72 Chevy 4x4 (converting 4 speed to automatic)
 

What all is involved in converting a 71-72 Chevy 1/2 4x4 ton from a factory 4 speed to a automatic. I mainly need to know is the transfer case and drive shafts the same? Other than the trans and related items what else would be needed? I know the column and pedal set up would be changed.

Thanks,Ray

Re: 72 Chevy 4x4 (converting 4 speed to automatic)
 

Iam doing one right now. Just take the clutch rod out and patch the hole in the fire wall,remove the clutch pedal and plastic bushings, get a auto floor shifter of some kind (B&M has a truck mega shifter that works good and does not cost alot), your going to have to move the transfer case mount and lengthen or shorten the drive shafts depending on what tranny you use. I would do some searching around and find a 350/205 or 400/205 combo for sale or do what I did and get a turbo 400 tranny and a tranny adapter to put a 350 or 400 tranny to the 205 transfer case.

Re: 72 Chevy 4x4 (converting 4 speed to automatic)
 

If you go with the turbo 350 the overall length will be the same

Re: 72 Chevy 4x4 (converting 4 speed to automatic)
 

Kwmech, I was planning on going with as turbo 350 trans/ with a 205 transfer case. So the drive shafts will be the same?

Drbyrdman, was you truck a factory 4x4? This seems like alot of changing for me. I was hoping that all was needed to be done was changing the trans and transfer case.

Thanks,Ray

72 4x4 converting a factory 4 speed to an automatic
 

I posted this in the 4x4 section as well,just trying to get alittle more info. I am looking at 72 4x4 that is a factory 4 speed. Are the driveshafts the same length from a 4 speed versus automatic truck? Would the tranfer case be in the same location? I am just trying to figure what all is involved in switching over a manual to automatic.

Thanks,
Ray

Re: 72 Chevy 4x4 (converting 4 speed to automatic)
 

It`s as simple as swapping the t-case/tranny combos and deleting uneeded manual pieces like clutch pedal & linkage and adding Automatic shifter.

Re: 72 4x4 converting a factory 4 speed to an automatic
 

Pretty sure you need the the transfer case, tranny, and driveshaft from an automatic for the conversion......transfer case shifter should remain in the same location and 4-speed.......

Re: 72 4x4 converting a factory 4 speed to an automatic
 

when i first picked up my 68k10 4speed a few months ago i was thinking of doing a swap to an auto, i determined that the best route was getting a tranny and tcase from a newer truck, and i was going to have a driveshaft built if needed, the driveshafts, the tranny xmember and the linkage's seemed to be the bigger problems
but nothing some drilling a floor shifter and custom drive shafts wouldnt fix
hope that helped you some
good luck

Re: 72 4x4 converting a factory 4 speed to an automatic
 

The drive shafts are the same length so you can reuse them. Outside of the tranny and auto transfer case you will need the shift linkage and steering column. It is a pretty straight forward swap out.

My 71 snow plow had the manual (3) on the tree transmission that I swapped out and it sure is easier to plow with an automatic!

Jim

Re: 72 Chevy 4x4 (converting 4 speed to automatic)
 

flex plate for the auto and you will be lucky if you don't have to alter driveshaft lengths. Oh tranny lines for the cooler.

when i did my daughters, I left the clutch petal and after disconnecting it stuck it under the carpet so that it would still be there if we ever wanted to go back to the 4 speed, which the son in law did.

Re: 72 Chevy 4x4 (converting 4 speed to automatic)
 

I've done the same swap :

If the truck currently has an NP205 ( standard ) and your installing an NP205 ( auto & TH350 ) the drive shafts will remain the same, the cross member will remain the same & stay in the same location.

Other things you'll need:

auto steering coulomb
auto linkage & frame bracket
trany cooler & lines
kick down cable & brackets
flywheel
starter
flywheel cover
remove clutch peddle assem or you can install an auto brack peddle assem
patch floor hump or get a new one for an auto
The nutral safety switch is needed on the coulomb instead of on the trany

That's everything I can think of at the moment.

Gary

Re: 72 4x4 converting a factory 4 speed to an automatic
 

That, and you might want to pick up a automatic 4x4 floor hump. Otherwise you will need to block off the stickshift hole.

Re: 72 4x4 converting a factory 4 speed to an automatic
 

No the driveshafts are different, the rear shaft will have to be shortened. The 4speed trans is shorter than the 3speed.

Re: 72 4x4 converting a factory 4 speed to an automatic
 

I believe JimK is correct. If you are talking about a swap from a 4speed/NP205 to a TH350/NP205, the driveshaft lengths are the same and the xfer case bolts in the same position on the frame. The difference in overall length between the two trannys is offset by the adaptor that mates the tranny to the transfercase.

Re: 72 Chevy 4x4 (converting 4 speed to automatic)
 

Thanks for the replies. I would be going with turbo350/205 set up.I moreless had everything else in mind, I was mainly worried about the transfer case position and the lengths of the driveshafts.

Thanks,
Ray

Re: 72 Chevy 4x4 (converting 4 speed to automatic)
 

Make sure you remove the pilot bearing from the back of the crankshaft or when you put in the auto the snoute on the torque converter fits inside the part on the same spot and will push on it and could shorten the life of your thrust bearing in your engine. Not to mention it might bend or crack the flexplate.