87 v10 th400/208 to 465/205 swap

[Bladeboy1998]

I've got an 87 v10, came factory with a th400 and 208 transfer case, looking to swap to a hydraulic bell housing sm465 and np 205 transfer case. I've got a transmission, bell housing, and transfer case sourced already, but I'm unsure if I'll be able to reuse my front driveshaft, I know the rear will have to be changed as the transfer case doesnt have a slip yoke. I'm relatively new to all of this and may be in over my head as this all started with a hole in the engine block and somehow I dont have a cab or bed, and now I have a 6 inch lift for it! It's basically a frame off resto now.

I guess my main questions are the transmission crossmember and the front drive shaft, will I be able to reuse them? I found a truck in a local yard with a front shaft and crossmember but the shaft looks the same, the crossmember is hard to tell as the truck is buried. They listed it as an 87 but it's clearly not as it's a mechanical clutch, and the truck is a short bed so I cant use the rear shaft. Sorry for the long winded post, just trying to clear some stuff up! Thank you guys!

[b454rat]

I did the same swap almost 10 years ago. I had 700/208 but same difference. I can't remember about the driveshaft, but think used the one that came with the 205. The crossmember corresponds with the trans mount, so as long as you have a parts truck, should have what you need.

[FoxCustom]

Just did this swap (using a mechanical clutch/bellhousing - recommended for ease of service) in my V20 this summer.

I reused my factory crossmember by creating a notch in it for the 465/205 adapter to bolt to. Just a heads up, you’ll want to check that the spline count of your trans and t-case and the coupler are all the same.

The driveshaft had to be shortened from my original setup by Approx 2”.

And don’t forget the pedal assembly swap...................... it’s not terrible, but get that part out of the way first.

Best thing I have ever done for the truck. It’s a lot of work but you will be digging it!!!!

[Bladeboy1998]

You guys helped a ton! Makes me want to finish it even more now. My main problem is I dont have the transmission or transfer case yet, only a few pictures. Waiting for my buddy to bring it back from colorado. The front output of the transfer case throws me off a little, you'll see in the picture. I've not seen a driveshaft attachment like this. I appreciate everything guys, sorry for my rambling!

[Bladeboy1998]

My plan was to take the hydraulic bellhousing from the newer 465 there, put it on the older 465 with its matched 205 and I can mess with the crossmember as needed. Only thing that scares me is the front output on the blue 205 case, it's not like the one on my 208 and i dont know if he has a front shaft to go with all this stuff.

[b454rat]

208 had a flange, older 205s have the u-bolt style. Might have to get a new flange, pull it off m see spline count, they are readily available.

[Zoomad75]

For ease of service you want the flanged yoke that the 208 uses for the front output. The later 205's used a similar flange yoke so you can reuse your original front shaft. It's a lot cheaper to replace the yoke than going to the older style u-bolt yoke style shaft.

Having used both, the flanged style yoke is far easier to remove and install. Bonus is you already have that shaft.

[Bladeboy1998]

I'm hoping to be able to have a flange style yoke, reusing the same shaft would be even better! So I've gotten mixed answers, are they the same length shaft?

Hell am I lucky enough that the 205 and 208 have the same spline count for the front output?

[b454rat]

I don't believe they used the same spline. 205s used 2 or 3 different spline counts, 30 was the later count. Check out Offroaddesign.com, they have a lot of good info on cases.

[Bladeboy1998]

Will do! Thanks again guys!

[Bladeboy1998]

So from what I read on offroad design, the front output with the u bolt yoke has a 10 spline shaft, now I'll have to find either a 10 spline flange for the CV, or chang the output shaft entirely to one that I can get a flange for.

[b454rat]

It's been a long time, but don't think you need to tear whole t-case apart to change it. Even if you do, they aren't hard to tear apart...

[1976gmc20]

As I remember … the front output yoke on the 205 is pretty much like a pinion yoke on a differential: there is a big nut that holds it on a splined shaft. I had to have the front output seal replaced on my 73 and at that time I didn't have a big socket set to do it.

And darn, way back 1970s etc I just never dreamed that the 465 and the 205 would go away in new pickups

[CO71Blazer]

Looking at the 205 in the picture I'd do a complete tear down and rebuild. It is not hard at all and there are several great videos on YouTube that can walk you through it. That's when you can replace the front output with a 32 spline to match the rear and use a 32 spline yoke or a flange. Might also be a good time to swap in a 32 spline input gear. It requires the input bearing location to be milled out to accept the larger bearing, but any machine shop can do that easy. It's not a big job.

The 465 will need going through as well and you can swap in a main shaft with a 32 spline at that time. Again, nothing you can't do in a weekend with a shop press and a few tools. The end result will be an absolutely bomb proof transmission/t-case set up.

[Bladeboy1998]

Yeah I'll grab a rebuild kit for the 205, I dont know if I'm confident in doing the trans myself. I figure they've been sitting outside for quite some time so theyll need some work. Figure re-gasket them while they're out. I'm actually getting everything that is there both transmissions and the 205 and 208. So I'll have options

[Zoomad75]

Originally Posted by Bladeboy1998

I'm hoping to be able to have a flange style yoke, reusing the same shaft would be even better! So I've gotten mixed answers, are they the same length shaft?

Hell am I lucky enough that the 205 and 208 have the same spline count for the front output?

I've dug around but can't find the lengths of the 400 to compare to the 465, mainly from the bellhousing flange to the t-case adapter. Off the top of my head I think the 400 is longer overall, but that also depends on the style/type of the t-case adapter used. Pretty easy to put a tape measure to both once you get the 465 in hand. But I bet you might need to shorten the front shaft.

As far as the output shaft flange, the early 205 had a 10 spline front output up to 77 and 30 spline after that. ORD has the flanges available.

[FoxCustom]

On the front driveshaft length, I did have to shorten mine up. The 465/205 combo I am running uses the flange style front yoke. Even when you get it under the truck and installed, you can visually see how short the stack up is. Good luck!!!! Looks like you have a good pile of pieces to work with too.

[Bladeboy1998]

I actually found a guy local to me that stocks 205 parts. Hes got flanges and the output shaft in stock! I'll Probbaly go pick one up as soon as I get the trans and t case. I do remember hearing somewhere that the 400 was longer than the 465 so we will see when I have them both in hand. Either way I'm going to end up with 2 new or re worked drive shafts if I cant find a rear.

Yeah I've got a whole pile of stuff, I just scored a truck bed full of parts too for 20 bucks so I've got enough to keep me busy for a long time.

[FoxCustom]

Originally Posted by Bladeboy1998

I actually found a guy local to me that stocks 205 parts. Hes got flanges and the output shaft in stock! I'll Probbaly go pick one up as soon as I get the trans and t case. I do remember hearing somewhere that the 400 was longer than the 465 so we will see when I have them both in hand. Either way I'm going to end up with 2 new or re worked drive shafts if I cant find a rear.

Yeah I've got a whole pile of stuff, I just scored a truck bed full of parts too for 20 bucks so I've got enough to keep me busy for a long time.

Good to hear! Keep us posted on how the conversion goes! You’ll dig it

[57taskforce]

Just an fyi I rebuilt my 465 and 205 both for about $250 total including new gear bushings in the 465 and paint. It’s quite easy and there are several good videos of both. You’ll need a good press and an equally good set of lock ring pliers (not c-clip pliers). I did mine during winter when I could just go to the shop and play around a little here and there. I did some unnecessary things like blasting the cast and vatting the case shafts and gears. There are a few pictures in my build thread in my signature.

[Bladeboy1998]

Yeah I'm going to order a rebuild kit for the 465 and the 205, I have to change the front output on the 205 anyways so I might as well just make them all new so I don't have to worry. I'm trying to take a few 1000 mile trips this summer in it so I don't want to have to worry.

Can you guys give me any insight on the clutch pedal setups? I know the right way to do it is to find a set of 85-91 hydro pedals, but they want a large fortune for them so I am thinking about improvising a set of mechanical clutch pedals to work with the clutch master cylinder. I have seen a few guys say they have done it, but all the posts were from 6 or so years ago and nobody has replied.

I want to try to use a stock master cylinder and hose and slave for ease of replacement when it breaks on me ��

[Bladeboy1998]

Just scored a set of hydro pedals. Traded for my auto pedals so I'm set!