I have a '96 Accord EX with about 345k miles, automatic transmission. I just changed out the driver side CV axle (boot had been torn for a while). Did not replace the seal. Seemed to click into place just fine, and car runs just fine with no weird noises or vibrations, but almost immediately after this repair job (which was my first time ever replacing a CV axle on any car) my Accord (which has never leaked oil) suddenly has a serious oil leak - like loses a quart a day, and leaves a giant oil puddle on the ground wherever it's parked. The oil doesn't seem to be coming from the valve cover, the distributor cap, or anyplace else on the top of the engine. And it's definitely not from the oil pan seal. It seems to be dripping down around the interface where the CV axle plugs into the transmission, like it was leaking out from where the CV axle plugs into the transmission. Or might be coming from somewhere right above there that I can't see with the axle installed.

It seems really unlikely to be a coincidence that this leak starts RIGHT AFTER I do this repair job that I've never done before. Is there any way that this could be from a bad CV axle seal? Wouldn't that cause a transmission fluid leak though, not an oil leak? Is there some nearby oil seal or something that I might have cracked while tapping the axle into place? The fluid coming out is yellow, viscous, and the oil level in the car keeps dropping...so I'm pretty sure it's engine oil not transmission fluid I'm seeing?

Many thanks for any suggestions.

 

The left side axle attaches to a stub axle (#14 in the picture) which in turn goes into the transmission. Should I assume you replaced the left-side axle and you didn't replace the stub-axle? If so, then you didn't even get to the point where it would lose ATF.




The carrier for the outboard end of that stub axle is bolted to the side of the engine block. Did you remove that carrier/bracket at all? The bolts holding it to the engine might be the place to look for leaks.

 

Thanks so much for the reply! The replacement axle I installed looked just like the photo below. It sure seemed to slide into the transmission - is the stub axle hidden inside what I'm thinking is the transmission housing?

 

No, my mistake. I only looked at the drawing, I didn't read down the parts list. The center part (#14) is not included. Sometimes they "share" the same drawing for different versions and maybe that middle part is only on manual-transmission cars.

So...
I'm as confused as you. Anything related to the axle change should be ATF, not engine oil. How about things above that area?
Distributor O-ring?
Oil filter gasket?
I think there's a plug on the side of the engine block, but that's more towards the left side of the car.

Did you do anything else to the car at the same time?

How about when you removed the old axle. You have to use a screwdriver or crowbar to snap the axle out from the transmission. Look carefully at the area where you were prying.

 

Maybe it really is just a coincidence that an oil leak showed up right after I changed the axle. Car does have a lot of miles on it after all. I didn't do anything else during that repair except replace a worn out lower ball joint on the driver side suspension. Let me ask you this - besides the red coloration (and keeping in mind that this car's ATF is probably reeeeeeally old) is there any good way to tell the difference between ATF and motor oil? Wonder if I'm leaking both from two unrelated issues.

My plan at this point is to remove the new axle, replace the seal, replace the axle, and see if that stops the dripping fluid I'm seeing under the car. If it does, but the dropping oil level persists, I'll put some UV dye in the oil and see if I can track the oil leak down that way. Failing that, I'll start replacing the usual suspects (valve cover gasket, distributor O-ring, etc).

 

The ATF is a little red colored, but you might have to wipe it onto a white rag to see the color. When I had a 1998 automatic, there were times when it was difficult to see the red tint.

To me, engine oil takes on a particular smell after it's been in the engine for awhile. But I guess it's a matter of experience. It's only manual transmission oil that has a really unique smell.

The biggest thing is whether the level on the dipstick is dropping. Watch both the dipsticks to see - maybe you're right they both might be leaking. There's also power-steering fluid lines down there not too far away.