View Full Version : 4WD conversion???

06-13-09, 01:13 PM
Has anyone ever converted their rwd Caddy to 4wd?? The reason i ask is because ive heard of many other mods such as motors swaps, so i got curious. Can anyone comment on the complexity, cost, and or which parts they would use, such as suspension parts and which transaxle etc....i was thinking about a transaxle from a chevy truck maybe...

06-13-09, 01:54 PM
For reference, i have a 75' caddy fleetwood

06-13-09, 04:09 PM
I think the preferred method is to place the caddy body on a pickup or suburban drive train. I don't think it's that expensive if you can do it yourself.

06-13-09, 04:38 PM
You can also just add the transfer case to the back of the TH400, then remove the complete front suspension from the Caddy. Then, take the front solid axle and leaf springs (and mounts) out of something like an old Blazer and weld the mounts on the Cad frame rails.

Here is what it looks like when done to a Caprice wagon (note the 8 lug truck axles front/rear):


06-13-09, 05:19 PM
thanks for the insight fellas, Jay that wagon is NUTS!! Heres another question, instead of using a solid axle, can i use suspension parts out of the 75 eldo such as the cv shafts since it is fwd??

06-13-09, 06:28 PM
can i use suspension parts out of the 75 eldo such as the cv shafts since it is fwd??

Short answer: no.

06-13-09, 06:34 PM
that sucks....is it because they have different frames?? Also, is your 4wd manually or automatically controlled??

06-14-09, 01:37 AM
It can be done like Jay said but it completely removes the Cadillac ride from the car. It turns it into a truck. It would also be extremely hard (actually, impossible) to do it without also having to do a lift kit on the car. There is no room for the front differential because the engine and trans sit so low in the frame so the car has to be lifted to make room for another pumpkin up front.

06-14-09, 03:41 AM
I think your best bet would be finding a pickup frame that is the right length and wheelbase. Use the solid front axle from a truck. Here's some pics to give you an idea.


Personally I think its fun to do it on a car that's a roach like that white limo. Hacking up a nice example is a travesty, especially if you take it off road and get it all scratched/dinged up.

06-14-09, 04:30 AM
Although i can use a solid front axle which seems to be the most practical and feasible option, I need that smooth cadillac ride. Therefore, my goal would be to use a torsion bar set up. I want to use a np205 transfer case but dont know what front differential to use, 1 from a th 425 maybe?? However, there would be countless hurdles. These are some main ones i can think of.

Issue number 1: transmission/ transfer case clearance....would have to raise floor pans and go with dry sump lube

issue number 2: front differential suspension....would have to fabricate a frame to differential bracket...also custom cv axles

Issue number 3: frame modifications....maybe go with front section of eldorado frame?? or keep frame and make mods to the engine cradle

thanks for the posts guys any insight is welcomed and appreciated!!

06-14-09, 10:49 AM
You want it to be stock ride height and keep the "Cadillac ride" and convert it to 4WD? Not going to happen...

06-14-09, 03:54 PM
i actually wouldnt mind a modest increase in height 3-4 inches and although i would def not have as smooth a ride, it would have a smoother ride with torsion bars than with a solid axle and leaf springs...

06-15-09, 01:15 AM
If you're serious about doing this, you'd better do it right and go full on redneck. I'm talking solid front axle, manually floor shifted transfer case, 15" of lift, 39" tires.

06-15-09, 01:47 AM
^ Haha. Damn straight.

It also needs to have either side pipes or exhaust coming out the hood and a sh!t load of off-road lights mounted to either the bumper or on a roll bar on the roof.