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Helical LSD in a 4,2 minor axle
Posted: Sat Aug 30, 2025 12:12 pm
by MMT1968
Hi,
My reasonbly tuned 1275 Marina engine has now destroyed the diff in my axle. When changing the diff‘s oil a lot of metallic debris came out. As new diffs are no longer available and refurbished ones would not make anything stronger I think about a helical LSD for my axle. I think that could be more effective and cope with the torque of my engine.
Has anyone expieriences to share on that topic?
Thanks
Chris
Re: Helical LSD in a 4,2 minor axle
Posted: Tue Sep 23, 2025 9:57 pm
by kevin s
It will depend upon what has failed, if its the crown wheel/ pinion then fitting a torsen type diff could make things worse (one wheel won't spin effectivley acting as a fuse). If it is the diff then yes it should be stronger but bear in mind the halfshafts will be the next weak link.
Re: Helical LSD in a 4,2 minor axle
Posted: Thu Sep 25, 2025 3:47 pm
by Steve Phillips
I have used Quaife ATB differentials in Minors with original axles and those fitted with ford and other axle's. Never had a problem with them, they run silently both straight and in corners and you wouldn't know it's there until you put lots of power through it.
But it does depend on the rest of your axle.
A Quaife or other LSD will take the power but half shafts and CWPs might not.
BTW I have no connection to Quaife I'm just a repeat customer.
Steve
Re: Helical LSD in a 4,2 minor axle
Posted: Fri Sep 26, 2025 10:26 am
by MMT1968
Thinking about physics a helical LSD would reduce the peak load on the half shafts as the gear is in permanent contact. A long term used classic diff has got some play between the gears which rises the peak load and can break a half shaft easily. And if a half shaft breaks it’s not a big thing to change it.
Chris
Re: Helical LSD in a 4,2 minor axle
Posted: Fri Oct 31, 2025 9:27 pm
by MMT1968
In USA at Minimania I can order shims to adjust the position of the differential inside its housing thus adjusting the play between crown wheel and pinion as well as the back lash. These shims are to be positioned outside the differential bearings and are bigger in diameter than the shims normally positioned between differential cage and the bearings. That makes changes and adjustment much easier as the bearings must not be removed to alter the adjustment.
Does anyone know where I can order those shims in England or the continent? Orders of metal parts in the US are difficult at the moment.
Chris