What Tailshaft Are You Running

[The Dan]

why? theres twice as many joints to fail..

Yeah only if the joints used are under rated for the application. Many 500hp applications still use the factory tailshaft.

2 piece shafts are stronger. It's a fact and any driveshaft specialist will say the same.

Going back to a previous post by someone, the falcon tailshaft made from alloy....Aluminium is lighter, therefore it has a much higher critical speed and they use a 3inch tube from memory. The longer the shaft, the stronger the material has to be or you have to lighten the shaft and/or make the tube diameter larger as well. The larger the diameter and the lighter it is, the critical speed goes up further. That is why carbon fibre shafts are probably the best material you can use. Extremely strong, extremely light.

[bigmikespec]

Aluminum alloy has a fatigue life though... Not like steel.

[urtwhistle]

About 6 months ago I got my 2 peice rebuilt from my 300rwkw R34. 1st drive I popped the clutch at about 4k RPM in 1st and blew 3 uni joints to peice's. I then returned said tail shaft and it was then forwared onto spicer, who refused to warrant the parts as they beleived I had either put huge power or locked the shaft some how. My question was, "how would you suggest a way that I could snap all 3 uni's in 1 go with out smashing out the bottom of my car?" they couldn't answer me. Luckily the workshop that built it for me where as confused as I was and met me half way with building a complete new 1 peice shaft.

A 1 peice shaft deffinitly transmit alot more vibration into the car but from what I can tell should almost be indestructable as it's much bulkier then original.

regards

Chris

[jiffo]

About 6 months ago I got my 2 peice rebuilt from my 300rwkw R34. 1st drive I popped the clutch at about 4k RPM in 1st and blew 3 uni joints to peice's. I then returned said tail shaft and it was then forwared onto spicer, who refused to warrant the parts as they beleived I had either put huge power or locked the shaft some how. My question was, "how would you suggest a way that I could snap all 3 uni's in 1 go .......................

regards

Chris

Got any photos?

Reason I ask, the shop I use does routine maintenance work for BMW and Merc. Both these cars have non-replaceable uni joints same as the Skylines.

Whenever I get a shaft built it's done with new yokes that have conventional circlipped-in replaceable unis, there's very few Nissan components left when he's finished.

BUT the guys from BM and Merc won't have non-original components on their cars, they have the peened-in design yokes machined for circlips, pass them over to him and he re-builds the shaft.

There's practically no metal left in the yokes.

I'd be interested to see if your re-built shaft was done that way.

[Duncan]

very interesting point. mine used proper rebuildable unis as you said.

[urtwhistle]

Got any photos?

Reason I ask, the shop I use does routine maintenance work for BMW and Merc. Both these cars have non-replaceable uni joints same as the Skylines.

Whenever I get a shaft built it's done with new yokes that have conventional circlipped-in replaceable unis, there's very few Nissan components left when he's finished.

BUT the guys from BM and Merc won't have non-original components on their cars, they have the peened-in design yokes machined for circlips, pass them over to him and he re-builds the shaft.

There's practically no metal left in the yokes.

I'd be interested to see if your re-built shaft was done that way.

hey Jiffo,

unfortunatly I never took any photo's of the shaft when it sheered all the uni's. I know exactly what your saying, yes the shaft was the peened style and machined the yoke to suit the circlip style. when it failed, none of the actual yokes broke, it sheered the actualle centres out of all of them. I would have though that machining the yokes would have caused them to be weaker and snap there first but it didn't.

Chris

[T04GTR]

lets see. i wonder what most race cars and drag cars use.. as long as the driveline angle is in check (most of the time its not..) i cant see any problems. besides a longer shaft will have more twist and hence be nicer to the unies..

[Sherrybaby]

i had massive issues with mine... and i needed a new cv joint.. but apparently... (i got told) that there is i think it was 3 bearings.. like a centre and a front and a back...

it was weird...

But i dont know too much about tailshafts.... plus i think that mechanic was dodgy....

[jiffo]

lets see. as long as the driveline angle is in check (most of the time its not..)

Exactly right.

99% of owners don't realise you must run your flanges parallel.

That usually means packing the diff, stiffer engine mounts and some serious dimension checking.

Comparing a 25 box with a sliding yoke to a GT4 box with an output flange is also useless, the shaft must have some in/out flexibility either from the CV or a spline.

Running a sliding yoke style box with a worn out extension bearing is also asking for vibrations.

A stock 2-piece will let you get away with a lot of these faults, they may not even be noticed by the average driver, but a 1-piece will show them up big time.

Wonder how many 1-piece owners have fitted a shaft hoop where the centre bearing used to live?

[SkylineSky]

A 1 piece Carbon fibre shaft from PST in Florida is the only way to go , half the reciprocating mass and was $1500 landed in Aus. Has got 1350 uni in the front a lot stronger and lighter if you have the money...

[thatjonokid]

$575 for a hardie spicer 3 inch 1pce...i snapped my 2pce in half with my old setup so when i got my 25 and 25 box i wasnt taking chances lol...has been awesome

[owen25det]

what sort of horespower are the stock 2 piece shafts cappable of?

i know someone earlier said they have been using around the 500 to 600 hp mark but what application are you using your car for? street, drift, drag, track?

if anyone is using a stock shaft with slicks at the drags would be handy to know the following..

*horsepower

*revs on launch

*tyres being used

cheers

[skylinecouple]

Can anyone tell me how much free play there should be when you move the shaft up and down in the center bearing housing ? Mine has a little.

[NIS.26L]

just ordered myself a one piece cromolly tailshaft of uniqiue autosports for my r34gtr it has 360klw at the wheels,will let u guys know how it go's fingers crossed i dont get problems, its totally made will all new parts and its costing me $1500 john seems to know his shit we running a cv type flange on the rear and beefed up unis on the front with mark williams yokes

[abr33]

I have a new shaft being built atm, im running 3 inch heavier tube, with uni's that are a 30mm cap x 90mm uni with external clips and all replaceable uni's. Will be a 2 piece shaft. The builder said they make them for 1000hp drag cars with no failures. Should well exceed my needs.

[BLITZ-26]

where are you looking at getting these built from? is their specific shops that specialize in performance tailshafts?

[bigmikespec]

Hardy Spicer

[WMDC35]

Fark! i've got a 1 piece built by ADL, it's been fine so far, fark! i'm going to have to change it

[abr33]

where are you looking at getting these built from? is their specific shops that specialize in performance tailshafts?

Hardy spicer

Fark! i've got a 1 piece built by ADL, it's been fine so far, fark! i'm going to have to change it

Why?

[WMDC35]

Hardy spicer

Why?

Ring any tailshaft maker in your area and they should tell you that a tube shaft of the length required in a skyline (I think it's around 50inches) will go critical at 6000-6500rpm. The harmonic inbalance is usually so harsh that they bend or buckle as a result.

Of course it depends on the material they are made from, how thick and the diameter of the tube but 2 piece shafts are stronger, much stronger. We put 600+hp through them all the time without hassles

this info seems to be on the money, my shaft is just over 50 inches , compared with 4wd which is around 10 inches shorter