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I think there is quite a bit more to this than first appears...!
As well as needing the discs, pads, calipers & caliper brackets I think you may also need different hubs/arms, handbrake cable as well as the bolt on driveshafts (and you may therefore also need the wider 7.5" diff)....
I changed my Marlin Cabrio over from rear drums to discs but ended up swapping over the complete axle (as it's probably the easiest / cheapest way):
I'm resurrecting this thread as changing from drums to discs was something I always had in mind for my Cabrio rebuild.
Simon wrote:
and you may therefore also need the wider 7.5" diff)....
I changed my Marlin Cabrio over from rear drums to discs but ended up swapping over the complete axle
Did you replace swap out a 7" diff for a 7.5" one? Am I right in thinking the casing itself is physically bigger i.e. it's not just the internals that are a different size? I've seen mention that the width of the upper mounting 'tube' differs. Did you have to change the point where the Marlin diff carrier brackets mount to the chassis? Or change the brackets themselves, perhaps?
I gather it's possible to fit the Lobro flanges to a 7" diff previously used with Tripode driveshafts so that's an option for me - but it seems like a half-way house sort of compromise really.
How about the trailing arms - were you able to use the pair that came with the drum setup or did you have to replace them? I've read that the hole for the bearing/hub assembly is larger on arms used in disc setups.
Yes I swapped the complete diff over and, like you say, the casing is physically bigger on the 7.5" unit.
The main difference is in the attachment of the front diff mountings which are further part on the 7.5" diff (presumably by 1/2" ?!). However you don't need to change the Marlin brackets - the mounting holes on the chassis are just further apart. My chassis already had holes drilled for both 7" & 7.5" diffs - so yours may do too.
I'm not sure about the differences in trailing arms - I just used the ones that came with the disc brake axle.
Its actually quite a simple swap if you change the complete axle over (I expect you'll only run in to trouble if you start mixing and matching components).
Good luck & I'm happy to try and answer any other questions.
thanks for the info and good wishes. My chassis has only one set of holes. If the larger casing's 1/2" wider then that's only 1/4" on either side - presumably the pairs of holes on your chassis are either very close together or slots rather than individual holes?
That apart I think you're right - it seems a simple enough change.
