GMT600 question (swap from 6 to 8 lug)

[92yamaha]

Quick question: If I wanted to swap my 2003 Silverado 1500 front to 8 lug wheel bearings, what else would be involved? Would they bolt to the same spindles, a-arms, etc?

The backup argument: I really hate posting non-square body questions here, but you all seem to have WAY more knowledge than the participants of any other GM truck forums.

Anyway, I have a 2003 Silverado 1500 LS ext. cab short bed. I'm running into some issues with the crappy 10 bolt. My solution, in the past, to even a leaky 10 bolt, has been to replace it with a 14 bolt and just upgrade everything to 8 lug. In the event I loose my mind again and swap this thing to a 14 bolt (with ABS, etc.), What all is involved in swapping the front to 8 lug?

 

[beags86]

Gmt600?

That's the van platform. Your talking about the gmt800s. I don't know personally as I have never done the swap. But I would assume you would need the front pumpkin, halfshafts, and spindles. Maybe the a arms as well.

 

[sweetk30]

i know the old 88-98 style was everything including the welded on frame brackets .

so i would not expect it to be a bolt on item swap .

 

[Justin V]

Should be able to get a SF14bolt in 6 lug with disks and everything that will bolt in...

Just gotta look hard enough

 

[6.2Blazer]

Did a quick search as I've seen the question asked many times before. Here is an older post on Pirate4x4.

http://www.pirate4x4.com/forum/chevy/924103-gm-ifs-8-lug-conversion-2.html

Look at post #43. Basically the guy used parts from a 2500HD but had to do some machine work on the stock upper a-arm so the balljoint would work. This is the only guy I know of that claims he actually pulled the conversion off. I've seen lots of other posts but don't remember seeing any with a completed conversion.

The other direction I've read about is an 8-lug Dodge front wheel bearing that will bolt up to the 6-lug Chevy IFS. That gets the 8 lugs but problem appears to be finding a rotor and caliper setup that works. There are problems with the rotor being slip on or retained from the back with pressed on lugs, and the spacing with the caliper.

 

[diesel4me]

Time for a straight axle swap ?.....sounds like less work!..

 

[Blue85]

Should be able to get a SF14bolt in 6 lug with disks and everything that will bolt in...

Just gotta look hard enough

Bolt-in? Only if you can find the disc-braked 14Bsf that came in a few select models. If you go between coil/trailing and leaf vehicles, there's a lot of fab work there. You have to account for the difference in axle tube size, so that's new top plates and new spring plates or mods to the coil and link brackets.

Up front almost everything is different between the 1500 trucks and 2500 trucks. I wonder if you can swap the control arms and all. That post on Pirate made it sound like the 6-lug and 8-lug unit bearings use the same internal spline. If so, that would save you from swapping the diff and everything. However, there isn't any real strength gain up front just by going to 8-lug. The steering is very similar between 1500 and 2500, but they do have different offsets in the pitman and idler arms and different TREs. So that should probably all be matched to whichever knuckles are used.

Of course, selling it and buying a 2500 is much easier.

 

[bigjimmy82]

The oddball 1500HD trucks of that era may be what your looking for?

 

[sweetk30]

The oddball 1500HD trucks of that era may be what your looking for?

all the lift kits stuff says will NOT fit 1500hd . . . refer to 2500/3500 kits.

so i dont think any of this stuff will work for him .

 

[Stomis]

Sourcing an 8 lug unit bearing that will bolt to the half ton front end, if it exists, is by far the easiest solution.

 

[bigjimmy82]

all the lift kits stuff says will NOT fit 1500hd . . . refer to 2500/3500 kits.

so i dont think any of this stuff will work for him .

That's what makes me think the 1500hd parts would fit a 1500 light duty with ease

 

[sweetk30]

That's what makes me think the 1500hd parts would fit a 1500 light duty with ease

how do you figure ? ? ?

light duty lift kits say NOT for 1500hd trucks . . . must use 2500/3500 kits . . . = not the same stuff.

the few I have seen look just like a 2500/3500 with smaller gvw springs and torsion bars .

 

[bigjimmy82]

I misread your post, thought you where referring to 2500/3500 kits saying they didn't fit 1500hd.

Next option for op, buy a 3/4 truck?

 

[sweetk30]

figured as much . we cool .

and as said find/buy/fit a sm 14bolt 9.5 or just buy a 3/4 ton .

 

[6.2Blazer]

Sourcing an 8 lug unit bearing that will bolt to the half ton front end, if it exists, is by far the easiest solution.

As stated above a 8-lug unit bearing does exist that will bolt on, but the problem is finding a brake rotor and caliper that will work.

 

[Stomis]

As stated above a 8-lug unit bearing does exist that will bolt on, but the problem is finding a brake rotor and caliper that will work.

Yeah I'm just reaffirming that's definitely the way to go.