EH diff assembly into EK, what needs to be done?

[Bushcreature]

G'day all, I am planning to put an EH diff assembly into an EK, I am unsure of what needs to be done?
I belive I need to change the rear universal joint, brake cylinders and possibly the hand brake cables, is this correct?
Can people please tell me what needs to be changed for what.
Thanks!

[ardiesse]

Without meaning to be too much of a smart-arse, the answer to your question is "that depends".

I gather you want to swap the entire EK rear axle for an EH rear axle.

If you are keeping a king-pin front suspension with drum brakes, then in my opinion swapping the EK rear axle for an EH rear axle isn't worth the effort.
- The bump stops are different (on the body in the EK, on the rear axle in the EH). You can get by without changing the bump stops, it's just that the EH bump stops bear down on the mounting bracket and bolt for the EK bump stops.
- The union for the rear axle brake hose is in a different position in the EH. The bracket and piping would need modification to suit an EK.
- The EH handbrake cable is incompatible with the EK. Although the method of attachment to the body is the same in both models, the EH handbrake cable sheath is probably longer than in the EK.
- If you are running front drum brakes, you could probably get by with the 13/16" rear slave cylinders. But I don't know what effect there is on brake balance having semi-huck front brakes and duo-servo rear brakes.

If, on the other hand, you are planning on an HR front suspension and disc brakes, then it's more straightforward to use an HD/HR rear axle.
- Bump stops: as above.
- The HD/HR rear axle's brake pipework is more suited to an EK. You'd have to get a brake hose that's about two inches longer than the standard one.
- The HD/HR handbrake cable is also incompatible with the EK body, but it's a closer fit than an EH handbrake cable. You'd be best off raiding an HD or HR body for the handbrake cable mounting brackets and attaching them to the EK underbody. From memory you need to extend the handbrake cable clevis about an inch or so: make up extension pieces from sheet steel.
I've heard that there's a handbrake cable manufacturer making handbrake cables to suit EJ-HR rear axles fitted to FE-EK Holdens.
- If front disc brakes, then use the 9/16" rear slave cylinders and shoes to suit.

Your stock 3.89 EK diff will fit in the later models' rear axle housing. Then you don't need to change the rear universal joint.
If you want to use a 3.55 or 3.36 diff, you'll need to change the rear universal joint.
If you want to use a 3.08 diff, you'll have to confirm that it's a "coarse spline" diff. Plus the 3.08 casting's slightly different and you'll need a longer drain bolt. And one of the other studs will need to be replaced with a longer one.

Rob

[Blacky]

As Rob said - the main question is why do you want to swap them ? If its just for a ratio change its far easier to swap the centres - I think the EH diff is the same width as EK so your wheels should fit - if you want to run deeper dish rear wheels then an LJ Torana diff would be a better option as they are narrower.

[Mick]

handbrake cable easy sorted you can buy a a handbrake cable ready made to suit EJ to HR rear brakes on an FB/EK, if you can get a HD-HR rear drum to drum diff is easier as where the hard brake pipe on body for some reason runs on the left side of EJ/EH and right side of FB/EK and HD/HR so using an EJ/EH housing means swapping sides of the tab where the rubber hose goes to diff, from memory there is a thread size difference somewhere there also but easily rectified

i do the swap mostly because i usually need to but mostly for a silly reason i hate the look of FB/EK housings and the axle retainers are a stupid idea

[Errol62]

I did this in 1997 using the EH bump stops and hand brake cable adapted with some galvanised cable and u clamps. For the brake union I used the EK pipes and made a bracket to hold the union which tucked under the inner right u bolt where it sits on top of the housing. I took the old threaded cups off the rear uni and put the EH ones on. Bump stops worked fine. Later replaced the unis and used a conversion cable from Autocables/ Retro Spares at Eltham out of Melbourne. About $100 to suit EJ HR Torana into FE EK.


FB ute fixer upper, EK van on rotisserie

[Bushcreature]

Thanks to all.
I have an EH rear axle sitting here and it was chosen because you can still get brake shoes easily and it's also the same width as the EK.
What uni joint do I need to purchase, presume it is EH?
Thanks again.

[Blacky]

I would assume the EH uni would be the go - if you do the diff swap it might be a good idea to also fit the EH front brakes if available ? I did the EH swap onto my ute and it does make a bit of an improvement - not massive but noticeable.

[Errol62]

I reckon that EH diff you’ve got is the one I just posted about.

Toyo part no. RUJ-1786X2_5 for all red six uni joints, front and rear.


FB ute fixer upper, EK van on rotisserie

[Bushcreature]

Thanks again people. Clay, that would mean I have two EH rear ends then. The wagon has a HR rear, which will get pulled out for the VS, but that's a completely different build.