BenjaminCA
SILVER Star
I'm in the same boat. Same deal, installed a 2.5 w/ caster bushings and I get a slight deceleration chatter at hwy speeds. So a new DC driveshaft will help?
front rumble puzzler, not ujoints or spindles, help! (1 Viewer)
- Thread starter Hoosier Daddy
- Start date
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A 2.5 inch lift almost never needs a DC driveshaft. Most of the time the caster bushings are to help with steering wander. It seems most of the time when peole lift there cars a little, the old u-joints cannot handle the new angle. Usually, putting new u-joints all around will take care of the problem. This is why quality lift kits that go higher include the DC shaft.
I can't remeber the actual numbers, but a DC driveshaft is only good for trucks where the transfer case flange and the axle flange are greater than 4-5 degrees difference. Someone will know the actual numbers, but basically you should be alright and not need it.
I can't remeber the actual numbers, but a DC driveshaft is only good for trucks where the transfer case flange and the axle flange are greater than 4-5 degrees difference. Someone will know the actual numbers, but basically you should be alright and not need it.
Yes, castor correction bushings will help put the flange angle back closer to stock. It's just that the 2.5 inch lifts don't rotate the flange angle out so much that a nice tight stock driveshaft will "usually" work without vibrations. The old u-joints have wear lines inside them from running all it's life at a stock angle. Change that angle a little more, and the joint now has to flex a little bit more where the wear line has developed. For me, I had to replace all my u-joints when I first put my lift in so that a new wear line would form. Ultimately, (60k miles later) I had the slip joints worn out so that the low noise I had for a while was fixed with new slip-joints.
An easy way to tell if the u-joint is no good is to unbolt it from the flange, then use your hand to move the u-joint in all directions. An old joint will move smoothly inside it's usual range of motion, but there will be an obvious spot where the joint gets sticky, and gravity will not be able to pull the joint down from a twisted postition. A good joint will usually flop back and forth as you rotate the shaft. You will know a sticky u-joint when you see it.
An easy way to tell if the u-joint is no good is to unbolt it from the flange, then use your hand to move the u-joint in all directions. An old joint will move smoothly inside it's usual range of motion, but there will be an obvious spot where the joint gets sticky, and gravity will not be able to pull the joint down from a twisted postition. A good joint will usually flop back and forth as you rotate the shaft. You will know a sticky u-joint when you see it.
Hoosier Daddy
SILVER Star
- Thread starter
- #25
UPDATE - So I received my Chassis Ears by UPS today. Cool tool for $106, although the overall build quality appears fragile.
LEAD ONE - transfer case - noisy just in general, with some very minor whining noise, and a moderate amount of the vibration noise
LEAD TWO - front differential - very quiet in general, but this is where I heard the vibration noise most distinctly and loudly, although the difference was not huge.
LEAD THREE - passenger knuckle - very quiet, but heard the vibe a moderate amount
LEAD FOUR - driver knuckle - very quiet, but heard the vibe a mild amount (less than passenger side)
LEAD FIVE - t-case crossmember - very quiet, barely heard the vibration
With the Chassis Ears, I have discovered the vibration occurs as low as 18 mph, although you can't hear it with the human ear until around 40 mph.
Unfortunately I could hear the vibe all throughout the front drivetrain. However, I believe this test generally narrows it down to the front differential. I had to put the diff lead right on the pumpkin because there was no good place to attach it near the pinion flange. I would assume the passenger knuckle transmitted the vibe more loudly than the driver side because the passenger side is closer to the diff.
My next steps are to Drain and Refill the front diff, looking for metallic debris. I would still like to try another driveshaft just to be sure it's not a defect with my driveshaft, so I'll ask again for a loaner on the local forum.
LEAD ONE - transfer case - noisy just in general, with some very minor whining noise, and a moderate amount of the vibration noise
LEAD TWO - front differential - very quiet in general, but this is where I heard the vibration noise most distinctly and loudly, although the difference was not huge.
LEAD THREE - passenger knuckle - very quiet, but heard the vibe a moderate amount
LEAD FOUR - driver knuckle - very quiet, but heard the vibe a mild amount (less than passenger side)
LEAD FIVE - t-case crossmember - very quiet, barely heard the vibration
With the Chassis Ears, I have discovered the vibration occurs as low as 18 mph, although you can't hear it with the human ear until around 40 mph.
Unfortunately I could hear the vibe all throughout the front drivetrain. However, I believe this test generally narrows it down to the front differential. I had to put the diff lead right on the pumpkin because there was no good place to attach it near the pinion flange. I would assume the passenger knuckle transmitted the vibe more loudly than the driver side because the passenger side is closer to the diff.
My next steps are to Drain and Refill the front diff, looking for metallic debris. I would still like to try another driveshaft just to be sure it's not a defect with my driveshaft, so I'll ask again for a loaner on the local forum.
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I have to retract my statement with it being my front drive shaft as well.
Im back in your same/similar boat. Although my old drive shaft was clearly broken/loose/damaged the new to me one exhibits the the same type of vibe. I've been driving my truck for the last 2weeks with front DS removed and CDL on with ZERO noise. Installed the new to me shaft (w/ used ujoints as well) and I have the symptoms back again.
It IS much more quiet with the new to me front drive shaft, but same vibe/noise is there.
Here is the kicker in my case. I just did a axle swap (complete) and the truck it came from did not have this sound. I am lifted another 1" than his however.
<scratching head> off to the drawing board and re-reading this thread from the beginning... again.
Im back in your same/similar boat. Although my old drive shaft was clearly broken/loose/damaged the new to me one exhibits the the same type of vibe. I've been driving my truck for the last 2weeks with front DS removed and CDL on with ZERO noise. Installed the new to me shaft (w/ used ujoints as well) and I have the symptoms back again.
It IS much more quiet with the new to me front drive shaft, but same vibe/noise is there.
Here is the kicker in my case. I just did a axle swap (complete) and the truck it came from did not have this sound. I am lifted another 1" than his however.
<scratching head> off to the drawing board and re-reading this thread from the beginning... again.
Overall length.
Check to make sure it doesn't look like this.
See the cleaner area on the outside of the slip yoke, that's how much further mine stretched (again, mine is like 2% of the lifted 80 s on mud)
Y'all checked the pinion angles yet?
Hoosier Daddy
SILVER Star
- Thread starter
- #33
UPDATE -
So, I installed a different (used) front driveshaft, no change.
The front diff flange has no play up/down, in/out, side to side. There is maybe 1/4 inch play rotationally back and forth. No leak.
With one wheel off the ground, I rotated the flange by hand and it felt as smooth as silk, with no coarseness or roughness.
With the driveshaft off, there is NO vibration on the Chassis Ears tool.
I drained the front diff and found this:
There was a third piece that was half the size of the other two, but it was not photographed. Not sure what kind of metal shavings are considered "normal".
This thread has strayed a bit to the topic of driveshaft angles and lift. However in my case the vibe did not occur until a year after the lift and CC bushings, and it was not affected by adding an ARB bumper or later adding 1 inch spacers.
What should I do next? I think I'll just run it for a while longer and see what it does. My perception is that it seems do be subtly worsening over time. Giving it more time will either disprove that perception or the problem will ultimately declare itself.
So, I installed a different (used) front driveshaft, no change.
The front diff flange has no play up/down, in/out, side to side. There is maybe 1/4 inch play rotationally back and forth. No leak.
With one wheel off the ground, I rotated the flange by hand and it felt as smooth as silk, with no coarseness or roughness.
With the driveshaft off, there is NO vibration on the Chassis Ears tool.
I drained the front diff and found this:
There was a third piece that was half the size of the other two, but it was not photographed. Not sure what kind of metal shavings are considered "normal".
This thread has strayed a bit to the topic of driveshaft angles and lift. However in my case the vibe did not occur until a year after the lift and CC bushings, and it was not affected by adding an ARB bumper or later adding 1 inch spacers.
What should I do next? I think I'll just run it for a while longer and see what it does. My perception is that it seems do be subtly worsening over time. Giving it more time will either disprove that perception or the problem will ultimately declare itself.
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Hmmm so my buddy has owned at least 5-7 80's over the past 10 years.... He's bought every one stock, and lifed each 4"... (he's sort of crazy).
Anyways, he lifts and always gets a custom front drive shaft made with a double cardan joint at the x-fer case side because there is always a vibe associated with the stock shaft after a lift.
You mention that the vibes were absent when you removed front DS, I believe it would go away with a custom drive shaft to accompany the increased angle.
I know the rumble you speak of, I think... I get it in the rear driveshaft when on the highway, and after i take off the accelerator and coast under no load. That is when I lube the u-joints and slip yolk and it goes away.
In my experience, I've noticed that most problems are solved with the easiest most direct answer, and to me, I think its the driveshaft.
Anyways, he lifts and always gets a custom front drive shaft made with a double cardan joint at the x-fer case side because there is always a vibe associated with the stock shaft after a lift.
You mention that the vibes were absent when you removed front DS, I believe it would go away with a custom drive shaft to accompany the increased angle.
I know the rumble you speak of, I think... I get it in the rear driveshaft when on the highway, and after i take off the accelerator and coast under no load. That is when I lube the u-joints and slip yolk and it goes away.
In my experience, I've noticed that most problems are solved with the easiest most direct answer, and to me, I think its the driveshaft.
Hoosier Daddy
SILVER Star
- Thread starter
- #35
Here's a long-awaited update with more info:
First, a quick re-cap of the high points...
Since the last update I got fed up and took it to Robbie (AKA PowderPig).
He found that 3 out of 4 of my Slee 3 degree caster bushings were busted and suspected that this could be allowing the pinion angle to change between accel and decel, and would explain the slowly worsening course of the problem.
Therefore I ordered Ironman adjustable bushings and installed them with the 2.5 degree setting, hoping things would be all fixed. No luck. In fact it may even be worse now.
Robbie also noticed that my pinion seal was leaking a little bit. I am 100% sure it had not been leaking before I drove from Colorado Springs to Boulder to see Robbie, doing 75-80 most of the way. It vibrated like heck all the way up there. The pinion has not leaked any more since I got home, so I suspect the vibration itself was causing some leakage around the seal during that trip.
Here's the biggest piece of new info and I think this may be the key...
I measured my pinion angle today and it was at 7 degrees upward. The driveshaft was at 6 degrees upward. The TC flange was at 3 degrees in the other direction. (See image below). So, that's a 1 degree joint angle at the pinion and 9 degree angle at the TC flange. I do not have caster numbers (either with the old Slee or the new Ironman bushings) but will probably get a caster sweep this week.
I'm thinking these angles would fully explain my vibration, right? However it doesn't explain why it took a year after the lift to start vibrating.
I wonder if I should change the caster bushings to the 3.5 degree setting and/or get a DC driveshaft?
First, a quick re-cap of the high points...
- Vibration/rumble in-between accel and decel, progressively worsening over time.
- The issue arose a YEAR after the lift and Slee caster bushings
- Only does it with the front driveshaft installed. Rear shaft makes no difference.
- New Toyota U-joints up front
- Front wheel/trunion bearings are new and properly torqued
- No crazy amount of play in the pinion or TC flange
- I borrowed a different stock front shaft and it did not help
- Slip-joint is tight and clean
- Mechanic's Ears were not much help in locating the noise
- I measure 22.5" and 23" from center of hub to flare up front with my current set-up, which I believe is a 2.5-3 inch lift.
Since the last update I got fed up and took it to Robbie (AKA PowderPig).
He found that 3 out of 4 of my Slee 3 degree caster bushings were busted and suspected that this could be allowing the pinion angle to change between accel and decel, and would explain the slowly worsening course of the problem.
Therefore I ordered Ironman adjustable bushings and installed them with the 2.5 degree setting, hoping things would be all fixed. No luck. In fact it may even be worse now.
Robbie also noticed that my pinion seal was leaking a little bit. I am 100% sure it had not been leaking before I drove from Colorado Springs to Boulder to see Robbie, doing 75-80 most of the way. It vibrated like heck all the way up there. The pinion has not leaked any more since I got home, so I suspect the vibration itself was causing some leakage around the seal during that trip.
Here's the biggest piece of new info and I think this may be the key...
I measured my pinion angle today and it was at 7 degrees upward. The driveshaft was at 6 degrees upward. The TC flange was at 3 degrees in the other direction. (See image below). So, that's a 1 degree joint angle at the pinion and 9 degree angle at the TC flange. I do not have caster numbers (either with the old Slee or the new Ironman bushings) but will probably get a caster sweep this week.
I'm thinking these angles would fully explain my vibration, right? However it doesn't explain why it took a year after the lift to start vibrating.
I wonder if I should change the caster bushings to the 3.5 degree setting and/or get a DC driveshaft?
Hoosier Daddy
SILVER Star
- Thread starter
- #37
Any other thoughts before I make a $500 gamble on a DC shaft?
It's not a gamble but what you need.
Don't take my word for it, though.
Contact Ben at Slee, Jessie at High Angle, or Josh at AJIK with your angles and get a professional opinion.
Then, it's not a gamble.
Hoosier Daddy
SILVER Star
- Thread starter
- #39
I went ahead and ordered the DC shaft. Will update this thread once I get it put on.
And for completeness' sake, I got my caster checked today. It was +2.3
And for completeness' sake, I got my caster checked today. It was +2.3
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I have the exact same noise. While floating the gas at highway speeds there is a grind/vibrate. Goes away when on or completly off the gas. And.......I bought a DC shaft and it really did nothing to the noise. maybe a tad quieter. I have OME J with landtank castor plates. I cant stand the noise. To me I would think pinion bearing but they are tight like the OP's. I can't wait to hear your outcome with the DC. I wish you luck. Its a big purchase to make for no gain. I did it and it hurt the bank for nothing.
