long story short,
Custom tom woods one piece driveshaft seemingly cannot be balance. its too long,the shops don't have the correct flanges to attach it, or they wont spin it fast enough. tom woods balanced it twice but still its not working out.

94 extra cab with a 5vze/r150f to stock 4.88 gears sitting on 33s

All new engine and trans mounts, rebuilt transmission and transfer, rebuilt differential, driveshaft rebuilt 3 times last i counted. every damn thing on this truck is new, bushings, wheels bearings, axles, drums and shoes, rotors, pads, calipers, wheels and tires balanced, shocks, springs, torsion bars, ball joints, steering components, run out checked...everything. nothing,NOTHING is loose or misaligned, even took it to a frame shop thinking something is throwing the rear out. its as perfect as can be. shims are on the rear diff, the angles are perfect and every shop i've been to agrees that is not the issue.

the shaft is 68 1/2" long by 3 1/2" diameter steel. no one local can balance it, no place I stopped in the Carolinas, New Orleans, or my short stint in Texas could. In normal driving the vibrations gradually get worse from 3k to 3.7k rpms (driveshaft not engine) that's 60-75mph. Adding two clamps to the rear of the shaft did more than any shop I have ever brought it to could. Eventually this is going to wear itself out or the transfer case/rear differential.

sent an email to denny's driveshaft here in NY and its too long for their machine. this thing needs a high speed balance. OR is it just the wrong shaft for this truck? wrong diameter? wrong material?

last resorts

any help is welcomed

 

Is it a double cardan shaft? What are your angles?

I had a single cardan shaft on my lifted truck at first. The angles were correct and within limits of any listed specs. Even the drive shaft shop said the pinion angle was good and I had a high speed vibration. Highway speeds 70-80 mph. I tried altering the pinion angle up and down a few degrees and still had a vibe. I went through all the ˟˟˟˟˟ you did and I even pulled my trans apart. NOTHING wrong.

I put a double cardan shaft in and tilted the pinion up toward the T-case output to get the proper angle. ZERO vibration since. The drive shaft DID balance at the shop though. Just vibration once on my truck.

 

this driveshaft has a double cardan at the t-case and the rear diff is tilted upward, started with 2 degrees. While in TX and taking measurements at a shop we went with 3 degrees, no change. The owner was floored when we went for a test drive as he has never heard the noise or vibration before.

only reason i know its the shaft is that after driving back and forth on a single lane highway adjusting two clamps I've made the vibration slightly less.

thank you for the reply, i wish it was the answer!
truck driveshaft shops do not have toyota flanges, shops with toyota flanges can not run this big of a driveshaft, any place that can service it will not spin it past 3K(~60mph) which is where the vibration starts.

should i look into an aluminum shaft? a different diameter? back to a 2 piece?

edit: quickly looking up the critical speed of driveshafts it looks like mine is roughly 2.9K, so my driveshaft is just flat out wrong for 4.88 gears. aluminum has a higher critical speed as steel at the same diameter but is weaker, staying with steel i might have to go to 5" diameter. tha'ts ridiculous! maybe a custom 2 piece is the only way:/

any other ideas?

 

If it balances out at Tom Woods, what is different once installed? The load on the shaft is all I can think of. Assuming it was measured correctly. Maybe it deflects under load? Maybe it should be a larger diameter? I have friends that went to one piece shafts on their trucks with lift and 35's without problems. Try a call to Jesse at High Angle Driveline or any other shop that builds them for race trucks.

 

You don't have to run Toyota flanges. My Tom Woods shafts are 1310 or 1350 and bolt to our Toyota flanges. IDK if that would help you here though.

If you do any rock crawling or wheel anywhere you might contact the ground, a two piece shaft may be your best bet. Please follow up once you figure it out. Dead end threads suck. Good Luck!!

 

fwiw: "A one-piece steel shaft can’t be longer than 72″ from the center of the u-joint at one end to the center of the u-joint at the other end. If you have need for a driveline to be longer than 72″, it can be converted to a 2-piece driveshaft or built using aluminum tubing." https://www.driveshaftsoftulsa.com/p...minum%20tubing

not sure why that is.

the driveshaft vibration that i had manifested when letting off the gas at speed, there was a serious vibration that was repeatable, it turned out to be caused by no double cardan joint combined with the rear pumpkin tilted up, built for rock crawling.

fixed it with a tom woods driveshaft, but i'm running dual cases so it's a shorter driveshaft than what you have, plus you already have a double cardan shaft.

it sounds like you can't get a new driveshaft from a local source? new aluminum driveshaft fixed this problem, see if any of the troubleshooting steps are helpful: https://www.trifive.com/threads/high....174112/page-2

 

thank you for the suggestion, I called and was told a few things.
the driveshaft is just too heavy for these little trucks, a one piece this large is a lot of weight hanging off the transfer case.
the fact that i have 4.88 gears and only 33" tires means this shaft is reaching is maximum rpm very early, they were hoping i was going to say 37s! i'm thinking 35s next time around just for the sake of rpms.
the solutions are a larger diameter aluminum shaft, which might not even fit or back to a two piece design with a higher quality and dropped carrier bearing.

this shaft should have never been made. its an abomination!

if you own an old extended cab 6' bed pickup, id stay with a two piece driveshaft!

 

i got a front driveshaft from jesse maybe 10 years ago... he knows his stuff and makes a good product, $600(?)!, but it took him six weeks and the paint job on it flaked right off, i don't think that it was degreased before painting... it was a clearanced all-toyota double cardan shaft.

there are complaints about how he runs the business:
https://www.hardlinecrawlers.com/thr...riveline.9747/

i'd question the reliability of a two-piece driveshaft in heavy use, but then i've never tried either

 

thank you for the info.
feeling at a loss, rebuild a drive shaft off ebay, buy a dorman complete, have a custom one made, or see if a local shop can turn this one piece into a 2 piece?

edit: dorman reviews are garbage, nationwide junk yards here we go!

 

does the factory two-piece include a double-cardan joint? if so, getting a good one from a junkyard might be a gamble, what would it cost to have a local shop alter the tom woods that you have.

if you had access to a go pro or similar, maybe hook one up underneath to see if the shaft is flopping around.

 

It did have the double cardan joint, I called around and found a shop that will turn this 1 piece into a 2. I'll make an appointment in a week or so. Will get pics of before and after and updates.

thanks for the help guys!

 

Finally able to install the extra shims and call this complete. A normal looking two piece driveshaft, required 8 degrees of pinion angle lift. Super smooth to 110 and back. Paint came off next day but no matter.

The shop said the old driveshaft had serious runout on either end. The lesson? extended cabs should not run a single piece for anything other than crawling.

before:





after:

 

thx for the followup, seems kinda strange that nobody caught the runout problem.

 

X2 about the runout not being checked or noticed. A friend of mine went from a two piece to one piece shaft and I never heard a complaint about vibration. It was mainly for crawling but he did drive it to the trail.

I'm glad you got it fixed and thanks for following up. Dead end threads suck.

 

I had a single cardan shaft on my lifted truck at first. The angles were correct and within limits of any listed specs. Even the drive shaft shop said the pinion angle was good and I had a high speed vibration. Highway speeds 70-80 mph. I tried altering the pinion angle up and down a few degrees and still had a vibe. I went through all the ˟˟˟˟˟ you did and I even pulled my trans apart. NOTHING wrong.