GMT 800 Brake Conversion > Silverado HD 2500

[Big T]

So I used the 2" ream to do the top ball joint tapers of the 2500 HD knuckles. Used a new Moog ball joint to gauge the depth and no problems. Took about 30 to 45 minutes per knuckle using a drill press with the knuckle bolted down.

Question: How do I use the drill press to ream the lower ball joints? I need to come in from the axle side of the hole, but the upper ball joint portion of the knuckle is in the way.

 

[ak diesel driver]

How about a picture of your tool etc

 

[Big T]

How about a picture of your tool etc

Here's a pic of the set-up while reaming the upper ball joint holes.

 

[ak diesel driver]

So the holes aren't lined up with each other I take it?

 

[Big T]

So the holes aren't lined up with each other I take it?

See at the bottom of the spindle where I've used a bolt with washers to hold the spindle to the table of the drill press. I need to come down into that hole to ream it and I can't get the drill press down in their due to the upper portion of the spindle.

 

[ak diesel driver]

Looks to me like you'll need to use an angle drill and ream it by hand

 

[Big T]

Looks to me like you'll need to use an angle drill and ream it by hand

That's what I was afraid of.

Any input on the difference in Spindles? I pm'd Fermanator with a link to the thread, but no response.

 

[ak diesel driver]

so back to my earlier ? do the holes line up? If they were in line you could make an extension for the drill press to allow it to reach through.

 

[Big T]

Yes they do line up. So yes an extension rod with a chuck attached would do it.

 

[ak diesel driver]

how big is the shank on the reamer? If it's 1/2" you might be able to use a drill extension for like holesaws etc

 

[THEFERMANATOR]

I'm not sure on the spindles. All I know is there was one set for the 99-00 gmt-800 2500/1500hd trucks, then the 01-07 classic 1500hd/2500/2500hd/3500/3500hd nbs trucks, and the 2500 burbs were supposed to be the same ones. Havent ever looked into using van stuff. I'm quite happy with just the drw stuff on mine, have no desire to go this far into modifying my front end when what I have more than works for me.

 

[Twisted Steel Performance]

This might be a dumb question as I haven't been that close to the newer parts.... but does that lower hole not taper from the other side.. as in both tapered in from the outside?? I know you have look but I'm just thinkin here....

 

[THEFERMANATOR]

This might be a dumb question as I haven't been that close to the newer parts.... but does that lower hole not taper from the other side.. as in both tapered in from the outside?? I know you have look but I'm just thinkin here....

Tapers from the inside. Lower ball joints almost always have the load pushing upwards so the weight is pushing the joint upwards, that way it cant fall apart if the joint gets loose.

 

[Big T]

Tapers from the inside. Lower ball joints almost always have the load pushing upwards so the weight is pushing the joint upwards, that way it cant fall apart if the joint gets loose.

This ^^^ is correct.

My second issue is that the lower ball joint hole is larger. I was using a new upper ball joint to gauge the depth of the ream on the uppers, but it just gets swallowed in the lower hole. I need to order some lower ball joints to gauge the depth of that lower ream job.

SmithvilleD had no answer as he used Forged lower A arms from a GMT 800.

 

[Twisted Steel Performance]

I see......

 

[Big T]

how big is the shank on the reamer? If it's 1/2" you might be able to use a drill extension for like holesaws etc

It's 1/2". An extension ran down through the upper hole would do it. Thanks! Harbor Freight?

 

[snarl95]

http://www.gmt400.com/threads/nbs-front-brake-swap-for-obs-trucks.17805/

 

[Big T]

http://www.gmt400.com/threads/nbs-front-brake-swap-for-obs-trucks.17805/

Thanks. Forgot about the detail in that thread. It's a good reference.

I won't do the ream with a socket and ratchet. I would prefer to use the drill press with an extension. I ordered some Moog lower ball joints off Rockauto. Had not planned on replacing the lower ball joints, but they've got 60K miles on them and I'll be in there.

 

[Big T]

Well I found a 2003 Silverado 2500 HD at a pick a part boneyard near me. Just arrived in Inventory on 10/22, so the Knuckles should still be there. I will harvest them this weekend. Looks like the cost is $28 per knuckle.

 

[Big T]

Alright, I harvested the HD2500 knuckles today for my son. These are the right ones. For those considering this mod, the knuckles from a van of this era are taller, so don't bother with them.

I hunted around and could not find a 1/2" drill chuck with a 3/8" hex adaptor which would fit into a 12" extension. Could not find something online either, but I'll give that one more effort. I think my fall back for reaming the lower ball joint holes will be a 1/2" angle drill that my son has. Won't be able to get the pressure that I could from a drill press, so it will take longer.