Diffs

[RossMccormack]

Hi All,

I am a new Stag owner from Brisbane Australia. I have recently purchased a 1972 mk 1 Stag that has a leyland 4.4 ltr V8 motor fitted with the original BW 65 gearbox. Problem I have is that driving down the motorway at 95kph the motor is doing approx 3000 rpm. This would appear to negate the advantages of this V8 motor. I am sure the car has the original 3.7 diff fitted. I understand I can easily fit a 3.4 diff from a Triumph 2.5/2000 but I think this is still too low a ratio. Has anybody any knowledge of what type of diff or crown wheel and pinion that I could fit that may give me a ratio of under 3 maybe 2.7 would be good.

Great car but has a number of electrical problems that I am now getting sorted.

Any help would be greatly appreciated

Regards to all Ross McCormack reme@qldnet.com.au

[jbuckl]

http://www.weslake.co.uk/stag_diff.htm

[Stagdad]

If you go the BMW route there are other ratios avaliable that aren't mentioned on the Westlake site,eg I had a 1:3.25 LSD at one time.
Cheers Steve

[GDPR]

I have the diff from a Triumph 2500 estate which you might find over there relatively easily. It's a 3.45:1 compared to the standard 3.7, and the estate one has the same case as a Stag - the saloon diff will mean changing the rear plate for the Stag one, and the bolt holes are different so oil leaks can occur.......
Mine is combined with the zf 4 speed auto so that gives me
30mph per 1000rpm, so maybe that's another option...

Russ

[paul.twyman]

Afternoon all,

I have a diff question. Well it may not be but lets see what people think.

I have a standard Mk2 BW35 auto box and diff in my 75 Stag. The thing is that it has a Rover V8 in the front. Now at 60mph I am running at 3000rpm which seems a bit high to me.

What would you expect the rpm to be for 60mph? Should something (gearbox/diff) have been changed when the RV8 was dropped in?

[wilf]

Those RPMs are about right for the std diff and BW35.

Solutions: Diffs with different ratios, or the 4 spd ZF conversion. Or a manual conversion to the 5 speed Rover 'box.

[GDPR]

Or a standard manual overdrive conversion.....

[jakesmig]

I've got an LT77 5 speed box out of a Rover SDI in mine, which gives about 23.5 / 1000rpm with a 3.7 diff. I'm toying with going to a 3.45 diff which would produce about 25.5 / 1000 rpm.
John.

[Guest]

Hi Ross,
My 1975 Mk2 stag with 3liter stag engine,BW35 auto box and standard diff revs 3000 at 90KPH.The speedo is correct according to my GPS.I have got used to it and have given up worring about the higher revs than most Vee 8s.Enjoy it and hope you get the electrics sorted out before the summer is on you.
Anthony