d30 - lowest gears available ?

[shawn]

does anyone know what would be the lowest gear ratio i could get into a d30 that would be otherwise stock except for the big spicer u-joints. just thinking about this 9" that came out of a yj. havnt looked closely at it yet but i have the eliminator that is crying for new diffs and i am thinking long arms and stuff, plus 35s -or better.

just exploring options for now with cost also being a factor. - already taking into consideration the cost of re-gearing both axles.

trails are extremely tight in this part of the world and i would really like to crawl - for relatively cheap. 4.88s ? 5.somethings?

[mvusse]

Stock gears go down to 4.56.

 

Some aftermarket manufacturers make 4.88, but the pinion is so freakishly small I wouldn't trust the strength of them.

[shawn]

ok, after some mis-communication it turns out the 9" is from a 60s car (havnt found out what model yet) , 63" from wheel mount to wheel mount. hes not sure if it's a 28 spline or 31 spline. --- $100. aparently 5 on 4.5 bolt pattern. ----------- thoughts ?

[Incommando]

Pass on it. The passenger car 9" from that era had thinnish axle tubes, 28-spline axles (with the exception of rare special edition high-output models), and small (weak) axle bearings and is noticably weaker than later units. The very low pinion position of the 9" means it is not the ideal swap 4x4 candidate in the first place in the opinion of many. A late model 29-spline 8.25 is probably an all-around better axle for your needs than this particualr 9", IMHO.

 

Most axles of that time period are weaker than the later versions, including Dana 44's, 60's, and 70's. A mid-60's D44 rear, for example, used 19-spline two-piece axles and a weaker 10-spline pinion shaft and is nearly on par with the turdy-five. :(