and he liked my idea of diligently getting rid of it. My techs and I ended up opening up the transmission lines to the radiator, running the engine so that the red stuff spouted out one hose into a "discard" container while we added new "G 052 162 A2" fluid as fast as the red stuff was being expelled. We did that plus, as I recall, two entire sets of "G 052 162 A2" fluid changes to get rid of the red stuff to a huge extent.
I don't have the engineering insight to be able to say when it's prudent to cut corners and dilute the purity of the engineering of the original ZF quality. So, I tend to go with the official opinion for lack of knowing where else to draw the line. I dismantle a lot of these transmissions and I see the consequences of people cutting corners, and as time goes by, it makes me ever less keen on cutting corners because the consequences are so stark. It comes down to what one is trying to accomplish, I suppose. If the plan is to limp along for another year and then the D2 goes to the junkyard, then maybe cutting corners is fine. I like to work on the longer-life premise instead -- and often it becomes a self-fulfilling prophecy.
Above I've given one example of the implications of cutting corners by using red fluid, and that's that the ZF distributor (who doesn't sell me fluid and has my best interests at heart throughout a long and happy biz relationship) advised me to get rid of it.
My next corner-cutting story involved which brand of filter to buy. Do I have to buy the ZF one or could I cut corners and go with something else? The simple answer is that of course I could cut corners. I might just not like the consequences. So I focused on Gary Ferraro, who is highly skilled in rebuilds of the 5HP-24 variant of transmission. He used to cut corners as such and had enough come-backs that he could trace back to the non-ZF filters that he regretted it, so from then on, he just used original ZF filters.
The next corner-cutting story involves the effect of additives. I dismantled a D2 A8 ZF 5HP-24A that had failed, and whatever additive the previous owner had put in had literally eaten away all the black paint on the inside of the oil pan, and these shrivels of paint had gone all over the place. What a mess. I don't know what additive he used, but ever since that day I realized I couldn't justify to anyone why I'd add an additive to my transmissions, in violation of the ZF recommendation, so ... I don't ... for my cars anyway, and the used transmissions I sell.
It's hard to say whether cutting corners is prudent because many people who do this have just one such car and thus a sample size of 0001 and very little to compare it to, nor do they necessarily see the long-term effects. They might be real but indiscernible. For example, a friend of mine had a husband who liked eating two double bacon cheeseburgers every lunchtime. And for a while, he was just fine even so ... until he wasn't.
~T
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01-02-2018, 06:05 AM
#8
AudiWorld Member
Thread Starter
Thanks for your examples. The issue I have with use of the term "cutting corners" with respect to other trans fluids (for instance Valvoline Maxlife) is that it implies that Valvoline is lying when they claim it meets the Audi and ZF specs. Or they're mistaken?
Now that it's 2018, there must have been numerous developments made in the chemistry of trans fluids (and other lubricants). Would we seek out and install the old API service classification SH or SJ motor oils in our vehicles because that's what was specified back then? (They're up to SN now.)
I submit that putting in the very expensive, originally specified trans fluid brands may be "playing it safe", as opposed to the avoidance of "cutting corners". This does make some sense, as few of us are lubrication chemists. How lucky do we feel?
Now that it's 2018, there must have been numerous developments made in the chemistry of trans fluids (and other lubricants). Would we seek out and install the old API service classification SH or SJ motor oils in our vehicles because that's what was specified back then? (They're up to SN now.)
I submit that putting in the very expensive, originally specified trans fluid brands may be "playing it safe", as opposed to the avoidance of "cutting corners". This does make some sense, as few of us are lubrication chemists. How lucky do we feel?
01-02-2018, 08:23 AM
#9
I too think that if it meets the spec it meets the spec. Some red fluid does not meet the spec, Walmart non-synthetic is red and does not. Valvoline MaxLife is red and synthetic and claims to meet the spec. The original Esso LT 71141 was semi-synthetic although the current Pentosin product appears to be full synthetic. Given current lubrication technology over 20 years later I think it's probably no big deal to hit the LT "LifeTime" spec. Since the current Pentosin, Ravenol and Mobil and whatever comes over the VW, Audi, BMW, Range Rover, Jaguar, etc. parts counters is probably not the same as the old semi-synth factory fill they are probably all different, probably all better. Who knows which is the best and which is a sensible cost savings and which if any represent a foolish false economy? Based on what data?
01-02-2018, 08:42 AM
#10
Paint is gone from pan.
The previous owner had the trans cooler blown and it mixed coolant with trans fluid. It eats away the clutches and the pan paint. They don't sell any trans additive that would harm your paint.