Anyone else using difftechnics diff kit? I'm having vibration dramas. Help?

Hi guys,
I made a post earlier on about installing my diff kit.
After installing the diff kit at my mechanics I drove home. There were a few crecks and noises here and there but I didn't really pay attention to it. Untill I got on the free way. It started vibrating like mad... I called my mechanic and took it bAck to him. He told me that the cvs and unijoint are all stuffed or worn and need replacing.
But when I ask difftechnics about it he was adamant that there's nothing wrong with the kit.
Now the car is at home in the garage waiting for difftecknics to get back to me.

What do I do now. I want my car fixed. If I knew there was goin to be this much trouble with the kit. I woulda just spent the 2k on fixing my current stuff and just make do. But now I'm out of pocket 2k with 2 sets of diffs and shafts that are all stuffed..
Kon at difftecknics says he's chasing it up. But he's been flat out and under staffed. But dosent have time to check it all out. And I've been waiting for almost 2 weeks now since it's been installed. And it's still just sitting there.
I want my car running properly so I can enjoy the bloody thing.
Don't know what to do now. Any ideas guys? Suggestions or help of anysort will be much appreciated.
Thanks

Hey guys,
Completely forgot I posted this.. Remembered lastnight before bed when I was looking for an LSD. :p
Anyways I finally got a refund on all the previous shafts and ended up upgrading to the 1000hp items they said that's their only other option. I've now seen 2.8 rated shafts from driveshaft shop, which i believe is where my 1000hp items are from, they did say they were coming from the states. Anyways
So I had everything installed without much dramas this time.. Except that I forgot to get my original hubs back... Everythings been running sweet for the last few months now.. No difference in balance as alot of people have feared.. Difference in diff for sure. Seems to have more traction even though the diff seems sort of worn. :D happy Jan!! Now I Can't wait for a proper LSD.
Got a spare 4.4 sitting on the floor in the garage and will have that one rebuilt and swap it over soon.. The 4.4 is a much nicer ratio to play with..
:thumbsup:
I'll add fotos and stuff in another post at a later date.. Still don't know how to add photos on the iPhone and don't have access to another form of Internet access ATM.

Did Kon supply everything?

If they did then they should replace everything till it works properly.

I figured as much. He supplied the mounts and shafts. I got the diff. The front mount had abit of a gap when screwing it down. Asin when u tighten the bolt down completely there's a gap. But my mechanic just put some washers in to fill it up not really a big issue. But then the unijoint on the tail shaft has sprayed grease all over the back And he's also told me the inner cvs are worn out.
I don't mind replacing the uni joint that's only like $50. And get it balanced is another 150. But the cvs I'm not keen on.
Hopefully they will sort it out for me soon.
I'll give him a call tomorrow again.
Thanks for the quick reply.

Spoke to kon at difftechnics and he's been really good about it.
He's currently organizing some new shafts and stuff for a few other customers that have been enquiring about the kit and when it's all sorted he's happy to swap em back. So.. I guess I'll be awaiting his call. He said it should all be sorted in the next few days or so.

So who are these people askin about the kit.. U guys on this forum?
What he quote u? Hehe. :) maybe he can do us a group buy or something.
:)

Maybe it is a problem with your tailshaft being imbalanced and that is screwing up your uni joint.

Never heard of CVs on an R200 diff going bad...

I had similar thoughts with the uni joint. Kons isn't really positive that's it tho. But its possible.
I've only heard of cvs on skylines goin bad on the cars with big power or are old. Haha. Like u tho, personally I haven't seen it in person so that's y I'm opted for the r200 kit(more durability) instead of fixing my diff and possibly shafts(If not now in the near future) but I guess it's all going to depend on the phone call I'm waiting for.
These were on a boosted S I believe. And used for drags. But then he was sure they're still good. They changed coz the guy wanted to upgrade the shafts. I not sure. He seems pretty straight up.
I'm hoping the new items don't cost another arm and leg. I was happy to just balance the tailshaft and change the uni on it but send back the cvs for the new ones there making up and just pay the difference but he said they're a package.
So now I'm awaiting for kon to call me back with prices for the shafts for this kit.

Just a thought. I didn't find any shaft spacers for the skyline. I'm guessing their geometry doesent change as much when they're lowered. Could it be possible that even with the kit u still need shaft spacers if ur cars lowered?

Sorry I thought you already had the R200 kit in?

If you got a second hand S2000 diff from them with the CV's then its definitely the CV's. The wear point from the previous car would already be there and hence the vibration from being fitted to your car (which is most likey a different height - so the spiders in the CV will be in a diff wear point moving backwards and forwards creating that vibration).

Yeah i do. Sorry typo above. Edited.
I got the brackets new and the shafts second hand. Probably same thing applies.
I guess I'll wait for a reply on some new shafts or to reco/repair these.

Hey Guys, sorry for the slow ass update but here it is.
Vibrations are gone. Was the shafts that were rooted not the diff. So they were sent back and got refunded and ended up getting the 1000hp items with oversized hubs and extended studs. Difftechnics seem like good honest people and refunded the items as promised but then told me a 2 week turn around for the shafts. It took almost 2 months. Anyways
No more vibrations.. Wohoo..but urethane bush on the Nissan diff is essential as the stock ones with the Honda stock items are abit soft for driving hard. if u can replace it with aluminum or something solid, i think that would be best, so its mounted solid to the bracket like how the stock diff is mounted.
Anyways the car drives nicely. No noticeable weight difference but feels more planted..
Btw Thanks for the responses jbird.
And a huge Thanks to Bau@mod project for helping me sort all this crap out.