Oil leak

[22YukonDenali22]

Can’t be afraid of doing maintenance just because some people don’t do it right and have issues. There’s a centering tool that comes with the ACDelco rear main seal that ensures it gets installed right, if you follow directions you’re good to go. I guess if you buy a crappy main seal like a Dorman you deserve what you get. But I’ll never be afraid to replace any and all wear items with OEM quality when they’re buried like that. I mean, your trans went out at that mileage so who’s to say the main seal isn’t far behind. That’s my thinking anyway.

It's all perspective. The rear main was bone dry. I do oil changes synthetic every 3-4k, and routinely clean the pcv valve to try to limit excessivec crankcase pressure. I know the guy who was doing the actual internal tranny rebuild. I don't know the techs who do the reinstall, and their familiarity with the RMS. I paid these people money because I knew they were good with transmissions. If I needed/wanted a RMS replacement, I'd do it myself, or research and find somebody I was comfortable with.

 

[Sam Harris]

I hope you replaced the rear main anyway as a maintenance item while the trans was out. It sure would suck if it started leaking a few months or even a year or two later. I did when I had my trans was out, as well as the rear cover and gasket. It had 150k and was the perfect opportunity.

Yup. This is on my list when I replace the trans.

 

[Woodse]

99 Denali....165 miles. Mine goes in next week for pin holes in the pan. Front seal. Oils lines. Filter mount gasket.

 

[Larryjb]

Pin hole leaks in the pan?!?! That pan is pretty thick. This would be highly unusual.

I can understand the front seal, oil lines, and filter mount gasket. I suspect they mean the oil pan gasket.

Keep in mind that unless you get a boroscope up behind, it's pretty much impossible to see if the rear cover or rear main seal is leaking or not, unless it's really really bad. Mine was leaking and this is what it looked like:




Here's what it looked like before I removed the transmission: (looking up through the bell housing inspection hole)


You can see I had a lot leaking from the rear cover itself. I had less oil staining around the rear crank, suggesting that I had a lot more leaking from the cover. I was not able to see any of this through the inspection hole.

 

[JonnyTahoe]

Pin hole leaks in the pan?!?! That pan is pretty thick. This would be highly unusual.

I can understand the front seal, oil lines, and filter mount gasket. I suspect they mean the oil pan gasket.

Keep in mind that unless you get a boroscope up behind, it's pretty much impossible to see if the rear cover or rear main seal is leaking or not, unless it's really really bad. Mine was leaking and this is what it looked like:

View attachment 250813


Here's what it looked like before I removed the transmission: (looking up through the bell housing inspection hole)
View attachment 250814

You can see I had a lot leaking from the rear cover itself. I had less oil staining around the rear crank, suggesting that I had a lot more leaking from the cover. I was not able to see any of this through the inspection hole.

Guys are looking in that inspection hole and it looks dry so they think its not leaking. Great pictures Larry.

 

[JonnyTahoe]

Guys are looking in that inspection hole and it looks dry so they think its not leaking. Great pictures Larry.

Sure they all have Pin Holes. I wish I would of thought of that.