low range AWD?

FROM AWD'S TO 2-SPEED MANUAL SHIFT, IF IT LINKS THE REAR AXLE TO THE FRONT AXLE, POST IT HERE.
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arlon
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low range AWD?

Post by arlon »

I gave up tring to find a thread on what vehicles had AWD with low range. Seems they existed and it would be nice to have a list of what vehicles had that option that would fit the Astro in case I stuble across one in a junk yard. Any help finding that info would be appreciated.
2004 AWD Astro 2" lift, overnight-able
2003 Dodge/Cummins Quad cab
2006 Nissan X-terra MT
1985 LTD LX 5.0 HO
Plus wife's and kid's cars to take care of...

astroturf
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Re: low range AWD?

Post by astroturf »

This thread might help:

viewtopic.php?f=58&t=82
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Re: low range AWD?

Post by MountainManJoe »

True Full-time or All-time 4WD systems power both axles, all the time, without input from the driver. The Borg Warner 4472 found on pre-'99 AWD Astros is a good example (albeit one speed). The benefit here is that you always have full traction. Downside is, depending on the unit, you have clutch packs that wear out, viscous couplings that aren't perfect and wear. This doesn't apply to the 225 (which uses constant gear meshing like the Torsen type differentials).

AWD units with low range are:

NV242
Jeep Grand Cherokee
Jeep Liberty
Hummer H1 (both military and civvy)

NV244
Dodge Ram 1500 & Dakota

NV225
Land Rover Range Rover

NV235
Porsche Cayenne
VW Touareg

Then there are the automatic on-demand 4WD transfer cases which normally operate in 2WD mode until slippage occurs, such as your stock unit. Benefits are smooth on-road performance. Downside is that they are reactive rather than proactive.

NV247
Jeep Grand Cherokee

NV226
Chevy Trailblazer
GMC Envoy
Isuzu Ascender

NV236
Chevy Blazer
GMC Jimmy

NV246
Chevy SIlverado, Suburban, Tahoe
GMC Sierra, Yukon

Of course some of these units employ a combination of technologies. New Process Gear (renamed to New Venture Gear in '99 when it was joint venture between GM+Chrysler) has a standard naming convention. Any model number that starts with a '2' has two speeds. The second digit is the strength, and the 3rd is the type of coupling (about 8 different kinds).

Unfortunately, this board doesn't allow non-image attachments. If you want, PM your email and I'll send you some references.
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