[Jasonbailey1976]

Ok, I have a few questions regarding my transmission. First off I have a 93 d250. If I remember correctly I have a 46rh? I want to eventually make my truck 4wd.
Now, I understand most people will tell me its better to just get a 4wd truck to make it easier on myself for wanting 4wd. However, I like a project so I was thinking of just upgrading my truck little by little. As I understand it the same transmission is used for both 4wd drive and 2wd trucks. The difference being an extension housing. First where can I get an extension housing online? If not online then I'll just have to keep looking at the junk yards or for a donor truck. Also is the extension housing all I need? Or do I need to do anything to the rest of the transmission? I know I'll need a transfer case and a front axle, but for now I'm just thinking about the transmission. Oh, and a shortened drive shaft.

 

[aicomp]

I believe that you will need a 4x4 OD housing. the extension housing is also the overdrive, I also think the trans is an a518,( I guess basically the same as the 46rh).
Mike

 

[Jordan A]

All the parts you will need for a 4x4 conversion: the extension housing and 4x4 main shaft for the trans(try eBay) l, a 23 spline np205 tcase, shorten drive shaft, front drive shaft, 4x4 engine mount, 4x4 steering box mount and extended steering shaft. Spring hangers,

 

[Ruderunner]

You neeed a 4wd rear shaft, you can't just shorten the 2wd shaft. The NP205 has a fixed yopke and the 4wd shaft has the slipe yoke in the shaft. 2wd has the slip yoke in the trans.

AFAIK you don't need the mainshaft for the trans, just the complete extension housing. A 4wd housing will have the correct shaft in it and the adaptor to mate to the t case.

Gassers use the same extension housing, provided it's a A518 based trans (including the 46 and 47 rh)

 

[Ruderunner]

As for the actual swap, I haven't done it but...
From my research a complete 4wd extension housing (with gears and shafts) is basically a bolt in swap to a 2wd trans. There is some sort of endplay check needed, apparently adjusted by shims but tthats where my searching has come up a bit short on that detail.

And yes the 4wd trans crossmember,exhaust, T case and rear driveshaft (for the correct wheelbase) will get you the "back half" done. The front half is more complicated.

To add 4wd front suspension you need all the bracket for the shocks and springs, front axle, front driveshaft (to match the trans and t case combo) springs shocks and engine crossmember, also the correct steering shaft (from column to box) and the mount for the box. The steering box is the same for 2wd vs 4wd.

It's do able but not a beginner kind of project unless you have lots of time to lay the truck up when the "unexpected" comes up.

 

[Jasonbailey1976]

Ruderunner, where did you find your information? Was it on this site or another like it? I'd love to be able to read it. And you said something about it comming up short? I take it good detailed info is a little hard to come by?

 

[Ruderunner]

Most info came from this site and from a junk yard friend. He's swapped housings on other trucks but could tell me much about the endplay. Nor have I been able to find out here.

 

[aicomp]

Most info came from this site and from a junk yard friend. He's swapped housings on other trucks but could tell me much about the endplay. Nor have I been able to find out here.

Hi,
The ATSG manual for the a518 has all the info on rebuilding the entire transmission. You can find one on Ebay.
Hope that helps a little,
Mike