4X4 Drivetrain Tutorial Links? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

rizdif · 07-10-2009, 11:56 AM

I'm new to the intricacies of the 4X4 drivetrain as compared to that of the old Firebirds I've rebuilt.

Can anyone point me to a good primer on what I'm going to need to know to swap the 4-sp manual setup out of my '68 K20 and replace with an AT of some type.

Recommendations on hardware appreciated as well. The truck will be lifted eventually.. probably 4" max. I'd like to line up everything I need prior to starting if possible.

TIA !!!

msgross · 07-11-2009, 09:50 AM

well, there are a lot of variables when doing this swap. The best thing is to swap all of the parts from the donor truck. This includes the transmission, transfer case adapter, transfer case (upgrade to NP205 from a 70 or newer), transmission crossmember, transfer case brackets, shift levers, transmission cover (if coming from a 67-72 truck), steering column with linkage (unless you are doing a floor shifter), brake pedal setup, radiator with transmission cooling lines, driveshafts (if same wheel base truck).

Those are some of the things on the top of my mind. Not a quick upgrade but doable.

Might as well address the front drum brakes too, any solid axle chevy will bolt up but then you have to change master cylinders, brake lines, brake booster, proportioning valve etc... if they work fine then stick with what you have until you find the "need" to swap things over.

**special-K** · 07-11-2009, 05:28 PM

Read,read,read.If that`s not enough,ask,ask,ask.

Basically,the difference in the driveline starts with the transmission tail shaft and housing.They are shorter and made to mate with a coupler/mount/pedestal commonly called the adaptor.Spline counts and bolt patterns have a few variations,mostly with the output end of the adaptor where it mates with the transfer case.There`s the different transfer cases to get familiar with and the front driveshaft.Then,there`s the front drive axle/steering.You`ll get to know it in no time.One thing that`s good is it`s all simply designed with basic components.

vtblazer · 07-12-2009, 06:37 AM

As SpecialK mentioned, it's all here for the readin'.

Some auto tranny info for ya:
http://www.race-track.com/news.asp?TOPIC_ID=532
http://www.maliburacing.com/auto_tranny_id.htm

...and gear ratios:
http://www.grimmjeeper.com/gears.html

Easiest swap IMO would be to just go with a th-350/205 combo with an on the floor cable shifter, then it's only a matter of cross members & drive lines to match up.

A donor truck is always helpful if you have the space and the means to pick it up and dispose of it when you done.

07-10-2009, 11:56 AM	#1
rizdif Registered User Join Date: Jul 2009 Location: Salt Lake City, UT Posts: 10	4X4 Drivetrain Tutorial Links? I'm new to the intricacies of the 4X4 drivetrain as compared to that of the old Firebirds I've rebuilt. Can anyone point me to a good primer on what I'm going to need to know to swap the 4-sp manual setup out of my '68 K20 and replace with an AT of some type. Recommendations on hardware appreciated as well. The truck will be lifted eventually.. probably 4" max. I'd like to line up everything I need prior to starting if possible. TIA !!! __________________ '68 Chevy - K20 Longbed "Time is an excellent teacher, unfortunately it kills all its pupils."

07-11-2009, 09:50 AM	#2
msgross Registered User Join Date: Jul 2006 Location: Central PA Posts: 12,201	Re: 4X4 Drivetrain Tutorial Links? well, there are a lot of variables when doing this swap. The best thing is to swap all of the parts from the donor truck. This includes the transmission, transfer case adapter, transfer case (upgrade to NP205 from a 70 or newer), transmission crossmember, transfer case brackets, shift levers, transmission cover (if coming from a 67-72 truck), steering column with linkage (unless you are doing a floor shifter), brake pedal setup, radiator with transmission cooling lines, driveshafts (if same wheel base truck). Those are some of the things on the top of my mind. Not a quick upgrade but doable. Might as well address the front drum brakes too, any solid axle chevy will bolt up but then you have to change master cylinders, brake lines, brake booster, proportioning valve etc... if they work fine then stick with what you have until you find the "need" to swap things over. __________________ The Garage: 1968 K-10 SWB - "Project Money Pit" 1996 Z-71 - "huntin rig" 1969 C-10 LWB (SOLD) "Project flip that truck or else" 1993 Passport, F@rd 1-ton (SOLD)"Project Cousin Eddie" My Garage Build "The 1,000 footer" Last edited by msgross; 07-11-2009 at 09:52 AM.

07-11-2009, 05:28 PM	#3
special-K Special Order Join Date: Nov 2004 Location: Mt Airy, MD Posts: 85,862	Re: 4X4 Drivetrain Tutorial Links? Read,read,read.If that`s not enough,ask,ask,ask. Basically,the difference in the driveline starts with the transmission tail shaft and housing.They are shorter and made to mate with a coupler/mount/pedestal commonly called the adaptor.Spline counts and bolt patterns have a few variations,mostly with the output end of the adaptor where it mates with the transfer case.There`s the different transfer cases to get familiar with and the front driveshaft.Then,there`s the front drive axle/steering.You`ll get to know it in no time.One thing that`s good is it`s all simply designed with basic components. __________________ "BUILDING A BETTER WAY TO SERVE THE USA"......67/72......"The New Breed" GMC '67 C1500 Wideside Super Custom SWB: 327/M22/3.42 posi.........."The '67" (project) GMC '72 K2500 Wideside Sierra Custom Camper: 350/TH350/4.10 Power-Lok..."The '72" (rolling) Tim "Don't call me a redneck. I'm a rough cut country gentleman" R.I.P. ~ East Side Low Life ~ El Jay ~ 72BLUZ ~ Fasteddie69 ~ Ron586 ~ 67ChevyRedneck ~ Grumpy Old Man ~

07-12-2009, 06:37 AM	#4
vtblazer Registered User Join Date: Oct 2003 Location: Central Vermont Posts: 8,538	Re: 4X4 Drivetrain Tutorial Links? As SpecialK mentioned, it's all here for the readin'. Some auto tranny info for ya: http://www.race-track.com/news.asp?TOPIC_ID=532 http://www.maliburacing.com/auto_tranny_id.htm ...and gear ratios: http://www.grimmjeeper.com/gears.html Easiest swap IMO would be to just go with a th-350/205 combo with an on the floor cable shifter, then it's only a matter of cross members & drive lines to match up. A donor truck is always helpful if you have the space and the means to pick it up and dispose of it when you done.



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