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View Full Version : Front D44 Gear Break-in



goldensd
05-12-2009, 11:53 AM
OK, so I've pretty well completed most of my build for this winter, and am driving the ZJ this week to get the gears broke in and to check for adjustments and lose stuff that need to be taken care of.

For new gears to break-in, I've got the Atlas, and the Front D44 that need to go through the break-in period. BUT driving it last night, it clicked with me that on the Dana 44 with the selectable hubs, I have nothing turning (I still had the 249, when I changed my gears in the D30 so never thought of this). So I guess to do it by the book, you'd have to lock in the hubs and 4x4 and drive around for the 500 or so miles in 4 wheel drive, which also seems a bit hard on stuff.

I reread the Yukon books and did some looking around, but couldn't find anything that addresses breaking in gears when you don't have them turning under normal conditions. Since the gears in this case rarely get used, do people just ignore this, or is it still suggested to lock it in and do a lot of around town driving?

IndyZJ
05-12-2009, 05:07 PM
Why not take advantage of your atlas and drive around in front wheel drive to break them in? I wouldn't think it would hurt for them to be broken in, and you can school the ricers on fwd burnouts :D

rstrucks
05-12-2009, 11:09 PM
Why not take advantage of your atlas and drive around in front wheel drive to break them in? I wouldn't think it would hurt for them to be broken in, and you can school the ricers on fwd burnouts :D

X2 on the fwd break in. I don't think you need to do it for too awful long though. A few heat/cool cycles ought to be good enough - IMO.

goldensd
05-13-2009, 01:27 AM
Thanks Guys, I think I'll make some 4wd trips around town this week to get them set, but don't think I'll be hitting to much with fwd only, as the Atlas only allows that in 4low, and with the 4.3:1, it is looking like my top speed is about 20 mph. Now that I'm writing this, it also just clicked that the Atlas book didn't say anything about running the 4wd during break-in either, just 500 miles and change the oil.

However, after driving and tweaking the caster and toe-in the last couple of days, I think I finally got it pretty good. Hit 80 mph tonight down the freeway with 1 finger on the wheel and no vibes. Locked it in 4wd and hit 50 with the same. Since I didn't cut and rotate the outer "c"s on the axle, I ended up having to sacrifice lining up the driveshaft like you're supposed to, but I did put the axle to full droop and spun the shaft by hand and don't feel any binding, so I think I am going to chose the better handling over the proper driveshaft angles.