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2010 R56 N14 engine with Aisin automatic tranny. We swapped out the engine and before mating the tranny back, we replaced the torque converter seal (with Oreily's National seal 710893). ATF was drained and (over) refilled and filter was replaced. Then, after engine was running, we drained out extra ATF.
Now ATF is dripping at the bell housing.
Anyone tried using national seal 710893 with luck? It looks the same as OEM. I am sure we did not damage it.
Maybe it is not ATF but engine oil coming down from, say, vacuum pump? I will put dye in engine oil and check again.
I am sure it was not leaking before and the OEM seal was still soft but we chose to replace it since we were at it.
Rear main seal? Oh man. It is also new.
Your comment is welcomed.
Lex2008, I read your "Additonal tips on removing & installing engine on auto R56 Mini Cooper S N14 engine"54. Very helpful. Thank you.
Looks like I am experiencing the same:
Please tell me why the leak even if I have to remove the tranny again.
Installation procedure PTFE lips do not have the same elastic properties as rubber lips, which makes them more susceptible to damage.
Therefore, special care must be taken during installation and handling to prevent damage and help ensure proper operation and function. Shaft features such as keyways and splines, as well as drill holes, ports and sharp-edged shaft steps have the potential to damage PTFE lips. Whenever possible, these obstructions can be covered by using thin-walled installation tools made from plastic or metal. PTFE lip orientation during installation will determine the installation method.
Seals with care must be taken during handling and installation see for visualisation: Fig. PTFE seals.
Installation is more difficult when the shaft is installed against the PTFE lip (Fig. PTFE seals: a and c). This type of installation becomes even more complicated when the hardware is difficult to access or visually obstructed and may not be possible if an installation tool cannot be used. In any case, when the shaft is installed against the PTFE lip, SKF recommends the use of an installation cone or “bullet”. In lieu of installation cones, longer than normal lead-in chamfers on the shaft would be required. However, shaft features that could damage the seal (keyways, etc.) must still be covered, possibly with tape. If the shaft is installed with the PTFE lip, a smooth, burr-free radius or chamfer on the shaft end is all that is required, provided that no damaging shaft features are present as noted above (Fig. PTFE seals: b and d).
Some seals have two PTFE lips facing opposite directions. In this case, installation is always against one of the lips and an installation cone is recommended.
The crankshaft hub seal and the rear-mail seal are both PTFE seals.
Notice they tell you at two points not to use oil on the seal. At the end of the clip, you'll see the 4-hour clock; you can't have any rotation on the sealed shaft for 4 hours. Notice also the use of special tools required to install the seals. They are designed to prevent damage to the seal during the installation process.
I learned this the hard way with my front crankshaft seal. Even the Bentley service manual says to lubricate the seal and that is incorrect according to the seal manufacturer.
I'm not sure if the transmission seals are PTFE, but base on you're problem, I'll bet they are.
Hmmm, but the o'reilly's National seal 710893 is Material: Fluoroelastomer (FKM).
Let me see if I can do more troubleshooting....
Here is the instructions for installation of the (OEM) seal (which is nothing unusual):
Maybe it got damaged when I pushed the TC in.
Last edited by Derek Chung; 10-06-2022 at 02:46 PM.
I feel your pain. I got a kinda funny story. A mechanic at mini told me they had an N14 with the same AISIN tranny come in for a leaking seal. He changed the seal TWICE and it leaked both times, so without the owner knowing they bought a used tranny with the original seal in it and put that in rather than try a 3rd time. YA I know...that's kind of unethical and doesn't reflect well on a dealer that they cant successfully change a tranny seal. He showed me the drawer ful of shaft seal tools. They weren't short on the correct tools. Which is why he told me DONT TOUCH THE ORIGINAL SEAL. It was too late by the time he told me.
Now, I spoke to 2 transmission specialists near my house that work on a lot of Minis. They said its BS that the seal cannot be changed successfully. They do it all the time. They totally dismissed that notion. Maybe they know what mkpb608 mentions, that you must not oil the seal and then you must wait 4 hours.
You should be able to tell if the oil you're losing is ATF once you've dyed it....if you and only if you can find the point of origin of the leak. Also smell the oil. That can help determine which it is. If it was gear oil it would be SUPER easy, as we all know.
Yes the vacuum pump could leak onto the bell housing but I think it puddles up on the bell housing or drips down the front...not between the trans and motor, and you'd be able to chase that leak to that stupid vacuum pump.
Can you push a camera up between the bell and housing and motor and see? If I recall the flywheel blocks most visual access.
This afternoon, I pulled the front end out 8 inches, and connected the upper and lower radiator hoses together, bypassing the radiator. I noticed a small puddle of ATF (brownish red, not the new clear engine oil that now dyed to yellow) by the gear selector. Previously I refilled the ATF thru the fill plug right next to it. Maybe the o-ring on that plug is bad and some ATF came out when tranny is warmed up and dripped down to the bottom of the bell housing. Anyway, I brake cleaner sprayed everywhere and dried up all I could and ran the engine until it is 200F, then checked, nothing. All dry. I am done for today. Maybe tmw when I check the bell housing, there will be no drip, then I will button up everything and will drive it around..... if drip comes back and it is ATF, it has to be from inside the bell housing.... Tired. I don't know if I want to remove engine + tranny to replace the seal again without knowing a way to 100% succeed.
Will see if there will be a puddle of ATF by the gear selector. If so, it could be vacuum pump that leaks only when engine runs at high speed...or I really need to find the right size o-ring for the T55 fill plug next to the gear selector.
So much fun working on a car that everytime u have to remove a couple dozen things first.
Last edited by Derek Chung; 10-06-2022 at 07:05 PM.
Hmmm, but the o'reilly's National seal 710893 is Material: Fluoroelastomer (FKM).
Let me see if I can do more troubleshooting....
Here is the instructions for installation of the (OEM) seal (which is nothing unusual):
Maybe it got damaged when I pushed the TC in.
I understand your frustration.
Number 1, the National seal is not the OEM seal.
2. The Bentley service manual says to lubricate the crankshaft hub seal when you ARE NOT supposed to; Bentley got that information right out of the BMW book, and the information is incorrect for the reasons previously mentioned.
I've been trying to find what type of seal the OEM transmission seal is, but I haven't found it yet.
Yesterday I hand-pumped 4 PSI of air into the vent hose on top of the vent hose. It is holding and there is NO LEAK at the bottom of bell housing after 30 mins of waiting. Then, with the engine running (so that ATF is circulating), I cracked opened the bottom drain plug and pressure gusted out. I don't know how much pressure the seals are supposed to hold but that tells me it is not from the seal (at least not when the tranny is stationary).
Then, I drove the car around and it came back with drips at the bottom of the bell housing. I smeared it on a white paper and compare it with the engine oil which has been dyed. With my UV flashlight, I can tell no dye on the smear from the drip at the bottom of the belling housing, so it has to be ATF.
It has to be leaking ONLY when the tranny / shaft is certain position, That is why leak is there after engine is run always, and when it is stationary, only somethings it would leak.
Maye TWO seals instead of one?
I am tired and I am about to give up.
I am tired of this and I am giving up.
Last edited by Derek Chung; 10-09-2022 at 09:26 AM.
Yesterday I hand-pumped 4 PSI of air into the vent hose on top of the vent hose. It is holding and there is NO LEAK at the bottom of bell housing after 30 mins of waiting. Then, with the engine running (so that ATF is circulating), I cracked opened the bottom drain plug and pressure gusted out. I don't know how much pressure the seals are supposed to hold but that tells me it is not from the seal (at least not when the tranny is stationary).
Then, I drove the car around and it came back with drips at the bottom of the bell housing. I smeared it on a white paper and compare it with the engine oil which has been dyed. With my UV flashlight, I can tell no dye on the smear from the drip at the bottom of the belling housing, so it has to be ATF.
It has to be leaking ONLY when the tranny / shaft is certain position, That is why leak is there after engine is run always, and when it is stationary, only somethings it would leak.
Maye TWO seals instead of one?
I am tired and I am about to give up.
I am tired of this and I am giving up.
What tool are you using to set the depth of the seals?
Can you take the trans to a transmission shop and ask them seat the seal?... Problem is they could blame you for poor installation if it leaks.
Flush like how the old seal was.
I know. newtis.info says we should use a special tool 24 4 250. I don't have that.
It is not from the CV axle seal. That I checked. It is not from the ATF cooler either.
This morning I looked under. No drip. It really might leak only when engine and tranny is in certain position in relation to the seal.
I will start the engine every hour and check leak to see if it is really position dependent.
Flush like how the old seal was.
I know. newtis.info says we should use a special tool 24 4 250. I don't have that.
It is not from the CV axle seal. That I checked. It is not from the ATF cooler either.
This morning I looked under. No drip. It really might leak only when engine and tranny is in certain position in relation to the seal.
I will start the engine every hour and check leak to see if it is really position dependent.
One of those CV axle seals in the automatic transaxle is for show because it's bone dry behind it.. The driver's side i think. I rebuilt the the axle a few months ago.
However when I pumped 5 psi of air into the tranny via the vent hose, it is holding up and no ATF gusting out at the bottom:
These are two coopers with N14 engine (rebuilt one week apart) + Aisin GA6F21WA tranny, one with OEM torque converter seal (that previously had an oreily seal), and one with oreilly seal. Both leaking exactly the same way now. Seals were installed flush and I have done that a dozen times with other cars (BMWs mainly)
Tomorrow we will take out the engine + tranny and try to pinpoint the problem. This is crazy.
One of those CV axle seals in the automatic transaxle is for show because it's bone dry behind it.. The driver's side i think. I rebuilt the the axle a few months ago.
Went under and thoroughly examined the axle seals. They are dry.
"They are dry". The "they" means the CV axle seals.
It is still leaking ATF. It really could be the front oil pump big o-ring..... Today hopefully I will find out after taking everything apart (the 4th times.)
And I used OEM seal.... and I examined everything. Torque converter neck, no scratch on the metal where seal sits, pressure tested the TC, made sure the seal sits perfectly flush.... carefully push in the TC into the tranny shaft....
No leak after installing. No leak during and after 30 mins of idling. Took it out for a freeway ride.... came back and checked under and I got this:
STILL LEAKING!!!.... and only when engine + tranny running at high speed.
This is the worst set back I have had for 30 years of fixing cars. I am literally crying inside now. This is for two mini coopers, both 2010, one is R56, another is R57. They have N14 engines and same tranny.
What could that be???
1. I use valvoline maxlife ATF. It is thinner than the OEM Fluid and hence easier to leak out?
2. The bushing inside the front pump is worn on both trannys, allowing more ATF to pass thru and when running at high speed with high pressure, some leaks out? I don't recall / believe they were leaking prior to taking the engine off.
3. With the engine separated, somehow the torque converter is not bolted on to the flexplate perfectly inline anymore hence the neck is not concentric to the seal, allowing fluid to leak out when running at high speed?
Or 2 and 3? Separating engine and tranny disturbed the "concentric" when the bushing is worn?
Remember the tranny held up 5 psi of pressure overnight. Seal is sealing (when stationary) unless the TC neck is not concentric to it and is spinning really fast (like 4k engine rpm...)
Is that nub on TC a tight fit, by design, into the center hole of the flexplate, thus, forcing the TC to be concentric to the flexplate?
Is there a star torque pattern to tighten the 6 bolts on TC?
If above does not explain the problem, I have no idea... Please help / comment.
Last edited by Derek Chung; 10-13-2022 at 05:49 AM.
I did not take a pic but here it is that I found on internet:
Essentially for the seal to seal (especially at high speed of rotation), the neck of the torque converter has to be CONCENTRIC to the seal.
To be concentric, this pump bushing (front pump bushing, stator bushing they call it) has to have no wear. Can't count of tightening the 6 tc bolts to get the tc to get concentric to the worn bushing (therefore seal) unless u are very lucky and somehow tigthten the 6 bolts very evenly,
When engine is not running (or idle), a bit off concentric is ok as the seal will still conform to the neck of the tc. But when engine is at high rpm, the rubber of the seal cannot react quick enough conform to the neck, hence the seal leaks ONLY AT engine HIGH RPM.
At least that is my theory and I could appreciate if someone can comment.
If that is the case, I need to replace the pump bushing. That means taking the tranny apart.
10-06-2022, 09:49 AM
