5.1 GPO Van Diff

delta · 22 Jan 2016, 15:36 (Ref:3607128)

Anyone know of or have a 5.1 BMC GPO Van diff please.

MGDavid · 22 Jan 2016, 17:22 (Ref:3607155)

none here Iain but I know of a 5.3 that might be available

delta · 22 Jan 2016, 20:15 (Ref:3607199)

Quote:

Originally Posted by MGDavid

none here Iain but I know of a 5.3 that might be available

Yes please . I got it wrong about 5.1 being GPO van it is a 5.3

Brian A · 22 Jan 2016, 21:13 (Ref:3607215)

Quote:

Originally Posted by delta

Anyone know of or have a 5.1 BMC GPO Van diff please.

Iain - I have both a 5.125 and 5.375 sitting in the garage. They both have the 8 tooth pinion with either the 41 or 43 tooth crownwheel. I am not sure what the 5.125 came off as I've always associated the GPO van with the 5.375 ratio. I've kept them as reserves in case I run out of the 4.875(8:39) that I need for the Elite and Mk 9. They now really need to be treated as consumables with the level of power being put through them!

I did try a 5.375 in the Elite a few years back, but it is more of a sprint/hillclimb ratio and over the years I've worked out that the 4.875 is the optimum diff for the Elite.

Certainly happy to part with the 5.375 and could be talked into selling the 5.125 if I could get another spare 4.875 (I'm down to my last one....)

delta · 22 Jan 2016, 22:02 (Ref:3607226)

Ok thanks Brian and David . I'm off to South Africa Tuesday back Feb 15 th . Can I contact you then please . I remember we used the 4.875 on the 17 so I might just have one .

zefarelly · 23 Jan 2016, 09:10 (Ref:3607271)

Are they not being reproduced yet ? THe Ford ones have been for some time . . .

MGDavid · 23 Jan 2016, 10:54 (Ref:3607287)

Not AFAIK. Heathrow Transmissions are fitting new 3.9s and 3.7s so I'll ask them next time I'm up there.

Mike Bell · 23 Jan 2016, 12:18 (Ref:3607295)

Billy Bellinger is having ten sets of 4.875 ratio made at the mo.

Geraint Owen · 23 Jan 2016, 12:24 (Ref:3607297)

what sort of value are we talking about. I may know where there is a 5.1 and a 5.3. I can approach, but it would help the conversation if I have an idea of what sort of money they are. I dont know if they are £5, £50 or £500

Geraint

GORDON STREETER · 23 Jan 2016, 15:33 (Ref:3607329)

Quote:

Originally Posted by zefarelly

Are they not being reproduced yet ? THe Ford ones have been for some time . . .

I seem to remember using those Austin/Morris diffs in Ford axles in the old Hot Rod days ? I don't think I'm imagining it but I suppose I am getting on a bit

Mike Bell · 26 Jan 2016, 07:26 (Ref:3608031)

As this thread got lost on page 5 after the calendar entries, thought would bring back to P1 in case anyone has more to add.....

delta · 26 Jan 2016, 11:57 (Ref:3608084)

Quote:

Originally Posted by Geraint Owen

what sort of value are we talking about. I may know where there is a 5.1 and a 5.3. I can approach, but it would help the conversation if I have an idea of what sort of money they are. I dont know if they are £5, £50 or £500

Geraint

Thanks Geraint, I guess you would have to ask the question how much the seller wants. I am normally pretty good estimating prices for parts like this. Off the top of my head around £250.00 for each diff.

one-two · 29 Jan 2016, 16:30 (Ref:3609078)

To go back a few posts, and slightly off-topic, I am interested in Brian's comment about 4.875 being right for an Elite. Can I ask if that is with a standard ratio ZF box and 15 inch wheels with 5.00L's please? I am sorting out ratios and a diff for something that is quite like an Elite, but isn't one! Many thanks, Robert

Geraint Owen · 29 Jan 2016, 17:51 (Ref:3609091)

Quote:

Originally Posted by delta

Thanks Geraint, I guess you would have to ask the question how much the seller wants. I am normally pretty good estimating prices for parts like this. Off the top of my head around £250.00 for each diff.

Damn....I have just checked and the diffs were in a pile of stuff stolen from my fathers workshop about 2 years ago........ggggrrrrr

Brian A · 29 Jan 2016, 21:19 (Ref:3609144)

Quote:

Originally Posted by one-two

To go back a few posts, and slightly off-topic, I am interested in Brian's comment about 4.875 being right for an Elite. Can I ask if that is with a standard ratio ZF box and 15 inch wheels with 5.00L's please? I am sorting out ratios and a diff for something that is quite like an Elite, but isn't one! Many thanks, Robert

The ratio works with both the ZF and MG Magnette box. I have both boxes but prefer using the MG one.

Rear wheels are the standard 15 inch with 5.00L15 Dunlops (4.50L15 on the front).

When I first got the Mk 9 Lotus, we changed the diff also to 4.875 and it works on this just as well. But remember the short stroke Climax (FWA and FWE) loves high revs. If your engine has a more restricted rev range, the 4.875 might be a tad too low geared.

one-two · 30 Jan 2016, 10:30 (Ref:3609222)

Very interesting Brian and many thanks. I have a small Climax engine in the car I am preparing, but don't expect to rev it much beyond 7.5K. All the other parameters are the same. I had been thinking of 4.5 or 4.7 max for the diff, so your 4.875 got me thinking. The car is a Lotus 7 S1. Many thanks again, Robert

MGDavid · 17 Feb 2016, 16:29 (Ref:3615488)

Iain you have a PM...

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