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Old February 6th, 2011, 02:03 PM
Wolf Fabrication's Avatar
Wolf Fabrication
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Thoughts on Higher Gear Ratios

'83 110 with disco 200tdi, LT77, LT230. 3.54 gears rolling on 35's. T-case gearing was changed to 1.4. The truck drives perfect on pavement, decent off road. When I hit anything steep, say over 30 degrees, I need more "ompf" or rolling energy to get over it if I am at a stop. I don't want to change my R&Ps as I don't want to affect on road drivability.

The are the only options I have come up with:

1. New R&Ps, plus a Roverdrive to compensate while on road will run about $2500 plus the PITA to change R&Ps. Since I am running Disco drivetrain I am thinking the Roverdrive linkage won't work.

2. Ashcroft underdrive, $2800 and comes with a cable linkage. Relatively easy to install.

3. GBR low range kit: $1900

Any thoughts?

"The most unreliable car in the world is the most reliable car in the world." -Jeremy Clarkson refering to the Range Rover

Wolf Fabrication
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Old February 6th, 2011, 02:59 PM
carlosz's Avatar
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frank stein "frankie" in action RIP
Join Date: Jun 2006
Location: east coast
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all of them are great ways to resolve your issue, the lower the gear output the better advantage you have over your torque curve. generally a diesel begins it torque at about 1000 rpm and maxes at 1700 to 1800 beginning to drop at 2000 total run out at 2150 to 2500. (if your pump is set beyond 2500 rpm you are running the risk of a trown rod or runaway engine... where it revs to self destruction not much to do about stopping it unless you run a stick trans, then you may be able to stall it)
the strongest of your r/p set up is the 3:54.1 which is your stock this is good for up to 32's (tires).
generatively speaking anyting over 32 inch tires is is reccomended that lower r/p be used to mantain road abilities.
so i would reccomend the 4:10/4:11.1. is is a noisy set up as it takes alittle while to break in and even then some remain noisy all their life span (sort of a wheel bearing humm).
with the under/overdrive units unless it is a complete internal regearing set up or the replace unit is internally refurbished with said gears you will have issues with space.
that is to say if the over /under is offered as an external attachment you dont have much room under the truck for said attachment.
with the r/p you relieve some torque stress off your axles specially off road. so you run less risk of axle breakeage.
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