sweetask1ng

iTrader: (2)

So I just got an oil change and the guy says there's a leak in my rear differential... He says he doesn't know what it could be, any of you have any advice? Its a 98 z28 convertible with 78k on the clock.

jonm3456

its most likely at the rear pinion seal, at the front of the rear diff. The other most common area is at the diff cover, diff cover gasket. Hope this helps...

keliente

iTrader: (22)

Would help to know exactly where it was leaking from....front, rear, axles, etc

https://ls1tech.com/forums/gears-axles/412366-rear-end-faq.html

sweetask1ng

iTrader: (2)

He said it was coming from the rear axle, and then in the notes on the report he said rear differential.

keliente

iTrader: (22)

That is still very vague, I assume he means the rear cover? Replace the gasket.

sweetask1ng

iTrader: (2)

I have no idea... Is replacing the gasket hard/expensive? Newbieeeeeeeeeeee

RoadHazard

iTrader: (1)

A leak at the pinion seal is very common in the F-body so my guess would be that. It's a PITA to do. But if it's only the gasket, it's an easy fix. Go to installuniversity for instructions.

chromeplated500

iTrader: (10)

+1 for the pinion seal both my F-body leaked, the diff cover would be easy to replace though...

thunderdan74

iTrader: (1)

it can also leak from the pinion nut if the splines are not sealed properly.

Fibbado

iTrader: (8)

If he said that he doesn't know what it could be don't take it back to him to fix it

sweetask1ng

iTrader: (2)

multiplied by 1000. Haha no way it's going there for that! But in his defense he was just a quiklube guy at a chevy dealership. In any case I'll have them tell me exactly what's going on and try and figure out how to fix it. Maybe I'll learn a thing or two.

whoopwhoop

It is not hard to do, if you do decide to do it yourself, on thing that i found with changing my rear dif. fluid and my trannie fluid is...make sure you have a oil siphon pump. You can buy it at almos any auto parts store and it makes life a lot easier! instead of trying to get a bottle or funnel into the fill plug, just use the pump. It made my job a LOT easier. Another note if you do it youself, change your trannie fluid while your down there...i used Royal Purple and noticed a hell of a diffrence. My Firebird is much more quiet and i got a 10 hp gain just by changeing the trannie fluid and the rear diff. Hope this helps

BlackScreaminMachine

iTrader: (17)

When my 32k stock 10 bolt was removed, there was def a dark spot on top of the housing and near the vent area. Techincally its a leak BUT it wasnt anything critical.

Get under the car and look, feel and see if there is any oily residue,

omcar

iTrader: (10)

It could be a clogged vent tube (top right on diff) as I had. Just ran a very tiny drill bit through it and it was fine.