There's a dying sea lion in my rear axle

97 - Upcountry - 4.0 - AW4 - D35 - ABS - 150k miles.

So for the last couple of weeks now, when I take any kind of turn at low speed, some part of my rear axle sounds like a dying see lion. Seems like it's coming from the left rear side. Kind of a deep warbling groan that oscillates as the turn is made. I have no idea what this might be.

The rear diff is an LSD, and it has plenty of oil in it. I don't use friction modifier in it because I really don't care if the LSD part works or not, it's fine open for my purposes. I thought it might be the clutch packs in the rear, but if so I don't know if that could cause long term damage or not, or if it will just continue to make noise.

Any ideas what this might be, and how quickly should I get it addressed? I'd hate to have my rear axle speed by me down the highway in the near future.

... you need to put the LSD friction modifier in it

The friction modifier reduces the friction of the lubricant. Without it, your LSD is locking more not less.

X-defector said:

I really don't care if the LSD part works or not, it's fine open for my purposes.

Click to expand...

Correct me if I am wrong, but doesnt an LSD need special fluid to work in both the open and locked modes?

rearry? the friction modifier makes it grip less? I didnt put any in my 8.8 because I plan on welding it eventually. Glad to hear being cheap paid off. Thanks Castiron!

I thought it made it more grippy, but then I figured I should make sure before saying anything... googled it and whaddya know? It reduces friction.

i would open the diff and give it a look. your LSD could be broken. mine was falling apart inside the axle, making some noises. so i opened it up and found this:





this is what prompted me to swap in a 97+ 8.25

My son's '96 was quivering, gyrating (wait, this could be fun!), and the shop teacher said to try another tube of the additive. Pretty much cured it.

i would pop the cover and check before adding more additive to it, especially if its totally shot like mine was. and i used lucas gear oil that already had limited slip additive in it. then if it looks all good try using the correct gear oil and proper additive

check the center pin for wear around the spiders. get the tires up and pull the cover. the clutch reduild kit is pretty cheap and a good driveway mechanic can do it in 3 hours tops. or just throw in the aussie and wat for the 35 to surrender. :greensmok

So friction modifier increases the lubricity of an already highly-refined low friction oil designed to minimize friction and wear. Who knew! :greensmok

Screw replacing the clutch pack. For a lot less effort I can snag a 8.25 and drop that in there, hell with the ABS. Maybe I'll start looking for one of those....

thats the smartest route, and the exact one i took

If you really, really want to keep your ABS, check out fyrfytr1717's thread on putting ABS into a dana 44. I'm not sure how that crosses over to an 8.25 with regards to brake backing plate modifications and the axleshaft shoulder dimensions, but with enough time you can usually do any sort of mod you want.

I'd just junk it and go with an 8.25 though like you're considering... 100 bucks for a 29spline 97+ 8.25 (get the spring plates with it) , 50 for U-bolts, a little money for brake lines and incidentals and you're done in an afternoon.