Prop spacings

Guys, I am sure this has been asked countless times before but after installation of my rocklobster box, I have fitted the props and have a 25mm gap between the tbox and input prop from the gearbox - with the splines pushed right into the gearbox, should I get a 25mm spacer or get an 18mm spacer to allow a few mm for movement/expansion.

The rear output shaft fits bang on between the rear diff and the xbrake disc on the tbox again with the splines pushed all the way in and the vehicle sitting on level ground (with my 4.5'' springlift fitted) again is this okay or do I need to allow for expansion. I cant see that the distance to the rear diff will decrease anymore than when the vehicle is standing on level ground?

I have the ORA fitting kit and a samurai mini prop, also a 15mm spacer.

Yeah thanks for that info Gaz. The issue I am having difficulty getting my head around is how do I work out how much 'compression free travel' do I need to allow in the propshaft splines when the vehicle is standing on level ground. My concern is that if the springs were to compress at the same time causing the diffs to move up and thus closer to the tbox, I was worried if the spline faces met this would cause damage, if that makes sense.

The mini prop from gearbox to tbox is less of a worry to me since I really cant see the distance between tbox and gearbox changing much since they are both effectively bolted to the body/chassis.

Smoggy wrote: My concern is that if the springs were to compress at the same time causing the diffs to move up and thus closer to the tbox, I was worried if the spline faces met this would cause damage, if that makes sense.

It won't cause any instant damage, but if you hear some weird clanks and clonks while hitting some bumps on the road, I suggest you solve the problem immediately before any real damage occurs.

Also, If you know someone with a tractor or something, he might help to press the rear end down carefully so you can check how that prop shaft behaves under full spring compression.

What agreat idea Paul, I never thought of that one.

Incidently I just got off the phone to Rob at ORA and he was extremely helpful - suggested bolting the miniprop up as is or maybe fitting 12.5mm spacer at most and regarding the tight rear prop he said I could trim a half inch of the male and female slip joints in the prop if necessary. He also suggested checking for any crud within the female and clearing it to gain a bit of free space