AWD Debris on Front Differential Magnetic Plug

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

ezstriper

Full Access Member
Joined
Nov 2, 2010
Posts
112
Reaction score
32
it was a change after they were having issues, but you guys use whatever you want
 

6speedblazer

Member
Joined
Mar 17, 2017
Posts
92
Reaction score
42
OK, I'll look around for the info, thanks a lot. What exactly did you replace in yours?




That's what I'm afraid of... I've dumped so much money into suspension refreshing that I guess it's time to turn to the drivetrain.

i replaced the all the bearing and seals. pinion bearings were fine, but figured since i was in there might as well refresh it
 

ivin74

05 NBS Nali
Joined
Aug 3, 2014
Posts
2,262
Reaction score
2,306
Location
Htown, Texas
My AWD front diff has the same problems. Somewhere along the way the diff vent tube fell off the plastic fender well. Dangling upside down, breathing water, salt, sand for what looks like a few years. Here is what I found during winter when I was looking for a mysterious leak on the garage floor. It was the pinion seal puking fluid, which lead me to this..

View attachment 184509
The vehicle was serviced by the dealer during this time. They never noticed greasing, changing the oil, changing all fluids. Too late now the damage is done. The drain bolt has the same metal as yours, fluid looked like this...
View attachment 184510

After 5 Mobil 1 75w90 drain and fills over 2 years, its alive. Not leaking. The drained oil is clearer, but still get the metal buildup on the bolt like yours, still get silver in the gear oil. Something is toast, the end is near. I do a lot of DIY, but rebuilding diffs require skills I don't have. Setting the preload, backlash, etc. are not something I want to learn on this truck. I've been researching, there are a few that rebuild my 3.73 front diff on eBay and sell for +-$1,000. From what you mentioned in your post, you seem capable to shotgun the diff and be done with it. I do think the front diffs in our GM AWDs are a weak spot, and should see yearly maintenance. I just changed the rear diff fluid which is also 75w90 syn, and at 155k the fluid was "good". No silver fluid, hardly anything on the magnet.


I was like you (06 Escalate) the first time I paid $1200 bucks to rebuilt my diff but after if failed the second time (18 months later) I was like hell no, not another $1300. The weak link on these diffs (GM 8.25 IFS) is the adjuster lock tabs, they are known for breaking off creating creating play on the internal parts. To avoid this from future failures is to rebuild your self and center punch the adjuster threads after the backlash is set. These diffs are not hard to rebuild if you have patience, I rebuilt mine for $200 and that included buying some of the specialty tools I didn't have. It was a great learning experience and would do it again if I had to.
 
Last edited:

6speedblazer

Member
Joined
Mar 17, 2017
Posts
92
Reaction score
42
I was like you (06 Escalate) the first time I almost paid $1200 bucks to rebuilt my diff but after if failed the second time (18 months later) I was like hell no, not another $1300. The weak link on these diffs (GM 8.25 IFS) is the adjuster lock tabs, they are know for breaking off creating creating play on the internal parts. To avoid this from future failures is to rebuild your self and center punch the adjuster threads after the backlash is set. These diffs are not hard to rebuild if you have patience, I rebuilt mine for $200 and that included buying some of the specialty tools I didn't have. It was a great learning experience and would do it again if I had to.

they really are not bad at all to do.

i had 200 in parts, i got a master rebuild kit with all the seals, bearings, crush sleeve, pinion nut ect. then i had like 80 bucks in that stupid adjuster tool.
 

Davidh

TYF Newbie
Joined
Jul 17, 2017
Posts
8
Reaction score
3
I hate to chime in, I had just bought my 2004 Tahoe with AWD and reading what you guys found pushed me to change my front diff oil, I had the same stuff on the plug what you had. I'm doing the same filled it with new oil and going to drain next month to see what it looks like. My truck as 185,000 on it. I'm looking forward to see what yours looks like when you drain it. Thanks for all the information my first Tahoe and just learning.


Sent from my iPhone using Tapatalk
 

06Escalade

Full Access Member
Joined
Oct 25, 2016
Posts
87
Reaction score
23
I was like you (06 Escalate) the first time I almost paid $1200 bucks to rebuilt my diff but after if failed the second time (18 months later) I was like hell no, not another $1300. The weak link on these diffs (GM 8.25 IFS) is the adjuster lock tabs, they are know for breaking off creating creating play on the internal parts. To avoid this from future failures is to rebuild your self and center punch the adjuster threads after the backlash is set. These diffs are not hard to rebuild if you have patience, I rebuilt mine for $200 and that included buying some of the specialty tools I didn't have. It was a great learning experience and would do it again if I had to.
How much time did it take? How long would i be without the truck which is a DD? OP, not trying to hijack your thread, I think this applies to you also.
 

6speedblazer

Member
Joined
Mar 17, 2017
Posts
92
Reaction score
42
How much time did it take? How long would i be without the truck which is a DD? OP, not trying to hijack your thread, I think this applies to you also.

once i had all parts on hand, mine took 4 days to rebuild. but im on 12's at work. so that was pull diff day 1. day 2 explode diff then clean and inspect all parts, day 3 install new parts and assemble diff, day 4 install and test drive. took me 4 days but only getting to work on it for an hour or two a night.

should be a single day job for any decent shop
 

ivin74

05 NBS Nali
Joined
Aug 3, 2014
Posts
2,262
Reaction score
2,306
Location
Htown, Texas
once i had all parts on hand, mine took 4 days to rebuild. but im on 12's at work. so that was pull diff day 1. day 2 explode diff then clean and inspect all parts, day 3 install new parts and assemble diff, day 4 install and test drive. took me 4 days but only getting to work on it for an hour or two a night.

should be a single day job for any decent shop



If you have all the parts, oils, etc and tools on hand you can knock it out on Saturday, most of the tools I borrow them from Autozone, do not waste you money on buying the tool that is out there (its junk and useless) to adjust the locking adjusters, its cheaper to buy a 33 mm socket at HF and make ur own adjuster tool. Using an impact gun saves a shit load of time.
 

oldchev

Full Access Member
Joined
Mar 30, 2014
Posts
116
Reaction score
50
Location
Santa Maria, Ca
Go to YouTube and search 8.25 IFS front diff rebuild. I think the guy is BroncoCarl. It a two parter and fun to watch. After seeing that one (plus other stuff online) Its a "can do" for a DIY guy.
 

Forum statistics

Threads
128,802
Posts
1,805,637
Members
91,785
Latest member
Eliteweapons
Top