Anyone know if '89 and '92 rear axles are interchangeable?

[D21Driver]

Good Evening Everyone,

The high cost of fuel is making me think about changing to a taller rear axle ratio. Does anyone know if the rear axle from a '92 two wheel drive (HF35) with an automatic is a direct replacement for the axle in my '89 two wheel drive (HF37) five speed? They look the same and the width between the springs is the same but my luck is not always the greatest so I thought it best to ask before proceeding. Thanks!

PS: Just out of curiosity, does anyone know what was the tallest ring and pinion set offered for the H190?

[RT22]

i would not swear on it but the housings should be the same as few companies would have different housings on same basic model vehicle. parts sharing saves cash in production, just be sure they are both 2 wheel drive as many times 4 wd may have beefier axles.

[D21Driver]

Thanks RT,

Unless it's been swapped at some point the donor axle is definitely from a two wheel drive, it's still in the donor truck. I think I found an answer to the tallest ring and pinion for an H190, it's a 3.364. Pricey though, I think i'll have a go at this 3.545, it's not a big difference but it would probably help some, plus I'd have a spare axle. Thanks for taking the time to reply, I appreciate the information.

http://www.nissanpartszone.com/componen ... 0-333.html

[Novajoe]

I'm guessing you don't do much highway driving. The extra tq from a shorter ratio would help some in the city, but it will kill your mileage on the highway since your rpms will be higher at cruising speeds.

I might just be mis-understanding you, but you do realise that the higher the final drive, the shorter your gears will be right?

That said, all of our axles are the same length, so that's not a problem, the only thing I might be concerned about is whether the yoke would match to your driveline. i'm not sure if these are all the same.

[D21Driver]

Thanks for taking the time to reply. By taller i mean a lower numerical ratio, I have a 3.70 axle ratio but would like to go to a 3.545 or perhaps even a 3.36 if i can find one. The majority of my driving is on the highway and I rarely haul anything heavy so I am definitely looking to reduce my rpm at cruising speed. I have been employing the techniques of the hypermiling community and am consistently getting 29 or 30 mpg. It's so nice to see 400+ miles before seeing the low fuel light. I am hoping that a change in the final drive ratio might help me achieve low 30's consistently. I probably need adult supervision, i can turn just about anything into a hobby. :-)