R100 Posted July 20, 2010 Share Posted July 20, 2010 Ive been told that geminis and or Piazzas run a holden diff head, same or similar to a commodore. Ive also heard some have a salisbury LSD head. What truth is there in all this ? Dont the geminis and piazzas come from japan ? if so why and would they have a holden diff. Where are the holden geminis made, do they run a holden diff. Are the piazza lsd heads made in japan or by holden. Cheers Quote Link to comment Share on other sites More sharing options...
cletus Posted July 20, 2010 Share Posted July 20, 2010 geminis made in australia have a borg warner diff, it looks like a commy one but they have smaller axles- there may be other differences as well smaller gears etc australia has/had local content rules where a oz made car has to have x amount of oz made stuff- eg the oz r31 skyline having a bw solid axle instead of the independent rear like japan and some odd combinations like some old coronas had a holden 4cyl in them in oz dont know about pizzas though Quote Link to comment Share on other sites More sharing options...
mikuni Posted July 20, 2010 Share Posted July 20, 2010 All of the above applies for Holden Geminis, and possibly Holden Piazza's, however I've never seen one of those, only Isuzu so unsure. The early Isuzu Gemini diffs are different though. They are a Japanese car and although I'm not sure on the make of diff, it is similar to the Isuzu Piazza's in that you can bolt an Isuzu Piazza diff head into it and the brakes on to it. - edit - I should probably highlight that the only reason to do this is because the Gemini diff housing is 50mm narrower and has the panhard rod bolt on the opposite side to Piazza (passengers instead of drivers side) I'd be just a little bit careful here though, especially if buying whole parts cars just for diffs because you never know what you are getting. It is a straight swap to upgrade an early Isuzu Gemini diff to a later Holden/Aussie diff, so it may have already been done. Same goes with Piazzas and even Chevettes I guess. And even after all that work, you will still have a smelly torque tube diff anyway. Which reminds me, the later model Isuzu Piazza diffs aren't the same either, they are a 4 link setup with no torque tube. I bought 1 site unseen for $1 years ago and was gutted to find that it was completely different (after it arrived from where I bought it)! Quote Link to comment Share on other sites More sharing options...
Jase Posted July 20, 2010 Share Posted July 20, 2010 what he said + later diffs are essentially a commodore housing shortened etc with torque tube and 23 spline axles alot of people in oz swap the vl centres in retain the torque tube and add shortened commodore axles, the commodore brakes etc bolt up, to eliminate the slop in the torque tube we ran a highspeed bearing in mine in the nose of the tube, the problem is theres a few different housings that came in the gem, jap early as in your coupe-piazza guts will go in oz early - torana and early commodore guts will go in oz late-borg diff essentially that vl guts and brakes go on diesel diff is same as jap early i think Quote Link to comment Share on other sites More sharing options...
CUL8R Posted July 22, 2010 Share Posted July 22, 2010 The Type of diff is Borg Warner Type 78. Falcon from around xc - XF from memory, and valiant, Falcon LSD would be the cheapest option. These are 25 spline from memory (??) So thats where my knowledge ends.. My twincam diff is not however a BW type 78, so I havent done any further research as to what to do in regards to putting the LSD into it.. At a guess either shortened or resplined axles, or may be able to swap gearsets & use center, but I really dont know, so basically the bottom half of my message is useless... Quote Link to comment Share on other sites More sharing options...
RUNAMUCK Posted July 22, 2010 Share Posted July 22, 2010 Vals are definately 25 spline. BW diffs are a great big fail IMO. Although they reckon the four pinion ones are less shit. Quote Link to comment Share on other sites More sharing options...
Jase Posted July 23, 2010 Share Posted July 23, 2010 BW diffs are crap thats why i have one mini spool about $95 oz or weld it Quote Link to comment Share on other sites More sharing options...
RUNAMUCK Posted July 23, 2010 Share Posted July 23, 2010 spools or locky's with BW's result in snapped axles. (at least in Vals anyway) Quote Link to comment Share on other sites More sharing options...
Jase Posted July 23, 2010 Share Posted July 23, 2010 yeah reasonably heavy car 25spline axles, beauty is the 28's are pretty strong or moser makes 31-40 spline custom jobs you'll never kill can't say i've broken an axle other than in my landrover being a douche 28's are easy to get although pcd would be 5x114 4x114 or 5x120 Quote Link to comment Share on other sites More sharing options...
R100 Posted July 23, 2010 Author Share Posted July 23, 2010 Cheers for all the replies. I guess as i get more into my conversion ill be asking more questions. The engine in my gemini will be 220hp max so the diff will need to handle that, altho im sure the 185's will break traction befor the duff snaps. Fingers crossed. Quote Link to comment Share on other sites More sharing options...
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