Disc brakes on56 cj5

Is there a year of d 30 front end that I can swap with my d 27 without hassle to get disc brakes. (jeep is going to stay with 134 F & t-90 I think) I just started this project for my son. I have the frame blasted and painted and ready to start. My son is 6 so I have some time for the rebuild for mainly road use. going slow and looking cool.

 

You don't have to swap the D27 to get disk brakes. If you go to a D30, you'll need to regear ... the later Jeeps used taller gearing.
http://www.earlycj5.com/tech/brakes/diskSwap/disc_conversion.shtml

The disks were optional starting in 1976, but almost every CJ had them from then on.
http://www.jeeptech.com/wiki/index.php/Axle/Factory/Front/Dana_30#CJ_Dana_30s

The narrow CJ D30 is also 2" wider than the D27.

Welcome from Boston! What's your location? There's a place to add location to your header in the control panel (User CP).

 

can I do the rear the same way or is that overkill

 

I think you have to weld caliper brackets on the axle to do the rears. The rear brakes don't provide much stopping force anyway ... 11" drum brakes on the rear would match the front disks well and are a lot easier to install.

 

would you change the 5:38 ring and pinnion for mostly road use.

 

Not for mostly road use. The low ratio 5:38 is going to make your top speed lower and generate higher engine rpms. 3.73 to 4.27 is probably more appropriate for on-road use. As a reminder remember that the gears in front axle have to match the gear ratio in the rear axle.

 

is that a yes or no?

 

That's a No.

 

Good suggestion Lynn!

 

Overdrive!

Not only are they effective, but they add real value to your Jeep. If you don't like it, or want to try something different, you can easily remove it and sell it for nearly what you paid for it.

Low axle gearing (high numerically) is desirable - IMO it would be a mistake to change the axle ratio. Folks pay lots of money to get low gears.

 

Thanks all.

 

Yes you can put disc brakes on the frount and rear of your JEEP.You will need caliper brackets,and calipers from a chevy pickup 4X4 pre 88.Early jeep CJ-5 rotors 77-78,or ford f150 4X4 from about 85. You should use a check valve in the brake lines as well.2psi for disc and 10psi for drum.I have this same set up on my 58 CJ-5.

 

I have disks in the front and 10" drums in the rear and no problem stopping. Just wanted to add that data point and say it's cool you're building the Jeep for your kid. I'm sure my son will get mine some day (if there's anything left to get )

 

The 5.38's are the best setup for a 4 banger IMHO. An overdrive will probably cost you from around $500 to $1,000. Still cheaper than changing both axle ratios and something you can do yourself.