Hot Rods Driveshaft rumble, problem solvers unite!

Ok, last week I went to pick up a small punch press and of course I had to have a little bit of fun on the trip. I noticed a new rumble start up that had never been there before, a co****ness like a hot inline four type of rumble in the driveline. I confirmed it was driveline related and only under load on my return trip and careful not to blast it apart.

Today I finally got to jack it up in the air and crawl underneath. Everything seemed to be pretty normal.

This doesn't seem normal though, looks like the cup is spinning in the yoke!

My thinking is that I pounded the snot out of this poor 1330 and am going to need to upgrade or at the very least replace. But would this cause the rumble I'm feeling or is there something else lurking just beyond?

 

Had something similar happen to a buddy once. He had bought the suburban, ran good, but went through u-joints in 6-8 weeks. Not hard driven. We had to use a conversion joint also. Finally we found out the yoke was worn out to the point of using a conversion. Replaced the yoke and everything was fine.

The biggest problem, it was worn so evenly that it looked like someone replaced the factory yoke. He drove that thing for years after and never replaced a joint again.

 

you might be OK with just a new cross. But if the new one is a slip fit in the yoke, then a new yoke is in your future.

Looks to me like you broke a couple of needles and it seized up.

 

Pulverized is more like it! Remember what's in front of that trans...




I figured the yoke was toast and by the looks of it the forward yoke on my driveshaft is pretty much done too. I'm just wondering aloud about the chances of anything else giving up.

 

I'm chasing a thrumming/vibration in my 56. I think the yoke isn't in the trans far enough. I could see how you could be eating up driveline parts with that mill! Or is one of those for heat and the other for cool?

 

I have had a few car show "experts" think they are dummies or hollowed out. Just why would I go through all that trouble just for eye candy?

 

1330 behind that motor? damn, you're as brave as I am....

 

btw since you need at least one new yoke, get the next size up this time

 

Thats the plan

 

the bore size of the yoke expanded,,,sometimes from ware sometimes from abuse,,a new joint wont fix it up grade too a 1350 joint and a larger diamater shaft ,,best with d.o.m. tubing

 

thats some very nice air replacement devices you have on your motor . that motor must make at least 200 hp. all kidding aside . one bad *** motor.

 

First off , I have always loved that truck. Then when I seen under the hood at the HAMB Drags. Holey Cow!!!!! Anyway, I worked at a driveshaft shop for 13 years. So I have a little experience. I think what happened is that that journal of the u-joint got a little starved for grease. With the power given to it got a little hot. When it does , it starts gettin a little galded. You will probably find the journal that looks like it has been machined to fit some needle bearings.

Well when that happens the needle bearings dont just keep rolling around the journal while the journal is spinnin. It is like draggin a broom stick over corgated metal. Bump, Bump, Bump.

Get my drift/ Well with this added friction the press fit between the U-joint cap and the yoke gives away. And the cap starts spinnin.

It is the broom stick/coregated metal surface causing the vibration or growling noise.
Replace the joint and the trans yoke.

It looks like you are lucky and it happened to the trans yoke. And not the weld yoke. Which would require a trip to the shop. KING

 

I have had 9 second cars with that 1310 u joints in it. 1350 got upgraded to before anything broke. But on a drag car with SLICKS or these days Drag Radials. It is more important.

NOTE> My 1310 was a solid joint without a grease fitting. Which means it doesnt have a hole drilled between all 4 caps and outward to the grease fitting.

 

the cap on the welded yoke is loose too, you can see it's been moving

 

^^^^^^Yeah ok, missed that. Is that a aluminum shaft? You could ping the inside of the yoke where the cap mates with a punch. And hold it from spinnin too. Because it doesnt look like it has been spinin. Just looks like it moved a little.

 

KC, thanks for the clear and concise explanation. Pretty much confirming what I had figured because everything else seems to be fine.

the caps in the driveshaft have not moved as much as the ones in the trans yoke. I may just replace the yoke and peen the drive shaft to keep moving until I have a better financial window to replace the whole deal.

 

Plan B you could put a 6cyl in and call it a day...

Good Luck

 

Like this 560 cubic inch V6? I like your thinking!

http://i280.photobucket.com/albums/kk166/kellyo77_2008/IMG_0161.jpg
http://i280.photobucket.com/albums/kk166/kellyo77_2008/IMG_0160.jpg

 

Last weekend I pulled the old drive shaft out. You could push the caps out of the yokes with your thumb. There was some brinelling on the rear joint, but not on the front, and it was enough to make some noise but that was about it.

So,

I replaced the drive shaft completely with a new one. I had a 3.5" .083 DOM steel shaft to made to replace the alumnium one and equipped this one wiht 1350 joints and forged yokes. Installed a Strange forged 4340 yoke on the diff.

Took it for a freeway blast last night and ZOMG! It seems even worse. Any load made so much noise. I pulled the diff out and everything seemed fine. Checked the gear pattern and didn't notice anything that would stand out as wrong. Next step was to tear down the ge****t and inspect the bearings.

I think I found the noise

 

Get in touch with Denny's Driveshafts........these guys helped me out so fast it wasn't funny.

 

Hmm, thanks for the suggestion but I'm not so sure they can tell me anything I don't already know.

 

Hell Steve let's blow some weld on that ,throw it in the lathe and it will be good as new!

 

Update, well I'm still at it and still have not found the solution. I do feel as if I'm making some progress.

Gears swapped out, problem still there at 3500 RPM (drive shaft speed)

Made my torque arm adjustable, changed pinion angles from parallel to the engine and trans, to pinion and drive shaft parallel, and even went to pinion down with the angle of the engine to drive shaft matching drive shaft to pinion, problem still there at 3500 RPM but can create new orders of vibration.

Decided to go through the axle again just to verify it's integrity. Found the right rear wheel bearing to be slightly, uh, off I suppose. So when in doubt, throw it out and a new set of high quality bearings installed. And while doing so I found my wheel studs on the driver side were twisted from hooking up! Replaced and thrown in the lathe and spun to 1000 RPM, no shake and no run-out what so ever on the flanges. Nice!

Installed and the shake is still there at 3500 RPM

Under the suggestion by my drive shaft guys, I ran the engine and trans through the gears, 3500 RPM in fourth and up to 5K in fifth and it's smooth as gl***. Elevator smooth.

Sent the new drive shaft back to the guys that made it. They had installed Brute Force universals and found them to be improperly machined and the shaft would not balance consistently. So the replaced the joints with Neapco joints and rebalanced the shaft. They said it was also not true because when they welded it they had the Brute Force joints in, so they had to straighten it.

Still vibrates at 3500

The drive shaft is 3.5" diameter, 0.083" wall DOM tube with forged ****er ends and is 62" long center to center on the caps.

I stuck my dial indicator all over it just now. these are my readings:

Rear of shaft: 0.000" to 0.020" as it's spun. There is a balance washer welded to the low side 180 from the high point.

Middle of the shaft" 0.000" to 0.005"

Front of shaft: 0.000" to 0.005" and there is a balance weight but not related to high or low spots.

If I was setting this up, 10 thou of run out seems like a bit too much for something that spins this fast.

I'm going to flip turn the shaft 180 on the pinion yoke and check it again to see if this new Strange 4340 1350 yoke is poop.

 

i know this may sound idiotic, but with that much motor, why do you have overdrive?

get rid of the stupid OD, put highway gears in it, and enjoy life.

Works for me.

 

How fast did they spin the driveshaft when balancing it. Worked on a Mustang ,changed 2.79 gears to 3.50 got a terrible vibration.Had driveshaft balanced it was an all new ***embly. Vibration lessened but far from being good. Replaced with a used shaft ,vibration was gone.Turned out driveshaft shop only could spin it up to 3000 RPM not enough for the new gear ratio.Good Luck we spent a lot of time checking other things because the driveshaft shop said the balance was perfect.

 

If I were to slow the drive shaft down through another set of gears, I would stay out of the range of vibration but it still doesn't solve the problem. I ran smaller tires before and spun it at a higher rate and didn't have this problem.

I thought you were an engineer and loved solving idiotic problems

Just turned it 180 and checked it run out again. Now the rear reads 0.000" to 0.014" so I lost 0.006" of run out. The readings are the same at 90 degrees to the U-bolts, the only difference is in the end play of the cap. At least that tells me my yoke is pretty damn close.

 

The shop said they spun it over 4000 rpm. Who knows if they just threw that out there to satisfy me.

 

ElP. Tell me more about the shake...You said you ran the engine and trans to 5 grand with no problem, was that in the shop with the driveshaft removed?

On the road, does the shake happen in all gears at 3500, or just 5th gear? Do you notice it more holding it steady at 3500 or coming up to it or down from higher rpm?

I know it's hard to describe on the internet, but try to give me every detail of how the shake feels.

Good luck, -Abone.

PS. I went to the dyno shop today and boy are you in trouble this August....

 

Somehow this seems like BS to me.
I don't know for sure what the balance equipment is but I thought that it (used to be) was part of the lathe they use to fit the shafts up. I wouldn't want to be standing there in the same building when that shaft goes to 4000!

Tire balancers don't run the tire and wheel up to road speed do they? they use senitive stuff and computers to calculate a slow speed imbalance, right?

I've had experiance with a couple of out of wack driveshafts. There is something to do with harmonics that repeat at certain rpms. And to solve that you need to be straight and true with no runout or balance weights.
So each yoke needs to be machined true and balanced with out adding metal or drilling holes. and the shaft has to be true the same way also. The added or subtracted weight will balance it out at a certain rpm but will cause a vibration at a different frequency or rpm.

And isn't 60 inches the max lenght that a shaft should be. ?? Some kind of physics involved there too. Or just practical application knowledge, the old timers knew from trying to make longer than 60 that it just don't work. I guess your'e close at 62. might be time for a two piece with a hanger.

GP the DP

 

Exactly.

Third forth and fifth, at 75 MPH is where it rumbles.

It feels exactly like a U-joint that disintegrated. I've had plenty of them so I know.

I just got back from a quick spin. I flipped the drive shaft and reset my pinion angle to .5 degree more pinion up so now I am at three up in the front on the engine, one degree up in front on the drive shaft and 2.5 degrees up on the pinion. I think I am on the right track, It was better for the short blast I just did, the drive home tonight will tell for sure.

****, I better get my launch down