Driveshaft length

maverick

New Member
Joined
Jul 28, 2005
Location
lancaster sc
I'm finishing up my off frame on my cj-5, 4.3, th-350 an dana20. My rolling chassis is ready to set the engine an i was wanting to use the factory mount location with small block mounts. Before i set my engine i wanted to ask whats the shortest rear shaft you guys have run to see what i can get by with. It looks like i'm running about 12" to 14" right now i havent measured it yet. I will be running about 2" of lift with 16" wheels not that wheels will make a difference just info. I'd like to do this now than later if i need to go forward with the engine, hands on info please, I'm pretty good at guessing myself.
 
i have a cj-5 just put a t-18 in it (which is 5 1/2 inches longer then the t-150 that was in it now due to lift my driveshaft angle is all screwed up to get what i need im having to stretch my wheelbase. which is not all bad mind you. if it was me in your position youll be money ahead to go as far forward with the engine as possible and still have your transmission tunnel line up. nm i just read your post again and you have a th350 you can use a cable shifter for tranny just get the and you can make adjust your dana20 linkage to fit.
 
Thanks for the input there Renegade, Ive done quiet a few rebuilds, but this is the first auto. i've done. I looked around on the driveline sites an seen them as short as 10" with cv's. I just seem a little skeptical of this, I've had several cj-7's an that little extra length goes a long ways on the driveline mods. I have about 6" of space to go forward but I will have to remove the front axle housing stop, was looking for a way around this but I will have to do it I guess. Thanks again.
 
wbcarever had a CJ5 in his shop that was SOA with a SBC350 and an Automatic. the rear shaft was about 15" long or in that range. Never took an exact measurement, but it was DAMN short. The one in my CJ, also SOA, with aT-18/D20 is about 23". I stretched my wheelbase. Not because of the shaft, just because I wanted to. I would suggest this. being that short, I'd go with a regular joint and not a CV. a regular will run at a greater angle than a CV.
 
From my experience, it's not the length that matters much - it's the angle the joints are working at. can you figure out your driveshaft slope?

And yes, I realize that a shorter driveshaft typically operates at a steeper angle, but he might be OK with a short DS...
 
Rich is right, the angles will be you main hurdle. Running a center limiting strap to limit down travel might be a simple solution to keeping a CV alive.
 
My angle is not going to be far off stock, because at this stage of build i have a lot of up an down varibles to play with far as engine placement, even if I get to use factory holes in frame for engine mounting which is what was desired because of balance. I just didnt want any problems with pulling slip yoke apart, from the driveshaft sites i've looked at they predicted 2 1/2" of working splines of a 10" driveshaft at vehicle rest. With what little i have of lift I did not know if arc of rearend would be a problem at articulation with this short of driveline. An by the way this is a mild 4 wheel drive build its not going to see anything aggressive on purpose. Thanks for the info. Hey after you get my age you get tired of buying shit twice an you hate like hell to tare stuff up, but i do understand the youth an wanting the adventure, high cost hobbies eh.....
 
I also run a limiting strap in the rear of my rig, which helps with decents, but also to prevent the D/s from dopping too far...

But it's a bandaid.. :lol:
 
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