ZF S5-42 to LT 230.

[Sitec]

Hello all.
Well, those that know me or have been looking in the 101 FC section will know that I'm about to fit a Cummins 6Bt and ZF gearbox (UK sourced) out of a Daf 45 truck into my 101.. I thought I'd put a thread about the conversion here.
For those who have not seen the Cummins 'Lump', here it is!

[Sitec]

http://www.aulro.com/afvb/101-forwar...-101-a-26.html

Here's a link to the 101 thread which is a slow build up to something a little different....
Right.. The start of the conversion consists of making a plate (25mm happens to work (I hope!)) which will bolt to the ZF gearbox, and then carry the transfer case in the right place.. I've started by cutting the excess lugs off the output flange on the gearbox where the prop would have been attached.. I've also removed the input gear from a spare transfer case to see how I'm going to attach the two..

[Sitec]

The proposed idea is to weld the original flange to the input gear on the transfer case.... The reason I'm going down this route is because a friend Nick in the UK has fitted the same engine and box to his Ninety ('The Big Purple One' on YouTube), and the gearbox failed last week. He thinks its due to the fact that he had a floating shaft between the two boxes and did not have the output flange bolted to the shaft as it was originally, which allowed the shaft and gears to 'float' within the box.. Not only that, I figure a 50mm hollow shaft with a 10mm wall thickness will withstand more power than the original LT77/R380 output shaft.. Pic of plate and gear before machining... I'll be able to access and bolt the new gear assembly to the gearbox via the rear PTO hole.

[Sitec]

Two templates are then made. One of the Transfer Box, and one of the Gearbox. Using these placed back to back with the thru shaft points in the same place gave me the plate size, and a center point to work to. Plate thickness was decided as when bolted in place on the back of the ZF box, 25mm brought the transfer case mounting face flush with the outer seal face of the gearbox.. Time will tell if it works out.

[Sitec]

Once I had the center point, I was able to start drilling the conversion plate to suit the boxes. I've started with the gearbox, as these bolts need to be countersunk so as to give me a flat plate for the transfer case. The ZF S5-42 gearbox is all metric so I'm using M12 x 40 socket head cap bolts. The four M12 holes were then drilled first, and then a 17mm drill bit was used to start the countersink on all four holes. Once started I was able to sharpen the drill to give me a flat shoulder inside the hole to take the cap head bolts. Once fitted to the gearbox I'll affix the top of the plate to the various M8 bolts at the back of the gearbox. Before I bore the center hole out I'll be able to drop the second template on the conversion plate and mark all the transfer case hole centers.. More to follow when I get to it!

[clubagreenie]

Easier than modifying your drills for the counter bore for the cap screws, get a counter bore bit. It has a tip that sits in the shank hole to center and guide the larger drill.

[DasLandRoverMan]

Smart thinking, Watching with interest.

[Dougal]

This should stop all the bollocks about whether or not a 4BD1T will fit in a 101.

Yes a 6BT will, but we're still unsure about the 4BD1T.

Looking forward to following this one.

I did converse with Nick on one of the forums about gearbox chatter and tensioning the adapter shaft to the gearbox main-shaft. I made the same mistake with my Isuzu box, I've just fixed that last night (been planned for a while) by making a tension nut which fits inside the adapter shaft but threads onto the end of the gearbox main shaft. A large cap screw runs from the LT230 end of the shaft to the tension nut and pulls the whole lot together.

I need to reinstall everything before I can test it.






I try to stay away from welded adapter shafts. Yes I know some people do it and have no problems. But I prefer to know it's good rather than just hoping.

[DasLandRoverMan]

A 4BD1T will fit a 101, it's been done.

Smart idea with the tensioner nut, looks tidy.

[Sitec]

Ha! Love it! That conversion all looks very neat. I hear you re welded shafts, but still not convinced that the original input shaft (same size as the old RR/Disco 10 spline axle shafts) will withstand 400-500 nm of torque. Time will tell I guess. Length is also an issue with my conversion.. I have to get the transfer case as close to that ZF box as possible or I'll have a 300mm long rear shaft!!