Too much backlash?? New 5.38 Regear Question
 

Just had my diffs re-geared to 5.38s a couple weeks ago. Today I hit the 500 mile break-in point, and after changing the rear fluid, I jumped up to inspect the front. I took a video of the amount of rotational play (backlash?) while turning the front drive shaft, and it seems excessive to me. But, I also don't really have any memory of how it was before. I was hoping that someone could try doing the same on theirs and see if they are seeing the same play. Thanks for any feedback!


Edit: also, it's leaking a little at the pinion.

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It's normal for your drive shaft to move that much. Remember, backlash is measured with a precision dial indicator. The variances of being within an acceptable range vs. not are not gonna be something you'll feel/see by moving your drive shaft. If it was THAT far our of spec, you'd already have been able to tell in that first 500 miles.

Now, as far as a leaky pinion seal, that would kinda suck. I would clean it up real good and keep a close eye on it. If it continues, I'd probably say something to the shop.

I was thinking backlash because the drive shaft is directly coupled to the pinion gear. If the driveshaft can move that much, doesn't it mean that the pinion gear is moving that much between touching teeth on the ring gear?

Also, would issues with the front diff show up in only 500 miles of 2HI driving? It's all coast under no load right?

What you are seeing there is all the backlash in the ring/pinion, spider and side gears, axle shaft splines, and possibly some in the axle shaft u-joints.

Thanks, Ronjenx! That makes sense now. I was seriously worried about that much movement, but now I get it. I will clean the pinion good and watch it, per the suggestion. If it still leaks, I'll take it back to the shop. I appreciate the feedback and explanation guys.

Yeh, that looks like normal play to me so no worries friend.

Phew! Thanks for the great info and quick replies everybody. I can roll with confidence now. Loving the 5.38s BTW... I've got a MC 2.5 (put me just shy of 3), and 315/70r17 duratracs (just shy of 34" at 30psi). They may be a little too Geary with this setup, but I still like them, and will like even more when I jump to 37s next.

regearing is usually one of the hardest things for people to pull the trigger on. So many people driving around overgeared. Feels nice to have some guts back doesn't it? :thumbsup:

As an aside, did you remove the diff covers and actually take a look at the gears at 500 miles, or just drain and inspect the oil? I'm kinda anal, and like to remove the cover at every gear oil change just to visually inspect. LubeLockers make that task much easier since no scrapin' old RTV.

I didn't, but I have been teetering on getting lube lockers anyway for the last year. I think I'll get some, then open them up and visually inspect at 1000mi. I was kinda planning on changing the oil again anyway at that point. I sprayed some brake kleen in the diffs to try and flush out as much metal as I could. So the fear that some brake Kleen and metal shavings are still floating around in there made me want to change it again anyway. Thanks for the advice!