NBS/Astro knuckle brake upgrade.

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99GMT425

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So, I'm confused. 2wd and 4wd spindles are not the same on gmt400s....
I have not done a 2wd swap but the Astro vans used the 2wd and 4wd knuckles from the gmt400 trucks in the 2wd and and awd applications respectively. I don't see why 2wd Astro knuckles wouldn't swap to a 2wd truck but again I have not tried it. I have only done the awd astro knuckles to a 4wd gmt400.
 

454cid

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I have not done a 2wd swap but the Astro vans used the 2wd and 4wd knuckles from the gmt400 trucks in the 2wd and and awd applications respectively. I don't see why 2wd Astro knuckles wouldn't swap to a 2wd truck but again I have not tried it. I have only done the awd astro knuckles to a 4wd gmt400.

Aren't they kind of small? I thought the Astro was originally based on the S10.
 

ccreddell

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Well, the early Astros were S10 based, but the OP is saying that the late model 6-lug astros are using a spindle that is close to the GMT400. Thats interesting. If, in fact, they are, and use a hub instead of a shaft with inner and outers, then there are possibilities. I found a hub that bolts to the GMT800 spindles that is 5-lug (although its 5.5x5), but that can be redrilled. Oh, and another thing; A Jeep SRT8 uses a 15" rotor that is 5x5. Yep, Im already playing with that....
 

someotherguy

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Oh, and another thing; A Jeep SRT8 uses a 15" rotor that is 5x5. Yep, Im already playing with that....
...and I believe from 2012-up, big ol' 6 piston Brembo front calipers. :D

Just check the pricing on the consumables, though. Those OEM-application big rotors are usually pretty expensive. Yeah you can score them used for a deal, but you'll need to replace them eventually and it's tough to find someone selling used ones separate from the calipers. The JGC SRT has been around long enough though that the aftermarket may be offering them. Centric just finally released their copy of OEM Hellcat rotors for significantly less than OEM.

Not exactly the same caliper/rotor setup as the JGC, but I swapped Hellcat 15.4" 2-piece rotors and 6 piston Brembos, onto my 300C SRT8 -
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The fullsize modern Mopar cars have a 5x115mm bolt pattern which is just a few RCHs larger than 5x4.5" (small Ford pattern) but there appears to be plenty of room on the rotor hat that a good machinist could dual-pattern it for 5x5" if you can find or re-drill a suitable hub...a good set of Hellcat front brakes can be had used for about $1000-$1200 or so.

Richard
 

99GMT425

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Well, the early Astros were S10 based, but the OP is saying that the late model 6-lug astros are using a spindle that is close to the GMT400. Thats interesting. If, in fact, they are, and use a hub instead of a shaft with inner and outers, then there are possibilities. I found a hub that bolts to the GMT800 spindles that is 5-lug (although its 5.5x5), but that can be redrilled. Oh, and another thing; A Jeep SRT8 uses a 15" rotor that is 5x5. Yep, Im already playing with that....

Yes my original post was based on the fact that 90-02 awd astro vans used the exact same knuckle as 1500 4wd gmt400 trucks. GM designed the 03 and up astro awd knuckle to bolt in place of the gmt400 knuckle on the astro and use the newer style brakes and hubs. (The location of the ball joint and tie rod holes was so close for me, my truck was still in alignment after the knuckle swap)

For those interesed in bolt on brembo brakes, the 18 and 19 full size suvs and old body style trucks had a 6 piston brembo option that bolts right to these astro knuckles. Chevy logo part# 84263234, gmc logo part# 84263235
 
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454cid

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Wow, I didn't realize they made AWDs as early as 90. I thought that was more recent. Reading the Wikipedia article, it seems the original Astro used parts from more than the S10.... the front suspension was modified B-body.

Too bad there wasn't an 8-lug Astro :)
 

someotherguy

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Yes my original post was based on the fact that 90-02 awd astro vans used the exact same knuckle as 1500 4wd gmt400 trucks. GM designed the 03 and up astro awd knuckle to bolt in place of the gmt400 knuckle on the astro and use the newer style brakes and hubs. (The location of the ball joint and tie rod holes was so close for me, my truck was still in alignment after the knuckle swap)

For those interesed in bolt on brembo brakes, the 18 and 19 full size suvs and old body style trucks had a 6 piston brembo option that bolts right to these astro knuckles. Chevy logo part# 84263234, gmc logo part# 84263235
Yep about $2K+ depending on where you buy 'em. I was looking at them for my Silverado SS as they should fit without issue, but, so far I haven't seen the service parts being offered separately. That 2K could turn into a whole lot more when it's time to replace pads or rotors, as it was originally with the Hellcat Brembos.

Richard
 

99GMT425

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Yep about $2K+ depending on where you buy 'em. I was looking at them for my Silverado SS as they should fit without issue, but, so far I haven't seen the service parts being offered separately. That 2K could turn into a whole lot more when it's time to replace pads or rotors, as it was originally with the Hellcat Brembos.

Richard
85263246 pads
84023777 84024778 rotors
About $750
 

someotherguy

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85263246 pads
84023777 84024778 rotors
About $750
Good to know they're available now but I think you mistyped the 2nd rotor part #; it's 84023778. Can't find the pads with the # you posted, either.

I wonder why there are two different part #'s for the rotors? They appear smooth in the kit pictures, not slotted, so I don't understand why there would be 2 part #'s as they should be identical.

Richard
 

99GMT425

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Good to know they're available now but I think you mistyped the 2nd rotor part #; it's 84023778. Can't find the pads with the # you posted, either.

I wonder why there are two different part #'s for the rotors? They appear smooth in the kit pictures, not slotted, so I don't understand why there would be 2 part #'s as they should be identical.

Richard
Pads are 84263246
 
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