AWD Front Differentials

ANYTHING TO DO WITH MAKING YOUR VAN MOVE EXCEPT FOR THE ENGINE ITSELF.

Topic author
ihatemybike
I plan to be buried in my van
I plan to be buried in my van
Posts: 2224
Joined: Sun Jan 06, 2008 6:57 pm
Location: Elgin, IL

Re: AWD Front Differentials

Post by ihatemybike »

Anyone know/have pics of the difference between the 1997-98 and 1999-2002 front diffs? I know the front drive shaft is longer on the 1999-2002. Is the added length due to a change in the diff case or transfer case design? Did the mounting flanges change?
Aaron

2005 Astro (Gandalf) - AWD, 4.3L, 3.42, 130k+ miles
1997 Astro (Grumpy - $250 Rally Van) - AWD, 4.3L, 3.42, LSD, 2" lift, 31" tires, 335k+ orig engine, $30 eBay fuel pump
Prev Astros:99,97,00,94,87,86

Topic author
ihatemybike
I plan to be buried in my van
I plan to be buried in my van
Posts: 2224
Joined: Sun Jan 06, 2008 6:57 pm
Location: Elgin, IL

Re: AWD Front Differentials

Post by ihatemybike »

Been looking on the net for the parts needed to rebuild Grumpy's front diff and came upon something very interesting. According to http://www.parts.com the internals of the front diff are the same 1990-2005. Thus I conclude, should be able to find any front diff in good condition and be able to rebuild Grumpy's.

Also, the only difference between the 1997-98 and 1999-2005 diffs is the companion flange.

Parts.com 97 Astro front diff
Image

And just to kick myself in the butt, if I would have spent less than $20 on seals and took the time to install them when the weather was better I could have saved myself all this headache.
Aaron

2005 Astro (Gandalf) - AWD, 4.3L, 3.42, 130k+ miles
1997 Astro (Grumpy - $250 Rally Van) - AWD, 4.3L, 3.42, LSD, 2" lift, 31" tires, 335k+ orig engine, $30 eBay fuel pump
Prev Astros:99,97,00,94,87,86

hausdok
I am merely driving my van
I am merely driving my van
Posts: 14
Joined: Fri Dec 11, 2009 8:09 pm
Location: Waverly, Il.

Re: AWD Front Differentials

Post by hausdok »

How about the 98 diff swap to one from same or 97 blazer. Will this work? My 91 took one ok. Did turn it into a rwd only but it carried me down the road for 5 more years or more. Do they have a 4wd switch in the blazers that year? My buddy had an oldsmobile blazer type (silloette?) and it was set up like a awd astro with the viscous transfer case. Guy in Minnesota has one but hasn't called or written to let me know for sure if he has the GT4 or not. Am anxiously waiting....
I am a doctor of houses, need help ask.

91 AWD Astro 224000 project for later
98 AWD Astro 137000 driver
84 HD XLH in the garage
91 dodge Dakota alt driver
Wife has 06 Pacifica

LiftedAWDAstro
I have my van tatooed on my cheeks
I have my van tatooed on my cheeks
Posts: 4379
Joined: Sat Sep 09, 2006 3:35 pm
Location: New Haven, NY

Re: AWD Front Differentials

Post by LiftedAWDAstro »

Yes you can use the front diff from an S-10 blazer. You won't have AWD anymore though unless you switch the axle disconnect or use the outer stub and axle shaft from the Astro diff. For a 98 with the viscous transfer case, you may very well destroy the t-case running with no front diff. You will also find your van will not stay put if you park on a hill unless you set the parking brake.
Current rides:
2013 Toyota Tundra DC 4x4
2008 Dodge Nitro 4x4
2005 Nissan Sentra 1.8S Special Edition

Mileage spreadsheet

Vans owned:
1986 Safari 2.5L 4 speed manual - scrapped
1995 Astro 2WD conversion 4.11 posi, shift kit, DHC rock rails - sold to Skippy
1998 Astro 4x4 D44, D60, NP231, full hydraulic system with 9k# Milemarker winch and snow plow - sold to Lockdoc
2003 Astro AWD all stock - traded for a 3/4 ton truck
2005 AWD, 4.10's - sold to skippy
Post Reply