Rebuilding A GM 8.25 IFS Differential **56K Beware! Pic Heavy**

IMISSMY97

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:welcome: to :tmc:
I don't know why, but the pics are blurry on my end to. I remember looking at this thread when he started it 100 years ago, but don't remember if the pics were blurry. :dunno:
I'm thinking it might have something to do with photobucket

Definitely FotoBhucket- I found this thread November 2018, and, and it's only been blurry since like, maybe August/September 2019- I know this because between limited time, commuting, and all the issues that keep coming up with this rebuild for me, I have to take weeks at a time away, this I keep referencing this thread. I hate when things like that happen- it just encourages my paranoia to save every single thing I find useful because one day Google decides it can't sell me anything from it, and won't find it- even though it was before.
...Kinda like the time I spent over 2 hours trying to find the "World's Most" streetcam view video of a guy fighting off 9 people circling him- DM me if you have a link or file on that, BTW :fingersx:
 

IMISSMY97

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So, I went Full-Metal ADD on the GMFullsize IFS thread yesterday... I'll try to keep it concise here-

I've had the weirdest issues with my 02 Tahoe Z-71 front diff:
*WHY would everything measure and seem perfect, torqued and finished, but when I go to torque the axle-tube and actuator fork/whatever it's all called onto the case, there is no Freeplay. The diff is essentially locked up. I set the backlash using a vice to hold the ring gear, tried setting backlash with case torqued and at something lower in inch pounds- I think because I didn't understand preload- but still, no difference. No parts out-of-order in the axle tube, I changed arrangements, even took out the washers for giggles to see what happened- I don't remember but i'm pretty sure it didn't make a difference- I know one washer out - about .090"- didn't make a difference. Remove the tube -all good again....

Details:
*I didn't touch anything on the pinion side-
(it seemed to have no slop or serious wear or leakage of any kind-hearted adjusters gave out, carrier bearings need replacing.)
*I changed adjuster settings and checked patterns 3x and ended up with a WEIRDLY Perfect, barely off-center mesh pattern. With that I set the adjuster tabs with a reading around .007" backlash-.015" yoke movement, using a vice on the ring gear HOWEVER-
Backtracking and racking my brain- all I can think of is that I didn't set preload on the pinion, and I used a hammer and punch to move the adjusters- which my original theory was that the lateral force drove the adjusters back into the housing enough to mess things up, or when I set the tabs.

*Second:
My pattern is now on the outer 1/3 of the ring gear... I'm in the process of playing with adjuster settings, disassembling, resetting them into the case with a hammer and installation tool, then rechecking, readjusting, repeating... So I'm not all done with the sideways part, but:
The first time I set it up, and it locked on me when I put the axle tube on- if I was cranking on it with a breaker-bar, couks that have crushed the sleeve further pulling the pinion out? It should take a LOT of torque to so that right?
I'm just tired of messing with this, frustrated, and confused. It's bad enough my Z-71 has had ALL of the "...yeah that's normal" problems, hence my twgline, but also some REALLY weird ones...and this stuff... Yeah. Ideas?

Also, thank you to Bigredmariner here, and axisT6 at GMFS. I've got a few time-saving tips, serious shorcuts for removal and disassembly, but I'll share another time.
 

BeeTrap

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I know that this is an older thread, but this set of information, thanks Bigredmariner, is why I joined this website. I crave visual help and instructions whenever I attempt to do a repair on my truck. I just 'resealed" the transfer case in my 1994 GMC K1500 due to my letting
it hit the concrete, a little, when I had the transmission rebuilt. I really had no problem in getting the seals and "small hardware kit" for
transfer case. Now I am needing to work on the front IFS differential/axle due to slack and leaks. The problem is finding a source for
everything I need/want. I have found only one source for the two rubber bushings that support the driver's side. I have found a kit that
contains the two output shaft bearings and seals and the seal for the pinion, BUT it is for 1997 and newer. So, my question is where or
who is a good single source for ANYTHING inside or outside of the IFS front diff on my "Big-Red"? Thanks for any guidance.
 

OldCracker29

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I can't help you, but I'll bump the thread...good luck!
 

Black02Silverado

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I know that this is an older thread, but this set of information, thanks Bigredmariner, is why I joined this website. I crave visual help and instructions whenever I attempt to do a repair on my truck. I just 'resealed" the transfer case in my 1994 GMC K1500 due to my letting
it hit the concrete, a little, when I had the transmission rebuilt. I really had no problem in getting the seals and "small hardware kit" for
transfer case. Now I am needing to work on the front IFS differential/axle due to slack and leaks. The problem is finding a source for
everything I need/want. I have found only one source for the two rubber bushings that support the driver's side. I have found a kit that
contains the two output shaft bearings and seals and the seal for the pinion, BUT it is for 1997 and newer. So, my question is where or
who is a good single source for ANYTHING inside or outside of the IFS front diff on my "Big-Red"? Thanks for any guidance.
Not sure if he gets on here anymore. Have you tried rockauto.com? Bump for @Bigredmariner
 

BeeTrap

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Thanks for the responses. Yes, I have looked at RockAuto which does have SOME of what I need. Later I will post what suppliers I have found for each of the parts, have almost everything covered, may help someone else. Just wondered if there was some better source. Thanks guys.
 

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