944 NA Rear Brakes

[Wally]

Very nice Bill! Good pics also!

I see that you have grinded the ebrake pivot arm, which should still be ok I think, but did grind the hub as well? It looks camfered, but I don't know if thats original or not anymore.
Grinding the outer edge of the hub some more should be no problem either I think.

BTW, you don't need to work with studs either, as drilling 4 more M14x1,5 holes in the equally thick hub is much more easy and you can use the longer Audi bolts

Tnx,
Walter

[Bill K.]

The hub has not been modified, just the ebrake pivot arm (in many places). There is no clearance behind the hub flange as the ebrake is right behind the wheel bolt circle.

The hub is 11 mm thick at the bolt circle. A disk rotor spacer of about 21 mm is needed (same as 944 83-85.5).

So, I'm interested in facing a few mm off the back face of the T4 hub to make clearance for press-in studs like these at PAP-Parts.

For Porsche wheels, 14mm studs are used. With my plan, the T4 flange will only be 9 mm or so -- enough to hold the studs?

[raygreenwood]

Be careful in drilling to many extra holes in the stock stub axle. It has a tendency to warp when that happens. Wether it has something to do with interfereing with heat transfer or just relieving stress. I don't know. But I had it happen twice, many years ago. I went to a five bolt pattern from something American. Ray

[Wally]

Some creative grinding got the 944 NA ebrake skinny enough to seat the T4 hub without rubbing. Backwards ebrake shoe springs for clearance.

Hello Bill,

Did you take into account that the handbrake lever pivots in such a way that the grinded down part moves outward somewhat when the handbrake is applied?

Walter

[Bill K.]

Your right. There is limited cable travel because the ebrake pivot will bind on the outer stub axle flange and limit further pad spread. I'm not sure that it will hold as well as stock. I need a spacer to mount the 944 hub so it can be tested...

[Bill K.]

I'm considering the above option where the 944 backing plate would get a square hole milled in it that slips over the 412 trailing arm mount and holes drilled to mount a custom spacer to provide the needed clearance for the stock 944NA ebrake. It's the same idea as in the picture below from Club VeeDub Sydney.



It's more machine work, but the 412 outer stub axle doesnt need to be modified for clearance like with the skinny ebrake pivot modification and the ebrake will work for sure.

Still considering better options...got any?[/img]

[Wally]

I like the solution you have shown!
I also only now understand the above alu machined 944 part
However, I wonder where the extra material in the alu 944 part is to do that amount of milling/machining?

As a side note: my steel 924 Turbo backing plate looks to be made from cast iron, so welding to it will probably not be possible

I am sure other solution for a rear disk brake set-up can be fabricated, but I will probably pursue this route first.

[Bill K.]

However, I wonder where the extra material in the alu 944 part is to do that amount of milling/machining?

My sketch is not so good at showing what needs to be done to the 944 backing plate. The bearing retainer needs to be removed down until a flat surface is obtained. This flat surface is where the custom spacer seats. The surface is below (inboard) the surface where the ebrake pads rest. The backing plate also gets a square hole milled through it to go over the trailing arm mounting plate and three holes to mount the spacer. The spacer is a round disk with a flat to clear the ebrake cable housing and has a matching square pocket to clear the trailing arm with 4 holes to mount to the trailing arm. We'll see...

[Bill K.]

I went another route...



... welded a bracket to the axle carrier to secure the 38mm aluminum 20th Anniversary Edition Golf 4/Jetta 4 calipers (with internal, cable actuated ebrake). Rotors are 944NA (20x290mm). Cost so far -- $315 for both sides.

Modifications:
1. Type 4 hub machined down to 155mm diameter to clear the rotor.
2. Type 4 backing plate cut down to serve as spacer only
3. Type 4 axle carrier shoulder ground square to seat caliper bracket for welding
4. Steel bracket modified to fit axle carrier and welded
5. Hub centric adapter to center rotor and wheel on Type 4 hub (later job)
6. Type 4 hub drilled for studs (next job)

More pictures at www.vwbughead.com/412/

[func412]

Very nice and light setup indeed!

What comes to my subaru rear brake conversion, it is showing green light also. It looks like the caliper adapter will be attached in place of the original brake shield... and what comes to measures it looks like the adapter will be straight 5 mm steel plate. We´ll see soon how it goes.

[Wally]

After spending some quality time under the car this evening, I had an idea..
This may sound too simple to be possible, but I'll share it anyway:
Wouldn't it be possible to just mount the 924T bracket on the back of the bearing housing?? Just longer bolts at the front bearing cover and using nuts on the rear of it.

The 924T bracket is part number 23 in this pic:


The above pic of Bill K shows the nice room behind it. Its a little cramped, but that would be bolt-on and the gained recess would provide enough room for the handbrake parts...
I only need to know if that bearing cover that protrudes the trailing arms can (easily) be pressed off? It cannot be one piece with the arm..can it?
Ray?

Thanks for your thoughts,
Walter

[Bill K.]

I only need to know if that bearing cover that protrudes the trailing arms can (easily) be pressed off? It cannot be one piece with the arm..can it?

The bearing housing appears to be two pieces -- inboard and outboard.
The inboard piece seems to have the bore for the inner race and is welded to the c-arm inboard of where I made my weld for the bracket. The outboard piece seems to make up the outer race bore and square bearing cover mounting plate and is welded to the inboard piece just inboard of the square plate.

Taking your idea further... perhaps cut the 944 BP to fit over the T4 square plate then make 4 brackets to hold the BP to the rear of the square plate

I avoided custom milled parts, can use stock Porsche pattern vented rotors, have cable ebrake, and was able to do this mod with a saws-all, 4" grinder, dremel, and MIG using $4 brackets as a base.

The AC Industries cast iron bracket for emergency brake applications didn't work out because the Golf caliper carrier was going to hit the casting when the caliper was located to obtain correct pad placement on the disk. I didn't want to hack up the brackets... As Ray has observed, they are nice/stiff brackets. Mine are for sale -- $80+shipping for the pair (my cost). I'll be returning them in a week, so speak up if you want them...They would be great for putting the standard bug solid disk upgrade w/ ebrake on the rear (CB Performance Rotohub, etc.).

Perhaps there is another vented rotor/big caliper/ebrake combo that will work with the ACI brackets. A bolt on combo would be great! Keep looking.

[Wally]

As I stated before, I had an idea how the 944 rear brake conversion could be done, so lets go to work :

These are actually 924 Turbo rear flanges, but they should essentially be the same off a 944. The 944 part is just made of the nicer alu...
I think most pics speak for themselves:





Here is where part of the machining comes in: Its a turned down 412 axle flange, so the 944 handbrake lever is cleared:



What I still miss is the needed custom spacer/adapter. Funny thing is, I measured about 21mm being needed also
My idea is to attach the spacer with maybe 6 M10 studs/bolts to a high grade alu spacer. The 5x130 comes into the spacer, as well as a ridge for excellent centering.


Hope to have the spacer in a few weeks...

I'll keep you posted.
Walter

[Wally]

Sooner than expected

[func412]

Nice work! I hope that aluminum "spacer" is strong enough.