Rear Differential Bushing Leak
 

So - I saw, what looked to be burnt oil on my freshly installed exhaust system, so I took it to Nissan - A buddy of mine works there - and he said it's the rear differential bushings + drive shaft.

Warranty is covering the drive shaft but obviously not the bushings... My question is - the smart move is to just order the rear differential bushing set off of Z1 Motorsports for $65, instead of $1500 + labor from the dealership - and have a buddy install it - right?

Am I missing something? The Pros of the forum / 370z's are there cons / pros to this route? Should I add anything to this change or replace anything while I'm doing this work already? What's the best route for this?


Here's the part I'm looking at...

https://www.z1motorsports.com/z1-pro...t-p-10356.html


Thanks guys. I am not super smart about all this - just know what I read and see on here!

Did you mess up your driveshaft? The bushing will wear out and pop from normal wear and tear.
Yeah, get some after market bushings and change them out instead of Nissan changing out the whole $ubframe. Its not as hard as alot of people make it out to be as long as you use the right tools and take your time (sawzall is involved and you have to be careful cutting out the bushing collar so as not to put any burrs on the subframe...ask me how I know..lol).

So this all started because I saw that burnt oil/grease on the exhaust.

The car is running perfect other than that. So then they put it up on the lift and saw the bushing and the drive shaft issues.

So I don't know of when / how / or where I would of damaged the driveshaft - the mechanic was vague about the issue - it sounded more of a let's do this to avoid other issues down the road than an immediate issue.

He said there's more oil or 'grease' on it than he'd like to see - He is afraid of it twisting / moving too much - if that makes sense?

It doesn't seem to be a 'pressing' issue but I am warrantied out on it... so I might as well do it - if it's covered.


(I bought this car used with 20k miles on it - the guy got it in 2015 and I bought it Nov 2019 - so it wasn't driven much. But this could of been an issue from the beginning. I got it from out of town - and didn't get my mechanic to look at it before the purchase.)

Thanks for the response!

I guess if its covered then get it changed out. You didnt feel a vibration, hard to turn, weird noises etc? Unless they saw that it was chipped, or something.

You might also want to weigh your options on the bushings. SPL solid bushing seem to be the favored bushing. Some have even gone SPL everything with their suspension (Rusty).

Oh, and after the bushings are replaced, change out the diff fluid, falls under the "while im at it" situations.

Naw - so no issues. No chip - no nothing - He just said it looks quite greasy - as in it may be leaking? I wish I knew more about drive shafts! ha!

also - can you link me what you would get - the z1 motorsports SPL solid bushings don't say they are usable for the 370z... Am i missing something?

And yeah I'll do the diff fluid also. Thanks for the tips - I'm down to do whatever else if it makes sense and while I'm at it category :D

It's a 2016 nismo with 30k miles on it.

Drive shafts dont leak...can you ask your buddy what exactly was wrong with it?

Just do a search on Z1 for 370z diff bushing. Youll even see the type of diff fluid to use. If you REALLY want to do more than just maintenance, you can get a finned diff cover for better cooling and slap on a diff brace..

Whiteline makes a great diff bushing set also.

Yea - I'll check with him tomorrow. I"m sure I just didn't get something right on it and I'm mixing the drive shaft issue up with the bushing issue.

I'll check into those diff parts also - once I talk to the performance shop that's going to do the install.

Appreciate you taking the time to help!

That big old bushing is filled with silicone, not grease. And it's nasty. When that bushing goes bad. It normally leaks down the diff cover. The bushing has 2 chambers filled with the silicone. Only one chamber normally lets go.

I've installed 3 diff bushings so far. 2 SPL's and 1 Z1. The SPL's were easier to install. They're a solid bushing, where the Z1 is poly. The poly moves around during installation. The poly transmits less vibrations.

Alright so yeah - Silicone leaked down my Diff - thought it was diff fluid.

So Rusty - which bushing do you suggest? If install isn't an issue?

I like the SPL's. But that's me.

Question. You do have the black streaks on your diff cover? Correct? The reason I ask. Some have blown gear lube out of the breather hose. The end of the breather hose is on the driver side of the sub-frame. So, it will drip on the exhaust on that side.

yeah - here's what it looks like

Yep, diff bushing.

To change to bushing out. You're looking at at about 6 to 8 hrs of work. Depending on skill set. To drop the diff. You got the exhaust, drive shaft, axle shafts, frame bracing, sway bar. It's best to work from the front of the sub-frame. Install the new bushing from the front. Push it all the way in. Until the front of the bushing is flush with the sub-frame. This should get you where the diff should be. Bunk had to drop his diff a second time, and push the bushing a little deep to get the front 2 bolt holes to align up.

Thanks man. What a pain in the ***. Damn Nissan. Why even allow this out on these cars... I've got 30k on the car...

Nissan has this style of bushing in different areas of the car. The lower rear front control arm bushings, the front sub-frame frame bushings.