I've got my self a fresh car transporter trailer, it was cheap but needs refurbished. The axle stubs on the indespension units were bent & had disc hubs so I thought I'd cut them off & weld on the bolt-on stub axle flange from the back of a modern FWD car so I had cheap & readily available bearings & brakes.
The problem is the stub dosent seem to take the weld very well, it looks fine but when I just had a tack weld on & I tried to adjust the alignment to make the toe/camber right I found it was prone to breaking the weld right out of the stub flange taking a tiny section of the flange with it. I can't see my weld all the way round the flange being weaker than the four M10 bolts which held it onto the back of the car but do you think there is a danger of the hubmetal breaking away from the weld? The stubs I have are off a Ford, is there a method of welding that works with this type of metal? I wondered about disimilar or cast rods, I've been using MIG. Or should I be looking at those from another car such as a VW or Vauxhall that use a similar bolt on stub axle? I'd just go & get new suspension units with proper brakes etc but the trailer may not be staying all that long so I dont want a fortune in it.
I welded extra steel into the VW front hub carriers from my autograss car to strengthen them without any problems.

Buy new stubs & hubs Here!

I thought about using stubs like those on there as I can get them at work (as an agric engineers we stock bits to build & repair ATV trailers) but they're just a touch on the light side & I really want brakes on it. By the time I get backplates, shoes & drums it's going to be the price of new units.
I'm thinking the welding may be OK, it still took a fair bit of force to break a 1/4" tack & it's welded all the way round 2 1/2" square but it's just the way the weld gave way without "giving"any. If you tack two bits of ordinary steel you can bend it about at bit before it lets go.

Locost way of doing it is to find a rear axle from a FWD car, cut off the hub flanges complete with drums, bearings wheels and tyres.

Dismantle at home, clean the cuts until dead flat and weld onto the indispension arms, reassemble the hubs etc onto the arms - job done.

I did this years ago on my trailer, you could buy the suspension arms without any stub, but they don't seem to be available these days

The original stub axles weren't just welded to the front were they? They go through and are welded at the back on my indespension units.

Mark, thats excactly the way the way I have planned to do it, but the hub assembly from a mk6 Escort is bolted on.
Pete, the stubs that are on at the moment are welded front & back of the arm, I ground the welds flat & the section of stub left in the arm knocked out to leave the original hole, I'll weld through the middle of that too.
I've decided to weld one on, load my Scudo van onto the trailer (much heavier than anything it'll really see) & go for a run on some tight, twisty & bumpy roads & if it's OK with that I'll do the rest. If it breaks then I'll not be far from home & on quiet roads with 3 wheels left to get me back.

Test run done & the trailer is back in the workshop up on axle stands for the other three hubs to be done.
I gave it a fair bit of stick, the tyres were scrubbing sideways across tarmac which twisted the wheels about a fair bit while doing a sharp turn & it all works fine.