As the title says.

I'm thinking of doing a bit of weight saving. I've got the 6.5inch diff and its a good few kg lighter than my existing 7inch diff.

So I am after a couple of driveshafts, the inner CV tripodes are smaller than normal ones. I'll have to shorten them so condition isn't critical, but the inner CV joints need to be servicable.

I don't want to do a swap (with my current set-up) as my existing shafts have been shortened.

Thanks,

Matt

Jeeez!
Will you really notice the difference? And is the expense/effort ratio worth the hassle?

If you're chasing every kg to save weight as many people do then the 4kg weight differnce from one change is actually quite a lot. If Matt can get the joints cheaply then the swap will be very resonable. It all adds up eventually.

Sorry to ask in here but bit on topic when diff's are quoted at 6.5 7 or 7.5 is that the measurement across the top mounting holes, never actually measured it?

Adrian

To answer the questions:

Why bother with this marginal weight change?

Well, presently I have a 3.14 diff. My existing driveshafts have a built in weakness (there is a machined groove that retains the boot, and I am told that these have failed in RGB in the past). Further the present diff is a bit high in my install as I ended up with bigger wheels (14's instead of 13's) than originally planned.


So,
I kind of need a new diff to help low speed acceleration (3.62 instead of 3.14).
New halfshafts are in my future too, as one big breakdown is about the cost of diff replacement.
Also if I sell-off the 3.14 then I will be in profit.
Finally, I can save 4kg on the diff, and another 1kg on the shafts.

The car weighed 476kg at SVA (wet), and I am keen to "add lightness".

Costwise:
diff = £35
driveshafts = £25
modification to shafts = £75
new boots = £25

so, £160 to add 5kg of lightness, seems like a good mod. Especially as the 3.14 diff is worth £250 2nd hand.


Matt

Dimension details:
I am told that the dimension is the diameter of the crown wheel.

By some fortunate coincidence the top mounting bar also has the same dimension for the 7 and 7.5inch diffs. The 6.5inch diff comes with the same mounting interfaces as the 7inch diff, but is smaller in every other way.


Half-shafts for 6.5inch diff have inner CV joints with 23splines, and so are no use on other diffs. I suspect that a few folk have these "rubbish" shafts in their shed and hopefully want shot of them. I could buy brand new ones for £38 a side but what is locost about that?

Matt

Bit off the topic but what size mm is the driveshaft nut on the drum. I have got to borrow a socket off a mate so it would help to know what size to get?

41mm socket