RedlineAZ

iTrader: (50)

Alright, so tonight I realized I have a blown rear subframe diff. bushing. I did a bit of searching, and I still have a few questions about it. I have 60k miles on my enthusiast z (has vlsd) and had a brand new Diff installed with 4.08 gears maybe 10k miles ago. The bushing obviously needs to be replaced, but I'm not sure which option is the best, OEM or a solid bushing. I know a lot of guys that drift like the solid ones, but I use my Z as a daily driver and the only action it sees is the occasional launch or some hard downshifts. I've heard the bushing stops a lot of vibrations/whine and absorbs a lot of the force when you do some hard launches or really get on it, but that it risks cracking the subframe or causing the force to break something else. I basically want to know what you guys think would cause it to blow out, and how to prevent it from happening again. Is this common with the 4.08 gears? Also, this happened about 1k miles after installing my GT-SPEC rear tie brace(which is attached to the subframe). I don't know if it has anything to do with it though. Thanks for the input in advance guys!!

winchman

Drill some holes in the rubber seal, flush out the remaining fluid, and refill with Shoe Goo. It won't be as soft as the original, it won't be as hard as a solid, but it'll only cost about $4.

michael815

It's funny you said this I was thinking last night that I could fill the one blown section with silicon which, I think will last longer then shoe goo but I don't know. I will look into this.

Z1 Performance

iTrader: (564)

So the same person who said you shouldn't remove the front strut brace is suggesting that you can fix the rear differential bushing (which helps support an ~80 lbs pumpkin and is under contant load) can be fixed with what is essentially rubber cement? If this was the case, surely nissan would have used shoe goo instead of the route they chose to go?

To the OP - it's unfortunately somewhat of a common issue on these cars, particularly if you do alot of track time. Unfortunately, you can't buy the bushing by itself (at least last time I checked) from Nissan, as it comes pre-presed into the subframe (so you have to buy the whole subframe).

It is a more expensive route, but it's an ideal time to upgrade to the SPL solid kit. It replaces ALL the differential bushings (the 2 sets of ear bushings up front, and the rear one) with solid CNC'd aluminum. Not only will you never have to deal with this issue again, but you'll eliminate wheel hop as well (if you drag race, etc) at a launch.

If you were going to fill it with anything, I'd suggest urethane, but given all that is involved, I don't know if I would trust a home remedy to this issue. It may work in the short term, just not sure of the long term. Hopefully it works out whichever route you go

rcdash

iTrader: (18)

Z1, does anyone make a urethane bushing for that location yet?

RedlineAZ

iTrader: (50)

Thank you so much man. I really appreciate the time you took to respond. Do you know if there is any negatives to having a solid bushing there? I head of someone cracking their subframe but I can't find where I read that anymore. I would also like to know if there is an Urethane option. Also, should I not drive the car anymore until its fixed? Thanks for the input guys, you have no idea how much I appreciate the help!

Z1 Performance

iTrader: (564)

rcdash - I've never seen one, only solid ones. We spoke to Whiteline about it last year when they came to visit the shop but nothing ever came of it.

calin

iTrader: (39)

Ouch!! Sorry to hear dude . Good luck getting that fixed

AcidJake75

iTrader: (64)

If you cant afford the SPLs. this is a great alternative..

http://cgi.ebay.com/ebaymotors/PRO-S...item563dc532bf

JasonZ-YA

iTrader: (60)

Redline,

First off, the bushing failure is a shot in the bucket and a very very common occurrence..... track, daily drive, etc....doesn't matter it can and will happen to anyone........

the remedies people are mentioning are horrible idea's.......

as rcdash asked, no one makes it in urethane and no smart company will.........

it will "creep" and turn to a "tear drop" shape and wont hold center, thats the reason why Nissan uses the filled bushing in the first place.........their design of rubber wall thickness, etc just doesn't hold up and it ruptures..........usually on higher mileage Z's, so it has 'some' longivety but not having a replacement available goes to show their miscalculation...


going solid isnt horrible and vibrations, etc are minimal if that.....just go solid....

I know many that daily drive with solid bushings as a replacement to their blow one and they cant even tell a difference....
-J

Z1 Performance

iTrader: (564)

I use the solid kit on my own car, and it works very well. The only potential negative is some have said it transmits a bit more noise (since you no longer have a soft material to absorb it). Alot of guys do this mod when they are doing a new ring and pinion or a new LSD, since you're taking the pumpkin down anyway. So, how much noise is attributable to the ring/pinion install (which can be very tricky to setup perfectly) vs the diff, is a bit up in the air. That being said, at least on my own personal car, which I did with a new ring and pinion and LSD (and my ring and pinion isn't even for a Z, and alot of involved custom stuff), and I have not had any such noises -it's as quiet as it is stock

As for driving it, I can't really say to be honest, I've never personally driven a car with it blown. At first glance, it's probably something I'd take care of sooner rather than later. While there are 2 other bushings there, the pumpkin is quite heavy and it is connected to very important parts of the car (driveshaft, which then slips into the transmission), so to avoid any other issues from developing as a result of the diff "sagging" in place, I'd probably tackle it asap

JasonZ-YA

iTrader: (60)

I would also like to say, your 4.08 gears, your gt spec brace, etc......none of that makes a difference, the bushing will blow regardless......

to be honest, most of those i see that dont race and ONLY daily drive, dont know how to drive a manual car and do a lot of mis shifts, etc.........creating that jerk motion that comes from driveline shock, etc....this is what creates a moment about that diff studd and rocks the diff.......THAT OR, they are idiot douche bags that occasionally punch it at the light, or drive spiritly, but do so with out knowing how to shift, drive, etc............

I drift the hell out of my car, and after many drift events, i replaced mine with solid and did so and it wasnt blown............

if you want it, its yours, but its a waste of time and would have heartburn sending it to you really.....

-J

RandomHer0

iTrader: (9)

If he only replaced the 1 bushing with a solid one, I doubt he'd notice a difference in noise/vibrations.

Z1 Performance

iTrader: (564)

well, a urethane one could be possible, at least theoretically, with a sleeve through the center for the bolt, and a hard metal edge to the outer position, sorta like the control arm bushings are designed. I've never looked into this with any real thought, though, but it might be possible. Since this is a mount, and not merely a pivot point, I don't know if it would be possible, so who knows. But the solids work so well, and eliminate the issue permenantly, it's a no brainer solution IMHO

Z1 Performance

iTrader: (564)

it's only sold as a front/rear set, because you would not want a solid bushing at one mount and soft rubber ones at the other 2

JasonZ-YA

iTrader: (60)

how you describe, is exactly how it the oem one is currently configured........

it wont work.......

*edit, anything else would have to be so hard its nearly a solid, and an aluminum cnc would then be ideal over it......not worth making or chancing to being to weak...

-J

RandomHer0

iTrader: (9)

Hmm...didnt SPL sell them separately with v1? I'm sure I bought mine like that.

JasonZ-YA

iTrader: (60)

OP, here is the solid diff bushing INSTALL HOW TO:

https://my350z.com/forum/engine-driv...?highlight=spl
Go down to post 12 as thats a better method!

Im currently working on making this much much easier to remove, but my design isnt finished yet....once it is, ill post about it...


-J

JasonZ-YA

iTrader: (60)

Random, Z1 Perm is right...you dont want oem rubber up front at the diff ears and solid only in the rear...

that can create a "diveboard" effect...

-J

Z1 Performance

iTrader: (564)

used to, but hasn't been that way for a long time