"Drum to Disc" conversions 67-70 pics and videos

[Gregski]

just want to start off by thanking Keith for putting together one hell of an amazing and detailed write up on this topic, I would just like to augment it from the end users perspective, following Keith's advice I will be converting what I think is a '69 six lug to a six lug disc setup, I would like to add some pics and videos

[my truck is registered as a 1971 GMC that's why I am not sure of the frame's origin]


DRUM TO DISC CONVERSIONS 67-70

67-70 truck with

67-70 Crossmember Installed:
1) There are many advantage to leaving your 67-70 crossmember in place to add disc brakes.

2) 67-70 truck owners can now purchase "year specific" standard and drop spindles, from many aftermarket suspension vendors.
* No need to change ball joints.
* No need to change tie rod ends.
* These new "conversion disc brake spindles" are a true "bolt-on" mod to add disc brakes to your truck.

3) The 67-70 a-arms can also be used with any other (71-72 or 73-87) spindle, with a simple ball joint change.
* The upper and lower ball joints and outer tie rods must match the correct year of spindle you choose.

4) You will need a "conversion" rubber brake hose to connect your disc brake caliper to your existing steel brake line.
* 71-72 rubber brake hoses can be adapted.
* Much longer 73-87 brake hoses can also be adapted.
* Aftermarket steel braided brake hoses are an option.

5) Keeping your original 67-70 crossmember allows to to leave the engine and transmission in place.
* No need to remove drivetrain.
* No need to temporarily support the engine, while removing the crossmember.
* Complete disassembly of the front suspension also allows you the ability to clean, inspect, replace or rebuild all the individual components.


Links:
*http://www.classicperform.com/discdrop.htm
*http://www.earlyclassic.com/Tech.asp...20That%20Truck
*http://www.customclassictrucks.com/t...all/index.html


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67-70 Truck With 6-lug Disc Brakes:

6-Lug Drum to 6-Lug Disc Conversions:
1) This 6-lug disc brake swap will include all of the above 5-lug information.

2) The only difference is the use of an aftermarket 6-lug rotor.
* These rotors are new castings.
* These rotors have been drilled with the correct 6x5.5" 6-lug pattern.
* These rotors have the correct 7/16" lug studs that match the original drum brake lug studs.

3) Several aftermarket suspension vendors sell these rotors,... such as:
* ECE (Early Classic Enterprises).
* POL (Performance OnLine).
* CPP (Classic Performance Products).

4) All 63-70 "conversion" stock height and drop spindles will work with these 6-lug rotors.

5) All 71-72 stock oem and drop spindles will work with these 6-lug rotors.

6) If using a 73-87 spindle,... it must be the HD spindle, that works with the 1-1/4" wide rotors.
* The 81-87 LD spindles will not work with these 6-lug rotors.

Links:
*http://www.earlyclassic.com/tech.asp...arly%20Braking
*http://www.earlyclassic.com/tech.asp...h%20And%20Whoa
* http://www.classictrucks.com/tech/05...all/index.html

6-lug Rotors:
*http://67-72chevytrucks.com/vboard/s...ght=Disc+Brake

[Gregski]

so one of the first things I learned was that the drum spindles on my truck were two piece, the steering knuckle is a separate piece that bolts on to the actual spindle, I've been told some were one piece and some were like mine

I also believe the actual spindles are identical, in other words there is no right hand side spindle and a left hand side spindle, the same spindle the same part number can work on either side, if that is so that is absolutely brilliant engineering, but please correct me if I am wrong

I could not Google any info on that part number: 3944974 GM17

please let me know if I am misreading it

[Gregski]

here is what all the jazz removed from one side looks like, bagged n tagged!

[Gregski]

if you want to keep your alignment close to what it was, pay attention to these little shims that sit on top of the upper control arm rod

[Gregski]

I will be using the 1971-72 disc brake spindles so the stock lower control arm ball joints need to come out

here I am using a control arm puller kit that you can rent from O'Reilly's (I think it costs $145 bucks but you get it back when you return it)

[Getter-Done]

Great addition

[Gregski]

and because I have trust issues, here I am trying that stock OEM lower control arm ball joint in the new 71-72 disc brake spindle, and as you can see it is too big to fit in there

[Gregski]

Originally Posted by Getter-Done

Great addition

thanks, just trying to help, and give back to the forum community, it has saved my _____ on too many occasions

[Gregski]

if you never seen a lower control arm in the wild before here is what they look like and what holds them in place to the crossmember

yes they are dirty, they are covered in half a century of dirt, rust, and road grime

[I will be pressure washing mine, wire wheeling them, phosphoric acid washing them, and media blasting them as well, then DIY powder coating]

[Gregski]

and this is what the upper control arms look like, can you spot the difference between these two?

[Gregski]

the one on the left was original, the one on the right had it's ball joint replaced

how do we know that, well the factory rivetted them on, and the aftermarket ones are bolted on

we start off by removing the aftermarket ball joint, cause it is much easier to remove

[Gregski]

Top Tip: when buying a truck look at the upper ball joints to see if they are stock, ie rivetted on or bolted on, ie replaced (it will make you look like you know what you are doing, ha ha) seriously though and this is going to be controversial, but the only reason farmers and construction workers back in the day would replace one of these was cause the truck was wrecked, trust me! they did not hot rod these trucks back then, they used them, these trucks built America after all

[Gregski]

things get a bit more abrasive on the other side

Top Tip: if you want to grind metal quick use sand discs (the lower the grit the better, here I think I am using a 36 grit flop disc), them grind stone wheels are for Hollywood movies where they wanna make sparks ie special effects, [I'm looking at you Splash Dance]

[Gregski]

hope you enjoy this video 1967-70 Chevy C10 Drum Brakes, Control Arms, Spindles, and Stuff

[lolife99]

Great thread!

[Gregski]

Originally Posted by lolife99

Great thread!

oh wow, thank you so much

[Gregski]

now you aint gotta take the rod out of the upper control arm to complete the swap to disc brakes but if you come this far it could use some fresh rubber boots at least

a 1 and 3/8ths socket and a 9' breaker bar will git you started

and them ol' cylinder head bolts you've been holding on to for the last 6 years will finally pay off and come in quite handy when it comes from keeping that rod from spinetizing

[Gregski]

and then you can finish the job with a wireless impact when nobody's lookin'

Fun Fact: PB Blaster works great at lubretizing them threads, ACE Hardware knock off, not so much!

and for what it is worth, having worked on five different generations of these trucks and SUVs I must say the GM Engineers knocked it out of the park on the second gen dimes, (67-72) awesome, awesome trucks!

[Gregski]

if you get one of them 1-3/8ths sockets it may come in a large ratchet size, so you will need a smedium adapter, like so

it's a big sucker, so here's the natural progression to get you back to a 3/8ths, you're welcome

[Gregski]

and here it be all extrapulated and such

[Gregski]

I cleaned it up to see the part number, can someone let us know if they are both the same or is there an East and a West side rod?

[Gregski]

I usually go the extra mile and bedazle all the sharp edges on the parts no one will ever see, it's a sure fire way to stretch a little weekend project into a couple months worth

[Gregski]

and here's a little stare and compare of the two upper control arms, one has already been tickled a little with a wire wheel

[Gregski]

your upper ball joints may be stuck in the spindles so tight you may need to cut them on the truck to get them off (I used an angle grinder and a sawsall) here I am pressing out the remaining tips out of the spindles just so I can try them on the new 71-72 spindles to see why we need new / different ones

you don't have to press the cut ends out of the spindles if you don't want to, these spindles are not going back on the truck

[Gregski]

and here once again we are proving Keith was right, and the new 71-72 disc spindles will require new 71-72 like ball joints

the old 67-70 upper ball joints are also too big for the new 71-72 disc spindles