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

great posting cookie

its a ongoing problem for so many 2+2 z owners

im still working out if its a drive shaft vibration

my garage are telling me its tyre noise ? did they tell you that ??

thanks again

Yeah this problem is baking my noodle aswell!!!

 

Since getting the car back from having the Auto rebuilt the car is still vibrating. However, I was wondering whether it's tyres on mine. AndyP suggested that it could be my wheel geometry etc.

 

Reason being that mine will do it from cold say in the morning but once the car has done a few miles it stops!

 

Could this be due to the tyres having warmed up? Also the car has been standing on those tyres for eons which can't be good. Flatspotting etc.

Timmy

 

...I'm in the middle of the same problem, and I think it's your gearbox rear mount. It sags when not used (thats the theory) - therefore the problem is most noticable when the car is first used after it's been standing for a while. I use my car every day, and if I don't use it over a weekend, the vibrations are very noticable when I first start driving, and get less as the car 'warms-up'. I'm just about to replace the mount so I'll let you know if the theory is correct.

 

 

That would be a pain in the arse - especially as that bit will have just been removed ..... Ahh well, at least it's easy and cheap-ish to fix if it is the case.

Does this mount cause a jolt when applying and coming off the go pedal?

 

Feels like the whole engine and gearbox are moving! Not more dollars? Can't take much more, am already upto my eyes with the IMO FFS!!!

 

 

antleeds

 

I did not have a garage look at my car, i do most things on the car myself. I had the vibration for a long time and only noticed the center bearing sagging when changing the exhaust center section (removal of the restriction washers seems to make a big differance to my car and does not take long ).The cost of the center bearing £135 + vat approx , when having removed the propshaft that also brought the clicking u/j to light. 1 piece propshaft seemed the way to go looking at TT net so thats what i did.

Was there much difference in weight or strength?

Can't say i noticed any weight difference although you have to remember the stock propshaft is supported in the middle. The propshaft tube used is aparently the same thickness as the nissan tube which is no more than 3mm from looking at the bits i have left, the outside diameter was the same. So for strength i dont know, time will tell, it seems fine at the moment.

What about the rear CV joints? I've never heard anyone mention these on the forum before. After all, they can't last for ever, and there are four of them!

 

Just a thought

Simon.

ok question time

who has had a one piece fitted ? and what kind of miles had the car done when you had it replaced ?

is there anyone around the leeds area that knows of someone who can manufactor a 1 piece?

mine starts at about 38 mph and its a slow drone with slight vibration through the car

it does not ware off just remains constant and its driving me mad totally mad

the garage have said its tire noise due to the fact iv`e two different makes on the back ? anyone agree with that ?

should i try changing rear tyres first

and input would be very well received

thanks in advance

ant

trying at the top again

any advice very much appreciated its getting me down

thanks

I don't know much about 300ZX's, but I do know a bit about propshafts. My speciality is composite shafts, where a 1-piece shaft can be used instead of a 2-piece steel shaft. I found myself in this discussion because I was e-mailed by someone from the US asking if we could do a 1-piece shaft for his 300ZX (take a look at our website), so I started to look around to see if this was a general requirement.

 

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.

 

I note that the new 350ZX is being launched with a one-piece composite shaft (not produced by us, unfortunately!). Composite shafts are mainly only used in Motorsport, being a bit staggeringly expensive for most road cars, so I don't think it's going to be viable for us to set up to produce them for 300ZX's (unless nearly every owner would like one.....)

Very interesting reading. Cheers for that mate!

 

So going one piece over two piece may not be a good idea then???

 

I did wonder why Nelson charge so much for an OEM replacement and yet a one piece jobby is about 300 squid!!!

 

 

ruddy hell i thought id got this thing sorted by replacing with a 1 piece shaft but that post has put the cat right in em

ok calm down !!! any one with a 1 piece ? what kinda miles had it done b 4 u replaced it ? has anyone just had the bearing done ? in fact any additional info would be very welcome

cheers folks , and to the last post for such a detailed reply

Hi Spinning,

 

I have a one piece prop shaft manufactured by

www.reco-prop.com

 

It is stronger and lighter than stock and I have covered around 3000miles with it fitted.

 

Should this company have mentioned anypotential problems to me before proceeding with a one piece prop?

 

Any further comments you have would be interesting.

 

I know of lots of people in the U.S who have either fitted a carbon fibre or aluminium propshaft.

 

Steve

On friday I ordered my self a single piece carbon fibre shaft from

ACPT

 

[ed: Bugger - html is turned off!]

 

Simon

 

 

[This message has been edited by WillyEd (edited 24-02-2002).]

wow what have we started we have even one of those firey torch things going

i think we need the advice of the godfathers

geoff tt , mac1, timmy turbo they seem to know all things grasshopper

so lets call on the gods and see if we are in favor ??? wwwhhhhrrrroooooooo are u there ????

after all that i think when i smacked mine against a kerb it could be the tyre so im gonna try that this week b 4 anything else ,but all input welcome ciya

As some of you will know, I've been trying to get rid of the vibrations for some time now. Started with replacing the centre bearing (small improvement)changed the relationship of the rear cv flange to diff (small improvement) then replaced (second hand - thanks Shaun) the rear gearbox mount - and the vibes have gone. The replacement mount was 3mm deeper (less sag) - and it made all of the difference. It's an easy job, 6 14mm bolts and 2 12mm nuts. I'm sure that the vibes can be cured even easier. If you remove the cross beam that supports the mount (remember to prop up the gearbox first) and place about 3-4mm of rubber strip into the mount, round the 2 12 mm studs then replace the cross beam, you will in effect raise the sagging mount (and gearbox).

 

While the car is up in the air to give you access to the mount, run the engine, car in gear and check for any out of true movement - it's easy to see. You can also check how good (round / buckled / flatspotted) your wheels and tyres are.

 

...so, after trial and error, I've got it down to the rear gearbox mount. Mines a 1991 jap auto.

 

...good luck.

Cheers for that guys. Will be getting mine checked out shortly.

 

Ant,

 

I'm not a guru where Tech is concerned matey, sorry! I leave all that to AndyDuff, SteveE, JeffTT, AndyP, Az etc.

 

P.S. sorry if I never mentioned ya! LOL

 

 

 

------------------

This is possibly the most helpful thread I have ever read - and why I joined this forum so Hi Guys & Gals.

 

I have seen / felt much of the behaviour reported by Cookie, antleeds et al so hopefully the following history may help others.

 

My 1989 Jap import 300zx TT 2+2 manual has had a vibration since I bought it. It is relatively intermittent. It is definitely related to road speed rather than engine revs so thought aha! That'll be wheels, then.

 

New Tyres (Bridgestones), wheels balanced all round. No improvement. Bugger.

 

Off to that nice Mr Mandela. Heat shield rattle they said - we've fixed it. No they hadn't.

 

Read ZClub mag. Someone said centre bearing and recommended a prop shaft specialist near Gatwick. Went off, got charged £385 for dropping the exhaust and rebalancing the prop and fitting new UJs. Seemed a bit better but no real improvement. Bugger again.

 

Got back to Mr Mandela and he said there didn't appear to have been any rebalancing done. They contacted Nissan on high and were told no idea - change the propshaft. Which at £750 + VAT + labour seemed a little extreme.

 

My good lady has used the same local mobile bloke to look after her cars for donkey's years and he seemed trustworthy enough so I just got him to have a test drive and poke around underneath. (Car up on stands, me "driving" to get the vibration to come back.)

 

During the test drive, the vibration got worse under acceleration (as usual). Colin interpreted this as a pointer to the propshaft i.e. load = vibration, no load = no vibration.

 

Yes, he said, definitely something to do with the propshaft. Also the centre bearing is out of alignment i.e. the prop shaft is not rotating in the centre (if you see what I mean). He also held a straight edge up to the prop and it marked it but only on one side thus proving the shaft was wobbling eccentrically (oo-er missus).

 

While the car was up on the stands, he also noticed that the rear Bridgestones had a marked radial run-out (i.e. outside surface of tire off centre compared to wheel / hub). But IHHO this was not the cause of the vibration.

 

This is as far as we have got at the moment. If I have read the postings here correctly:

 

- centre bearing vibration can be cured by single piece propshafts;

- single piece propshafts are not necessarily a good idea as they can "whirl" at a lower critical speed than a two-piece one;

- if it does it worse when cold or not used for a bit, this could well be the gearbox rear mount issue.

 

I have found a number of links about propshafts and my bloke also claims to know a good one. I have e-mailed a few and will post any replies that look helpful.

 

Otherwise I guess my next steps are to

 

a) see if there are any more bright ideas here

b) get the propshaft checked by a propsahft specialist with a good reputation and

c) fiddle with the gearbox mount as mentioned here already

 

Thank y'all kindly.

Gio

 

Interesting what you have written. I had similar problems up until 2 weeks ago.

 

I have had my Z for about 6 months now and have noticed that I get a vibration at around 65mph which remains. At 80 is was terrible and after that it became lesser but a faster - if you know what I mean.

 

I balanced my tyres and got the tyre fitter to check the alloys, which he said looked fine but the vibration remained...until.....

 

I bought new wheels! Bigger mind so new rubber too but NO VIBRATIONS now. At last. Feels like a diferent car.

 

Unless yours are new wheels too, I would try somebody's wheels that you know are ok before you carry on throwing money at it.

 

You can come up and try mine on if you like.

 

 

Gio

...get the back of the car up on axle stands and run the engine in gear, go through the revs and feel for vibrations. Then remove the wheels and do it again. If the vibrations go, then its the wheels/tyres. If they remain, do the gearbox mount.

 

good luck.

Hi Cos, Hi Jack

 

Good suggestions guys - that's what I will try next. Thanks a heap.

 

Gio

HIYA LADS

HELLO LADS

fab posting jack > loved your idea of wheels on and off because ITS CHEAP and should ? give a idea to possible cause ,well at least you know what it isnt

i dont drive my car much and havent had it out in a few weeks but as soon as the weather improves i will be trying out your idea .again a big thankyou for all your input and poss solutions to the wobbling z`s ciya