260z Mustache bar orientation

[Daedalus-Z]

Hi Guys,

          Bit of an odd question, I went to replace the bushings for the mustache bar in the 260 yesterday and noticed that the bar was actually mounted differently to the way the manuals suggest it should be, the 'curls' in the bar that hold the bushing faced forwards instead of backwards. I've actually managed to mount it the other way... but the amount of forced required to get everything into position afterwards was a little worrying. Based on the shape of the back diff cover I think it's an R200, should the mustache bar in fact be mounted the way it was originally?

 

 

[handsandwhich]

Here is the way it should be. "curls" facing toward the front of the car. I don't know how it could possibly mount the other way unless there is a different bar or diff in there somehow?

 

[MaygZ]

There are two styles of moustache bar.  The early girls (very early) had a straight bar.

[handsandwhich]

When the diff was also mounted towards the front more as well? I guess if your car has had a minor hit or two over the years, this can cause the orientation of the bar and the holes to not line up properly either.

[Daedalus-Z]

Hmm as it turns out Yes: it is possible (though incredibly difficult) to mount it the other way around.

 

The diff was in the stock location as far as I can tell, though as a result of my odd mounting it's now under a fair amount of tension pushing it towards the front. I *may* be able to be left like this, but TBH I think I'd rather not risk it

 

Thanks heaps for that.

[Enzo]

The R180 diff has the bar mounted with the curls to the rear and the R200 diff has the bar mounted with the curls to the front. The correct bar has to be used with the correct diff. They are not interchangable.

David.

[jamo240]

Heya

 

Some of the chaps on here have excellent knowledge on which year cars had what, but in a nutshell, the early 240's had the R180 diff, and the curls on the bar faced rearward. This configuration caused problems with the rear driveshaft angles (too much angularity in the plan view), and early Z's were/are known to chop out the splines between the stub axles and drive shaft flanges. I have removed a number where the retaining nuts are only still in place due to the staking, but have become loose, and the spline has noticeable wear. So much so that the flange and axle have to be replaced. To correct this, Datsun moved the diff rearward by turning the mustache bar around, offsetting it by the diameter of the curl. This corrected the vibration/wear problem.

 

By 260Z, the R200 had come along, which has a different offset in the rear case to accomodate larger gears etc. The mustache bar is different for an R200 to accomodate the different diff, and from memory, the two studs that go through the mustache bar from the diff cover are larger in diameter too (c/w R180).

I have an R200 in my 240Z, and simply put the mustache bar and diff from a 260Z straight in. Mine is a 73, and I am pretty sure had the late model fix for the diff from day 1.

 

I can't remember what they did with the front diff mount, but it is pretty straight forward, as I am pretty sure I have all the original 240Z diff mounting brackets in place, with only a change to the rubber mount.

 

You will of course need the appropriate propeller shaft to go with the diff offset rearward. The early Z's had the flange type gearbox, whereas the later ones that went with the diff position change had the slip-yoke style.

 

Cheers

 

Jamo

[gilltech]

I have an un-modified early '74 260 2-seat, manual, R200 diff - yes the bar curls face forwards. There's no way that the bar could be reversed or the R200 diff wouldn't fit, or at least on my car it wouldn't. Your bar was the right way around originally, I think the manual you're looking at is for a 240 with the shorter R180.