OK- would putting a 2 speed rear in my '70 FJ40 be a good thing or a total screw up? I know the original rear (which I have) has fairly low gearing, hence the awesome off roading abililities, but I have to do some serious highway driving to get to the boonies, and I was wondering if it would be worth it. Thanks for your help.
About 2 speed rer ends.....
- Thread starter qonos
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What is that 2-speed rear end from??
The only place I've seen those were on a dump truck and a water truck I used to drive at a carbon plant I worked at. They are very big units from what I've seen. I think they used to put them in early model Fords as well. Do you have access to one or are you just throwing the idea out there??
I wouldn't think you would need to get a 2-speed rear end. Of course, it all depends on your budget, your setup, what you plan on using the vehicle for, and what you plan on doing in the future. If you had the t-case in 4 wheel drive and you shifted your rear 2-speed axle into its low range then you would have to make sure the front axle ratio matched the rear 2speed axle low ratio or you would create problems. There would definitely be some issues putting something like that into a vehicle like a cruiser that wasn't meant for it. It would be really cool if you could pull that off though.
That would be good. You would have to have manual hubs to disengage that front axle. Finding the proper gearing for a 2-speed rear axle to match your 4.11 front and installing that might be interesting. As far as size goes, if you kept your stock front axle there would be a significant size difference. The only 2-speed rear ends I've seen are massive.
If you can find one and trust your mechanic to do a good job, go for it! And if you do, document the progress and post some pics up, I'd like to see it!
it would be easer to install a OD trany or a ranger od
35inchoverdrive
Forge Specialties
It would be less of a headache to swap in an H55f or other 5spd. You could also run some tall skinnies(33x9.50's, or 34x9.50's) for the cheapest solution.
Most of the 2 speed rears are huge and dont have gearing options they are kinda old school on trucks. so i dont think it would be worth it.
It would be unique to have the 2-speed rear but it could definitely get tricky!
Not bigger in width. Taller.
Example...
if current tire is 235/75R15 it turns about 710 RPM at 45mph and is roughly 28.6" tall.
If changed to a 33 x 9.5/15 it would turn at about 636RPM at 45mph and is roughly 32.7" tall.
The difference is similar to a 1.116 overdrive and for a highway speed example your old truck and tire combo going 55mph down the highway would be going 61.38mph with the new tires at the exact same engine and driveline speeds.
(Edit: to stick with 45mph example: 45mph w/ old set of tires would be 50.22mph w/ the new set of tires.)
