 | Home > Maintenance & Modifications > Two Wheel Drive Transfer Box |
 
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| hank Member Since: 12 Sep 2016 Location: South Wales Posts: 2301   
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Just thinking out loud really
Are there any 2wd transfer boxes out there that are straight fit, plug and play with a Puma? Years back I had a company Ford Ranger with switchable 2wd / 4wd transfer box, this was based on the TDCi engine though not sure on gearbox. Wondering whether switchable 2wd for road driving as per earlier Defenders would provide improved fuel economy > 110 XS Double Cab |
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5th Feb 2019 6:22am |
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| Retroanaconda Member Since: 04 Jan 2012 Location: Scotland Posts: 2656 
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Ashcrofts do a kit to convert an LT230 to that arrangement I believe.
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5th Feb 2019 6:39am |
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| bankz5152 Member Since: 02 Feb 2017 Location: South London/North Kent Posts: 2179 
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Syncro Gearboxes do a 2wd/4wd selectable mod for the Tx boxes
https://www.syncrogearboxes.com/research-d...3737242_o/ Instagram @defender_ventures Empire Tuning - Agent Last edited by bankz5152 on 5th Feb 2019 8:27pm. Edited 1 time in total |
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5th Feb 2019 8:27am |
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| Litch Member Since: 10 Mar 2013 Location: Oxfordshire Posts: 765 
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"Wondering whether switchable 2wd for road driving as per earlier Defenders would provide improved fuel economy"
Was never an option on the Defender. It was the standard set-up on S1, 11 & 111 (Stage-1 excluded) and even some of the very earliest One Ten's (with 2,25) were offered with this option but that is as far as it went, believe it had been dropped by 1985. Can't believe it would be a nice drive, have driven both my 101 & 90 with a prop removed and there is a noticeable difference and the vehicle just doesn't "feel" right. ONE LIFE, GET IT! |
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5th Feb 2019 8:24pm |
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| Timo K Member Since: 23 Aug 2012 Location: Helsinki Posts: 171 
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There is no point. For one, the frankly negligible fuel savings would also warrant a fitment of freewheeling hubs. Otherwise you are basically using the rear wheels to push the front wheels, all the drive line bits would still be rotating as per usual. Amount of time and effort required for all of that is better spent on practicing more economical driving...
It's often heard from the Toyota/Nissan crowd that the 2WD/4WD transfer case and freewheeling hubs are superior because of the fuel savings standpoint, but the numbers don't really back that up. Granted, they mostly have larger displacement engines, but I would argue that Mercedes G's proves them wrong. They also have full time all wheel drive like a Defender and have similar economy to Nissans and Toyotas with similar power levels. I think the economy argument for selectable four wheel drives is a gimmick to try and hide the fact that it's an inferior system. |
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6th Feb 2019 12:27am |
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| hank Member Since: 12 Sep 2016 Location: South Wales Posts: 2301
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In the Middle East I drive a Chevrolet Tahoe which has switchable 2wd/4wd, which was the trigger for these thoughts.
It's got a 5.3L V8 and I've noticed a fair difference in fuel consumption driving 2wd and 4wd. Although not scientific/mathematical each week I do similar mileage/driving and fill up every 8th day. Then I switched it to 2wd and was filling up every 10th day. Not that it matters as fuel is cheap. Perhaps I'll do some fuel economy calcs over the next few tanks. But sounds like it's not an avenue worth exploring on the Defender > 110 XS Double Cab |
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6th Feb 2019 4:47am |
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| blackwolf Member Since: 03 Nov 2009 Location: South West England Posts: 17450 
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Does the Tahoe have a conventional centre diff when in 4WD, or something like a Haldex unit? If not a conventional diff, that might well explain the difference in fuel consumption.
To me, the fact that the Defender has full-time 4WD is a huge superiority over all the current generation of other make pick-ups, which, as far as I know, are part time. |
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6th Feb 2019 8:44am |
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| hank Member Since: 12 Sep 2016 Location: South Wales Posts: 2301
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It uses New Venture Gear 246 transfer box...
Automatic all wheel drive with 2wd, and 4wd lock modes and low gear. NVG 246 "AutoTrac" four wheel drive system. 2Hi, Auto 4wd (100% of torque is transferred to rear wheels until it detects a need for extra traction. Dry multi-plate clutch is used to transfer torque to the front), 4Hi (50/50 split), 4Lo, all button activated. 2.72:1 low range gear 3.73:1 GM's 10 bolt IFS front with Central Axle Disconnect (CAD) GM's corporate 10-bolt live axle with g80 limited slip (opt) and 3.73:1 gears > 110 XS Double Cab |
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6th Feb 2019 9:35am |
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| blackwolf Member Since: 03 Nov 2009 Location: South West England Posts: 17450
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That sounds essentially like a Haldex unit. Value-engineering 4WD!
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6th Feb 2019 10:16am |
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| Slideywindows Member Since: 09 Sep 2016 Location: North Essex Posts: 1286
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I've always found it strange that Land Rover came to a different conclusion about permanent 4wd to many other manufacturers, and assumed that the others remained with switchable 2/4wd, due to cheaper costs of manufacture. Could be wrong.
Land Rover did offer a 2wd/4wd transfer box on the very first One Tens at extra cost, but due to lack of demand they dropped it when the Ninety was introduced 15 months later. (An early One Ten with a switchable transfer box - and factory fitted freewheeling hubs as standard - is now a rare beast) Can't recall any great demand during the last 28 years for Land Rover to supply a 2/4wd option on the Defender, and there must be a reason for this. Incidentally, the very first 80" Land Rovers also had permanent 4wd but that was soon dropped. |
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6th Feb 2019 12:18pm |
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| MK Member Since: 28 Aug 2008 Location: Santiago Posts: 2422  
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Just guessing. Probably it was cheaper for LR to go for permanent 4wd than unpgrading the rest of the rather weak transmission (dodgy diffs and two-piece halfshaft). The std part-time 4wd is ok for most of the time but the lack of central diff can be a downside in some situations (i.e. slippery curves).
In the old S2&3 the yellow 4wd knob was quite useless with their low power and torque 2.286cc engines. Puma 110" SW ............................................................. Earth first. Other planets later |
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6th Feb 2019 12:38pm |
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| discomog Member Since: 09 May 2015 Location: Notts/Lincs Border Posts: 2530 
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Surely a new 2WD/4WD transfer box and freewheeling hubs just makes this project uneconomical. Not sure the rear drivetrain could handle it??? Defender 90XS SW
Mini Countryman Cooper S Morgan Plus 8 |
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6th Feb 2019 4:46pm |
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| Caterham Member Since: 06 Nov 2008 Location: Birmingham Posts: 6300 
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I'm not so. To me it sounds bl00dy complicated  |
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6th Feb 2019 4:54pm |
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| blackwolf Member Since: 03 Nov 2009 Location: South West England Posts: 17450
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To me it sounds like a salesman making a simple and cheap system sound high-tech!
The Haldex unit essentially uses an electronically-controlled multiplate clutch to engage the front drive when required. You will find them on things like the Yeti, the Evoque, and in fact just about every selectable 4WD vehicle now (heaven forbid not the new Defender, but I wouldn't rule it out). So translating the blurb above, in 2WD the clutch is always disengaged. In 4WD the clutch is disengaged until the traction control ECU detects that 4WD is actually needed, whereupon it engages the clutch pack, disengaging it as soon as possible afterwards. Johnny Owner thinks that he's in 4WD, but actually he's just delegated decision-making to a computer. When in 4WD there is no centre differential action of any kind. It is much cheaper to make since there will a traction control ECU anyway (for the legally required DSC/TC function) and instead of a big, expensive, precision-made mechanical lockable centre diff with many wearing parts, there's a small, cheap (at least to the manufacturer), off-the-shelf bought-in Haldex unit, which has few wearing parts. Provided that your sales blurb can make it sound like the customer is getting something cutting edge instead of an iron-age differential, the majority will believe it. The system would not work on a Defender (well, not a Td5, TDCi, or V8 Defender anyway) since the rear driveline isn't strong enough (this, of course being the reason that the LT230 and full-time 4WD was introduced with the original Range Rover and Stage 1 V8 Landrover). |
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6th Feb 2019 5:20pm |
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