Hi guys new here, My 2002 Volvo V70 X/C I recently changed the driver side axle cause it was kinda bad, few days later I noticed oil leaking from the axle brown/golden oil..to be extra sure I cleaned the whole engine underneath and I did put uv dye on the motor then checked the leak trail from the axle with a black light it had uv dye on it. At this point don't know what to do I thought it could've been the radiator that is internally cracked or a rear main seal that went bad but to leak oil from the engine to the transmission is 99.9% impossible almost, I already ordered a axle seal cause I know its bad or out of place, but what worries me the most is the oil mixing up...Any help would be greatly appreciated.

 

If the rear main seal of the engine is leaking significantly the oil would leak out at the bottom where the engine and transmission housing are bolted together.
Have you checked the dipstick for the trans' to see if the fluid level is low or the color is wrong. Trans' fluid should be a pinkish red color and it has a distinct smell also.

 

The leak somehow is internally I thought about the rear main seal or the radiator since the car has the tranny cooler inside the radiator but the coolant is absolutely clean with no contaminants, engine oil went down and tranny fluid went up to the point that its very noticeable on the dipsticks..and both fluid are the same color brown/golden..tranny fluid like you said it's supposed to be pink/red. The tranny it's so overfilled right now that it started leaking thru the driver side cv axle.

 

CG there is no possible way for engine oil to leak and fill your transmission. Transmission fluid can often look brown when its old, if very old it can look like motor oil. Also when checking the transmission fluid this must be done while the car is running or else you will have a very high reading on your dip stick when you do.

 

I was thinking the same thing theres no possible way 99.9% its impossible, the other 0.01% is if the rear main seal somehow fails and oil gets thru the tranny but its very rare...dont know what to do really I poured BlueDevil RMS Sealer read a lot of good reviews about it. I also thought about the radiator been broken internally but the coolant is as good as new no contamination at all.

 

No. It is 100% impossible. You need to diagnose this as if you're a veterinarian working on a horse, not a unicorn. If you know what I mean.

 

SOLVED: It was somehow overfilled I believe it had water cause I went thru some back roads looking for adventure and had to go thru some puddles maybe a foot high maybe higher, cause I did a change of tranny fluid this morning along with engine oil and filter change, It hasn't leaked yet its been a few hours and I used the car already.