Hi, I'm looking into removing an H165 differential that's in a 1200 ute (I assume it's post '74) and replacing it with an H145 differential out of a '71 1200 Sedan.

I've done a bit of searching and researching and found out a bit, but its hard to get some concise info. My main concerns are fitting the U-bolt pieces and shock mounting plates to the smaller diameter diff housing. I understand the Ute and Sedan shock mounting style is different and Im assuming I'll need to adapt the Ute pieces to the H145 somehow - that's question 1. Maybe I could just use all the 145 diff U-bolt pieces except swap the bottom plate with the Ute one so the shocks still mount correctly? I'm not sure. Some of you guys might have played with this stuff a bit more than me and hopefully someone knows.

The next issue I think I might have will be with the driveshaft and distance between the gearbox (running an A12) and diff changing with the smaller diff. Does anyone know if there is some play in the gearbox/driveshaft join and if there is enough to compensate for a possibly smaller or shorter diff? Or alternatively if someone knows exactly which bits are needed and from which car (eg. driveshaft, shock mounts, brake splitter, handbrake mount etc.) to get the H145 into the Ute and running, that'd be appreciated.

Thanks.

so you puting the ute diff in the sedan or sedan diff in the ute?

alright, why are you doing this? im assuming the that ute diff is going back into the sedan???

for h165 into sedan

you need to use the diff, u bolts, bottom plate and tailshaft from the ute
you then need to use the brake lines from the sedan diff on the ute one and weld on a nut for the splitter block to mount to
you need to either swap handbrake cables and fabricate mounts, or you can just shorten the ute handbrake cable to work with the sedan
you need to weld shock mounts onto the diff to replicate what the sedan had
you will also need to either add the load leaf from the ute to the sedan spring pack or add a spacer that will do the same job so that the ute U bolts arent to long

sedan diff into the ute

need sedan diff and tailshaft, can use sedan U bolts if you remove the load leaf from the spring pack
you will need either coupe or wagon bottom U bolt plate(for the shock mount) i think they are similar to the ute one
you will need to either lengthen the handbrake cable some how, or adapt the whole ute handbrake cable assemlby to the sedan diff
need to swap brake lines from the ute diff to the sedan diff and make up a mount for the splitter block

think thats about all

ROconnor - My main concern is the sedan diff into the ute for now so i can keep it on the road with little downtime but PIGDOG is right, I am planning to put the ute diff into the sedan.

PIGDOG - Thanks for the info mate, I thought i'd see a few question marks over why but I'm planning on putting a more torquey motor in the Sedan and the ute owner is more concerned about a highway friendly ratio. It's certainly fine by me
So it seems there's a fair bit of work involved in doing this. It's obviously not as straight forward as 'Bolt-on' would suggest. For the shock mount, you mentioned getting a coupe bottom plate. Does that mean the ute one is un-useable?

Also, while your here you might know this too; the sedan has an Auto box, so will that driveshaft still be useable how you mentioned or will I need to source a Manual one?

Thanks again

Yes, putting an H145 in a ute is a good idea. Reduces unsprung weight.

As long as the 1200 still has an A12, this is the way to go. If you are hauling heavy weight with the ute, keep the H165.