Leaky pinion seal - NC w/LSD

[DallasRob]

Hey.

My '08 GT has been marking it's spot lately. I changed the gear oil in February (60k) and when I checked it last night it took 10oz to top it off. As I understand it, the level can be up to 1/2 inch below the fill hole, so I'm not terribly worried right now. I put in 75-90 Mobil 1 LS so maybe that has something to do with it.

I cleaned everything off and took it for a spirited drive. When I checked it again, the drain and fill plugs were dry but the aluminum rail right under where the driveshaft and diff meet was wet. The drive axle seals were dry too.

I called the dealership and not only do they want an arm and a leg to fix it, they want the other arm and leg too. I looked it up in the service manual and it's procedure has you pull out the diff and completely disassemble it just to replace the seal. Ouch.

I've heard rumors that it can be changed with the diff still on the car. Can anyone confirm or deny?

Who's the local go-to guy for this sort of thing? If it came to it, I could pull the diff, but I wouldn't trust myself cracking it open.

Thanks in advance,

Rob
'08 Dark Blue Mica GT

[sammm]

What part of DFW are you in?

[DallasRob]

Beltline and the North Dallas Tollway. Between Addison and Richardson. I'll travel for someone good, though.

[sammm]

Give Track Dog Racing a call.

[OZMDD]

John Wags is also a good resource on this.

[DallasRob]

Give Track Dog Racing a call.

Ill give them a call Monday. Thx

[DallasRob]

John Wags is also a good resource on this.

What is his handle so I can send him a pm?

thx

[cone-cerned]

What is his handle so I can send him a pm?

thx

johnwag, but he hasn't posted in about five weeks.

[MarkSipe]

Just had these guys do my RX8 diff in Fort Worth in early May
.
http://www.standardtransmission.com
.
I did the vehicle disassembly and took everything to them. $180 for all new bearings, seals, and pinion crush sleeve from Mazda Motorsports. This shop charged $285 to tear down the original diff, install the new parts along with an OS Giken LSD, painted the housing, bead blasted the rear cover, bead blasted the diff mount, and pressed in the delrin bushings .Fully rebuilt S2 4.77 diff with OS Giken LSD and delrin bushings

[DallasRob]

I thought that I should follow up with the resolution.

I went over to Track Dog (great bunch of guys, btw) and had William and Mo take a look. We all agreed that the leak was coming from the pinion area but it didn't look like a normal leak because the fluid wasn't being flung around in that area. It was just going straight down. We set up an appointment for Mo to replace the seal while I waited.

Mo was able to pull the seal without removing the diff and found that the seal had been replaced before. The leak wasn't coming from the rubber part of the seal like you'd expect, but from a small scratch in the housing that seals against the outside metal part of the seal. It looked like whomever replaced the seal before had used something to pull it that scratched the mating surface of the housing. It was a tiny scratch, but enough to allow some fluid escape when there was some pressure.

Mo put a tiny bit of silicone over the scratch and installed a new oem seal. A week and a half later and the area is still dry. I got charged for two hours of shop time at a reasonable rate and for the seal. I couldn't be happier. Highly recommended.

[DallasRob]

Just had these guys do my RX8 diff in Fort Worth in early May
.
http://www.standardtransmission.com
.
I did the vehicle disassembly and took everything to them. $180 for all new bearings, seals, and pinion crush sleeve from Mazda Motorsports. This shop charged $285 to tear down the original diff, install the new parts along with an OS Giken LSD, painted the housing, bead blasted the rear cover, bead blasted the diff mount, and pressed in the delrin bushings .Fully rebuilt S2 4.77 diff with OS Giken LSD and delrin bushings

Wow, that's a good looking diff. I'll keep them in mind if I ever need a rebuild.