Thoughts on this leak? with photo!

highmiles · Post by **highmiles** » 07 Jul 2019, 15:16

I am working my way towards finishing up the rebuild on my "free" 2003 S60... up and running but dealing with a variety of issues not necessary associated (but are they...) with the rebuild. History, car came to me with engine disassembled, I rebuilt and reinstalled the motor. I did replace the main seal and the seal at the transmission/torque converter.
There is a fairly large transmission fluid leak. The leak does not occur when running and idling, but was easily able to reproduce it today, car on the lift, son running the car in gear, after 30-60 seconds the oil appears just above the right drive shaft and runs down from there. See photo.
I have a new drive shaft seal on order. It seems likely the issue, but the appearance of the oil on the case above makes me question this assessment. Is there any other place to look for? Pretty convinced that if the transmission seal were improperly done the leak would appear at the weep hole. Hoping someone says that is exactly what an axle seal leak looks like....
Thanks, John

XC70Rider · Post by **XC70Rider** » 07 Jul 2019, 15:55

It appears ATF is coming from above the axle seal? If it is I would check the TC for leaks.

On AWD P2s the passenger axle goes via the bevel gear and rarely ever leaks from that tiny axle seal.

highmiles · Post by **highmiles** » 08 Jul 2019, 07:23

It does appear first above the axle at the engine/transmission connection where the flywheel can be seen. This car is FWD only.

My theory on not being the torque converter (read, "man I hope I don't have to drop the transmission...",) is that the leak does not start until the car is in gear, where the torque converter would be spinning and have fluid pumped to it with the engine running and in park. We had the car on the lift and running for several minutes as I had my son turn the wheels back and forth to see if I could see any leaks in the power steering, the leak did not occur then. Once in drive it took about a minute for the leak to really start flowing. My other thought is that a leak at the TC or seal would show up at the bottom of the bell housing, seems like it would be difficult for the TC to spin the fluid out past the flywheel and land where shown, and all the leak seems to come from there, vs. some from the weep at the bell housing.

I suppose this is somewhat academic at this point, I have a new seal on the way, seems the easiest possible fix to try. Will report back.

highmiles · Post by **highmiles** » 14 Jul 2019, 06:48

Despite my hopeful prognostications... changing out the axle seal had 0 impact on the leak, so I will be pulling the transmission. It seems like there are two places it could be leaking from, the torque converter seal at the transmission or the torque converter itself. I suppose either could have been damaged when I was wrestling the rebuilt motor back into the car.
Other possible leak areas I should look for?

On the axle seal, I set it in a bit further than the old one, were I to to it again I would have left it out more, but I don't think this is a problem. Any thoughts on this?

Thanks!

Post by **MoVolvos** » 14 Jul 2019, 17:20

highmiles wrote: ↑14 Jul 2019, 06:48
Any thoughts on this?

Thanks!

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Not sure how much you are loosing but put some dye in the motor oil. Unless both are leaking you should be able to figure out which rabbit hole to go down. You either have dirty trans fluid or it looks like motor oil on my end of the monitor.

Post by **abscate** » 14 Jul 2019, 18:32

That’s a motor oil leak indeed. Nice call, BKM

On edit..I have no clue as why it correlates to being put in gear. Have you put it up on the lift and idled it for 30 minutes in park?

Post by **MoVolvos** » 15 Jul 2019, 03:25

abscate wrote: ↑14 Jul 2019, 18:32 That’s a motor oil leak indeed. Nice call, BKM

Thanks abscate and let's hope so.

highmiles · Post by **highmiles** » 15 Jul 2019, 10:14

Thanks, I appreciate the thoughts!

I agree that it looks motor oil-ish in the photos, but the dipsticks tell a different tale. I put about 100 miles on the car working towards getting past the "not ready" to inspect OBD II message that the is required in this area of NC to pass inspection. Accomplished that, but found the transmission fluid a full quart low afterwards. Once the fluid puddles on the ground it is pretty dark (I have yet to change the transmission fluid,) where the oil is still new looking. The car can idle for extended periods, no leak, drive around the block, pull back in the garage and it will drop a puddle 8" around in no time. My guess is that under load the pumping force pushes the transmission fluid past the seal.

I replaced both the torque converter seal and the rear main seal before putting the motor back in, with the transmission coming out I will have access to both again so we will see. I suspect the TC seal. The car sat for some time before I got it with the motor out. I wonder if I did a poor job cleaning up at the new TC seal? I have also been reading about "repair sleeves" for a shaft that has worn and now won't seal up. I kind of doubt that here though. Hopefully it will be clear when I pull it apart.

Will report back...

Post by **abscate** » 15 Jul 2019, 12:20

Yeah, that sounds like a TC seal, sorry. Good news is it easy to do (once you drop trans)

Post by **cn90** » 16 Jul 2019, 07:45

Is Turbo leak a possibility?