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Rebuilding my front end

All those years with the TSB's and consumer complaints about the lack of steering in parking lot maneuvers GM finally addresses the issue on the GMT-900 trucks 2007.5-2010 NBS with a larger volume pump and the 680 gear box.

I'm going to keep looking on craigslist for a 2008-2010 2500HD truck being parted and buy the gear and shaft, might even be the early 2011 will fit.
 
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I can confirm the GMT800 Delphi 800 series, (#64 casting) has the same 3 bolt to frame mounting pattern as my 8600# '95's original steering box (#84 casting). Newer box needed the 3 grooves in splines pitman arm as compared to the 4 groove pitman arm on original box.

The spool/barrel valve out of the newer Delphi from GMT800/'04 K2500HD (bigger 79 mm rack piston) had slightly bigger orifices than the 1/2T (smaller 70 mm rack piston) spool/barrel valves - makes sense to feed the larger displacement piston/chambers. Imagine it follows the pump flow capability should match the steering box.

There's a vendor called Chevy Trucks Only on ebay that might be a good source to see about getting this matched set. I got a matched GMT800 hydroboost, lines, & pump at reasonable cost from them, to do the mock up for upgrading my truck's brakes to GMT800 dual piston setup.
 
SmithvilleD said:
I can confirm the GMT800 Delphi 800 series, (#64 casting) has the same 3 bolt to frame mounting pattern as my 8600# '95's original steering box (#84 casting). Newer box needed the 3 grooves in splines pitman arm as compared to the 4 groove pitman arm on original box.

The spool/barrel valve out of the newer Delphi from GMT800/'04 K2500HD (bigger 79 mm rack piston) had slightly bigger orifices than the 1/2T (smaller 70 mm rack piston) spool/barrel valves - makes sense to feed the larger displacement piston/chambers. Imagine it follows the pump flow capability should match the steering box.

There's a vendor called Chevy Trucks Only on ebay that might be a good source to see about getting this matched set. I got a matched GMT800 hydroboost, lines, & pump at reasonable cost from them, to do the mock up for upgrading my truck's brakes to GMT800 dual piston setup.
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That's Just Chevy Trucks.com, or?
 
C20ELEPHANT said:
All those years with the TSB's and consumer complaints about the lack of steering in parking lot maneuvers GM finally addresses the issue on the GMT-900 trucks 2007.5-2010 NBS with a larger volume pump and the 680 gear box.

I'm going to keep looking on craigslist for a 2008-2010 2500HD truck being parted and buy the gear and shaft, might even be the early 2011 will fit.
Click to expand...

I wasn't certain if you're considering upgrading a GMT400 or GMT 800? For those wondering about the viability of adapting the 680 box, here's a pic of the GMT800 lower steering shaft, & the GMT 400 middle & upper shafts. The intermediate shaft's fit into the GMT800 lower shaft isn't quite tight & would need to be welded.

I don't have an entire GMT800 setup to fully understand how it's supposed to collapse in a crash & where their clunking noise issue happens?20160111_131309.jpg

Is SS170 the correct part number for the SuperSteer idler arm bracket that fits GMT400?
 
The upper shaft is where the GMT-800's collapse at. The clunking sound was because GM decided to abandon the time tested and proven double D shaft design(round shaft with a flat on each side), and went to a splined design. Over time the splines loosen up, and just like the infamous driveshaft clunk, the splines clunk i nthe shaft making the noise. The correction is to go to a double d design intermediate shaft. I have one out in the travel trailer out of peps truck I'll try and get a picture of to show the difference. But GM had the slip portion in the lower shaft in the GMT-400, and moved it to the upper shaft inside the cab in the GMT-800's.

And yes, the 170 is the one that fits. If you order the complete supersteer kit, be prepared to get the wrong braces. I believe I was the first to buy one of there complete kits, and there website pic of the kit shows the wrong brackets. SUPERSTEER DID make it right right away by overnighting the right ones to me as soon as I called them and told them about it.
 
By initially getting the wrong braces, you mean the wrong Cognito braces to fit GMT400? I'll be interested to see how you like those over time. They seem like a good idea.
 
Yes, they sent me the cognito braces for a 99-06 1500. They look similiar, but are much lighter duty, come with metric instead of sae nuts, and the idler support bracket was about an inch off of working.
 
THEFERMANATOR said:
Talked to redhead, and they made a not in my file about it, but want me to drive it for awhile before replacing it to see if it works itself out or not. I did tell them it seemed to get better after driving it some, and they said many times they work there way out, so he doesn't want to replace it just yet.
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FERM: How did the redhead box turn out, I'm looking for gear boxes now.
 
I'm still in the air on recommending the redhead box...on the 01' mine whines more than I'd like, but the steering is perfect...Don't know if that is a fair trade off or not...
 
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