Yeah, that is true, I'm just not too sure how I wanna go about it. I'm not seeing much of a drop for any available 6 speeds though. so it looks like I'll probably be droping to a 3.21 and another 3500

 

eww. why would you want such a sucky gear ratio? rpms do not directly translate to better or worse mpgs. the equation is more complex than that. The key is keeping the engine somewhere in its peak torque band, where it's producing the max power efficiency. For anything you might save on the highway, you'll be losing during acceleration when the engine is then working harder than it should to get up to speed. Plus you'll be spending hundreds and hundreds on a perceived benefit that may or may not ever happen. and if it does, it'll take a non-insignificant amount of time to actually pay for itself.
that first year I had her I went from 28" tall tires in my Dak RT (3.92 axle ratio) to 31" tires (meaning an equivalent gear ratio of around 3.55) and saw no benefit on the highway. none what so ever. I did pick up a noticeably more cushy ride due to the extra sidewall though

 

Ok, just an update. I finally made it home tuesday night and drove the truck for the first time yesterday. Holly damn!!!!! My problem is most pronounced in 3rd gear but I can still hear some nasty stuff trying to happen in 1st and 2nd too, so I am now leaning towards my berrings being gone on the main shaft. i believe that if it were a broken tooth on the 3rd gear that my noises would be isolated to 3rd only. 4th and 5th are the same as they've always been. Looks like I'm fixing to learn how to do a rebuild on the 3500. I haven't had a whole lot of luck finding a replacement or an upgrage other than the 4500 and I just dont wana go there. These trans are freakin rare. the avg price seems to run around 700 to 1000 for a used and roughly 1250 for a rebuilt. I have found where I can get new ones for about 1650 though. so much for keeping it cheap.

 

Well explained. My room mate went from 3:73's to 4:10s in his Mustang and saw only a 1mpg loss on the highway and actually increased in city mpg. He put in the gears for better accleration and he ended up using about the same in gas.

And yeah, my buddy with a CJ7, wants my nv3500 bad lol.

 

Ok fellas, I just got some really conflicting info from a prety reliable source yesterday. This guy has been operating a 4wd specialty shop for over 10 yrs so I felt like his input would be pretty reliable espescialy since he was willing to drop bad news on me and not try to sugar coat anything or fast talk me. but he did drop one little nugget that I was totaly not expecting. We discussed my problems and what I could expect to see as cost but when we started talking about interchangeability he told me that the AX15 was also available. I knew this but dismissed it because I had heard that it was kind of a sub-standard trans. He explained to me that the AX15 is actually a better trans than the 3500. This is the 2nd time (the 1st time was from a pretty reliable source too) that I have been told that the AX is essentialy a toyota trans with a dodge bellhousing, but he is the 1st person to say that the AX is actually better than the 3500 stating that most people encounter less problems from the AX. Could this be because there are less of them being used? or perhaps that they are being used more comonly with 6cyl engines? He got kinda busy with calls and other customers so I didn't get to quiz him any further. Either way, I am beginning to feel that it's gonna be too expensive for me to build my trans so I'm fixing to be back on the hunt for a replacement. only ? now though is which one.

 

ok, another update. with all that I've found about my trans and feeling the need to start getting something done I decided that my next move was to just go ahead and pull the trans. pulled it out, set it on some saw horses fliped it over and letit drain for a bit. while it was on it's lid I decided to pull the plug. as the plug came out you couldn't help but notice the 1 1/2 x 1/4 inch long piece of metal dangling from the plug. I just stoped right there. from what I've been told these gears are pretty dang expenssive so I don't think I'm even gonna mess with trying to build it right now. I have found another NV3500 kinda close to me for $600 so I guess I'll be makin a road trip next week.

 

This is pretty rare for a NV3500. How many miles are on it?

 

275,000. I have no idea why it would go out, lol.