I am a long time lurker here, First time poster.

I have a 2006 Base 6 Speed 350z.
I bought the entire rear differential (still with axle hubs and such) from
a wrecked 2004 with LSD (also a 6 speed car).

I removed mine and bolted the 04LSD right in, No issues, Just time.

Go down the road and about 40mph, things start to vibrate... Until about 50.
Then they come back about 65 and never go away again.
Not a small vibration but a good humming one.


So I go through everything for 4 more hours,, Everything is correctly bolted
in place and torqued properly. Put it up on a Rack and run it some, You can see it vibrate/wiggle and MAYBE the adapter plate the driveshaft bolts to wiggle... But its very hard to tell truthfully... This was at a constant speed.


Remove the 04LSD, Put my Base back in... Everything is perfect now..

So I went back to the place in town that I got the differential from (local salvage) and told them something was warped and I wanted a refund... 2 hours later, I was asked to leave....

During all of this, I was told that maybe the plate on the differential that accepts the driveshaft "could" be tweaked......

Well I have mine that I could try.... Good grief... But this requires me to change it back out and try it...

Advice? Anything else I could look for..
This has become a HUGE thorn, I have a good mind to stay Base....

Thanks so much everyone.
This is my first 350z, But I have owned 2 300ZXtt's long ago. I'm a Z fan through and through.

 

Had someone tell me that I could have possibly not mated the drive shaft to the flange on the differential properly.?

 

You have to make sure the driveshaft and rear end flanges are mated perfectly flat to each other, but they don't have to be rotated to any particular position for balance....balancing is only an issue when you change u-joints.
The yoke flange may be bent though, since a lot of weird things can happen to wrecked cars, like a pole vault using the driveshaft as a pole. Maybe you can drop the shaft and swap yokes from diff to diff, I don't know for sure.

 

Thanks, I will swap the Yoke to my current Base diff. that is in the Z and see if I get that vibration. I'm really hoping that's all that is wrong...

Also I remember the flange on the LSD diff was a little rusty on the end,,,So I wonder if there is enough accumulation there to make a difference on balancing...

 

I highly doubt rust would be enough to throw anything out of balance...

My guess is possible damage to the yoke on the dif you got, just take em apart and swap em out if you can

 

You may have purchased a VLSD that was badly worn. If the ring and pinion were damaged or the lash not properly set, that might also explain the vibration you are feeling. What type of diff fluid are you using?

 

I went with Redline diff fluid in it, 7590 I think it was, I researched it on here and ordered what most people recommended.

The chunk has never been opened up (from the factory).

 

I don't know if I could have the skill to take these apart and make 1 good one.... I can "tinker" with the best of them, But I am ignorant how to set lash or whatever inside these things.....

 

Not many people are skilled enough to repair a LSD. Usually, the ring and pinion wear in together when the lash is set properly. So "tinkering" isn't going to help put together any worn out diff parts. Money would be better spent taking it to a specialist who can properly assess your diffs condition and possibly get an estimate of the repair. If you find it is the ring and pinion, PM me as I have a VLSD unit with low miles for sale.

 

Thanks, I just sent you a PM about your LSD.

 

Yeah, if you're asking about it then maybe you should have a pro check it out. I've done it before, but not without help.