2015-11-24

New LSD from Titan


My car was fitted with a limited slip differential when I bought it. I've never known what kind of LSD I had, and I've never had any problems with it. One time long ago I asked Caterham what type it was and they responded that according to their files it was a Quaife ATB.

When I took my rear suspension apart to change wheel bearings I took the opportunity to remove the half shafts and look into the diff. It had a cross in the middle, and according to this guide it was a ZF, or Titan! That meant it was a plate type diff, and on those the discs eventually wear out. So I took the diff out. (not very easy I should add)

It was a ZF diff. And it was not worn out. So now I had the options to put it back, refurb it, or replace it.

I decided to replace it with a Titan with different ramp angles. Mostly because I wanted to try something new, and it is said that the Titan is very good. And now when I know how to do it I can play with ramp angles and pre-load if I want.

I did the work myself which a first for me. It was not that hard but time consuming as I didn't want to mess up. I replaced the rear bearings and seals but left the pinion as it were. Tried to set 0.01mm backlash but that was not very easy to get precise. But I got close enough, I hope.

Here is a good guide. and here is the workshop manual.

The original ZF diff had 45/45 ramps and weighted 6691g.
The new Titan diff have 30/90 ramps, carbon plates, and weights 5902g. 40ftlb (54Nm) pre-load.

30/90 ramps equals no locking while trail braking, and heavy locking when accelerating out of corners. 45/45 means equal locking when accelerating and braking. When the rear wheels are locked the car will have difficulties to turn and understeer in tight corners. It also means the rear tyres will have a better chance to transfer power into the ground, both when braking and accelerating.

I'm looking forward try it, but I doubt it will happen before spring.
And hope I never need to take the diff out again.

Update: Two short test drives made. It works!

2 comments:

  1. Hi, what is your feedback on the new Titan diff? :) best

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    Replies
    1. Hi,
      This season has been a bit of a mess, but what I can say is that the difference was not huge. In the beginning I had a hard time with corner exit oversteer as the locking was a bit early and abrupt, but after a while it was much smoother. Also, as I changed dampers last winter it took a while to find a new setup that worked. So it is hard to tell what was caused by the dampers, setup or by the diff.

      One positive thing is that I now much more easily can tell when the diff is locking and when not. If that is because of the new diff or increased awareness I don't know!

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