Fitting late type diffs

Post by **ianselva** » Mon Jan 17, 2005 10:42 am

Has anyone had problems fitting a late type diff with the level plug to an earlier axle ? I have just tried and found that the flanges on the bearing caps foul on the inner casing.

Post by **57traveller** » Mon Jan 17, 2005 1:31 pm

The later 4.22:1 diffs don't have the level/filler, it's in the axle casing along with the drain. The earlier 4.55:1 diffs do have the plug. Does your axle casing have both filler and drain or just the drain?

Post by **ianselva** » Mon Jan 17, 2005 1:43 pm

I'm actually fitting a 4.9 which has a level plug in the casing into an axle with a level and drain plug.

Post by **Kevin** » Mon Jan 17, 2005 1:50 pm

I thought you were asking if a later diff fitted to an earlier axle, but your last post suggest an early diff into a late axle or have I read it wrong, or are you talking of an even earlier type of axle. and where has the 4.9:1 come from as I though the lower ratios were 4.55:1 and 5:375:1

Post by **ianselva** » Mon Jan 17, 2005 1:56 pm

I thought it was the later type diff but 57 traveller informs me otherwise. I also have the same problem with a 5.3 diff with a filler plug. I'm not really bothered about which bit is early and which bit is late , I just want to fit them together. I can easily file down the flange/ grind out the casing just not sure which to do yet.

Post by **57traveller** » Mon Jan 17, 2005 3:20 pm

I'm confused.

Post by **wanderinstar** » Mon Jan 17, 2005 5:56 pm

Why do you want to put a 4.9 diff in a Minor in the first place[or do you mean 3.9].I would think a 4.9 will let you climb mountains but will do nothing for M.P.G.
Wanderinstar.

Post by **Willie** » Mon Jan 17, 2005 6:13 pm

If you look carefully on the rim of the crown wheel you will see
the figures which denote the number of teeth on the crown wheel
and the pinion. i.e. 38/9 etc. What are they????

Post by **ianselva** » Tue Jan 18, 2005 8:39 am

I'm fitting 4.9 diff to my racer , not a road car . BMC diffs are fitted to lots of historic race cars because BMC did such a wide variety of ( supposedly) interchangable diff ratios from 3.4 to 5.3. I have 4.9, 5.1 and 5.3 for mine.
However I have found this minor ( no pun intended) problem fitting some of the ratios . I merely raised the subject to warn others that not all difs wil fit all axles without mods , which may not be obvious when you're on your back under the car.