I need more gear! Have some questions...

[josh86k10]

I went to Windrock today, had a blast, but I need more crawl gear. Right now I've got a TH400/NP208/4.56 gears and 39.5's. Luckily for me....my brother has a freshly rebuilt TH400 (short 203 output shaft)/203/Ford 205 doubler set-up sitting on a shelf, no rig to put it in, and he needs money. That said I need to stay away from too many added expenses (like extensive driveshaft mods) because I'm not exactly loaded myself. I'd go look at his setup with a tape measure, but the doubler set-up is 4 hours away from both of us (my father's house) so I have a few questions. How much will a short adapter 203/205 doubler change my driveline length as compared to my current 208? I've currently got 17" of available extension in my front shaft with the Saginaw CV. Here's what I'm thinking: Let my brother keep the Ford 205 (wrong side drop, he had Ford 60's). Get a flanged front output, slip yoke 205 with the slip yoke. If it only needs to be a few inches longer, just use my existing front shaft and just let the slip make up for the difference in length (17" of extension is WAY overkill for my suspension anyway). The stock 205 flange is the same bolt pattern as the 208 flange, right? My current rear shaft has 1350 joints, so theoretically I could just have it shortened a few inches and keep using the slip yoke for the time being. I've got access to a shop and tubing bender to build the crossmembers, unless some combination of stockers will work? Are there any flaws in my thinking? Will a flanged/ slip yoke 205 do what I want or will it be too long (make my rear shaft too short)? It's a short bed truck with the axle moved back 1.5" by the way. Does such a 205 exist? If so what truck will I find it in? Thanks in advance.

 

[boz42]

I can't see anyway stock shafts would work.

The biggest problemis figuring out how to hang a 32 spline chevy 205 on a ford 31 spline shaft & round ford pattern.

Do you know the brand of the doubler? That will detemine the length. ORD's is the same as a 400/203 combo.

 

[josh86k10]

I should've figured there'd be a glitch somewhere. I didn't realize the Ford 205 doubler would be a different bolt pattern/ spline count. I should've though, Ford always seems to have to be different.

 

[boz42]

For that matter Chevy is different between each transmission.

At least all the Ford cases will swap between all the Ford transmissions. All thier stuff is 31 spline round pattern.

 

[josh86k10]

At least all the Ford cases will swap between all the Ford transmissions. All thier stuff is 31 spline round pattern.

Since you brought that up, I've been doing some homework. I guess GM was the one flip flopping on this one, what with different shaft lengths and 27 v. 32 spline and all. I guess I'm just used to Ford being the complicated one from all the different engine versions, surprising they'd use a "universal" t-case set-up. Of course I'm certainly no Ford expert.

 

[boz42]

You are right. Chevy used 10, 27, & 32 spline t-case inputs. 32 spline comes in long & short versions.

Ford engine have 2 different bell housings for the transmissions. I am no expert either, but I have owned some of both. Each has their advantages & dis-advantages.

Real men wear Bow-Ties.

 

[josh86k10]

I guess there's no practical way to get his stuff to work with my passenger side drop d60 then, huh? Looks like I'll have to spend some green to get a better crawl ratio.

 

[boz42]

I think you would be better off to find another set-up. The best way to use it would be running a ford 60 under your rig. That would require a fair amount of work though.

 

[blazinzuk]

Now I am no 205 expert either but chevy did have a round pattern 205 don't know if its close to the ford pattern or not. Also I think you could use the Ford input in the chevy case. I am pretty sure the Ford case used a big bearing like the chevy but with the 31 spline input.

I hope someone knows if what I said will work or not

As said your driveshafts probably won't work but lengthing shortining driveshafts usually isn't that expensive

 

[josh86k10]

Also I think you could use the Ford input in the chevy case. I am pretty sure the Ford case used a big bearing like the chevy but with the 31 spline input.

From ORD's website:

The "big hole" case is used with female input gears, examples being the GM 32 spline and the Ford 31 spline.

So it looks like making the GM 205 31 spline may not be that big of a deal. Plus I did a little searching on here and it seems to be a possibility.

However, I have found that the GM and Ford 6 bolt round patterns are slightly different. Apparently they'll bolt up but the assymetrical patterns result in it being 77 degrees off. In which direction I do not know. Some folks have talked about opening up one hole and it working however. I'd love to know if this is actually feasible. I am willing to redrill the GM 205 if that will make it work/ isn't that huge of an undertaking.

I would love to find an economical way to make this work. If anyone can confirm or refute the input swapping and/or let me know for sure if there is ANY reliable, economical way to adapt the 2 bolt patterns I would be greatly appreciative. Thanks guys.

 

[boz42]

Another thing would be that the Ord doubler has a machined spot in the adapter for the rear shift rail to clear. that make cause a problem putting the shifter on the other side. Might require some clearancing.


That is cool, I didn't even think about the ford & chevy round pattern may be the same. I was concentrating on why it would not work, instead of making it work.

 

[josh86k10]

I'm not sure who made the doubler, but I know it wasn't ORD. I think it may be from Murfreesboro.

 

[josh86k10]

That is cool, I didn't even think about the ford & chevy round pattern may be the same. I was concentrating on why it would not work, instead of making it work.

Maybe the glass is half full instead of half empty after all.... Maybe.