Thread: ZF S5-42 to LT 230.

Seeing the debate led me to down 5 minutes thinking... Not necessarily a good thing, but the idea might hold some merit?

Anyways, the theory Nicks 90 **** the gearbox because the shaft was floating seems sound, it would perhaps help a little to know what the failiure was (spline failure? Something internal caused by the tail shaft floating? ) but assuming it was the adapter shaft floating and not much more I'm thinking why go to far away from what is fairly simple idea?

We know the adapter made up with the RTC5090 shaft and ZF output did the job, so why not work with that to produce what's needed? Have a look at the picture and I'll try and explain it.



RTC5090 is a hollow shaft, usually secured to the back of a ZF4HP22 with a long bolt, so the idea is make up something similar to go down the middle to which will attach to the back of the ZF, obviously it will need to go in from the front as the nut will be too big otherwise, but if you make up the nut with extension on the end and machine flats to allow tightening then there's a reasonable possibility it would all go together and work.

I suppose you could also cross still and pin it (through the threaded section) if you were worried about it loosening off.

Unless I'm missing something then it keeps it all simple, there's some leeway for movement and alignment between the two boxes, and everything SHOULD (emphasis because maybe I'm oversimplifying) be working as designed with no new stresses on the system.
And, should the adapter break it wouldn't be impossible to get apart and change.

Also worth noting (not sure what transfer ratio you were aiming for) that the 1.003:1 input gear WILL NOT come out of the PTO hole as with the 1.2, 1.4 and 1.6, which might also scupper your plan.

Originally Posted by DasLandRoverMan

Also worth noting (not sure what transfer ratio you were aiming for) that the 1.003:1 input gear WILL NOT come out of the PTO hole as with the 1.2, 1.4 and 1.6, which might also scupper your plan.

Use a big enough hammer and it will!!!! Jokes aside, I didn't know that, and yes, that's exactly the ratio I'm using...... Interesting.... Re bolt thru the shaft... Said shaft is only approx 25mm thick.. Minus the 12mm of material that's missing for the center bolt... Add to this the 500+ nm of torque from the 6bt and that's the first reason I'm avoiding the shaft... The second reason is engine/gearbox/Tfer case length... From Nicks pics the space between the ZF and the LT is 50+mm... Mine will be 25mm, and the slim line fan will be mm from the rad, and the rear prop is still going to be very short... Length is the issue, which is why I went with the ZF. Was wanting a late Allison 1000 6 speed auto! I have the adaptor shaft coming with the transfer case, so might have a rethink once it all gets here.... Cheers for all the input tho.. All food for thought!

Depending on the radiator you're using you might be able to shunt it forwards a bit (bearing in mind the steering arms are down there) and get a bit more length at the front.

Drop the back of the transfer box a bit and it won't hurt as much having a shorter prop either.
I mean, it's not like you'll be doing winch challenge off roading is it?

If I have any other bright ideas I'll let you know.

Originally Posted by DasLandRoverMan

RTC5090 is a hollow shaft, usually secured to the back of a ZF4HP22 with a long bolt, so the idea is make up something similar to go down the middle to which will attach to the back of the ZF, obviously it will need to go in from the front as the nut will be too big otherwise, but if you make up the nut with extension on the end and machine flats to allow tightening then there's a reasonable possibility it would all go together and work.

You mean like this?
http://www.aulro.com/afvb/projects-t...ml#post2009912

The simpler (fewer parts) but harder (more work) way is to simple drill/tap the output shaft of the gearbox for the tension bolt. If it'll come out remotely easy then that is the best path to take.

Originally Posted by Sitec

Use a big enough hammer and it will!!!! Jokes aside, I didn't know that, and yes, that's exactly the ratio I'm using...... Interesting.... Re bolt thru the shaft... Said shaft is only approx 25mm thick.. Minus the 12mm of material that's missing for the center bolt... Add to this the 500+ nm of torque from the 6bt and that's the first reason I'm avoiding the shaft... The second reason is engine/gearbox/Tfer case length... From Nicks pics the space between the ZF and the LT is 50+mm... Mine will be 25mm, and the slim line fan will be mm from the rad, and the rear prop is still going to be very short... Length is the issue, which is why I went with the ZF. Was wanting a late Allison 1000 6 speed auto! I have the adaptor shaft coming with the transfer case, so might have a rethink once it all gets here.... Cheers for all the input tho.. All food for thought!

That 12mm of material in the centre does very little work in transferring torque. It will not make the difference between shaft survival and failure. The material and heat-treatment will.
I have more torque than you from my 4BD1T. Follow my shaft calc results that I linked to earlier in this thread.

The torsional capacity of a shaft is calculated by:
J = pi/2(Do^4-Di^4).

My LT230 input shaft is 26mm spline minor diameter.
Solid shaft
J = pi/2*D^4
J = pi/2*26^4
J = 717,816 mm^4.

Hollow shaft (I put a 13mm hole through).
J = pi/2*(Do^4-Di^4)
J = pi/2*(26^4-13^4)
J = 672,952 mm^4

The 13mm hole reduces the torque capacity by only 6.3%. It is not significant.

There is a 6BT and LT230 powered 6x6 landrover in the UK. Last reports were his input shafts were doing the job fine.

Spent Saturday doing the pre summer blitz on the block... Everything mown down really low and one last bonfire to go up. Planned to do it today but they announced total fire ban here in Region 2 SA yesterday. Been a nice warm one too. Anyway, got into plate drilling today. Managed to drill all the holes, tap the three M10's that needed doing, and drilled the two locating dowels that support the transfer case to the plate. The four bigger M12 holes are the ones that locate the plate to the ZF box, using recessed M12 12.9 Cap Head bolts. The top of the plate will be affixed to the top of the box via a horizontal plate that will be bolted to the back of the conversion plate. The cutout is the start of plate shaping, and is for the front output casting. There should be about 20mm clearance between the output casing and the side of the ZF. So far so good. Once the plate is bolted to the back of the ZF I can get an accurate measurement for the shaft mods. I shouldn't have the prop shaft clearance issues that Nick, Ash and Tom had in the Defenders as the 101's higher.

Well, the plate is all drilled, inc the large 85mm center hole to allow for the final drive casing of the ZF to sit thru it. It's now away having a small bit of milling done on the ZF face to clear the speedo drive housing. To help with the heat issue in the gearbox, I've ordered one of these.... The extra capacity sump...

And then the sump got me thinking..... As its open in the center, there now probably wouldn't be enough support in the middle of the transfer case... especially with the extra power/torque... so I've just knocked up a 3mm plate that I'll sandwich between the sump and the transfer case. That'll stop the housing spreading!!

Oh, and here's where it all has to bolt too! Should have started the thread with this pic!!!