disk caliper mounting on dana 27a closed knuckle

i've read the articles on disk brake conversion.

for my 69 cj5 with a dana 27a closed knuckle front, i can't tell where the calipers actually attach to the knuckle using the pins.

i can get loaded calipers, rotors, hose, etc from my napa for $143 for both sides, incl new proportioning valves. this are all to fit a 78 cj.

but when i look at a 76-78 cj with disks it appears that the mount is part of the open knuckle.

i keep hearing that this is a "straight" fit in.

what am i missing?

the alternative is that i can get for finned 11" brakes complete from the backikng plate on out off a 74 for $25 each if i take them off. I'll probably need to rebuild them though.

i know that disks vs 11" drilled drums is a "favorite discussion" here. but it might be an easier conversion.

i.e. any help/opinions would be appreciated.

steve h. aka zed.

btw, sparky i like the new masthead for the site! everytime i drop outta sight for a while (i.e. to catch up with my nonjeep day job...) you do something cool to the site. nice job!

 

advice on the 11 drums... keep an eye out for Bronko guys switchin over to disks. I was able to pick up 2 sets of backing plates complete with new shoes and hardware for about 25 buks a set. got them on ebay.

 

You need caliper mounts off of a 76 to 85 Chevy 1/2 ton 4x4. They mount where the backing plates were. That price you got sounds pretty good from NAPA. Be sure the rotors are 1 1/8 inch thick. The 7/8 inch ones usually are cheaper and some guys have gotten the wrong ones.

 

re. the 11inch drums. excellent advice $sink. thanks!

re. disks, now it makes sense! would mounts from a chevy s10 or equivalent s10 blazer with disks work? thanks mortten

is this the part you are speaking of?


thanks again.

 

That's the one. The Chevy used a Dana 44 front axle. That's why the mounts will fit the 27. Same bolt pattern on the axle. I think the S-10 had independent front suspension and a different setup where the bracket mounts but don't quote me. I do know that the Chevy 4x4 and 2x4 calipers are different. You have to use the 4x4 calipers. Don't ask me how I know. You can find those brackets used for around $50.00 a set.

 

I'm not 100% positive, but I do not believe those Jeep calipers will fit the Chevy bracket. You need CJ rotors, but chevy calipers, hoses, banjo bolts, etc.

I shopped NAPA, Quadratec, and my local Jeep club. I paid $40 for my brackets, the rest of the parts were new, and I've got about $150 a side into mine; worth every penny.

 

Yes. Chevy calipers, bolts. hoses, etc. CJ 1 1/8 inch rotors.

 

How do I know which chevy axles are right? I happen to have a set of blazer axles, but I thin there 87?

 

Look for a six bolt pattern on the bracket. '87 "should" work, but order '70s calipers so that you get standard, not metric, hardware.

 

gotcha, that's what i figured, thanks! but i probably would have forgotten to change them on the list...

 

I'm gonna go against the grain on this one and say that if you are gonna keep the closed knuckle front end just put on some 11" backing plates and be done with it. You can find 11"setups no problem at any swapmeet. The reason that I say this (I just did the conversion on a 3-a 25 front end) Is that the closed Knuckle axle just isn't worth the work. IMHO if you are going to go with the discs, do yourself a favor and get a 30 open knuckle front end. This does away with Knuckle pudding, wiper seals, and problems with upper bearing lube. It is just a better all around design and much easier to work on at home not to mention in a foot of mud on a trail. Hope these ramblings make some kind of sense.

 

Not to mention a used 30 is probably going to need new rotors, pads, and brake hoses at a minimum, anyway.

Amen. Got a D30 and Detroit just awaiting install, and still not sure if I can bring myself to do it.

 

daryl, your post makes perfect sense. i understand your viewpoint. i'm familiar with the closed knuckle (i have rebuilt my share) and agree that it can be a pain and that the open knuckle is a much more friendly answer. trust me, i considered this....

but $$ are always a concern. i've been reading jp mag forever and remember offroad and fourwheeler magazine from when i was a teen and have always marveled at how the push is to build things to extreme.
not every one is out to break their machine. i love and am content with "old style jeepin' "

with the 4.88 diffs i have (and am happy with) i'd rather not spend the scratch to replace my 27a. my cj runs beautifully now and there are other things on the list first. new seat belts/harnesses, 8k lbs winch, finish tbi conversion, build a new rear tire carrier, etc. to make it more "self sufficient" on the trail.

the 10" drums on my 69-5 are fully capable of locking up if i need to stand on em. the disks are for water since i don't like that feeling of wet drums on a down hill trail. i am still considering 11" in the front and keeping the 10 in back. although i can get all four corners with finned drums from a 74 cj for $25 a corner if i take em off myself.

i can then drill the drums as per others on this site for wet stopping.

right now it seems for the $ i can convert to front disks (including new proportioning valves), keep the rear 10" drums cheaper than rebuilding the 11 inch drums on all four corners.

but until i actually turn the wrenchs and pickup the parts the jury is still out.

so yeah, putting 11" drums on the 27a and being done with it is still an option. there are certain things i like about pre-AMC cj's that i want to keep while taking advantage of technology that came along later for safety and fuel efficiency.

 

I fully agree with the above. I also have 4.88's and low gears to keep off the skinny pedal a little. So far so good. I did put a power lock in the front recently and am in the middle of the disc conversion. I used 82' Chevy 4x4 full size blazer backing plates and calipers. I have a couple of pics in another thread "dana 27 rebuild"