RayVoy said:We think your missing a link.
Pittdawg said:You are right. Here it is:
Gear Vendors under/overdrive, Application Guide 4 Wheel Drive 4-Speed Automatic Models.
I just got off the phone with them. I am very disappointed. You have to flip a switch to access each overdrive gear, "it cannot be set up as fully automatic on your platform". Boo.
Additionally, I was told the split gears will give little to no mpg benefit and the only benefit is for drag racing or towing to help keep the engine in the "sweet part of its powerband".
If I don't tow or drag race, the only benefit is the final, taller "over overdrive gear" when cruising on the highway. $4k including installation for a 2 mpg gain on the highway seems like quite a waste.
Shdwdrgn said:Regarding this and towing... what is the reduction from 4LO? Seems like it cuts the gearing by 3:1 or even 4:1, so the option of 2:1 would make a lot of sense for low-speed towing of heavy loads.
northcreek said:There is no reduction it's either 1 to 1 or OD.........
Shdwdrgn said:I don't understand... When you switch to 4LO, there is a huge gearing reduction when compared to 4HI.
Pittdawg said:I was trying to have my cake and eat it too. I installed 4.10 gears which I love but I lost about 2 mpgs on the highway (and gained about 1 mpg in the city) so a taller overdrive would get back my highway mpg but with the cost and constant need to turn the extra overdrive on and off it just doesn't make sense. You say why sweat 1 mpg overall loss? Well, I changed jobs recently and travel about 50 miles on the highway each way which I wasn't anticipating when I installed my gears so now highway mpg has become a bit more important.
the roadie said:I think the question was about the NP226 transfer case in the vehicle already. It's a 2.7-to-1 reduction in 4LO. As I've posted many times, on the most aggressive trails I run, I always run out of ground clearance or traction before I run out of torque in 4LO, even climbing 40 degree sandstone Moab Utah "fins". There are plenty of underdrive units out there for rock crawling that can do an additional 2-to-1, but my impression the GV units were mostly for motorhomes.
navigator said:I think he actually wants the extra OD more so he can get better mileage on his commute.
northcreek said:That's the wrong "he" that you are talking about.
Why do I feel like I'm in the "who's on first" skit?....Mike
Pittdawg said:I am the op. I was mostly interested in the mpg gains from the extra overdrive but was also intrigued by the claims on the website that it essentially turns our 4 speed autos into 8 speed autos increasing power to the wheels and mpgs. Turns out those claims are mostly bogus and/or impractical for a daily driver. It sure would be cool if car manufacturers made different tranny overdrive ratios for different rear end gear ratios.
Pittdawg said:I am the op. I was mostly interested in the mpg gains from the extra overdrive but was also intrigued by the claims on the website that it essentially turns our 4 speed autos into 8 speed autos increasing power to the wheels and mpgs. Turns out those claims are mostly bogus and/or impractical for a daily driver. It sure would be cool if car manufacturers made different tranny overdrive ratios for different rear end gear ratios.
Pittdawg said:I was trying to have my cake and eat it too. I installed 4.10 gears which I love but I lost about 2 mpgs on the highway (and gained about 1 mpg in the city) so a taller overdrive would get back my highway mpg but with the cost and constant need to turn the extra overdrive on and off it just doesn't make sense. You say why sweat 1 mpg overall loss? Well, I changed jobs recently and travel about 50 miles on the highway each way which I wasn't anticipating when I installed my gears so now highway mpg has become a bit more important.
northcreek said:Because you have a 2wd you could actually install a manual gear box behind your transmission( there are kits to do this).It's an old trick that has somewhat come back into fashion lately...Mike.
Pittdawg said:I would love to do that but my left knee arthritis rules that out. I actually had a stick shift Lexus IS 250 prior to this truck and LOVED that car! The leather seats were unmatched in comfort as compared to any other vehicle I've ever rode in and that close ratio 6 speed manual was perfectly mated to that high revving 2.5 cylinder 6 cylinder engine. That car just kept pulling from idle to redline like you wouldn't believe!
northcreek said:No there is no clutch work involved,here is the link,you can do OD on the cheap with this kit...Mike.
www.OverDriveIt.com Toll Free: Customer Support 1-928-522-6762 Flagstaff Az.