75 280 Rear Suspension Work & Disc Brake Conversion (MilkFab)

[Zed Head]

Here's a variation, maybe even the inspiration for (or vice-versa), of the Silvermine adapter flange.  It doesn't have the 4 mm problem.  Lots of other good details in the thread too.  And he was selling them.  Doesn't look like he's visited Hybridz since late May though.  

https://forums.hybridz.org/topic/128943-z31t-axle-swap-can-fit/#comment-1204163

 

https://forums.hybridz.org/topic/128951-fs-z31t-axle-adapter-flanges-for-s30-r200-slim-design/#comments

[HusseinHolland]

8 hours ago, Zed Head said:

Here's a variation, maybe even the inspiration for (or vice-versa), of the Silvermine adapter flange.  It doesn't have the 4 mm problem.  Lots of other good details in the thread too.  And he was selling them.  Doesn't look like he's visited Hybridz since late May though.  

https://forums.hybridz.org/topic/128943-z31t-axle-swap-can-fit/#comment-1204163

 

https://forums.hybridz.org/topic/128951-fs-z31t-axle-adapter-flanges-for-s30-r200-slim-design/#comments

Thank you ! That's the thread I read originally, then couldn't find - that confirms the need to have the flange flush with the existing depth, which is what I plan to do anyway.

[HusseinHolland]

Dropped off the stub axles to get the outer flange nubs cut to accept a centering ring, and the inner flanges to be cut down to 25mm, with a 3mm depth shoulder 49MM OD. Silvermine flanges will have the center cut to 49 (from 45)mm to seat on the shoulder, with a total depth of 29mm same as stock offset.

I'll add pics when I get them back

[HusseinHolland]

Degreased, then soaked the rear tube/hubs in acid, then cleaned up & treated them with rust convertor. I'll paint them tomorrow.

 

[HusseinHolland]

Got the stub axles & flanges back from the machine shop. Now I have to weld everything.

Hubcentric flange for locating the wheel

Inner flanges modded to accept the Silvermine flanges (also modified to be centric). Collar is to increase the weld surface area 

Will be like this. Total depth to inner surface is 29mm, same as stock. 4mm inset for CV cap, which I will remove if the stub axle depth becomes an issue

[Zed Head]

Are you going to weld that yourself?  Curious about the materials also, are they similar steels?  That is a high stress area, and you'll have all of the force passing through the weld.  You'll want a proper match of metals and welding wire and weld depth.  It's on the inside so you'll only lose motive force if it breaks, at least no wheels will fall off.

You're too deep in to it now but did you ever confirm that you need that extra distance?

 

I spent a few hours building an adapter for the other ZX 3x2 CV axles so I get the urge to fabricate.  I never used it but it was fun to build.

[HusseinHolland]

On 7/15/2023 at 2:26 PM, Zed Head said:

Are you going to weld that yourself?  Curious about the materials also, are they similar steels?  That is a high stress area, and you'll have all of the force passing through the weld.  You'll want a proper match of metals and welding wire and weld depth.  It's on the inside so you'll only lose motive force if it breaks, at least no wheels will fall off.

You're too deep in to it now but did you ever confirm that you need that extra distance?

 

I spent a few hours building an adapter for the other ZX 3x2 CV axles so I get the urge to fabricate.  I never used it but it was fun to build.

I am - I did today actually. Got put off with all the exhaust work. Good thing, since I only weld a few times a year, I had practice before doing the flanges. This was all TIG work, not wire-feed MIG. All the pieces are mild steel, at least they puddle/ flow at the same rate.

I wanted the stock offset, as I have seen several posts & YT vids where the Silvermine flange offset was an (binding) issue - especially if the car is lowered at all. He does say it's only for stock height cars, up to 1" lowered. I'm using the Eibach spring set from MotorSport, so I don't know if that ends up more than an inch difference or not. 

Clamped the outer ring so I could weld it flat.

removed the hub/flange so I could weld the outer ring. I added a collar to act as a heat sink & prevent the ring from warping.

Got a little hot on one side, but it's far enough inboard that I didn't get any distortion - getting down into the narrow gap on two sides was a bitch - which was another issue with some of the ppl using these flanges as intended.

After that I (MIG) tacked the hubs into the flanges - with them clamped in a vice to make sure they stayed flat

then I welded the inner lip, to make sure they stayed put before seaming the outer ring to the hub

Then finally welded the rings to the hubs - kept the two clamped to together to act as a heat sink

pressed 2" studs

space for CV flange, without diminishing total spacing from diff to outer flange

Hopefully get it all back in the car tomorrow - wheel bearings, strut inserts, driveshafts, rear disc brakes

 

 

 

Edited July 22, 2023 by HusseinHolland
remove extra pic

[Zed Head]

 That's a lot of weld.

Don't forget to measure your distance pieces.

[HusseinHolland]

5 minutes ago, Zed Head said:

 That's a lot of weld.

Don't forget to measure your distance pieces.

I assumed they matched pairs to a car - but I will check the markings to make sure I put the correct one on each side.

[Zed Head]

They can apparently get squashed from hard usage or accidents.

[Captain Obvious]

Wow that's a lot of work. It looks great, but I can't help wondering if there would have been an easier way to skin that cat.

He says from his comfy armchair...   

[HusseinHolland]

10 hours ago, Captain Obvious said:

Wow that's a lot of work. It looks great, but I can't help wondering if there would have been an easier way to skin that cat.

He says from his comfy armchair...   

If a flange were made that didn't have the 5mm rectangular recess for the stock flange (useless anyway, since we all know the flange OD is not concentric), and just had a 49mm bore, then one could 'just' machine off the stock flange (can't just cut it off on the backside or offset will be too shallow) & have the shoulder machined. Then there would only be a deeper shoulder, and only one weld around the hub. I believe it is better to weld around the hub that out at the flange where it is much more prone to warping.

Edited July 22, 2023 by HusseinHolland