Aluminum Differential Bushings
 

Well after working 12 hours i stayed late at work and finally got these babies made. Cost to me was nothing other than my time so it's a pretty good deal. The finish is bad because they were test fitted several times in the differential bores and it is a slight press fit (.0008 in). At this time i have no plans to make any more, and I'm waiting on Z1 to ship me my F'ing stub shaft before i will be able to drive the car again. After i get the testing done i will decide whether or not to continue replacing more rubber including the sub-frame mounts (would be delrin) and the rear differential mount (steel insert in aluminum).

http://lh3.ggpht.com/_aGh0BqVKJaU/S6...0/DSC00288.JPG

Cool. Youz gotz skillz. :tup:

thats why they call it skilled labor in the classifieds (i'd put a smiley here but i don't remember the text for it and firefox is fricken killing all the little html buttons)

So what's the theory behind stiffer diff mounts?

less drive train motion in the rear keeps the axles from moving and prevents wheel hop. basically the stock mounts allow the differential to shimmy over a quarter of an inch and that shaking is translated through the axles to the suspension causing wheel hop. but on the other hand the stiffer mounts are going to transfer a lot more vibration and noise to the chassis of the car because they won't be dampening anything.

Gotcha. +1 Rep for the explanation. So are these for launching and drag racing primarily?

pretty much, it will have a minimal effect on power-on handling, but changing out the subframe mounts for stiffer ones really helps stiffen the rear end and keep it from getting squirrely, but subframe bushing will make the car extremely loud and transfer a lot of vibration

Good stuff... how long until they're on the car?

like i said ask Z1 they have to get me a base stub shaft to replace my VLSD shaft so i can finish the install on my Quaife. Apparently Nissan has back ordered the shafts but if anyone knows where i can get one please tell me. My car has been in the air for 2 weeks now and i'm starting to get pissed.

Edit: they sent me the wrong one the first time so i started the install only to find out it was the wrong one and my differential is already apart.

That sucks. Sorry man. Cars don't belong in the air for two weeks. Not the ones we want to drive anyway. GL!

Rep +1 for creative skill. I will be watching for the final results..

$10 bucks says too much NVH. This car is a mess when it comes to vibrations.

The approach I took to reducing diff movement was to add spacers in the bottom of the front diff mounts. This removed all the slop on the bottom of the diff mount and can be done without removing the diff assembly.

yeah the only problem with those spacers is that you are streching the stock mounts which may cause them to tear and they will leak black liquid silicone all over the diff, that and they will still have horribly bad side to side motion.

RCZ yeah i'm waiting to see how bad it will be but it probably won't be as bad as doing the tranny mount because the subframe bushings will still be isolating it from the chassis where as the tranny crossmember is hard bolted to the frame. time will tell once i get my car on the ground. went over to my local parts center and asked them about an axle flange and they said it's showing that it could be here in three days if i ordered it but i'm having them call to make sure first. If that pans out i might pull my order from z1 but i won't know until tomorrow or next week. my bearings hadn't come in yet today but he said maybe tomorrow. is there anybody on here high up in nissan that could pull some strings and get around the infamous nissan internal backorder?

To avoid stretching the stock mounts, I made thin spacers fit both into the air gap in the round casting under the stock flexible mounting and under the casting itself. There should not be any vertical compression of the stock flexible mounting material with this approach as the casting itself is movement constrained to the downside. With the spacer inside the circular casting, there might even be some reduction in side to side movement. My objective was to prevent wheelhop on dragstrip starts where side to side motion is not the main concern.

So did it prevent wheel hop?

Highly interested in both spacers or replacement altogether if it actually gets rid of wheel hop.

you get side to side motion all the time it's not just cornering. the torque twists the differential causing the up down, and as it transmits that power to the axles it creates both front/back and side to side motion of the differential the hole thing moves around just like the engine does.

Great mod, I know alot of track racers have replaced theses on the 350, theres alot of slop in the stock ones.:tiphat:

https://www.fontananissanracing.com/...uspension.html

Just got back from the dragstrip. No wheelhop! 13.4@106

got my half shaft ordered nissan was the hold up but it should be here next week some maybe i'll have a review for next sunday or monday

Edit: back ordered again won't know until the 5th when i'll even be able to get one.

well i took it out but it was wet here and i don't want to push my makeshift stubshaft too hard just yet but when they did break loose the wheel hop wasn't as bad as it was before. Slight gear noise on acceleration, no noticeable increase in vibration so i think i have a winner.

Any of you guys know were I can get new differential mounts?

SPL makes a set for the 350Z, which with a little work can fit the 370Z. I've emailed them about this, the bushing on the 370Z is slightly smaller so it takes a little more effort to squeeze the 350Z bushing in. They also told me that they're going to a release a 370Z diff bushing set in the next few months.

Thanks for the info Ray! I took my car by jays shop today and well we had it up on the rack he noticed my differential mount broke. This is on my list to do ASAP as this is my daily driver.

Please let us know when they do?:tup: