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PostPosted: Sun Jul 16, 2017 9:44 am 
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Joined: Wed Sep 09, 2015 11:22 pm
Posts: 199
It's a 2.76 with the overdrive primary and first motion input gears fitted.

I've got a NOS Rover boxed od primary somewhere.


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PostPosted: Tue Jul 18, 2017 2:14 pm 
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Joined: Sun Sep 22, 2013 1:47 pm
Posts: 669
Location: Coastal VA USA
Yes I run a 2.76 with two (O/D) drop gears. I find the (O/D) first motion shaft input gear in core trannys. The Primary gear does not stay with the tranny till I get them. I have three in service now and a fourth about ready to return to the road. Using the really wide ratio tranny allows good acceleration in all gears. Fourth gear is fairly useless under 50 mph. Third gear carries the same ratio as a 3.44 FD. The 1000 rpm drop between gears requires a engine with some torque.

I'm about to pull the 1360 Cooper S with this gear box and replace with a 998 with 3.1 CWP. Son Alex (age 17) and his sister Lizzy (age 16) are becoming drivers. Alex got his drivers and Lizzy got her learners the same day last week. I bought my first mini roughly 50 years ago. Son Alex is 50 years younger than I am, while not as excited about minis as I was it has been his and my only transportation since he was born.

Getting back on topic, I'm beginning to think of the 3.44 as the new 4.1. I drove a 4.1 for two years of college. My autocross car had a 4.35 and looking at my chart there is a 30 mph difference at 3000 rpm between the 2.56 and the 4.35 CWP. With (O/D) drops and so many CWPs there should be a ratio that works for most. Steve (CTR)


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PostPosted: Thu Nov 08, 2018 5:25 pm 
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Joined: Sat Mar 07, 2015 8:40 pm
Posts: 283
Update...

Been on the rollers at SMMC (thanks guys) and it’s official my car is a screamer!!

All the readings pointing to a 4.1 diff... no wonder my ears were bleeding on the A34 going up!!!

Now it’s a case of how looow to go :D

_________________
Cheers

Kevin


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PostPosted: Thu Nov 08, 2018 7:53 pm 
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Joined: Fri Mar 20, 2015 5:25 pm
Posts: 1353
I've two 1293cc Cooper S cars both with these final drives. The 3.44 is nice and smooth for a road car. The 3.65 is nice for town work even with an upgraded camshaft :D :D

Alan


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