SPL solid aluminum subframe and differential bushings - REVIEWED

[n00b240]

Alright fellas, Here is my review on the SPL solid aluminum subframe bushings and the differential bushings. As well as a little background information for the noob. Hopefully I can be of some help to people who are interested in this modification. Feel free to chime in with questions, feedback or additional commentary. For the record, I drive a red 1996 240sx. It has 129k miles, no accidents, and bone stock. First off...Why would anyone want to perform this mod on their car?

Well to the unsuspecting S14 owner our cars are filled with rubber bushings, both in the subframe and the differential. These rubber bushings help to eliminate or dampen and drivetrain noise and vibrations. In english they help to make the ride as smooth and comfortable as possible.

These rubber bushings, depending on how you drive your S14 have a limited life span, of about 40k to 90k miles, before its a good idea to replace them. If you are like me, which you probably are, around 115k miles you will start to hear some knocking of the subframe. This knocking is because the rubber bushings have worn out so much that now the chassis is knocking up on the subframe. I had a good 2 inches of play around space where rubber should have been.

An unwitting S14 owner will take his car into the shop and the mechanic will tell him, your bushings are worn and its gonna be a 1000 dollar job to fix. You say what the F? He tells you well, the only way to get these new rubber bushings is to buy a brand new subframe from nissan, and thats why its so expensive. Most probably go ahead with this job. The mechanic didnt lie, you cannot just buy new stock bushings.

Nissan offers Nismo bushings, these are fairly expensive, but less expensive than the completely new stock subframe install. However the downside is that these bushings are made of stiff rubber. They too will wear out over time, depending on how you drive your car. Basically the Nismo bushings are like the stock bushings. I wanted something that will last on my car, and help stiffen up my suspension.

I thought there had to be another way, and Lo and Behold after exhausting searching on 240sx.org, I came across SPL solid aluminum bushings and differential bushings. What I found out in this forum and another 240 forum was that people said you will get alot of drivetrain noise and that it gets really loud. Even the SPL guy Kuah (nismo freak I think) said that it will get really loud on the street and even louder on the highway.

I sucked it up and had them installed anyway. I thought, if I didnt like them, and the noise was too loud, I will just get the new stock subframe with rubber bushings. When I got a decent job (I just graduated from univ). And now for the Review...

At first, my seat started vibrating like crazy upon acceleration in first gear at 3k rpms. And with the windows up so I could hear the drivetrain noise, it was louder for sure, but not much louder. I was beginning to regret my decision. I thought I would not reach a final decision until I felt that I drove the car around alot more.

And today I am very satified. Drivetrain noise gets loud around 3k rpms and then dies off. Oh btw the drivetrain noise comes from the solid aluminum subframe bushings. It is not as bad as the SPL guy and others made it seem. On the highway, I feel like there is just a slight increase in drivetrain noise. HOWEVER. The solid alumunim differential bushings make a different noise. This noise comes from the drive shaft spinning and knocking up on the differential. Rubber bushings eliminate any noise from this. The sound I am hearing, is a fairly random, sound that sounds like a mildly deep throaty exhaust (with the windows up) that is not too loud.

Again the sound is random. But does occur occasionally in city driving. The words cannot describe how often this happens, but it is by no means annoying or crazy loud. It does take getting used to. Now I hardly notice it after 4 days of driving it. The highway driving is another story. You could say in less random, but more interval like. maybe every minute, there is a a sound that is more like a middle pitched drone. Or is that a middle pitched whine. That lasts about 7 seconds. This happens only on highway driving of speeds like 60+ mph. Definately bearable, now I hardly notice it unless I am in a blank state of mind I will hear it

So thats the sound review. For the suspension review. The car feels a hell of alot stiffer. Really really stiff, you will feel this on the corners, heavy cornering, hell even changing lanes. The car really sticks to the ground with alot less flex of the chassis. Is it too stiff? I dont know about any grades of stiffness. But The guys who installed it say that they thought it was too stiff for their liking. They said now you are going to feel everything

As I said before, I only felt more vibration in my seat around 3k rpms and then it died off. It wasnt an annoying vibration, and now it feels really good. Sometimes in the city I find myself driving around hovering at 3k rpms for that instant lower back massage. In the passenger seat and the back seat I had friends sit there, and they say vibration is nonexistant, I sat in the passenger seat while I friend hovered at 3k rpms and the vibration is indeed non existant for the passenger.

I think the guys are way off when they said now the car is going to be too stiff. Too much vibration and noise they said. The noise is not much louder than stock. Vibration is detectable around 3k rpms but not annoying. Car is stiff, but stiff enough to keep you happy. In the end, I highly recommend this upgrade to anyone wanting to replace their rubber bushings. If you have any questions or comments, I will do my best to help out. The upgrade is not expensive and way cheaper than the new subframe install.

Kudos, Quash

[masticatingcow]

Awesome write-up!

Where did you get them installed? How much did they charge you?

[D Money]

perhaps your exuast is hitting the seat bolts?? Strange its only your seat

[n00b240]

Another thing I noticed while driving today. Seat vibration does not occur in 4th or 5th gear.

I got them installed in a shop right next to SPL parts in Austin. their website http://www.splparts.com. It was 450 for the install. 280 for all of the solid aluminum parts. He may give you a discount if you buy more stuff.

Its insane how you have 225k miles there bro, To think my car will last that long, is still unfathomable.

Exhaust hitting the seat bolts??? Um not to be mean but that is completely wrong, its the differential. Because it is solid, i will feel the vibration, rahter than it dampened by the rubber bushings to nonexistence. Again the vibration is fairly mellow, so its really not a big deal, feels hella nice
Modified by n00b240 at 7:27 AM 12/26/2006

[n00b240]

Here is a link if you would like to try to install the bushings yourself, or show a shop guy to do it for you.

http://www.nicoclub.com/zerothread?id=97924

[PalmerWMD]

Good Write-up Noob.

Fred..

[Onizuka]

I'm assuming your on an OEM suspension?

[n00b240]

OEM suspension yes

[URM S14]

i was wondering if you could elaborate on ride quality...does it feel like stiff shocks or does the chassis just feel more rigid?i want to get both of these but want to be somewhat comfortable due to the crappy roads around here...

[scorsone]

I had installed the whiteline poly sub-frame bushings over a year ago and I too notice a rumble/whine from the rear end. I would compare it to the sound of a second exhaust note. As for the feel with older eibach/tokico I noticed a more solid rear end and much less lag in drivetrain squat under hard launches. However, I noticed a rapid degradation of the rest of the rear multi link bushings. I would recommend it to anyone interested in a tighter ride.

[n00b240]

Chassis feels hella stiffer. When cornering I notice alot less flex of the body. If you are asking about shocks, its prolly a good idea to replace those to get the stiff shock feel.

As for the whitelines, those are made of urethane right? aluminum>urethane

[URM S14]

do bumps feel worse with tehse bushings? cause ive got tons of bumps and cracks in the road around here...

[D Money]

do bumps feel worse with tehse bushings? cause ive got tons of bumps and cracks in the road around here...

yes, its the compromise for good handling

[n00b240]

I dont know if you can say that the bumps feel worse, as if it was a bad thing. But you could say you feel them alot more than with the stock bushings

[URM S14]

is anyone runing these with a clutch-type LSD? because im a little scared on how bad it might be with these peices and my clutch LSD (not installed yet). i fear it will be a bit much..

[n00b240]

I would think its a bit much, Ive heard one before, and it clacks like crazy in city driving, it is some loud clacking

[newpuy]

the link about installation is bad can you give me the link again please I have to replace the subframe bushin ( whole because the torn out )

[masticatingcow]

Just search for write up. This thread is almost 8 months old. Check the archived contents.