Driveline Fab

[stinkinlincoln]

I'm sure somebody on this board has been involved in driveline fab. I'm sure I have the welding skill to get them welded together good, I'm sure I have the machine equipment skills to get them put together straight. I'm wondering about balancing, I have found a few companies that make driveline balancing machines, quite expensive. I was also wondering if some techniques existed for balancing without dedicated machines. How important is balance for a front driveshaft on a rock crawling truck anyway, It probably doesn't need to be 10,000 rpm computer super wing ding dang perfect, just close enough. I have heard "just spin it in a lathe with washers strapped to it and move them around till it runs smooth" does this work? Can it work well enough for higher speed applications? Who are good suppliers of slip members and yokes? tube? I know a variety of metals are used to make drivelines. What are ordinary steel drivelines made from?
Just seamless tube, or some special alloy?

UPDATE!!!!!
Since I first posted this I purchased a driveshaft for $40 off Ebay it was 2 inches to long. I cut the slip yoke off and cleaned it up with a die grinder. Cut the shaft off nice and square with a bandsaw. Beat it senseless to get it back together. Used v-blocks a dial indicator and a BFdeadblowH to keep everything straight while I tacked and welded. Immediately after reinstallation I turned the hubs in and hit highway speeds with it (confident/stupid?). Any way no vibration. Months later still working great. I recently talked to a machinist that has made dozens of drivelines for big trucks and stock cars. He has special yokes for aligning shafts in his lathe. He says buy quality tube, yokes and keep everything straight within a few thousandths and in phase and there is very little need for balancing. I'm sure that extreme angles, super high RPM and lightweight shafts make balancing more important though. My local driveline shop wanted $400 to make me a new shaft. I'm glad my skills and info obtained from this message board allowed me to get the job done for 10% of that price

[Paul Seaman]

stinkinlincoln:
I have done most of this you are refering to, and the real difficult is getting the balance. Yes it has to be balanced, no matter what speed your driving it is still going to spin 4+ times as fast as the axle shaft {my axle ratio is 4.10:1 so the shaft is spinning 4.1 revolutions per one axel shaft revolution**. Vibration is your enemy in regards to longevity, vibration=failure. The last shaft I worked on was made of hardened steel tubing for an f350 on 44" gumbos. We sent it out to have it balanced, Patersons driveline in Indianapolis did the balancing act for I think $75. We reused the yolks and tube crowns from the factory shaft, but I know they are available from Moser and Strange engineering. Use Brute Strength U-joints from Precision they are the best and are Hardened. Precision is available at most parts stores but make sure you ask for the brut strength. If you have exact dimensions I'll find the part number for you just email me [email protected] I also have a source for most of the parts here locally so tell me what you need and I'll check for you.

Peace,

[Teeps]

I'm sure somebody on this board has been involved in driveline fab. I'm sure I have the welding skill to get them welded together good, I'm sure I have the machine equipment skills to get them put together straight. I'm wondering about balancing, I have found a few companies that make driveline balancing machines, quite expensive. I was also wondering if some techniques existed for balancing without dedicated machines. How important is balance for a front driveshaft on a rock crawling truck anyway, It probably doesn't need to be 10,000 rpm computer super wing ding dang perfect, just close enough. I have heard "just spin it in a lathe with washers strapped to it and move them around till it runs smooth" does this work? Can it work well enough for higher speed applications? Who are good suppliers of slip members and yokes? tube? I know a variety of metals are used to make drivelines. What are ordinary steel drivelines made from?
Just seamless tube, or some special alloy?

some guys use screw clamps, change the position of the screw to adjust the balance.

personally, I need to prevent NVH, by reducing flex, or driveline lash, you reduce oscillation, you reduce vibration and noise.

Vibration and noise = destry rear end, and transmission

My stock 1997 Tbird was limited to 105 mph for this reason.
Change from the stock 3.27 gearing to 4.30's like I have now, and I get first order bending below freeway speeds!!!! Yikes!!!!

So I had to use an MMC shaft, is both more rigid, and way lighter than steel.
Metal Matrix Composit, it's a special composite alloy comprised mostly of aluminum.

You can get them from http://www.dynotechengineering.com/

They are local to me here in Troy, MI

[walker]

Just to interject a bit of automotive trivia here, drive shafts on production cars were never balanced until the late sixties. I have built them in my garage and not balanced them and had no vibration. These were street cars only, not drag strip cars. Also, look on the pirate 4x4 site. I think they show many crawlers with front shafts made of 2x2 square .250 wall tubing. Ypu will not be turning many rpm crawling rocks.

[Paul Seaman]

Walker:
You are correct but the truck I mentioned before broke a perfectly built balanced shaft getting to the rock crawling grounds, he dropped into a mud slush hole, spun the tires, it hooked up and boom the shaft exploded {7.3L powerstroke with a bankspower kit, and a KluneV-8:1 transfer case** too much torque! You can break anything with enough torque!

[dyn88]

I had a 1970 montecarlo with a 1995 LT1 motor and 4l60e trans. One day my trans was leaking bad so i shimmied under it to see what was wrong. I noticed a clean spot where a weight had come off the driveshaft. I pulled the thing out and found that the bushing and seal had worn out on one side, due to vibration(the yoke was also trash). So for everyday driving Id say yes a balanced driveshaft is important. Also cheap insurance.

[stinkinlincoln]

Thanks for the info everybody. I saw a truck for sale on e-bay that had a square front shaft, I couldn't believe it. I'm not quite that low-tech, but I suppose it must be a low cost solution at a low rpm. Those guys probably plan on smashing it on a rock soon enough anyway. I've been to pirate4x4.com before but never noticed any square shafts. That site kicks butt, tons of good tech info and those machines are sick and twisted in a very good way. I don't think I would ever trust myself to make a driveline for a speed car, I definitely don't want to make a rear driveline for anything right now. What the ****, I think I'm going to take some used parts I got and try it, if the shaft craps I won't be out to much. If a pinion bearing goes out I'll just tell myself I needed to change ring and pinion anyway. Actually if it vibrates much at all, I'll just cough cash for a pro built shaft.
More opinions and info are always wanted, thanks again

[Daved]

I'd say homemade square front driveshafts for rockcrawling are fairly common and are just fine as long as you don't go at highway speeds (stay below 25 mph or so). If you are a decent fabricator you can make one.There are all kinds of discussions on the pirate site about it. Outer part is receiver hitch. Inner part is 1/4" wall 2x2. You can make the slip as LOOOONG as you want.

Its a given the driveshaft is going to get beat up on the rocks and the square ones tend to be bulletproof. Now the universals are another story.

If its never going to be driven on a road and trailered to the rock crawling place I'd even make the back one out of square tubing.

[mooseye]

Walker:
You are correct but the truck I mentioned before broke a perfectly built balanced shaft getting to the rock crawling grounds, he dropped into a mud slush hole, spun the tires, it hooked up and boom the shaft exploded {7.3L powerstroke with a bankspower kit, and a KluneV-8:1 transfer case** too much torque! You can break anything with enough torque!

And thus would be a good candidate for a 4x4x1/4 square tube driveshaft. lol Or better yet a carrier bearing.

[bigo]

I made a 22ich reardrive shaft and put in my mudtruck i built about 4 yrs ago . I cut 50 inches out of a longbed f150 and put it back together as a extreme shortbed, I done this as kindof trial and error and just ended up using it. I ****ed the rearend up, had to trim the sh#T out of the yoke to get it to clear and I never even looked at the shaft after i welded it, as I was planning to keep tweeking the truck, put a stock universal in as it came with the truck,put some 33-12.50 swampers on it, rebuilt my 302 (woke it up a smidge 280hp at the back wheels on my buddies dyno)and everything seemed fine no vib or nothing, so i just ran it figured id get it in the pit and drop that rear driveshaft. But this thing wont come apart I have took first in modified stock in 8 dragg pitts and 3 boggpits in the past 3 seasons, and thats winding it up around 3500 and dumping the clutch in 3rd 4lo then mashing her for all shes got which isnt the easiest on anything. but however i was trudgeing around in the snow and noticed that my ujoint is talking to me now , but im thinking so far so good ill put a new ujoint in this spring and see if i can do her in this season. of course I only runit in mud runs and piddle no road use. but this goes aginst everything ive ever heard maybe its just not noticebale to eye or ear or feel but my driveline probably doesnotice it.