4 speed swap question

[MDH33]

I'm accumulating the parts I need for the 4 speed swap and OEM PTO install in my 40. I was wondering what I should do about the driveshafts. Since the 4 speed transfercase will have different flanges than the 3 speed, I'll have to modify the driveshafts (flanges and length) correct? I'm wondering if it would be worthwhile to just replace the axles with later model (fine spline disk brake) units rather than spending a wad of cash to have new driveshafts rebuilt.

Any opinions? And anyone have some spare 4 speed driveshafts?

 

[subzali]

I think I have a spare early flange you can have. They're smaller so you can get more droop from your axle anyway

If your u-joints are in good shape, it's only a little over $100 to re-tube a driveshaft. Contrast that with what Ricardo's gone through with his front axle conversion.

 

[RicardoJM]

If your u-joints are in good shape, it's only a little over $100 to re-tube a driveshaft. Contrast that with what Ricardo's gone through with his front axle conversion.

Word Subzali!

That said, Martin if you can get your hands on 40 axles that are ready to go and good to bolt up for a cost your are comfortable with relative to the cost of the new driveshafts, then I would say consider going for the swap.

Otherwise, take the following under consideration in your decison process...

Let's say you decide to swap axles and the axles are of unknown pedigree/history. In this case you will likely want to do a full front end service - if not right away certainly soon after you bolt it up. It is at this point where the $$$ can quickly add up. Front axle seals, gaskets, trunion bearings, shims, i.e. the front axle service consumables will be about $100 to start. You will also have your rig down for the duration of the service, it is at least on long full day - could be a month if you're slow like me.

Likely before you start the service, you'll begin to think about taking care of a few things "while your in there". Break out the 10 key and start adding up the $$$
new/rebuilt calipers
new/turned rotors
new brake lines
new wheel bearings
new claw washers
new nuts
new knuckle studs
new o-ring for your hubs
adjustable proportioning valve
Are the things I recall just on the front end. I've not serviced a rear axle, but am sure it has it's own list of stuff.

 

[subzali]

I don't think Martin would want/need to replace his rear axle...but I was about that comment as well but think it just means front axle shafts/birfs.

 

[MDH33]

If I were to have new driveshafts built, including Toyota U joints, it would likely be pushing $400-$500. If I found a good set of 4 speed driveshafts, and a set of later complete axles (like the ones that Boulder76 is selling for $400) I would be spending about the same (not including the repairs Ricardo mentioned) and gaining disk brakes. Just thought it might be worth considering.

I guess if I could find some 4 speed driveshafts to cannibalize, that would be the easiest method.

 

[Rzeppa]

I simply had my old 3-speed drive shafts re-tubed. Englewood Driveshaft. The difference is about 3.5 inches. I had one worn u-joint (that needed replacing anyway) replaced while they were at it. Of course I re-used my 3-speed transfer case for the lower ratio. You hadn't mentioned if you already have the PTO box for the 4 speed t-case.

 

[74fj40]

Martin - we've got a couple of extra driveshafts you can look at to see if they would work....

 

[MDH33]

I simply had my old 3-speed drive shafts re-tubed. Englewood Driveshaft. The difference is about 3.5 inches. I had one worn u-joint (that needed replacing anyway) replaced while they were at it. Of course I re-used my 3-speed transfer case for the lower ratio. You hadn't mentioned if you already have the PTO box for the 4 speed t-case.

I am going to use a 4 speed transfer case rather than modifying my 3 speed case. I also have the proper 4 speed PTO gear to use with my PTO setup. I think the only modification is that the drive shaft for the pto will need to be lengthened (?).

 

[MDH33]

Martin - we've got a couple of extra driveshafts you can look at to see if they would work....

Awesome! PM'd you.