pacman1219

So i've installed a brz/frs LSD into my is250, however the passenger side - in Australia - (it'll be the american driver's side for you guys) diff seal is leaking. I've already replaced the seal on the diff, but every time i run the car on the hoist it starts dripping diff fluid out where the axle goes into the diff. I've been doing some reading and noticed that the cv shafts (axles) are different sizes depending on the side (816mm and 770mm - excuse the metric). Has anyone else experienced this problem? Should i just get another 816mm cv shaft and replace the 770mm one? Or is this not possible? really want my LSD to work

Jeff Lange

iTrader: (1)

You cannot swap the axles left to right, as the diff output flanges are not centered. If you have already replaced the seal, I would be concerned that either the axle isn't seated all the way in the diff or that the seal mating surface on the axle is damaged or scored. Were these things checked?

Jeff

2013FSport

iTrader: (2)

Did you fit the seal to the axle to verify fit? You grease the seal before install? If you knocked the tensioning spring off getting the axle in, this could do it.
Check the axle seal area for damage.
Verify the axle locks into place. It should not pull out by a simple tug of the inner joint.
Drive the seal in squarely using the proper tool and verify it is seated to the correct depth.

If you can answer yes without a doubt to all of these questions, we have a problem, but any one of them gets a No and you should try one more seal.

Oh and verify it's leaking past the axle and not from case/seal junction.

Jeff Lange

iTrader: (1)

Agreed.

The IS250 and BRZ/86/GT86/FR-S differential cases are the same, as are the seals. Something is up.

Jeff

2013FSport

iTrader: (2)

Thanks ^^!!
One more thing, running the car on the lift although it should not leak, the axles are unloaded and due to the drop angle, it may induce a wobble that doesn't occur under normal driving situations.

Are you doing this work yourself?

pacman1219

Thank you so much for your advice! I must confess that the car is at a mechanic as I couldn't get the original diff out without dropping the whole subframe (no room for rear bolts to come out due to fuel take position).
I'll have to follow up with the above information and confirm that this was checked, it is a little hard with it being at the mechanic.
Are you guys sure there wouldn't be a difference between the AUS and US models? In my mind there really shouldn't be other than steering wheel placement. Surely not the axles/CV dimensions?
Another thing, i got the LSD out of a 2014 automatic BRZ, i assumed this would be the same diff as is in the manual, because at least for us in AUS the automatic 86/FRS/BRZ received a LSD as standard after the intial 2012 yearly run (make).
Thanks guys, i'll keep you posted!

pacman1219

So the culprit of all these issues appears to have been a small piece of metal approx 9mm long, very thin (looked like cast, but not from a spline apparently) which was on the leaky diff side. I guess it was spinning around or forced into an awkward position when the axles went in, causing the seal to leak. It didn't rip the side the final time they checked the axles/diff seals, but i guess it may have pushed it. All appears to be well now, but i'll make sure there's no drips in the garage at home Can't thank you guys enough for your help, it was nice to get an understanding of the whole situation and exactly what is involved. Thanks guys!

Gville350

iTrader: (10)

Nice! Enjoy the new diff!