Do I need to shorten my 2 piece drive shaft?

[oldrx]

Currently there is no play in thy drive shaft yoke on the gearbox output, I was thinking of getting the driveshaft shortened but its a 2 piece so as the diff moves up/down the driveshaft cant move in and out on the yoke? What am I missing here? 

[smokin'joe]

please elaborate............. does it have centre bearing with UJ )like 2-piece Toyota) or a CV (like Holden Commonwhore ?

[morkster]

If it's an rx2 the rear is multi link so not much back and forth and has a centre bearing so front should be ok too as long as it's not tight?

[oldrx]

Yes rx2 with factory multi link rear. Its definitely tight, had to hammer the driveshaft to come out of gearbox but I can move the motor forward a little I think (have to check sump to X member clearance), maybe 5-10mm this would give a little room for driveshaft to move, would that be enough? 

 

 

[oldrx]

1 hour ago, smokin'joe said:

please elaborate............. does it have centre bearing with UJ )like 2-piece Toyota) or a CV (like Holden Commonwhore ?

Stock image above

[morkster]

Try it and see might be enough

[oldrx]

Jack the diff up and down to test ya reckon?

[shizzl]

So if you unbolt the centre bearing and disconnect at the diff end, it won’t slide into the gearbox any further?
13b in a 12a car pushing the driveline back a bit?

 

can you slot the engine and box forward?

the Mazda centre bearing is basically just a rubber bush. It won’t slide forward much if the car is already slammed.

 

usually around 20mm in out movement at the most. 
if there is corrosion on the splines it will be a prick to slide into and out

[oldrx]

13 minutes ago, shizzl said:

So if you unbolt the centre bearing and disconnect at the diff end, it won’t slide into the gearbox any further? Correct
13b in a 12a car pushing the driveline back a bit? Yeah that could be part of the cause

 

can you slot the engine and box forward? Yes but only 10mm max 

the Mazda centre bearing is basically just a rubber bush. It won’t slide forward much if the car is already slammed.

 

usually around 20mm in out movement at the most. 20mm sounds like a lot, I have been jacking the back up a lot recently and turns out there was 0mm available travel
if there is corrosion on the splines it will be a prick to slide into and out - No corrosion was just jammed in tight

 

[shizzl]

Yeah if it’s a 13b into a 12a body with unslotted crossmember it’ll definitely bind up your driveshaft. 
 

have a look at the gearbox mount, it may have aft loading on it pushing it backwards.

[oldrx]

20 hours ago, shizzl said:

Yeah if it’s a 13b into a 12a body with unslotted crossmember it’ll definitely bind up your driveshaft. 

Yeah I know what you mean but its all custom made + a collection of parts from different vehicles (in the customary fashion) - RX3 engine X member, custom breast plate, 12A rear plate, rx4 bellhousing, rx5 gearbox, custom gbox X member...

 

20 hours ago, shizzl said:

have a look at the gearbox mount, it may have aft loading on it pushing it backwards.

This got me thinking, I think I should bolt the d/shaft to the diff flange and measure where the center hanger wants to sit with diff at ride height, then shorten the rear half of the d/shaft to suit which will also give me a bit of travel at the gearbox yoke.