the plastic "fill cap" on trans pan: what's its mission?

[duk3]

Hi everyone.

this regards the transmission with Audi designation (if that's the word) GBF. Aka ZF part number 1060 040 101 aka Audi part number 01V 300 052Q.

I badly damaged my transpan on a raised manhole cover immediately past a big dip in road. The dip made the car's weight come up and back down onto the damned thing.

I was 2 blocks from home and decided to attempt to get it into my driveway while fluid was still in there. I listened carefully for any bad sound while driving to home, heard none, bought new pan.

On install, I needed to get the plastic fill splash cap off of old pan and onto new pan. I search to no avail for instructions and then went at it VERY carefully. Got it off w/out breaking it. Lithium grease helped it pop onto new pan and I was able to add 6 quarts of fluid without much overflow.

I drove it and it's was in limp mode with PRNDS all lit on the dash display. Hopefully it only needs more fluid. I wouldn't be surprised if my extra driving after broken pan pushed more ATF out than 6 quarts.

The problem is that when I just now stuffed a hose up in the fill hole, it pushed the plastic splash cap right off of where it seats. WTF! Why didn't the new pan come with a new fill splash cap part and why is this designed to snap on as if plastic will always keep its flexibility? I'm sure that this isn't just off of where it seats, but to come off so easily it's probably broken.

And the key question: what is it even for and can I drop pan, throw it, replace pan and fill?

I do not believe that this part adds any volume at all to the capacity of the pan.I think that the same amount of fluid fits before overflow with or without this. Maybe that's where I'm wrong.

I know someone could say it's to direct whatever hose I put up there to bend in certain directions but I don't see how I need that kind of help. please just tell me where to point the end of the tube if it's important.

And what if I stick my finger up in there and hook that plastic thing and pull it till it breaks? That's what she said. Do you think there's any chance that it breaks into few and easily retrievable pieces? If it's not a necessary part, ill try this before dropping the pan.

If it is necessary, does anyone have experience with this? Do I need to glue it on or something?

Thanks!

[duk3]

Scene of the crime


If anyone recalls me whining about this a few days ago, I was calling it a broken oil pan at that time which i realized after taking a real look.

[duk3]

the plastic part I'm talking about is depicted here in white and (probably) properly attached to the metal pan.

[Gin+]

If you immediately go in limp mode then it is probably a solenoid or solenoid wiring harness issue IMO. I've had my old transmission low enough on fluid to the point where the car wouldn't move and still not go into limp mode. Either way, you need to pull the pan and re-fit that plastic thing.

[diagnosticator]

You did not add enough fluid to the trans. The fluid temp must be monitored with VCDS, and fluid level only accurate when refilling if the fluid temp is below 40 degrees C. If the fluid was hotter, the trans will be underfilled at dripping overflow.

The plastic stand pipe that you pushed into the pan, is crucial for establishing the correct fluid level in the pan. It actually prevents fluid from overflowing from the fill port until the fluid level is correct.

The fluid level cannot be established without the plastic stand pipe installed. GEt a new plastic stand pipe from the dealer. It should have come installed on the new pan. Did you get an OEM pan from Audi, or aftermarket?

The fill tube is supposed to be a metal tube with a hook bent on the end, with this shape, you won't be pushing on the plastic stand pipe to place the fill tube into the pan, it simply hooks into the stand pipe. The stand pipe is not supposed to be removed, it's an install only fit. If removed and reinstalled it won't fit the pan as tightly as it should. That is why a new stand pipe should be used. Yuo could try using some epoxy to secure the used part in the pan.

The fluid level is correct, with the car level on a lift or ramps, and with the engine idling in Park, with the fluid temp between ~35C and ~40C, and dripping overflow begins from the fill port. Add fluid until dripping overflow begins from the fill port. At this condition, replace the fill port plug before turning the engine OFF. If you turn the engine off first, fluid will pour out of the trans and you will need to start over.

Usually, a trans fluid change requires about 5 to 6 liters of ATF. However since the engine was running after you hit the manhole cover, the trans pumped most of the fluid out of the torque converter as well as the loss of fluid in the pan. A "from dry" or total refill of the ATF takes up to 9+ liters of fluid.

Use only OEM ATF or ZF approved Pentosin ATF-1.

[duk3]

Thank both of you guys very much for your help. The info above helps me understand some of the details. Please consider a few follow up questions if you have time:

🔘I have a cable for OBD-II port to USB but only the freeware version of VCDS. Do you know offhand whether this will provide the temperature of ATF? Of course I can find this out on my own but thanks if you can reply a quick yes or no.
🔘The plastic standpipe... I'm about to find out which Audi parts department and how much and all that. I'll get a new one and hopefully fit it to the (to answer your question, Diagnosticator,) aftermarket trans pan that I bought from ECS Tuning. It did not come with a new stand pipe but it did have a new drain plug and fill plug w/ o-ring. About $33 I believe. Only a small complaint: not including a new stand pipe or a note on it seems to me to imply it is not just a one-time-install part. Like as if the common sense thing to do is to reuse it. ECS isn't responsible for teaching me anything of course.
🔘how is the standpipe essential for establishing the correct fluid level? The maximum volume of the pan with and without the stand pipe look at least very close to equivalent. Is it that w/out a stand pipe, a running car will drip fluid out if the fill hole from some moving parts directly above the hole? That would make sense. I just realized this.
🔘Having found the code "GBF" in my car's paperwork to deduce the ZF part number for the trans, I looked at a pdf from ZF and it told me that any fluid meeting the certain spec was approved. This doc from ZF didn't specify that pentosin or Audi's oem brand were better suited for the application. As such I used a less expensive Wolf's Head brand which met that spec (sorry I don't recall the number of it at the moment.) Did u mean, Diagnosticator, that the fluids you name are right for this application because of some other factor in this system besides the ZF trans? Maybe there are some non-ZF parts in this Audi which necessitate oem/pentosin?

Thank you!
🔘

[MacFady]

I can't speak as to whether your VCDS version will display ATF fluid temp, but as stated above, you'll only know if it's at the correct level by knowing the real time temperature of the fluid. That being said, do you have an infrared gun by any chance? I changed my ATF over a year ago and tried to get an "idea" of the temperature with an infrared gun (not the first). My car has been running fine, shifting smooth, for about 35k km's now. I suspect as Diagnosticator said, you might have felt you had the correct amount of fluid in, but given the circumstances of your mishap, your TC would have dumped a lot of fluid that most people don't otherwise have to account for when doing a normal fluid change.

[duk3]

That's what I've been hoping. Was about to do just that and add fluid when my little tube into the fill cap area knocked the plastic splash guard off.

If vcds won't help, I'll just not drive till car is cold and process repeated. Or contact my main man Glenn w/ vcds.

Just drove to a vw dealer an hour and half away to get the part. It was in stock.

For anyone wanting the number: 01v321432.

[diagnosticator]

A side view of the fluid level in the pan shows that the fluid level is higher than the sheet metal of the bottom of the pan, and is equal to the level of the opening in the plastic stand pipe, above the level that would be limited to the height of the sheet metal without the plastic stand pipe installed. I will try and find the diagram and post it. The plastic stand pipe in the pan is there for a reason, it is not an arbitrary part just to frustrate you. The ZF approved fluids list is separated into sections according to fluid base stock type, mineral or synthetic. Audi OEM fluid is ZF Lifeguard brand fluid relabled as Audi fluid. OEM fluid is not 100 percent synthetic. Pentosin ATF-1 is 100 percent synthetic, and can be found in the synthetic group of the list. ATF-1 is superior to OEM fluid and is cheaper to buy. I don't know for sure off hand if the limited VCDS will display trans fluid temp, but I believe it does. I have never used the limited version of VCDS.

Use a length of 1/4"OD copper tube bent into a sharp U shape at the end to use for the fill tube at the fill port. You will need to adjust the U shape to enter and remove the fill tube without getting stuck in the plastic stand pipe. You should be able to just hook the fill tube into the fill port without force.

[duk3]

Ok! Continued thanks to "D" and the other people chiming in. I got my part in hand and I'm walking home as I type. People all think I'm hunting pokemon. Someone just said "excuse me sir... blasi blasi... Pokemon?" I told her "nope, just Audizine!"

I have some other important things to do first and might not be able to work on the car tonight. Hope to report back with success.

[diagnosticator]

ATF that is approved according to the "Esso LT 71141" (or 71411) spec will satisfy the ZF spec for approved fluid. Pentosin ATF-1 meets and exceeds this specification. ATF-1 will resist oxidation degradation and maintain lubrication and provide the right friction coefficient for the clutches when subject to excessive heat due to borderline excess clutch slip, and can prevent trans damage when the trans slips more than the normal amount of marginal slip in the clutches. This is because synthetic fluids can withstand a lot hotter temps before break down compared to mineral and semi synthetic fluids. The superior properties of synthetic ATF justifies the higher cost of Pentosin ATF-1 compared to aftermarket brands of mineral based ATF, IMO. ATF-1 is still less expensive to buy than mineral oil based OEM ATF.

Other than friction heating in the clutches the fluid is heated by the hydraulic viscous friction of the bulk ATF as it transfers and amplifies torque from the engine through the torque converter to the transmission input shaft. The hydraulic viscous slip between the torque converter input and output heats the ATF as the differential RPM between the input and the output of the torque converter increases from about 5 percent minimum hydraulic slip to the maximum of 100 % slip when the torque converter output at zero RPM with the trans in drive or reverse, with the car stopped and is higher as input power from the engine increases with the maximum engine RPM at full throttle limited with the torque converter output stalled at zero RPM. Torque converter match to the engine power rating for normal factory engine power settings prevents the engine from achieving the torque peak RPM however. With the WOT engine RPM at the engine torque peak RPM at the torque converter stall RPM with the torque converter output at zero RPM, provides the best performance with a loss of fuel economy, when there is no TC clutch used. With the torque converter clutch locked up or engaged without any slip of the TC clutch, the hydraulic viscous friction heating of the ATF in the torque converter is zero because the torque converter input/output RPM differential is zero. Hydraulic viscous friction heating of the ATF in the torque converter is the cause of ATF and transmission overheating when pulling a trailer or climbing a mountain pass, and is a lot worse if any clutches are slipping to much as well, with increased ATF heating in addition to the normal hydraulic viscous friction heating of the ATF in the torque converter, with the TC clutch unlocked/disengaged or in programed slip mode. Excessive ATF and transmission heating due to malfunction or overloading is the #1 killer of automatic transmissions especially when mineral based ATF is used instead of synthetic ATF.

[duk3]

Wow, thanks for that description! I follow you and am glad ok have learned that about the TC and how ATF can get hot enough there to break down then stick around. Fully synthetic ATF for me for sure and now I know a good reason for why that is.

The Wolf's Head brand I mentioned us fully synthetic, BTW. Spec sheet here http://www.wolfshead.com/assets/3b_w...atf-030515.pdf Seems ok?

P.S. I didn't assume the splash cap was there just to piss me off. That's just serendipity. I did think however that maybe the splash cap was meant only for one or more functions that I could alternatively deal with on my own.for instance, the splash cap does ensure that a full hose any deeper than about 2 inches is bent in some angle of probably at least 30 degrees. This would probably be an essential angle for full tube as less would probably allow fluid to go vertically up and largely come right back down out of the same hole. But I don't need the splash cap to ensure my fill type is bent enough. Know what I mean? Also, maybe the people who put that cap in the design were doing so because they knew that some users would add the ATF at a high enough pressure that it splashed around a lot while filling and that the splash cap would limit the angles at which splashing liquid could exit the pan. If that was the only reason then I could easily go without it. The splash cap then would be meant to allow adding ATF at a higher rate without spill but I'd rather fill slow than put that plastic back in there. This latter idea seems compelling to me because it has been called a splash cap for one thing and secondly because the method of fill requires a certain quickness to complete before the atf gets too hot. But if that's true you could fill slow and be willing to do so repeatedly before finishing the job.

As for why I feel that the splash cap may not be meant to raise the "high water mark," it's the amount of additional fluid the splash cap permits. It seems like a negligible amount to me. One can always choose to be precise but without thinking in terms of the numbers, I suspect that the discrepancy between total ATF capacity at the low temp limit and ttotal ATF capacity at the high temp limit its greater than the additional capacity made possible by using the splash cap.

[diagnosticator]

The ATF temperature is crucial when refilling the trans pan, because ATF has a high coefficient of thermal expansion, and if the ATF is to hot when filling will result in a underfilled trans with the fluid temp is ambient. In the same way, if the fluid is filled with the temp to cold, the ATF will be overfilled with the trans at normal operating temp. Automatic transmissions are very sensitive to the fluid level and will not function properly with the fluid fill level to low or to high.

Believe what you want, but the trans fluid level cannot be established at the required fill level without the plastic fill port stand pipe installed in the pan. I cannot explain this any better. I don't understand why you speculate the stand pipe is really just an optional part. Your comments at least imply you believe the part has no functional purpose and can be removed without any negative effects. If you have convinced yourself this is the case, leave the plastic fill port part out and see how the trans operates with the fluid level at the level you think is the same as with the fill port stand pipe installed.

Let us know how it works out for you. I don't think you will be enthusiastic to report back the results.

[john_gonzo]

The limited version of VCDS will display transmission temperature.

[duk3]

Long post follows. If not interested, please just consider my question:

I understand that the pan should be level while ATF fluid is added but would someone clarify whether the proper place to measure for level is the top rim? With pan installed, I can place a small level where shown in the below image. Is that correct? Please confirm. Needless to say, level for this plane is different than for others on this 3d object. Thank you!


(Longer post:)

I was able to install a new plastic splash cap and reinstall new pan, then fill with fluid using VCDS freeware for a real-time temperature reading. I used all of the ATF fluid I had on hand (8 quarts, should have bought more.) I drove the car to go buy more ATF and it seemed to shift perfectly though I know it is too low. I've bought more fluid and will add that this afternoon.

Again, I believe that I took the splash cap off of the old trans pan without damaging it at all and it was only after pushing it onto the new trans pan plus some time going by that I noticed a fracture in the plastic. My new comment here is that the same thing happened with the brand new splash cap (though the fracture is much smaller and I believe the splash cap will stay in place this time.) My point here is that the diameter of this trans pan in the area of the top of the fill hole may be too large. I don't have the time to find out now but if someone were to read this post and buy this part, they might do well to measure this and possibly sand down, repaint the part in this area should they find it is in fact too large. If I were to do this whole thing again, I would still buy this part because it is a good price in my opinion and I'm glad ECS sells it (https://www.ecstuning.com/ES2142879/ .)

In reply to Diagnosticator, I apologize for comments that as you say "at least imply you believe the part has no functional purpose and can be removed without any negative effects." This is not what I implied but I know that I don't express myself well. To be clear, I wanted to discuss the function of the fill cap which I implied may not be to establish the correct trans fluid level. I do now believe that the fill cap is not necessary for this but I do and have throughout been certain that I believe it has functions. I speculated that for me in my situation, these functions might be executed through other means with what I had on hand which could be easier for me than going to purchase a new fill cap. That would require a correct identification of the functions of the cap which is why I tried to speculate further and to ask if my speculation sounded reasonable to you or anyone else. I understand now that you'd have rather not read that from me. I tried to ask respectfully and regardless of how my writing sounded, I do have respect and thanks for the help.

Finally, to give my opinion, I believe the function of the cap is to prevent rebounding incoming liquid and normal trans operation's circulating fluid from coming out of the fill hole during fill.