2WD to 4WD straight axle conversion guidance

[G. Mann]

Recently bought a 92 F350 CC DRW Longbed with a blown head gasket [thanks to everyone for the advice on that issue].

I've decided to pull the engine to do the heads and reseal the engine, fix what ever else it needs, AND get rid of the C6 slush tranny for a ZF5 speed which I "happen to have waiting". So my ever active mind says,
"This truck has everything I want except for 4WD" and now would be a great time to put that in also since the engine will be out and access will be soooo much better, so.....

What I want: Straight axle with leaf springs in front, 4WD front axle, divorced transfer case.

Who has done the straight axle? What axle should I look for [remember, it's a dual rear wheel truck]
Guide me please... recommendations?

Divorced transfer case selection? It's a crew cab so there is some "room" under there.

Thanks in advance.

 

[Greg5OH]

im no expert, but div NP205 is about all there is , 78 ford f250 had the correct driver drop we need. this is what i have. Just fabbed my own mounts. its 2:1 ratio.

DRW in the obs style doesnt matter for front axle, its all the same D60, just get the dually adapters (i think even the tw twin i beam should have adapters) and put them on to run your factory dually wheels.

If you make your midshaft correctly , you can use the auto rear driveshaft from an E40d (which i believe is longer than a c6) just chnage the front weld yoke to a fixed unit to accept the output of the np205-which btw you shoudl change the output to at least a 1350-as it came with 1330 most likely. I went 1410 on my entire rear driveline, 1350 up front.

 

[IDIoit]

which ZF5 do you have?
does it have the e-brake on the tailshaft?
if so, you can run a married transfer, besides that, greg is right the div NP205 is the way to go.
this is what ill be doing on my 98 E350,
but i will be using 05+ axles.

 

[G. Mann]

OK.. Thanks everyone. Looks like I need to clear up my question a bit.

The ZF5 I have is 2WD, no parking brake on the tailshaft.

The present front axle setup is the coil spring, twin beams, I want to replace those with a straight axle, leaf spring front end.

So looks like the divorced transfer case issue is down to one choice, it's covered. NP 205. So the question I need answered is what front axle do I need to be looking for to match up with my Dual rear wheels.

Also.. will the 2WD adaptors that let me run wheels that match the Dual Rear Wheels work as a "bolt on, no fuss" attachment? I've never done this before, so if you have, "In the land of the blind, the one eyed man is king".. applies.

And,, I don't yet know what ratio I have in the rear end. Since I may have to change both to get a match.. advise on that? Mostly light loads, highway speeds use. Possible I may add a gear vendors, which I also have, that is made to fit where the rear carrier bearing fits..

 

[laserjock]

What Greg was saying is that the only difference between a SRW D60 and a DRW D60 are the shape of the hubs. If you get a SRW axle, you can either buy aftermarket adapters that bolt right on to your current brake setup or change to DRW hubs to use the dually setup. So in short, you want a ford D60 to have the correct side drop etc. As far as what years to get the springs you want, I can't help you there. If you are converting to leaf springs look up freebird01's thread. He did exactly what you are talking about less the divorced case I think. He posted an update just a while back so it's probably only a couple pages deep.

 

[towcat]

read up. with pics too!
http://www.oilburners.net/forums/showthread.php?64522-87-Crew-Cab-Project

 

[Greg5OH]

OK.. Thanks everyone. Looks like I need to clear up my question a bit.

The ZF5 I have is 2WD, no parking brake on the tailshaft.

The present front axle setup is the coil spring, twin beams, I want to replace those with a straight axle, leaf spring front end.

So looks like the divorced transfer case issue is down to one choice, it's covered. NP 205. So the question I need answered is what front axle do I need to be looking for to match up with my Dual rear wheels.

Also.. will the 2WD adaptors that let me run wheels that match the Dual Rear Wheels work as a "bolt on, no fuss" attachment? I've never done this before, so if you have, "In the land of the blind, the one eyed man is king".. applies.

And,, I don't yet know what ratio I have in the rear end. Since I may have to change both to get a match.. advise on that? Mostly light loads, highway speeds use. Possible I may add a gear vendors, which I also have, that is made to fit where the rear carrier bearing fits..

if you want a GV, go 4.10s. if you do alot of light load freeway driving and your current rear end is a 3.55-id swap both front and rear for 3.73 from newer units. I havent seen a ford d60 with 3.55 front gears.

 

[laserjock]

if you want a GV, go 4.10s. if you do alot of light load freeway driving and your current rear end is a 3.55-id swap both front and rear for 3.73 from newer units. I havent seen a ford d60 with 3.55 front gears.

My 60 is 3.55

 

[Greg5OH]

woah thats pretty cool!

 

[laserjock]

Part of the reason I bought that parts truck. It's from Texas. Pretty clean rust wise and it had a 60 with 3.55's. For my purposes, I was going for hwy fuel economy. When I'm towing, as my dad used to say, she's. Got 3rd gear same as 4th (it was a t18 or 19). Mine will have 4th same as 5th. 4th and 65-70 should be 3000-3200. OD should be 1800-2200 at cruising speed.

 

[franklin2]

From that link above. This is the hardest part to convert to leaf springs. It's not a true bolt in, but with a little work you can do it. I think you need to drill some holes in the rear for the spring mount in the back.

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[Dieselcrawler]

I have done the 4x4 swap without that step that Jason did. never had an issue. and I wasn't ******* them at all
hell one of them is my 86 I have now in my sig....

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that used to be 2wd

 

[pastorjeep]

I think the easiest straight axle swap is the SD coil spring swap. Take a look at this (I am considering it for next year) and see what you think? http://www.fullsizebronco.com/forum/showthread.php?t=162366&page=5

 

[laserjock]

Talk to Greg5OH before you dive into a coil spring front swap. Not saying can't be done, but he went through the process of getting and measuring everything and ended up using an 06 frame. Just make sure to do your homework whatever you do.

 

[pastorjeep]

Jock, I am not sure what you are talking about on measuring? I have looked at five SD coil swaps and for the 2wd trucks like mine it is basically a bolt in affair. Control arm mounts bolt directly behind first cab body mount and springs mount in buckets. The only changes most people mention are building a track bar mount and changing pitman arm to a SD one.