Drum to brake modification / conversion question

[Selloutrr]

Hi,

I'm wondering what makes the Volvo C300 series drum brake to disc brake conversion so difficult?
Is it the weight (~5300lbs) of vehicle or the metric fittings if the European portal axle? Or just the fact it's a portal axel?

The conversion seems pretty straight forward in the sense that switching drum for disc is a common practice and a simple google search brings up 100's of aftermarket kits for mass production cars. In the very least these kits give a designer the basic parts to design for.

I know portaltek made a kit until they were bought out and from what I've read in researching had/have serious financial and supply issues. I've found several kits based on Mercedes parts and brembo calipers. As well as several dozen DIY'ers most using Chevrolet 2500HD calipers and a hodge podge of misc parts. However I have yet to read about the follow up after the install... We're they successful or an epic fail?

The portaltek seem to have a happy customer base for those who received product, but at over $4000 for brakes I'm not sure if its actually that the brakes are better or they spent so much they just assume they are...?

I'm currently in the design phase of making an affordable, reliable, easy to find parts locally, drum to brake conversion.

Can anyone give me feed back of success or failure they have had?

[roobar_and_custard]

Hi Selloutrr,
I agree, it doesn't look that hard to do. It is on the top of the list of modifications that I am planning on doing when I finally get started on my truck.
There is clearly no issue with braking performance, even with the weight (but check the GVM of most 4x4s for reference - I think you will be surprised). The major problem as I see it is the hub size.
There are two basic options for converting to discs, front mount discs or rear mount discs.
The rear mount requires a new hub to be made as it is impossible to resolve the mounting positions to the current hub. If you followed this path you could maintain your current wheels.
A front mount requires the hub to be machined down to allow the disk to fit over the wheel studs and also new wheels to suit. This is the option I am looking at... The BIG question is whether there is enough metal left in the hub after machining to maintain the structural integrity of the hub. I have yet to measure this up, and have seen some examples on the web that are perhaps not ideal in this respect. If not, then it is new hibs for this option too.
It'll be interesting to hear from others as you say.
Ian.

[Selloutrr]

Good point!, I found this link with a good explanation of Gross Vehicle Mass and weights for some of the popular commercial 4X4's if anyone is interested.
http://www.arb.com.au/products/old-man- ... m-upgrades

I did a bit of research on the options of producing a new Hub. The two manufacturing standards are CNC and Forged. The CNC is by far the cheaper route for mass production... However Forging is considerably stronger and less prone to break under abusive conditions.

I guess the next step is to design or reverse engineer a working set of Hubs in AutoCAD so they can be manufactured to exact specifications.

[roobar_and_custard]

I'm not convinced about the need for new hubs, especially with front loaded discs. I am hoping that it is possible to machine down and stil make work with the current. I think I am on my own here, with the exception of the one in the link below, although, the bolt set up looks dubious...
http://forums.lr4x4.com/index.php?showt ... 389&page=4

All the others I find on line look like new hubs... which may yet prove to be the right answer.

I just need to find some time to pull a wheel off and measure up to check. Hopefully in the next 6 months or so...
Ian

[roobar_and_custard]

Perhaps Gecko can chip in as his truck has discs...