Finned diff cover without AZC or T3 legs & brace

jonbills

jonbills

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Has anyone got a finned diff cover on their S30, without using an AZC or T3 dog legs & brace kit?

I've been swapping my Quaife into another diff, and I thought it would be good to fit a finned cover if I can. I've made a replacement brace that fits just under the moustache bar, but when I compare it to the original brace I fear my home made replacement might not be strong enough!
Anyone got any inspiration? Not sure I want to give up and buy the AZC kit quite yet.
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I’m trying to wrack my brains, I did have a finned diff cover. I had the back face slightly machined to remove the fins but just on the rear most flat face. Trouble is I don’t have it anymore I can’t remember if it did the trick or what happened to it. I’m fairly sure it did fit though.
 
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This is how others have done it.

You could do the same utilising a flatter but wider bar which will allow you to use the existing holes below, save you drilling the hangers, they are sprung steel i believe and not easy to drill.
 
The T3 and AZC braces are also much weedier looking that the stock brace, maybe they're not bigger than the one I've made.
The dog leg itself must provide a lot of stiffness against side to side movement, and for backwards to forwards movement, you're fighting with the front diff mount.

Maybe the original brace is chunky because people might jack the car on it.
I'll go a little further with my current plan....



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well, I went beyond the point of no return. I cut the original brace so there's no going back.
fingers crossed.

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There's no way it would fit with the standard brace, even with all the fins cut off.

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yep, thanks Mike. I'm glad I didn't cut the fins off to find that out.
 
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I think the forces your trying to contain with the brace are a twisting action that will screw up your tracking esp under braking or hard cornering. The rear control arms will try to pivot around the front mounting which is rigidly fixed to the body, pushing the rear mountings, which you’re working on, closer together. The existing brace controls this fairly well.
The AZC replacement brace mounts onto a billet drop section (don’t know what it’s called) which will be very stiff . As your keeping the thin steel dropper the higher you put the fastening brace the more spring it’ll have.
Using the four bolts that point to the rear of the car that held the old bracket, would it possible to make 4 bobbins say 60mm long and then you could run a piece of angle (or whatever) in a straight run across them all? May need a bit of a trim to miss the exhaust
 
Turn & Burn said:
I think the forces your trying to contain with the brace are a twisting action that will screw up your tracking esp under braking or hard cornering. The rear control arms will try to pivot around the front mounting which is rigidly fixed to the body, pushing the rear mountings, which you’re working on, closer together. The existing brace controls this fairly well.
The AZC replacement brace mounts onto a billet drop section (don’t know what it’s called) which will be very stiff . As your keeping the thin steel dropper the higher you put the fastening brace the more spring it’ll have.
Using the four bolts that point to the rear of the car that held the old bracket, would it possible to make 4 bobbins say 60mm long and then you could run a piece of angle (or whatever) in a straight run across them all? May need a bit of a trim to miss the exhaust
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Thanks Andrew, yes, I've been thinking about that a lot. The pivot for the control arm is the front inner mount, so the force on the rear is pushing against its strongest axis. In my imagination at least!
Anyway, in practical terms, what you propose is beyond my fabrication skills and equipment unfortunately. I should get it out for a run in the next few days and see whether I need to buy the AZC kit.
 
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jonbills said:
Thanks Andrew, yes, I've been thinking about that a lot. The pivot for the control arm is the front inner mount, so the force on the rear is pushing against its strongest axis. In my imagination at least
Anyway, in practical terms, what you propose is beyond my fabrication skills and equipment unfortunately. I should get it out for a run in the next few days and see whether I need to buy the AZC kit.
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Agree, the forces will push against the dropper in its strongest plane. See how it goes!
 
MaximG said:
What are the terminals for by the way?
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The sensors in the diff cover? I'm not sure - one of them seemed very like a temp sensor. The other... dunno. I thought pressure, but thats silly.
Mr.F would know. :-(
 
jonbills said:
The sensors in the diff cover? I'm not sure - one of them seemed very like a temp sensor. The other... dunno. I thought pressure, but thats silly.
Mr.F would know. :-(
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I think those terminals are for the temperature switch that controls the oil pump operation for the oil cooler set up on a z31 euro spec diff.
 
Ar'nt the fins there for cooling therefore might as well fit the standard cover if you cut them off. Seems a lot of faff to me for no gain.
 
Nigel Brook said:
Ar'nt the fins there for cooling therefore might as well fit the standard cover if you cut them off. Seems a lot of faff to me for no gain.
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Yes, the fins are for cooling. The cover is also deeper and so cutting the fins off still won't make it fit, so yes, it would be pointless.
 
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