Front big brake upgrade, again...

[Chris Rogers]

Would you happen to have the part numbers for the front spindles you used? Buying anything here in oz requires a VIN or they won't look it up. ( these trucks are sold as grey market here)

 

[realsquash]

Would you happen to have the part numbers for the front spindles you used? Buying anything here in oz requires a VIN or they won't look it up. ( these trucks are sold as grey market here)

I can dig them up today if I remember... You also need the lower balljoint that GM uses. I couldn't find a suitable aftermarket one, but it might exist somewhere. The GM one is fine, it has a smaller housing so it actually works better in the arm, too.

 

[ccreddell]

OK, not sure how I missed this one. This is something I also have been doing a lot of research on, and have both a GMT400 complete subframe and a GMT800 subframe Im trying to compare and see what and how to swap over a few pieces.

So far, what I have come up with, is that the GMT800 spindle is shorter than the spindle you are using. And because of that, I was going with re-reaming the lower BJ up from the bottom to use the stock 400 lower BJ. There are couple of shops out there doing this on 800s to lower them, and they re-position the upper arm pivot points to get the geometry back. But the 400s already have a larger distance between upper and lower pivot points so my thinking was;Stocj 800 spindles with the BJ coming up from the bottom will give about 3-4" of drop and the geometry will be a bit better ala tall spindle mods on early F-cars. I also found a hub off of early 2000s Dodge pickups that appear to bolt to theses spindles, has the same spacing, and are 5 lug. They are 5x5.5 but are easier to redrill to 5x5 that a 6-lug hub.

The same shops that are doing the BJ flip are using a Heim joint on the steering arm-so thats not a problem either. Corvette 13" rotors (and larger) would be fairly easy to have redrilled for the larger bolt pattern and lug size. Obviouly after maket rotors can be ordered any way you want them.

As for the rack, it appears to be extremely close in width, and mounting it like they do the F-body rack conversions is fairly simple also. My measurements didnt indicate that the horn on the front crossmember needed to be eliminated, but YMMV.

Obviously you would need to check final geometry on all of this as it is mocked up, but its not anything you would have to do anyway when completely fabricating a new suspension system.

 

[realsquash]

OK, not sure how I missed this one. This is something I also have been doing a lot of research on, and have both a GMT400 complete subframe and a GMT800 subframe Im trying to compare and see what and how to swap over a few pieces.

So far, what I have come up with, is that the GMT800 spindle is shorter than the spindle you are using. And because of that, I was going with re-reaming the lower BJ up from the bottom to use the stock 400 lower BJ. There are couple of shops out there doing this on 800s to lower them, and they re-position the upper arm pivot points to get the geometry back. But the 400s already have a larger distance between upper and lower pivot points so my thinking was;Stocj 800 spindles with the BJ coming up from the bottom will give about 3-4" of drop and the geometry will be a bit better ala tall spindle mods on early F-cars. I also found a hub off of early 2000s Dodge pickups that appear to bolt to theses spindles, has the same spacing, and are 5 lug. They are 5x5.5 but are easier to redrill to 5x5 that a 6-lug hub.

The same shops that are doing the BJ flip are using a Heim joint on the steering arm-so thats not a problem either. Corvette 13" rotors (and larger) would be fairly easy to have redrilled for the larger bolt pattern and lug size. Obviouly after maket rotors can be ordered any way you want them.

As for the rack, it appears to be extremely close in width, and mounting it like they do the F-body rack conversions is fairly simple also. My measurements didnt indicate that the horn on the front crossmember needed to be eliminated, but YMMV.

Obviously you would need to check final geometry on all of this as it is mocked up, but its not anything you would have to do anyway when completely fabricating a new suspension system.

Just for the record, an f-body rack will result in insane bump-steer. The only dimension that matters is center-to-center of the pivot points on the ends of the actual rack gear. An imaginary line drawn through the upper and lower control arm frame pivots (it's a little more complex than that to get it perfect, but this is easier to follow) is where those pivots need to land. On the GMT400 this is stupid narrow - I have to look up the dims but it was around 22.375". Good luck finding a rack that short. There are a couple options - a Corvette C4 rack is the right length, but depending on your steering arm length on the knuckle, you might not have enough travel and your turning circle (among other things) will suffer. Another option is to use rack from a Dodge Intrepid and siblings. This is a center take-off rack, and if you're creative about mounting it you can use it with minimal bump-steer and it has plenty of travel. You can also make a "drag link" that will bolt onto the center-take-off rack.

Almost all the racks (and I've spent a day in the junk yard measuring and bought the X-4000 catalog, trust me) you find will be around 24-25" pivot to pivot center length. Tierods are trivial.

 

[Chris Rogers]

I can dig them up today if I remember... You also need the lower balljoint that GM uses. I couldn't find a suitable aftermarket one, but it might exist somewhere. The GM one is fine, it has a smaller housing so it actually works better in the arm, too.

Thanks. Have a friend that has taken the ideal job at a Chevrolet dealer and didn't tell me. Have the part numbers for the GMT900 steering knuckle you are using finally. At $111USD they are cheap enough so I am going to buy both and get them to look up the ball joint as well.

With the BJ ( and I know I am probably asking a dumb question) is this a straight fit or do I need to fiddle? If I need to fiddle what needs doing?

 

[realsquash]

With the BJ ( and I know I am probably asking a dumb question) is this a straight fit or do I need to fiddle? If I need to fiddle what needs doing?

There are two part numbers for lower balljoints for 2014+ trucks. The aluminum knuckle, like I have, is a different sized taper. Neither of these will fit into the stock GMT400 arm, you'll need to fab something. There isn't much room inside the knuckle for clearance, so you would want to try to use the 2014+ BJ. I can get the part number when I get out in the shop later.

 

[What?]

I'm using the 2014+ aluminum knuckle (and wheels) from a 4wd truck on my 2wd truck. The upper control arm fits without isuse, but the LCA does not. The lower bj doesn't fit the knuckle, so I am using a GM 2014+ bj. But you have to do some kind of fab to get the new balljoint working with the stock LCA. I bought some DJM LCAs to modify but I ended up designing my own upper and lower control arms so I can do it all how I want (coilovers, sway bar, rack and pinion, geometry, etc). I also did a 9.5" 14BSF rear axle swap, but I designed my own 3-link.

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Looks nice. I'd like to see your build thread on this aside this brake thread.

 

[Chris Rogers]

There are two part numbers for lower balljoints for 2014+ trucks. The aluminum knuckle, like I have, is a different sized taper. Neither of these will fit into the stock GMT400 arm, you'll need to fab something. There isn't much room inside the knuckle for clearance, so you would want to try to use the 2014+ BJ. I can get the part number when I get out in the shop later.

Thanks. If you can that would be great.

If it means FAB work I may get chassis works to make it with that BJ as the truck is going on air anyway.

 

[Chris Rogers]

What's your background btw?

 

[ccreddell]

Just for the record, an f-body rack will result in insane bump-steer.

Actually, I was speaking as to the way it mounted, not that a Camaro rack should be used. The rack I was getting measurements off of was the GMT800 rack, which should be close depending on how and where it is mounted.