Rear differential bushings?
Here are the aftermarket rear differential bushing options that we offer:
Solid:
http://z1auto.com/prodmore.asp?model...ne&prodid=3971
Urethane:
http://z1auto.com/prodmore.asp?model...ng&prodid=4547
Solid:
http://z1auto.com/prodmore.asp?model...ne&prodid=3971
Urethane:
http://z1auto.com/prodmore.asp?model...ng&prodid=4547
Okay, lets get something clear............
There are 3 mounting points for 350z diff.
REAR: (see the SPL blue bushing shown)

There is a stud coming off the rear diff cover going into a bushing that is in the rear subframe.
The ONLY replacement for that is a solid bushing made by SPL parts or 350zmotorsports.com

FRONT: EARS - Solid
The front of the diff has tow bolts that go straight up into the fwd section of the aluminum subframe.
Those two ears require bushings on top and bottom of the ears.
SPL parts makes those solid

FRONT: EARS - urethane
Whiteline - makes those ONLY in urethane.

There is no other option for urethane in the rear sub frame mounted bushing....
Z1 is a great vendor! they can get you what you need!
Again, Z1 can help you out with those as well...
-J
Last edited by JasonZ-YA; Jul 14, 2010 at 07:38 AM.
If you have a blown rear bushing:
Then your only option is to go solid......
-If you go solid rear bushing, then you must go solid front ears as you don't want the diff to "dive board" effect on you with urethane front.
If your rear isn't blown:
but your concerned, want better performance, etc...
-Then you can look into doing urethane front bushings and bracing in rear to aid in avoiding a blown rear bushing. however the bracing will/can still lead to dive board effect issue.........
Review this thread:
https://my350z.com/forum/mid-atlanti...-bushings.html
Hands down..i would do solid at all 3 points and be done!
-J
Then your only option is to go solid......
-If you go solid rear bushing, then you must go solid front ears as you don't want the diff to "dive board" effect on you with urethane front.
If your rear isn't blown:
but your concerned, want better performance, etc...
-Then you can look into doing urethane front bushings and bracing in rear to aid in avoiding a blown rear bushing. however the bracing will/can still lead to dive board effect issue.........
Review this thread:
https://my350z.com/forum/mid-atlanti...-bushings.html
Hands down..i would do solid at all 3 points and be done!
-J
see technically speaking the rear OEM bushing is silicone filled...its like that because a urethane bushing would deform/creep to a tear drop shape due to the weight of the diff at that bushing. once deformed to that nature the bushing is pointless and wheel hope, etc would occur....
The silicone is there because of that reason...
OEM with black silicone busted and dripping down the diff cover:

-J
Last edited by JasonZ-YA; Jul 14, 2010 at 09:53 AM.
Now, a urethane may work paired up with some rear diff braces, but unless its sold and installed with them......then deformation would occur and whatever company built them would get bad reviews due to idiots installing them with out bracing......and all that has too many variables............ie, installation error, etc....
which is probably why no one has done it.....and i doubt anyone ever would...
-J
which is probably why no one has done it.....and i doubt anyone ever would...
-J
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see technically speaking the rear OEM bushing is silicone filled...its like that because a urethane bushing would deform/creep to a tear drop shape due to the weight of the diff at that bushing. once deformed to that nature the bushing is pointless and wheel hope, etc would occur....
The silicone is there because of that reason...
-J
Anyway just my opinion take it for what its worth. Someone still need to make a rear diff bushing I just don't dig the solid ones
Yes, the factory center rear bushing is leaking.
Seems the corect & only solution will be to replace with the aluminum one.
If I go with the aluminum rear & synthetic front bushings, will there be too
much flex in the front?
The car is a street car & not raced.
And can you install the solid rear bushing, without dropping the subframe??
Thanks for the help.
Seems the corect & only solution will be to replace with the aluminum one.
If I go with the aluminum rear & synthetic front bushings, will there be too
much flex in the front?
The car is a street car & not raced.
And can you install the solid rear bushing, without dropping the subframe??
Thanks for the help.
Last edited by Russ's 350Z; Jul 14, 2010 at 07:22 PM.
Its all good, its a forum..... i invite the discussion....
See thats the thing right there, their application........all uniform distributed loads with a larger net area contact with no single moment application...
See the 350z rear diff is actually quite unique in that it has only 1 rear diff stud which now takes a moment/torque off the drivetrain centerline......
Nissan 240sx:
- had two equally spaced rear diff studs coming off the rear diff cover, yet
what happened to 240's..............their harsh mounting lead to rear subframe bushings going to hell and swapping rear subframe bushings is a known issue on them....
Nissan 350z:
- Has the one diff stud mounted to the subframe taking moment loads off the centerline that if you look at the two front mount ears of the diff the bushings there are different.............the drivers side diff ear is also silicone filled yet the passenger side one is not.......its solid rubber with a larger metal race holding it in...
You can see all the front diff ear silicone splattered all over the floor here in this pic:

:Note that the diff is upside down in that picture:
Also the net area contact patch is the cross sectional area of the M12 stud coming off the diff.............that's quite small and the reason why the oem bushing is a sleeved bushing in the center, urethane cant hold that unless its held on each end and adhesive wont hold against the moment/torque over time..........it would separate before the urethane tore..........the sleeve on the oem is needed with hard rubber and the silicone YES for NVH but also that's the only low cost alternative that can support dead weight when parked........
-J
Urethane bushings deform and rebound. I have a set of urethane suspension bushings on my Toyota that have been there for ten plus years and there is no (neutral) deformation. They use urethane bushings on body to frame mounts, frame to suspension mounts, even engine mounts. Then any deformation because of weight would be allot better then an OEM mount. The silicone is used for noise and vibration. There are different densities of urethane.
Anyway just my opinion take it for what its worth. Someone still need to make a rear diff bushing I just don't dig the solid ones
Anyway just my opinion take it for what its worth. Someone still need to make a rear diff bushing I just don't dig the solid ones

See thats the thing right there, their application........all uniform distributed loads with a larger net area contact with no single moment application...
See the 350z rear diff is actually quite unique in that it has only 1 rear diff stud which now takes a moment/torque off the drivetrain centerline......
Nissan 240sx:
- had two equally spaced rear diff studs coming off the rear diff cover, yet
what happened to 240's..............their harsh mounting lead to rear subframe bushings going to hell and swapping rear subframe bushings is a known issue on them....
Nissan 350z:
- Has the one diff stud mounted to the subframe taking moment loads off the centerline that if you look at the two front mount ears of the diff the bushings there are different.............the drivers side diff ear is also silicone filled yet the passenger side one is not.......its solid rubber with a larger metal race holding it in...
You can see all the front diff ear silicone splattered all over the floor here in this pic:

:Note that the diff is upside down in that picture:
Also the net area contact patch is the cross sectional area of the M12 stud coming off the diff.............that's quite small and the reason why the oem bushing is a sleeved bushing in the center, urethane cant hold that unless its held on each end and adhesive wont hold against the moment/torque over time..........it would separate before the urethane tore..........the sleeve on the oem is needed with hard rubber and the silicone YES for NVH but also that's the only low cost alternative that can support dead weight when parked........
-J
Last edited by JasonZ-YA; Jul 15, 2010 at 06:17 AM.
C-Clamp method:
SPL parts instruction page they send you talks moreso about doing the large C-clamp method...........
when you drop the diff there is a lot of room down there for using a C-clamp and a large sleeve to span the bushing hole and press out the oem bushing and press in the spl solid one. Many have done it this way....
You can also see another thread where a guy did it by hack sawing the oem bushing off then using C-clamp here:
SUBFRAME DROP:
The subframe drop is actually not that hard, just time consuming.........
Tools like ratcheting wrenches, deep sockets and goose neck's are key....along with a helper.
You can see how i did mine following these links in the DFW lounge thread:
https://my350z.com/forum/8441229-post13866.html
https://my350z.com/forum/8460648-post14054.html
https://my350z.com/forum/8460429-post14049.html
-J
Last edited by JasonZ-YA; Jul 15, 2010 at 06:30 AM.
I would also like to note...........the solid diff bushings isnt all that harsh honestly...........if going on a daily driven car i wouldn't worry.......
To me there is no noticeable noise, vibration or harshness with the solid diff bushing install, but i do see and feel the performance gain in take off's due to no drivetrain slack....
I honestly wouldn't let going all solid worry you for a daily driven Z..
-J
To me there is no noticeable noise, vibration or harshness with the solid diff bushing install, but i do see and feel the performance gain in take off's due to no drivetrain slack....
I honestly wouldn't let going all solid worry you for a daily driven Z..
-J
SUBFRAME BUSHINGS:
Whiteline - 4 each upper supframe to unibody mount locations:

you can see the spl solid subframe bushing installed also in that pic.

-J
I agree that dropping the subframe is not that hard. The worst part for me was getting the exhaust off. Second hardest was getting the dealership to order the correct nuts for the nuts I was replacing. Third hardest was getting the car lifted high enough in the air.
-J
^ It obviously depends on the size of the person. I'm bigger than the average person so my car is on stilts so that I can drop my rear subframe.

cake walk...


I'm swapping out the bushings in the rear spindle/hub as we speak and thus far positioning the spindle in our press has been the most difficult part. You have to get it juuuuussssssssssssstttt right to get the force of the press to go through the driver to push out the bushing, otherwise you are warping the aluminum hub.

cake walk...


I'm swapping out the bushings in the rear spindle/hub as we speak and thus far positioning the spindle in our press has been the most difficult part. You have to get it juuuuussssssssssssstttt right to get the force of the press to go through the driver to push out the bushing, otherwise you are warping the aluminum hub.
Last edited by Kwame; Jul 15, 2010 at 09:53 AM.








