Paging TOZOM8.... Gear fluid leaking from front differential breather vent.

[4.2Crew]

This past week, I've replaced the front passenger side axle flange seal twice. Gear fluid is still leaking from somewhere. I even thought the differential filler plug may be leaking since there was gear fluid above and around it as well. After further inspection, it appears the source of the leak is located above the axle heat shield... Possibly the differential vent/breather, which is located above the flange heat shield and below the turbo??? BTW, it is definitely gear lube (not tranny fluiid or engine oil).........

Anyone ever access this vent/breather with engine in (or just lowered?

Also, if TOZO doesn't respond, does someone know the number (or name) of his shop in Chicago?

Thanks.

[DHall1]

Gabor.....I have his number if you need it. Can get it tonite

[4.2Crew]

Gabor.....I have his number if you need it. Can get it tonite

Appreciate it!!!

Thanks!

[SteveKen]

How much runout do you have with that flange? This might be your problem. If you can push up and down on it, then you have a bad bearing on the pass side of the front diff which needs to be replaced and then properly shimmed.



I PM'd you with Gabor's number and I'm sure that he will ask you this same question first, so hopefully you recall jiggling the flange. Otherwise, quickly reach up in there ans push up on the flange to see if it moves a lot.

[SteveKen]

Here's the other shot of the vent hole on the S6 transmission.

It looks like it was leaking from the vent hole, but The bearing was definitely shot with front diff fluid that looked like Hershey's syrup.

[4.2Crew]

That's a very interesting photo, Steve... The residual gear oil near the breather cap is perplexing. ....Soooo, the flange bearing was shot, causing diff fluid to leak from the flange seal, and eventually migrate upwards and directly ABOVE the heat shield (not in the pic.)

It sure looks like the breather/vent is discharging a oily residue! Does the base of the heat shield (where the 3 bolts attach it) fit flush against the differential? Or is there an opening between the shield and tranny for the fluid to be driven upward by the air wash?

Thanks for the chat and pics!

[Bigglezworth]

There is nothing - and I mean nothing else on top of the differential housing other than the vent. It would be obvious to be leaking from there as shown in the photo above by simply wiping your finger across the top. You are certain it's ATF fluid and not oil from the turbo?

[hahnmgh63]

He is saying he's certain it is gear oil (75w-90) from the front differential, not ATF from the tranny. But yes, it could be Engine oil. Was the front diff level low? If it is filled while the oil is cold and checked while warm it may seem a bit over full but if you check it while cold it should be level.

[4.2Crew]

He is saying he's certain it is gear oil (75w-90) from the front differential, not ATF from the tranny. But yes, it could be Engine oil. Was the front diff level low? If it is filled while the oil is cold and checked while warm it may seem a bit over full but if you check it while cold it should be level.

It is absolutely gear oil... It was quite low before changing the flange seal and I topped it off afterwards---only to have it leaking (from somewhere) again. Turbo area and related lines are dry and tranny fluid level is spot on at 35C.

[lswing]

Gabor was saying he burned a nice hole in his hand and was taking a few days off, so maybe give some time if he doesn't answer right away. Let new know if you need email also...of course typing might be worse for him.