Am i screwed? 8lug front disc conv.

[HarrisonTX]

I see lots of great topics about 1/2 ton front discs' and how great they are and all their glory. What about us 8luggers? my 3/4 '69 dosnt stop at all. Am i screwed?

Also, i have heard that to work on the rear brakes i had to pull the axles on the rear. Is that BS. (ive looked at my pads before and i definently didnt pull an axle) I do remember there were huge flat blade screws involved.

[panhandler62]

Somewhere in here there are topics on swapping in 8 lug disks. It's what I plan to do. I have a 3/4 ton and want to preserve all of the extra grunt that implies, somehting that going to 1/2 ton 5 lug hubs would compromise (just a little.)

On the rear brakes -- I have no idea why you would need to pull an axle to work on them. If you want to swap them you would, of course, but I don't know of any reason you couldn't put new shoes in without pulling the axle.

[semperfidoordie]

I was wondering the same because in a recent post: http://67-72chevytrucks.com/vboard/s...d.php?t=243307 I was asking about brakes because I have a 3/4 ton and my brakes are in a great state of disorder and a friend suggested changing to discs but I didn't know how troublesome it would be with an 8 lug compared to a 5.

[HarrisonTX]

Thanks pan. My buddy just said he had to pull axles once in a 3/4ton, maybe he is crazy. Both brake cylinders in the rear are out, front drum's needless to say it isnt stopping at all. Im a down shifting sob with that t400 in there.
It was my daily driver for years. I just need to pull the heads, and fix the vavle seals so it runs on 8 again, and do something with the brakes. Its such a pain working on anything with the ridiculous brackets i have going on.

[oteixeira]

It's been a while but I believe the rear of my truck (70 C-20 Camper) has to have the axles pulled out to get the drums off. Only way you can get to the shoes. If you have the "Industrial" rear, I think that means the Eaton, you will have the same issue.

Orlando

[rlm316]

I did the front crossmember swap in my '70 C20. Very easy to do. I don't think it was any different than the 1/2t. If you are planning to do a spring drop, you will only be able to get 1/2t springs. My rear is an Eaton HO52. The axles do need to be removed to access the brake parts. Also the rear axle bearings are in the brake drum and the are wet so be careful with the gear lube. The front drums are held in place with the large screws. Good luck, Lane

[HarrisonTX]

I do remember the huge screws on the front drums, those were super stuck.
I am not into lowering it at all, its a 3/4ton im not gonna lower it.
rlm316, You change the whole front crossmember for the disc brakes? isnt my motor bolted to crossmember?
Sounds like the rear cylinders going out is a kinda major deal, i have to pull the diff. cover to pull the axles huh.

dosnt just brakes only charge $99 for brakes, lol it maybe worth it, they would flip out.

[rlm316]

No you don't need to pull the diff. cover. The axles are bolted in at the end. Undo the 8 bolts and the axle comes right out. There is a series of locknuts behind the axle that you will need to remove to take the drum off. If you have a deep spanner wrench that would help you along. On the front suspension the basic set-up for our trucks is pretty much the same as the next generation. You could change the upper and lower control arms and the spindles without changing the entire crossmember. Just about all the parts for my '70 were the same as the ones for the donor '91 I used. You will need to change your brake lines to accomodate the new control arms, caliper setup. You need to change the lower control arm because the steering stop is very different from the drum to disc configuration.

[HarrisonTX]

So basically i need to get a lot of front end stuff from a 3/4ton truck, even all the way up to a 91 3/4ton will just bolt right up? Amazing. I think i have a frame laying around ready to scrap. out freakin standing.

So a ton of front end parts, all the way up to '91 model?
upper and lower control arms, spindles and discs off the doner, and new lines from autozone, off what year?
and it all bolts right up?

[No3Fan4Ever]

[QUOTE=HarrisonTX;2200361]I see lots of great topics about 1/2 ton front discs' and how great they are and all their glory. What about us 8luggers? my 3/4 '69 dosnt stop at all. Am i screwed?QUOTE]


All you need is some cash...........

http://www.performanceonline.com/sto...at=1077&page=1

stock or drop spindles with all the goodies

[KAILUAZ]

A PO did the swap about two owners ago, not sure what year/parts these are, stops really well.
Maybe a guru could ID these parts:

[rlm316]

'73-'87 pickup, '73-'91 suburban are the same. Brake hoses are for the donor, hard lines are for the year disc/drum mastercylinder/ prop valve you are using.

KAILUAZ, what size are your wheel studs? 1/2" or 9/16"?

[KAILUAZ]

Originally Posted by rlm316

KAILUAZ, what size are your wheel studs? 1/2" or 9/16"?

Fronts are 9/16",, rears are drums with 1/2".

[rlm316]

I am not sure exactly what year they changed but I think the guy at the parts store told me it was early-mid '80s. There should be some casting numbers on the rotors. Try writing them down and there is a thread here about finding GM part numbers. That should dial you in pretty close. You can't really rely on the caliper, it may have been replaced.

[GMCBubba]

if you have the dana 60 rear, you DO NOT have to pull axles in order to change the brakes.

easiest (and likely cheapest) disc upgrade is front crossmember swap which i've been told is easy. after i redid my four drum system, i was pleased with stopping ability. it pulls a little, but not bad at all. people who have added power booster swear that is the best thing they did for their drum brakes. discs are not necessary for good stopping power but do work well.

also, there are several other people who package 8 lug disc swap systems. but they do tend to be more expensive

[rlm316]

I forgot to say that this was for the Eaton HO52. Sorry for the confusion, Lane

[HarrisonTX]

I dont know what type rear, im not scared if i have to pull the axle's just a little odd to me, never heard that before i got the truck.
So some swap change the entire front crossmember, which would involve pullin the motor i would assume, while some just need doner upper and lowers, spindles, discs and minor things like that.

bubba, i have power brakes, dont i have a power booster any ways?

[GMCBubba]

harrison, i didn't knw if you had power or not. i'm "lucky" enough to have manual.

my understanding is that the motor mounts are on the frame rails, not the crossmember. but i don't know since i'm not the most experienced shadetree mechanic and i've never ventured into that territory

the "easy" swap is probably the whole crossmember since you just bolt it in place. you don't have to put anything together like you would if you bought all the separate pieces. that being said, you probably want to replace all the stuff you can replace anyway (ball joints, tie rods, etc). so it's probably 6 of one, 1/2 dozen the other

[Longhorn Man]

the motor mount towers are bolted to both, the frame rails, AND the cross member.
If you don't have the time/funds/energy to do the disk conversion, then at least fix the junk you have under there now, esp if you drive it more than once a year. 3/4 ton trucks have huge drums, and there is no reason for it to not stop well... booster or not.

[GMCBubba]

thanks for jumping in there longhorn man. i figured i was probably missing some of the details.

guess i need to pull a motor soon for educational purposes