[Canadian80]

Hi all,

I'm currently in the market for a 4.0L 6cyl TJ with manual transmission. I've done some research on this board and found some info. I've decided on the Dana 44 axle option. Now I've realized that in 2000, the manual transmission changed.

Can anyone tell me the differences, and the pros/cons for each transmission?

Thanks in advance,

-Ryan

[xantasm]

Pre 2000:
AX-15 5 speed transmission was used for inline six cylinder

In 2000:
New NVG-3550 manual transmission replaces the Aisian transmission on the models with the 4.0L engine (includes synchromesh on reverse gear).

In 2005:
6-Speed NSG370 manual transmission replaces the 5-speed NV3550 & NV1500 transmissions in all models

Jeep TJ Model Changes By Year

I really like my 6 speed in my LJ, its really easy and smooth to shift and has a really good even spread feel to the gears in both low range and high range. Only problem Ive had with it is getting used to having a 6th gear where reverse was in my old YJ with an AX-15. As far as the AX-15, its history speaks for itself. The AX-15 is a really tough transmission and was designed well. I dont have any experience with a NVG-3550 so couldnt say about it. In my LJ I really dont find the need to even shift into 6th unless Im on a long drive at freeway speeds. I use 4th and 5th gear mostly at 55-70. Honestly IMO they are both really good transmissions just the NSG370 has a 6th gear which is basically overdrive. Id say go with whats in the vehicle your interested in, and only worry about a 6 speed if you want a newer one.

[hal2814]

It's a pain in the rump to figure out what fluid to put in the later AX-15s. GL-5 will destroy the brass parts inside it. I think the current recommendation it is a certain weight motor oil. That being said, it is an excellent transmission and personally I prefer it to the NV3550. I drive the NV3550 now and it gets the job done but it's not nearly as smooth as the AX-15. I head the NV3550 is more of a heavy duty transmission and believe that but seeing what some people have put the AX-15 through, I'd wager it won't matter for most people (even just counting people of the off-road persuasion). I have no experience with the 6-speed.

[2jhanna]

personally, i would not base my purchase my purchase on what manual came. for example, pre 2000 had a distributor, where post 2000 have a coil rail. things like this also play into the mix.

by the way, the nv3550 is considered a heavy duty 5 speed.