Cracks in transfer case

[Squarescare]

Hey all I pulled the transfer case out of my parts truck with the idea of rebuilding it and swapping it out with my leaky one I'm running now but noticed hairline cracks on the case and was wondering if it's fairly normal for these old things or if I should just toss it? Thanks for any input here's some pics.

 

[nvrenuf]

Get some brake clean or solvent and get it CLEAN and double check. Casting flash lines are common and can look like cracks with dirt on them.

 

[Squarescare]

Get some brake clean or solvent and get it CLEAN and double check. Casting flash lines are common and can look like cracks with dirt on them.

So if they really are cracks then it's toast? I'll clean it up and double check but I'm pretty sure they are cracks. However they don't seem to go all the way through to the other side

 

[bucket]

So if they really are cracks then it's toast? I'll clean it up and double check but I'm pretty sure they are cracks. However they don't seem to go all the way through to the other side

It's very common for some case castings to have flash that REALLY looks like cracks.

 

[Squarescare]

So I've cleaned this case up and there are cracks or what I think are cracks, don't know if they go all the way through. Anyways got another question I hear the input shaft is different on these depending on the trans in the truck, I kinda thought they were all the same. This one came off a 350 turbo, my project truck has a 400 turbo in it and I've been told there's a different number of splines on shaft is that the case? And if so I assume I can change the shaft out while rebuilding it. Never messed with transfer cases or transmissions before so I'm pretty green in this area

 

[nvrenuf]

The input spline counts can be different; th350 = 27 and th400 = 32.

I’m guessing you have an np208, I don’t know if all of the inputs are a direct swap (ex; for an np205 there are input shaft bearing and bore size differences for a 32 spline shaft).

 

[Strick]

The TH400 and SM465 share the same large output shaft. The TH350 is smaller and while you are rebuilding your case that would be an excellent time to swap the input planetary for use on the TH400. I'm not a "hoarder" but there is not much that I throw out; it has to be totally useless for it to be scrapped.

HS

 

[Squarescare]

Ya they are both np 208s and thanks for confirming that guys, as for swapping it out I kind of wanted to build it and have it on a shelf ready to go, because there's nothing wrong with my np208 on the th400 other then it leaks a little so swapping planetary gears/ shafts would disable my semi daily driver until I finished rebuilding. I also have the problem of the th350 it's a good transmission and I thought I'd yank it out and have it around for if I ever had problems with the 400 but with different splines on transfer cases that kinda makes the whole idea dumb. Unless i save the entire drive line from parts truck, front and rear axle, 350 transmission and transfer case. The parts aren't as interchangeable as I thought. Maybe better off to just sell them and buy 400 turbo and compatible transfer case

 

[Blue Ox]

Die cast housings like they used on the 208s get wrinkles that look like cracks. Clean them up well to see if they're actually cracked.

AFAIK, there are only two input splines that fit either to 465/THM400 or the THM350/700R4.

Check the planetary carrier for cracks. They're notorious for cracking where the welds end. Other than replacement, or drilling and rewelding I'm not aware of any good fixes.

 

[Steelbuddha]

If those turn out to be real cracks, from the photos it looks like a good TIG weldor could make them go away.

[Pardon my old-school usage. A welder is a machine you use to weld. The weldor is the guy who uses the welder.]

 

[warrpath4x4]

post the pictures of it cleaned up, theres no need to waste money if its not cracked

 

[xm20k]

Just for a bit of reference.

Depending on T case used the output on a TH400 needs to be different length. Ignore the powerglide length marking that has nothing to do with a 4x that is to show were I need this one cut down when I find a machinist to do it. So a 205 will fit a TH 400 from a car or 2 wheel drive truck by just pulling the short tail housing

Shortest to longest is 6" then 7" then 9.25"

You must be registered for see images attach

 

[bucket]

There were 2 different lengths for the 205.

You must be registered for see images attach

 

[xm20k]

Correct! I knew I was forgetting something. The one that used the longer one used a slip yoke for the driveshaft, didn't it?

I didn't play with many 4x4 versions of these trucks.

 

[bucket]

Correct! I knew I was forgetting something. The one that used the longer one used a slip yoke for the driveshaft, didn't it?

I didn't play with many 4x4 versions of these trucks.

Both versions did. '80 and up got a slip yoke, but only if on a truck with a 1-piece shaft. The adapter changed in '85, along with the output/input combo.