This may help some people with vibration probs. I had a bad centre bearing (see ride section for all pics)and clicking front u/j. the cost of repair soon added up so i went looking for a 1 peice propshaft. I have found a local enginnering shop which made one up for me and having now fitted it vibration has gone. The new shaft uses the old front u/j which has been reamed out to a size of bearing more available (I asked for a rebuildable type with grease nipple) and the rear u/j which was okay ,these were then resleaved with new propshaft tube. The length of the shaft is exactly the same as when i removed it (did not break center u/j's). Machine shop had my propshaft for about 2 weeks but reckons could do it a lot quicker now. The quoted cost was £170 which turned out to be plus vat but that was fine and i can say the finished product looked and works great. The machine shop is Precision Engine Services (Aberdeen) 01224 789777 and ask for Lachie

The reason for any shaft being 2 piece is to increase it's critical speed, ie the speed at which it will start to whirl and potentially self-destruct. If you replace a 2 piece steel shaft by a 1 piece steel shaft you will without question reduce the safe max speed of the car. Presumably Nissan found that for the 300ZX to be safe at Vmax (160mph , or whatever) it needed a two piece shaft. With a one-piece steel shaft (depending on it's length and diameter) the safe maximum speed will have come down to 140mph, or 120 mph, or maybe even lower. Be REALLY CAREFUL about this if you're tempted to follow the idea of a one piece steel shaft

 

a great post but can i ask how could they fit the 2 seater with a 1 piece and many of the upgrade parts are 1 piece say made of carbon or alli ?

i was talking with the z centre who commented that 9/10 of enq re car vibration turned out to be prop related and replacing sorted the problem ??? and even just a little bump can knock the prop out resulting in vibration (mine started after a hitting the kerb ,but not hard ) im a bit confused but doesnt take much

and so the sargar continues

any comments very much appreciated

ant

oh any one nr leeds area ???

It's no wonder we don't get more problems with the propshaft, as in 4th gear it is spinning 1:1 with the engine. Thats quite scary as it's onls 12" from your ass!!!

 

And in 5th it's even worse 0.75:1 !! Imagine running at 140+ with prop running at 6000+rpm and letting go.... not nice..

 

Be very careful everyone. The hospitals have enough to do without picking steel shrapnel/carbon fibre shards outta your ass!!!

 

Regards

 

RCD

Hi antleeds

 

I did a sh**load of searching for propshaft places just in case the other suggestions didn't work. During this I found

http://www.propshaft.co.uk/

 

who are in Bradford. I have no idea how good they are except to say they were the only one (of about 4) I contacted who bothered to ring me back. At the moment I haven't spoken to them about the ZX so there's no info about their experience.

 

If they are not close to Leeds, apologies. If you're talking north of Hemel Hempstead, my vision goes all blurry and I spill my shandy.

 

Cheerio

 

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Guys mine is still doing it, always has done but it's not getting any worse!

 

However, I've just ordered a new set of 18's which won't be going on for another few months until the car has been kitted and sprayed.

 

Just that before I go lashing out on a new prop I wanna see if the wheels sort the problem out.

 

Will post nearer the time.

 

 

 

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GIO ur a start ,the prop shaft place you recomended is about 4 miles from my house and boy do they know there stuff .quiet a excentric bunch but well into what they do and they have done lots of z`s centre bearings . apparently the centre bearing is directly above the exhaust which is fine whilst under norm usa driving but when stuck in uk traffic the heat gets in and frys it (makes kinda sense ) . i took one of the guys out for a test drive and he was all over the car listening for the drone and its going back next monday for a day of investigation

i will keep you all posted with progress but its looking hopefull

thanks again gio

bye bye 4 now

The plot thickens!

 

I've been following up Jack / Cos suggestions with the results:

 

a) wheels off - still vibrates. So must be prop or centre bearing or rear gearbox mount;

 

b) showed the forum to Colin (the professional bloke what did the tests before) and he said this all made sense (so thanks, guys - I'm glad someone is speaking sense in this crazy world). We tried wheels off (as above). He spoke to some of his trade contacts - in particular a prop place in Luton - and they said this was known problem and even mentioned the rear gearbox mount like Jack suggests.

 

Colin dived back under the car, poked about (again - fnarr) and said that the mount had indeed sagged - and it would be worth doing that before anything more expensive!

 

So I've got one on order - cheapest from Japarts is £48.31 + VAT but has to come from Japan so will be 10 days. Nissan price is either £66.20 or £56.20 (wasn't listening properly - oops) and MJP quoted £50.58 but from Euro stock so not big freight delays.

 

Once fitted, I'll post results so expect to see this topic bounce back to the top of the charts unless the administrators get bored and can it!

 

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Gio

 

...I replaced a 10 yr old centre bearing (looked ok) with a new one to no avail. I replaced the gearbox mount and the vibrations went away. Now I can feel the flat spots the tyres form from standing overnight - I've become obsessed... need new tyres or maybe I should inflate them more.

Jack - yeah, it is sounding spookily similar. It was your suggestion which sparked Colin into the second poke around underneath after which he agreed with you - so thanks for that.

 

He said that the general oiliness (not a leak, just years accumulated weep / drip) of the area rots the rubber of the mount. Which is why it sags! He thinks it is probably a tad better to replace with new rather than shim with rubber over an old mount so that's why we're giving it a try.

 

Thanks for your pointer - v helpful. Will report once Japarts / Colin have done their stuff.

 

Cheerio,

 

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hiya lads just been to colect my car from the prop place gio recommended and its like a different car . the vibration has gone . i can now rev the car and the only way i know its reving is the sound and looking at the counter its thats smooth and the the rear gearbox mount looks the prim suspect . we replaced the centre bearing which had started to sag while the exhaust was off, but the rear box mount though didnt look that bad when compared to a new one you could see the amount it had sagged . there is still a droning noise and cos has kindly offered for me to try his wheels before i go replacing mine (thanks for the kind offer cos it people like you that make this forum so so good really appricated m8 ) . i was thinking about selling mine but after driving it this eve i remembered just what a super car the z is

oh the price for centre bearing ,rear box mount ,labour ,loads of other little bits came to £348 . the guys at the bradford prop place and are superb ,the best ,really worked hard, kept me well in touch with progress and cost advised of many cost saving ideas , for full report pls email me i will keep you all posted when ive been to see cos ,and thanks to everyone for your input,ideas and offers

ciya

Gosh, wow, some new html seems to have appeared.

http://www.netcomuk.co.uk/~webster/propvibesintro.htm

 

the story so far on thoese pesky vibrations!

 

Cheerio

 

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http://www.netcomuk.co.uk/~webster/gioindex.html