single piece tailshaft on gtr?

[Amaru]

Just looking for some general feedback (and hopefully within the next 60 minutes) as to what people would think of the following.

I have a 1992 R32 GTR, and the tailshaft bearing needs replacing. The mechanic has asked me if id be interested in putting in a single piece tailshaft, as then I wouldnt have to worry about cv joints, centre tailshaft bearings etc.

My main concern with this is, talking to a few people, it would punish the rear diff a hell of alot more than it does currently.

What are peoples opinions on doing this?

Thanks

Nik

[Steve]

Well, the original ones last for many years - and Nissan put the one that's in there, with a cv joint, for a reason. I am cannot understand why they would put a CV joint in a tail shaft for the hell of it, it would be cheaper and probably lighter to use one piece.

Can this mechanic guy give you a guarantee that a one piece wont fark anything up - and do it in writing?

I am always sceptical when a someone says they can do things better than the manufacturer, without having the R&D to support it.

[benjiman74]

I agree with Steve, Nissan put it there for a reason. Last year my mate put a one piece in his warm VL thinking it would eliminate the need for the centre bearing etc. The tailshaft was quite thick in the wall and it was balanced. Lasted around 6 months then let go at 210kmh, made a mess of the floor, stuffed the gearbox output shaft and also the diffs pinion gear. $3,000 later for floor and mechanical repairs. I know its a different car but the same principals apply, i remember touring car commodores raced with the centre bearing still in place.

[DAN00H]

Hi Nik

The problem you will encounter is this, the GTR does not have a spline shaft coming out the back of the box (ie: ford BW35, C4 & GM T350, T400, powerglide to name a few of the more common RWD) - it has a 4 bolt flange.

The spline actually moves in and out with the rear suspension (as these car are mostly live rear axle - I know this is kindergarten basics, but I have to make sure I'm explaining myself!!), where as the GTR has the diff centre mounted solidly to the rear cradle.

The trouble with putting a solid shaft into the GTR means you will have no movement between the rear of the box and the front of the diff flange. I would love to see how he is going to mount a solid shaft between the diff and box (which are both solid mounted, as on the normal falcs etc, you slide the tailshaft all the way into the back of the box, then bring it back to mate to the rear uni/flange on the diff)

So, unfortunatly in your case, the short answer is no (unless he is going to convert your rear box flange, to enable it to be the spline type - scary!!)

I looked at all of this only last night, as I finished bolting up my tailshaft.

One thing you need to look at is to make sure your current centre bearing has not come adrift of the lugs on the hoop mount. Remember I told you mine was fragged? when I looked at it, it had come out of the lugs - so now that it is back in - it is way tighter, very little movement.

Best of luck - let me know how it goes

Dan

[Skyrine-Dave]

ok.. so when using a RWD (RB25det 5spd) on a car equipped with the IRS (R200) rear end... you DONT want to use a single piece tailshaft ??

[DAN00H]

ok.. so when using a RWD (RB25det 5spd) on a car equipped with the IRS (R200) rear end... you DONT want to use a single piece tailshaft ??

No - not without some big work

[Fitzpatrick Speed Works]

i think you can on a rb25 as they arent solid bolted to the gearbox they slide in on a shaft if they do id say it would be cool... previous the vl is a very isolated incident a one piece shaft especially on lowered commodores is a good idea due to the agles a 2 piece creates from being lowered..

[Fitzpatrick Speed Works]

the idea behind a 2 piece is to reduce driveline vibration put simply, one pieces also need more frequent maitnance, that is why 2 pieces are a more popular facory fitment.

[Skyrine-Dave]

well i have a HR31 passage... Its RWD and has the IRS/LSD rear end. I am not too sure how it is mounted etc hence why i asked the question.

But having a think about it i can see how the 2 piece would work with the diff when it moves up and down.

I am nearing the stage where i'll need to get the yoke and tailshaft mated to each other, so this information is pretty valuable to me

[Amaru]

Thanks for the info people, im sticking with the two piece as its tried and proven

[Clint32]

yeah the rb25 box has a spline output shaft, i run a 1 piece and its no probs providing like anything its done right. they will be a problem if its run a angle but in a skyline its pretty streight so it shouldnt be a problem

[autObarn]

the idea behind a 2 piece is to reduce driveline vibration put simply, one pieces also need more frequent maitnance, that is why 2 pieces are a more popular facory fitment.

i think another problem with such a conversion is that most one piece tailshaft setups use a extension housing with a stronger extension housing setup to support output shaft better, the centre cv bearing setup allows only minor horizontal in out movements whereas one piece will transmit more vertical and radial whip like forces to output shaft and housing. constantly chewed out ext housing seals are signs of this excesive radial movement.

[Skyrine-Dave]

Hey guys,

I received this email from a very helpful guy at Hardy Spicer. He raises some good points to consider:

It is not generally a good idea to replace a two piece shaft with a single piece shaft for two main reasons:

 

           1.         The geometry between the gearbox and diff are different for the two different shafts. Changing from one to the other requires changes to gearbox and axle mounts to obtain the correct geometry. A one piece shaft also requires more room than a two piece shaft and often there is insufficient clearance to fit a single piece shaft; even if the transmission tunnel is big enough to fit a one piece shaft there are often complications with seat belt anchors, hand brake brackets, cross-members, suspension mounts, exhaust(s), etc.

 

           2.         The main reason for using a two piece shaft is related to the speed that the shaft spins at. A one piece shaft has a much lower speed rating than a two piece shaft of the same length. Shafts in many applications can be spinning at up to 2000 RPM faster than engine speed due to overdrive ratios in top gear (sometimes the top 2 gears) and a single piece shaft simply can not handle the speeds required.