Front differential rebuild GM 8.25 IFS (needs to be a sticky)

[ivin74]

Are there torque specs for housing bolts? Not sure if I missed that? What about the other bolts?

Differential Adjuster Lock Nut Bolt
20 Y
15 lb ft
Differential Carrier Assembly Case Bolts
47 Y
35 lb ft
Differential Carrier Bracket to Frame Nuts
90 Y
67 lb ft
Differential Carrier Assembly Mounting Bolts and Nuts
100 Y
75 lb ft
Front Differential Carrier Shield Bolts
20 Y
15 lb ft
Front Drive Axle Actuator
20 Y
15 lb ft
Inner Shaft Housing to Bracket Nuts
100 Y
75 lb ft
Inner Shaft Housing to Differential Carrier Assembly Bolts
40 Y
30 lb ft
Pinion Shaft Lock Bolt, 9.25" axle
53 Y
39 lb ft
Plug, Drain and Fill
33 Y
24 lb ft
Ring Gear Bolts, 8.25” Axle
120 Y
89 lb ft
Ring Gear Bolts, 9.25” Axle
138 Y
102 lb ft
Stabilizer Link Nut
18 Y
13 lb ft
Vent Hose Connector
28 Y
21 lb ft
Wheel Drive Shaft Inboard Flange Bolts
79 Y
58 lb ft
Wheel Drive Shaft to Front Hub Nut
240 Y
177 lb ft
Yoke Retainer Bolts
25 Y
18 lb ft

 

[Matthew Jeschke]

Differential Adjuster Lock Nut Bolt
20 Y
15 lb ft
Differential Carrier Assembly Case Bolts
47 Y
35 lb ft
Differential Carrier Bracket to Frame Nuts
90 Y
67 lb ft
Differential Carrier Assembly Mounting Bolts and Nuts
100 Y
75 lb ft
Front Differential Carrier Shield Bolts
20 Y
15 lb ft
Front Drive Axle Actuator
20 Y
15 lb ft
Inner Shaft Housing to Bracket Nuts
100 Y
75 lb ft
Inner Shaft Housing to Differential Carrier Assembly Bolts
40 Y
30 lb ft
Pinion Shaft Lock Bolt, 9.25" axle
53 Y
39 lb ft
Plug, Drain and Fill
33 Y
24 lb ft
Ring Gear Bolts, 8.25” Axle
120 Y
89 lb ft
Ring Gear Bolts, 9.25” Axle
138 Y
102 lb ft
Stabilizer Link Nut
18 Y
13 lb ft
Vent Hose Connector
28 Y
21 lb ft
Wheel Drive Shaft Inboard Flange Bolts
79 Y
58 lb ft
Wheel Drive Shaft to Front Hub Nut
240 Y
177 lb ft
Yoke Retainer Bolts
25 Y
18 lb ft

Thanks much! Do you know is there a technical manual for these? Where dp you find all the specs?

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[ivin74]

Thanks much! Do you know is there a technical manual for these? Where dp you find all the specs?

Sent from my SM-G925V using Tapatalk

I got all the specs on other forums.

 

[Matthew Jeschke]

I decided to only rebuild the one side for now as I don't have the tools to do the pinion :/

That said, I've got the passenger side output shaft taken off. I notice I have a small axle stub entering the differential case. This stub has a hole with a bearing inside of it that mates to the longer axle going to the CV / Wheel. That bearing small bearing in the hole is shot. I've no idea how to pull the bearing out and install a new one. Did you encounter that in your rebuild? I tried a blind hole puller, however we couldn't get it small enough.

Additionally there's a washer between the gears the slip ring goes over. The washer is beat up (somebody rebuild incorrectly and damaged it). I'd like to replace the washer but not sure of it's technical name. Or where to buy it. Any ideas?

Washer is circled in diagram.
Bearing is #26 in diagram, it goes into part #25.

Thanks

 

[swathdiver]

Additionally there's a washer between the gears the slip ring goes over. The washer is beat up (somebody rebuild incorrectly and damaged it). I'd like to replace the washer but not sure of it's technical name. Or where to buy it. Any ideas?

Washer is circled in diagram.
Bearing is #26 in diagram, it goes into part #25.

Thanks

View attachment 207367 View attachment 207368

I wonder if it comes with some other parts as none of my sources lists it or even names it. Let me check another...

Ok, in the diagram over at AllDataDIY, it looks slightly different. These are called actuator shims and there could be more than one. It says to order by thickness. #15522139



If I'm right, it's #10 in the above photo. What do you think?

 

[Matthew Jeschke]

Yes is #10 however i have only one. The diagram shows many which leads me to believe it is a spacer or shim?

I am curious how the slack is taken out of this. I am assuming using spacers like this one?. I see output shafts have some sort of adjuatment ring on the output shafts but i have no idea how to adjust either or what any of the factory tolerances are.

I guess to start i just need to figure out where to get that washer / spacer as new.

Former owner tried to install the axle with houaing on truck and beat up the washer before they realized the err in their ways.

So many questions lol

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[swathdiver]

It's called an actuator shim and to order by thickness though there was only one part number listed. So is your shim too thin and you need it thicker?

 

[Matthew Jeschke]

I figured out how you found it lol i am uaing GM parts direct to see parts in assembly now super cool.

So issue is they tried to put in axleshaft without removing housing. The shim was loose and they beat the heck out of it.

It has some rough edges now which has marred up the axle atuf going into the diff.

I am just going to order a new spacer. I found it on amazon thx to your geumious

I need to figure out how to remove the bearing in the axle stub tho. It is definately shot. Lots of play in it. I think i found the replacement... but cannot for the life of me figure out how to remove it.

I tried blind hole removal tool but was too big :/

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[swathdiver]

Well, in the manual it says you have to measure and use the size just under your measurement.

Alternate Adjustment Method

Note: Use this method only if the proper tools for calculating the shim size are unavailable.

1. Install the original shim to the shaft. Use the chassis grease in order to hold the shim in place.
2. Install the inner axle housing assembly to the differential carrier case. Do not use sealer at this time.

Caution: Refer to Fastener Caution (See: Service Precautions\Vehicle Damage Warnings\Fastener Caution).

1. Install the bolts and tighten to 40 Nm(30 lb ft) .
2. 1. Measure the shaft end play using the following procedure:
   1. Install the J 8001 or the equivalent on the axle tube end. The plunger of the indicator must be at a right angle to the axle flange.
   2. Move the shaft back and forth and read the end play. The correct end play is 0.03-0.51 mm (0.001-0.020 in).
   3. If the end play is incorrect, install a thicker or thinner shim as needed in order to bring the end play into the specified range.

Disregard the numbers out of sequence, that's the editor going haywire. The tool is a dial indicator that can move around and be attached at a right angle. The shims can be ordered in sizes from .05 to .15 in hundredths of an inch.

 

[Matthew Jeschke]

YIKES I'm at about 2.7mm end play! I pulled the shaft out as far as I could then pushed it back into the housing. I am pulling the shaft out as hard as I can by hand without hitting it.

However, I only have one shim on there right now. Where do you order more from?