4r70w 203/205 doubler??

[price209]

OK, can a 203/205 doubler be done behind my 4r70w? I will be running a 4.5" Lift and am moving my rear axle back 2-3". I have a stock 9" housing, not the high 9. I know everyone is going to ask why not atlas or stack? But I already have the 205 and i havn't bought my drivelines yet since putting in the 4r70w so going to the doubler will cost me 6-800 from what I found and an atlas will run over 2k. Will this combo be too long for my rear driveshaft?

 

[Broncobowsher]

I think it will be too long. It would take a real steep shaft angle with a lot of travel to think of pulling it off. I am sure you could get a shaft to work, and if it was just a play toy it would probably be OK. But that shaft running at that angle will not be happy with long highway cruising, will need a lot of grease pumped through it and will probably need to be rebuilt on a frequent basis.

I also worry about hanging that much cast iron that far out. the stock 4R70W adaptor housing that you will be using is aluminum and designed for huch lighter transfer cases with a lot less leverage. The only way I see that adaptor having a chance of living is if you didn't use the mounting pad and put the transfer case mount further back, at least under the 203 doubler and probably under the 203/205 adaptor would be best. That should reduce the stresses of all that heavy transfer case to levels that the factory transfer case adaptor could cope with.

Just because you have the 205 doesn't mean you have to use it. You can always get some money out of it by selling it. They are not that great, mostly just cheap and strong.

 

[price209]

I have seen several people running the c6/203/205 combo and I thought the c6 and 4r70w were almost identical in length. Are the people running that combo pushing the rear end out pretty far?

 

[allenfahey]

More options....
1356 Doubler

231 Doubler

 

[price209]

Has anyone looked into shortening the 4x4 adapter on the 4r70w. From what I have read, it is roughly 7" long. I spoke with a guy from Behemoth Drivetrain and he said he thinks he could cut down the tail housing and cut down/respline the output shaft so that the adapter would only be 2.5".

So dimensions would be 22.5"(tranny/adapter)+ 8"(203 gearbox plus 205 adapter)+ 12"(np205) for a total of 42.5". Stock C4 to D20 combo is 35". So with my rear axel in stock position my length to the rear driveline would be 7.5" shorther than with the stock C4. If I move the driveline back 3", I am only 4.5" shorter than stock with doesn't seem so bad.

I know that plenty of people are using the 4r70w/205 combo with stock wheelbases and If I have the numbers right the 4r70w/205 combo is 39" so 4" longer than stock c4/d20.

Anyone done this or think it could work? The truck is going to be a 50/50 split highway/trails rig.

 

[nvrstuk]

Don't worry about your drive line length if you set it up correctly if you extend the wheelbase

I ran a ZF/203/D20 for over 12 years with a rear driveline length of 23.5". I ate one rear ujoint and one CV in those dozen years, wheeling Moab, Rubicon, and dozens of places. I drove about 5k/miles/year... less now...

I now run a 4r70W with a KluneV and Atlas...not sure what the length is compared to your intended setup but I run a 22" long drive line now. One inch longer drive line and I'd be OK with a stock 9" with my Atlas hanging 1" below the frame rails with the stock 9" but I upgraded to a TrueHi9.

I could have run a limiter strap and kept the stock rear 9" by extending my wheelbase about 2"...

I run 2 crossmembers as Broncobowsher is right, that 205 is heavy and needs support...good support.

 

[Mountain Ram]

More options....
1356 Doubler

231 Doubler

Does the NP231 work behind a 4r70w? I have a 231/431 drivers drop doubler out of my Dodge ram crawler and would love to find a trans it would bolt behind. That 7.4:1 low range is hard to beat!