↓ Advertise on Defender2 ↓

Home > Maintenance & Modifications > Overdrive options??
Post Reply  Down to end
Page 1 of 1
Print this entire topic · 
nickh90



Member Since: 19 Oct 2009
Location: Nr Horsham
Posts: 195

England 1989 Defender 90 V8 Petrol SW Auto Java Black
Overdrive options??
Hi all,.

Sorry back from hols and lots of questions have built up:-)

I have a v8 defender which I am "personalising"! it has a TH400 3 speed auto box and shifter, Quaife ATB2300 centre diff internals. I would like to have an overdrive for motorway work or long runs when I can let the big torque do the work.

currently just a touch over 3k rpm at 70mph

Without buying a 4 speed auto, any suggestions?

Thanks

Nick
Post #203847 21st Jan 2013 2:34pm
View user's profile Send private message View poster's gallery Reply with quote
SteveG



Member Since: 29 Nov 2011
Location: Norfolk
Posts: 660

2005 Defender 90 Td5 CSW Belize Green
What tyre size are you running. For example, moving from 235/85 to 255/85 give the same kind of effect as most overdrives. Obviously the effect happens in all gears, but unless you plan to tow really heavy loads you won't be bothered by it.

Cheers

Steve
Post #203855 21st Jan 2013 2:58pm
View user's profile Send private message View poster's gallery Reply with quote
MartinK



Member Since: 02 Mar 2011
Location: Silverdale (Lancashire/Cumbria Border)
Posts: 2665

United Kingdom 2011 Defender 110 Puma 2.4 USW Orkney Grey
Nick - I'm sure you'll already know them, but I would call Ashcrofts:
http://www.ashcroft-transmissions.co.uk/index.php

Steve's comments on tyres sound really good as well.

I assume you would prefer 2k RPM at 70 (more like modern 6-speed cars)...? Defender "Puma" 2.4 110 County Utility (possibly the last of the 2.4's)
Post #203860 21st Jan 2013 3:08pm
View user's profile Send private message View poster's gallery Reply with quote
nickh90



Member Since: 19 Oct 2009
Location: Nr Horsham
Posts: 195

England 1989 Defender 90 V8 Petrol SW Auto Java Black
Thanks chaps..

I am running 315 75 16 AT tyres so near as damn it 35" - don't think I can go any further down that route Smile

I will call Ashcrofts and see what they say... thanks

yes 1500-2000rpm would be better on fuel and noise for sure!


Its so torquey its in top within 50ft of pulling away anyway.. well unless I boot it Smile
Cheers

Nick
Post #203873 21st Jan 2013 3:50pm
View user's profile Send private message View poster's gallery Reply with quote
nickh90



Member Since: 19 Oct 2009
Location: Nr Horsham
Posts: 195

England 1989 Defender 90 V8 Petrol SW Auto Java Black
Ashcroft do not do an overdrive unit Sad

Will look at GKN
Post #203911 21st Jan 2013 4:54pm
View user's profile Send private message View poster's gallery Reply with quote
bpman



Member Since: 21 May 2008
Location: Oslo
Posts: 8069

2008 Defender 110 Puma 2.4 SVX Station Wagon Santorini Black
you might find roverdrive unit ... not sure if it would work with a V8
Post #203933 21st Jan 2013 5:27pm
View user's profile Send private message View poster's gallery Reply with quote
jst



Member Since: 14 Jan 2008
Location: Taunton
Posts: 8051

 2011 Defender 110 Puma 2.4 USW Stornoway Grey
although you said no to it, why not get a 4speed box, cheaper i would of thought. Cheers

James
110 2012 XS Utility
130 2011 M57 bespoke Camper
90 2010 Hardtop
90 M57 1988 Hardtop
Post #204017 21st Jan 2013 7:52pm
View user's profile Send private message View poster's gallery Reply with quote
Laurie



Member Since: 22 Feb 2008
Location: Sussex, England
Posts: 2897

England 2005 Defender 90 Td5 XS CSW Bonatti Grey
An overdrive in good working order is likely to cost £1K 
Post #204021 21st Jan 2013 8:01pm
View user's profile Send private message View poster's gallery Send e-mail Reply with quote
yobbie



Member Since: 15 Nov 2010
Location: Isle of Wight
Posts: 713

United Kingdom 1999 Defender 90 Td5 Heritage LE Bronze Green
I'm running a Roverdrive unit on a TD5 with a tune with similar power & torque to a V8 (190 bhp & 300ft torque). At just over 60mph in standard gearing is 3000rpm (I do have a rev counter) with overdrive its 2000rpm the noise levels are much more exceptable but I wouldn't say the fuel consumption it greatly improved.
Post #204027 21st Jan 2013 8:12pm
View user's profile Send private message View poster's gallery Reply with quote
nickh90



Member Since: 19 Oct 2009
Location: Nr Horsham
Posts: 195

England 1989 Defender 90 V8 Petrol SW Auto Java Black
I could get a 4l80e or similar box from a Bentley for about £500 plus adapter plate and then fitting - need to research more!

I am running 350bhp now but could end up at 500 in the future so needs to handle it..

Starting to think the box is a better option but this one is brand new!!!
Post #204045 21st Jan 2013 8:31pm
View user's profile Send private message View poster's gallery Reply with quote
yobbie



Member Since: 15 Nov 2010
Location: Isle of Wight
Posts: 713

United Kingdom 1999 Defender 90 Td5 Heritage LE Bronze Green
I doubt a Roverdrive would handle that sort of power Shocked they got me to fit a larger sump for more oil capacity due to cooling.
Post #204047 21st Jan 2013 8:35pm
View user's profile Send private message View poster's gallery Reply with quote
Lodelaner



Member Since: 04 Feb 2010
Location: Lambourn
Posts: 632

United Kingdom 1988 Defender 90 V8 Petrol ST Shire Blue
How about 1.003:1 transfer gearing from the 3spd RRC Auto? JB

@Lodelaner Instagram

Youtube greenlaning and other LR related content
Post #205295 25th Jan 2013 6:17pm
View user's profile Send private message View poster's gallery Post Reply
Post Reply  Back to top
Page 1 of 1
All times are GMT

Jump to  
Previous Topic | Next Topic >
Posting Rules
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum



Site Copyright © 2006-2024 Futuranet Ltd & Martin Lewis
DEFENDER2.NET RSS Feed - All Forums