vaughn202

I am planning on replacing the rear axle assembly in my '97 F150 Extended Cab V8 with rear drum brakes. My axle code is H9, 3.55 ratio w/ limited slip.

The axle I'm looking at is out of a '00 F150 Standard Cab V6 with rear disc brakes. Axle code 19, 3.55 ratio, non-limited slip.

I know I will have to make some mods for the disc brakes, but I'm wondering if there is any reason this axle will not work that I'm not aware of.

Will the drive shaft bolt up? Are the shock mounts and spring perches the same? Will the anti-lock brake system work?

akdoggie

Driveshaft is too long (original). You'll need the d/s from the truck your getting the axle for correct length. Perches are the same. Master cylinder need replaced for disc rear brakes. I also remember something about one of the brake cables or both (?). The wheel studs are 14mm instead of the current 12mm you have also, so you'll need 2 lug wrenches for front and rear.

Just some of the things to consider. Personally I'm considering the swap. I've got all summer to do it. I may just go to a LS diff for the 8.8.

vaughn202

I went ahead and bit the bullet on this one. The rear axle assembly was such a good deal I couldn't pass it up. Went and picked it up yesterday morning.

For $100 I got a complete rear axle assembly with disc brakes and leaf springs already bolted on. It all appears to be in good condition, no signs of any leakage, or any damage.

All the measurements are the same, so it looks like it will work with my drive shaft. As akdoggie advised, I did have to buy new lug nuts though, since mine are a different size. The parking brake cable is too short also. I will have to figure something out on that.

As far as the master cylinder for the rear disc brakes, I am going to try it with my original one before buying one. I figure it is worth a try. The brake line looks like it will bolt right up.

At this point, I have the old axle removed. This afternoon I will start installing the replacement axle. I have been taking pictures of each step as I am thinking about doing a DIY on the project.

re54drider

Your master cylinder for disc/drum brakes will NOT work correctly with disc/disc. Disc brakes require more fluid to actuate than drum brakes. Your rear brakes will activate first with the setup you describe. Is this something you want?

vaughn202

Success!! I got it all back together this evening and all went well except for a couple of minor issues:

1. The ABS light is now on. Not sure why.

2. The parking brake cable is about a foot too short. My plan is to us a piece of the old cable to make an extension.

The test drive went well. No more annoying whining from the rear end. The drive shaft bolted right up, perfect fit. The master cylinder seems to work fine with the rear disc brakes. I tested the brakes several times from 45 mph to a full stop. As far as I can tell, the brakes function normally. I will post more results as I find out more.

akdoggie

Did you hook the sensor up on the rear diff for the ABS? (light on). Glad to hear the driveshaft bolted up ok. The two swaps we did, both required an 1 1/2 inch shorter shaft. The brake cable is another item we mentioned, being too short. The master cylinder is something I'd worry about. The other stuff is minor, but not enough fluid or too much to the rear could cause a problem. There are definitely different m/c's for disc and drum vs disc/disc setups. The only way to cure the lug nut problem is to later change out your front bearing/hubs with newer (2000 up) units. That would give you 14mm studs front and back.

Anyways glad it worked out for you.

cory-burt

wow that was an amazing deal! i just had to replace mine and i had to pay $1000 for a complete axle assembly from an autowrecker and still had to replace the calipers. this is what mine looked like on the inside lol

vaughn202

Yes, the sensor is connected. Could the ABS light be on because the sensor was disconnected without disconnecting the battery first?


I will watch it closely. I won't hesitate to change it out at the first sign of a problem.


Great idea about swapping out the front studs. I will plan on doing that the next time I do a brake job on it.

vaughn202

I took the ABS sensor out of my old axle and installed it in the new axle. Problem solved! Apparently the sensor was bad in the new axle. The ABS light reset automatically after I replaced it.

green@3d

A drum brake master cylinder has different valving inside it to respond to the spring return, verses a disk brake that uses the rotor to return the brake cylinders. For the life of me I can't remember what that valve is called. Residual pressure valve seems to be jumping in to my mind. I do know for sure that it is critical to proper brake operation.

On another note, want to sell your LS axle, I'm tired of getting stuck in the snow up here LOL