I have a 75 f600 with a 20' flatbed ramp body, it runs and drives great, has an eaton 2 speed rear axle, think it has 6.33 on the high side, not sure what the low side is. I found a 94 f700 dump truck in the junkyard today with a rockwell 2 speed rear, 4.88 on the high side, and it has 10 lug wheels. I'm getting the front and rear axles to put under my truck. Rear should be pretty straight forward, just swap the axle and make sure it has the same size u-joint and, hook up the 2 speed rear, and i'm assuming I can just cage the hydraulic brake chambers and run it. my truck has the parking brake on the back of the trans so I don't need it on the axle. Front axle should be a straight swap also, except it has disc brakes. Will the hydrovac brake system work ok with the front disc? I'm thinking it wont, and was going to see if I can get the mastercylinder and what looks like a hydroboost booster from the donor truck at the junkyard and adapt it to my 75 firewall.

Has anyone out there done this swap? I know i'll get more top end out of the axle swap, along with newer and easier to find brake parts. Any help with getting it all to work together would be nice.

 

What kind of brakes does the F750 axle have in back? Are these Lucas Girling brakes?

You should bring over the booster and controls along with the axles IMO.

For the most part, an F600 top speed is limited by both horsepower and rpm. The gearing lets you hit both at about the same time. Without a repower, you may be in the same boat despite the gearing. You may be able to go faster in 4 low than 4 high for example.

Maybe.

Checked all that steering gear business? You don't want a set up that goes left when you turn right....

 

not sure on the name of the brakes, is that what the parking brake cans are called? has a very complicated hydraulic mess on the firewall, but only one hose goes to the booster behind the master cylinder. figured I'd just do away with all that and use the parking brake on the back of the trans.

I know the gear might be a little high for the 359, but right now I never use first gear at all with a full load, and don't even have to split the gears, when I get into high gear it has no problem pulling the load. With the higher gears I can hit 65 on the highway, and on the hills I can always drop a gear. Thinking about a cummins repower in the future anyway.

Was not gonna change the steering gear, just use the one I have, so don't have to worry about it being backwards.

Thanks for the reply

 

Parking brake cans....

Like so?

http://ww2.justanswer.com/uploads/DA..._chamber_2.jpg

JMO but if you are going re-engineer the brakes, be sure you have a some open off-road test area available.

There are a couple of very detailed posts/threads on the Lucas Girling brakes here.

 

Lots of room is great advice.

HillBilly those girling brakes are not worth converting for.

The same amount of work and you could have air brakes. Your hydrovac will have to be completely swapped over to the girling.

Cheaper to just regear..