Has anyone ever "opened up" their center crossmember to fit a one piece drive shaft?

[superhondaz50]

I've been toying with the idea of a one piece driveshaft, aluminum 5" round for my lifted lwb truck. (A ram driveshaft might fit the bill, I need to measure). To do it I'd need to weld new bottom bracing onto the crossmember them cut out the old portion. Has anyone done this, or see any crazy issues doing this? Thanks

[rustytruck50]

I haven't, but id love to go that route without alot of messing around....anybody else offer up some info?

[Rufas]

I've done that on my bagged 70 LWB GMC. My problem is opposite yours. I needed to clearance my frame cross member. The one just forward the rear end.

[superhondaz50]

Originally Posted by Rufas

I've done that on my bagged 70 LWB GMC. My problem is opposite yours. I needed to clearance my frame cross member. The one just forward the rear end.

Nice!

[sick472]

I thought about that with my lwb 72, but could not justify the efforts. Somewhere in my research, someone said that there are practical limits to the length of a driveshaft and I was sticking in the neighborhood of 350 to 400 horsepower and similar torque values. So, I just went with the beefed up carrier bearing and two piece system. IIRC one of the driveshaft builders I contacted did not like the idea due to the length. Please don't let me squelch your plans, but do ask your contacts about how long they are comfortable building the shaft. Don't forget to check into all the shaft angles too. You may find that your rear end has to be set up for the single piece.

[superhondaz50]

Originally Posted by sick472

I thought about that with my lwb 72, but could not justify the efforts. Somewhere in my research, someone said that there are practical limits to the length of a driveshaft and I was sticking in the neighborhood of 350 to 400 horsepower and similar torque values. So, I just went with the beefed up carrier bearing and two piece system. IIRC one of the driveshaft builders I contacted did not like the idea due to the length. Please don't let me squelch your plans, but do ask your contacts about how long they are comfortable building the shaft. Don't forget to check into all the shaft angles too. You may find that your rear end has to be set up for the single piece.

Cool, I plan on using a 2012 Dodge RAM 5" aluminum shaft, it is 71" long, 1350 u joints, I believe 1 piece C10 shafts are around 67", so I should be good to go with a shortening job. My truck currently has the skinny 2" shaft, 1310 joints, and the terrible nutsack looking center support. It needs an upgrade lol

Should note I have a long tail slip yoke TH400, 250HP 350, nothing special.

[superhondaz50]

Alright, I'm going for this, my old driveshaft I was using with my old np833 manual tranny measured at 71.5", the Dodge shaft is 71", my new TH400 I'm installing is 6" shorter than the old manual, so the Dodge shaft will work good, just need to shorten it, and then open up the crossmember. I'll post build pics here as I go along.

[Acorn]

I think 5" might be a bit on the big side. I put a one piece 4" aluminum in my stock height c20. I modified my crossmember from the factory oval shaped driveshaft hole, to more of a rectangle shaped hole to give me just enough clearance. (Side to side, up and down) Once I welded some bracing in there, I really don't think I would go any bigger just because of the trailing arm mounts.
I can jack the truck up from the rear bumper until the springs max out and the driveshaft still comes pretty close to hitting.
How much lift does your truck have?

Something I thought about but never looked into, would be to buy a tubular crossmember for a lowered truck, and just install it upside down so the driveshaft tube hangs down.

[superhondaz50]

Originally Posted by Acorn

I think 5" might be a bit on the big side. I put a one piece 4" aluminum in my stock height c20. I modified my crossmember from the factory oval shaped driveshaft hole, to more of a rectangle shaped hole to give me just enough clearance. (Side to side, up and down) Once I welded some bracing in there, I really don't think I would go any bigger just because of the trailing arm mounts.
I can jack the truck up from the rear bumper until the springs max out and the driveshaft still comes pretty close to hitting.
How much lift does your truck have?

Something I thought about but never looked into, would be to buy a tubular crossmember for a lowered truck, and just install it upside down so the driveshaft tube hangs down.

Truck has 2" blocks in the back, might go a bit higher. Only going 5" since that's how the Dodge shaft comes, and the Dodge shaft is dirt cheap. The oval opening is a hair under 5", so I'll have to open it up .75-1" on the sides, then several inches down below, then I'll brace it up. Shouldn't be too difficult.

Got any pics of yours?

[Ironangel]

Originally Posted by superhondaz50

I've been toying with the idea of a one piece driveshaft, aluminum 5" round for my lifted lwb truck. (A ram driveshaft might fit the bill, I need to measure). To do it I'd need to weld new bottom bracing onto the crossmember them cut out the old portion. Has anyone done this, or see any crazy issues doing this? Thanks

I can come up with a dozen reasons why not...My question is why?

[superhondaz50]

Originally Posted by Ironangel

I can come up with a dozen reasons why not...My question is why?

To upgrade from the tiny drive shaft and weak nutsack carrier that likes to break.

[Acorn]

A lot of the second gen (94-01?) Gas powered rams had 4" shafts that were pretty long.
I'd go to the junkyard with a tape measure and look under any extended cab, long bed, full size vans etc. and see what you can find.

[Ironangel]

Originally Posted by superhondaz50

To upgrade from the tiny drive shaft and weak nutsack carrier that likes to break.

I wouldn't consider going to a one piece drive shaft an upgrade, in fact your down grading...A long one piece drive shaft wont handle rpm or the torque a two piece shaft will. Think about it and do your research, GM didn't do anything they didn't have to do to prolong longevity and meet the need. A two piece drive shaft was used in most all the muscle cars, Camaro's, Mustang's, to name two. And in a lifted application your inviting trouble by exposing that shaft to strikes from rocks and debris including the occasional opossum or dog. I've done the research years ago and have been running a stock two piece shaft (with the nut sack) behind a 450 HP L34 BBC motor for years with zero ill effect. It's your truck you do what pleases you but make no mistake. A one piece drive shaft is a downgrade not an upgrade..."Just Sayin" ~Ghoostriider~

[superhondaz50]

For sure, I just need to upgrade one way or another.

[superhondaz50]

So I gotta ask, how do you guys feel about the skinny driveshaft paired with a inland empire drive line heavy duty carrier?

[superhondaz50]

5" Dana shaft outta a 2010 RAM 1500. 1350 u joints. Hogged out center, gusseted in the from, used a piece of roll cage bar for the bottom I had leftover from the last cage I built. Solid.

[Rufas]

Originally Posted by Rufas

I've done that on my bagged 70 LWB GMC. My problem is opposite yours. I needed to clearance my frame cross member. The one just forward the rear end.

Been there, done that.

[Justin Jones]

Originally Posted by superhondaz50

5" Dana shaft outta a 2010 RAM 1500. 1350 u joints. Hogged out center, gusseted in the from, used a piece of roll cage bar for the bottom I had leftover from the last cage I built. Solid.

I had a buddy years ago that had a '72 GMC long bed with a stock height with the bottom cut out of his to use a one piece driveshaft. It was like that when he got it. He didn't make any effort to reinforce it either. He dogged the crap out of that truck and I don't think he ever had any ill effects from it.

"Supposedly" the one piece will transfer power a little better to the axle/gears etc.

[Richard2112]

As a rule of thumb, the longer a drive shaft is, the lower it's critical speed. That is, the longer shaft will tend to resonate at a lower speed than a sorter one. The beauty of a two piece is that it is difficult or nearly impossible to reach resonant frequency unless it is out of phase or badly in need of a balance. Resonance in a drive shaft can ruin a lot of things.