Help me diagnose a driveline vibration - Slinky 3" lift

[desmocruiser]

There is lots of great advice here, it is hard to listen to all.

The best direction is to follow some of the 80 series experience, Landtank etc. and go back to the point of a typical vibe free set up and restart the process or as Rick recommended a simple set up, 3.5” and caster plate set up.

My thoughts are you have changed so much both front and rear it is not clear which Created the change in vibration and which of these driveline mods are even helpful and it appears they are several that. Aren’t working well Together, always remember, less Is usually more!

 

[Box Rocket]

Fair enough - and agreed it's probably not the real issue here. It is the exact same lift my buddy has, with the exact same accessories in the front of the truck -we have the same bumpers, siders, etc. The only difference is he has an extra battery in the front, and I don't. Can't imagine the weight of the batter would throw off my angles.



The difference on the rear DS pinion flanges is .4*. I can probably get it down even lower, but cannot imagine this is the problem. The rear DS was recently serviced with brand new U joints, greased, and rebalanced. The rear used to vibrate separately (with or without the front DS installed) until I installed the longer Landtank LCAs, and then further adjusted the top UCAs to get it down to .4*. There is absolutely zero vibrations coming from the back now when there is no front DS installed.



I sold the slee arms. The vibration was just as bad with them as it is with the Delta arms, so swapping them didn't really make a difference. Along with the other parts I installed, I put in a brand new front axle housing - my old one was bent, which I could tell by the alignment camber reading, and the truck pulled pretty hard to the right. I really do not want to hack up the brand new axle housing to test a theory. My buddy is going to find his factory radius arms with the OME caster correction bushings, that is the closest I am going to get to restore it to "close to factory".



I swapped the tires front to back and side to side in the past. It didn't change anything. I was going to install smaller tires from my Tundra this weekend, but since the vibration only happens with a front DS installed, I figured it would be a waste of time. Plus I spent the better part of my Saturday installing/reinstalling various combinations of the two front driveshafts and the rear drive shaft to see what is causing vibes and when.

I think the next two things I want to try are wiggling the cross member like some of the others in the thread have suggested, and trying to lower the TC/transmission by 1/4" with a spacer like Darren suggested.

The only concern I have with the 1/4" spacer method is whether it will affect/damage the shift linkage to the transmission and the transfer case shifter. But sounds like a couple folks have dropped theirs by 1/4" and are not having issues.

No reason to "hack up" a new axle housing. Putting is some factory radius arms, with or without caster bushings, will be an interesting comparison to see if it changes anything.

With the tires, have you verified they are balanced properly? If they are not balanced, swapping them side to side, or front to back won't matter. Not trying to talk down to you at all. I know you've tried a lot of different things to try to find the cause. I'm making suggestions in an effort to help as well. Good luck.

 

[landtank]

Do you know what event bent the axle? If you found this after buying the truck it might indicate an accident and possible bent frame. I worked with a guy and we found just this. The repair was done by relocating the front radius arm frame bracket. We found this by using a tape measure and measuring the distance between the front and rear bolts in those brackets.

And I wasn’t advocating to install caster plates, just the arms and stock driveshaft as a check as i wouldn’t expect it to vibrate.

 

[digitalmarker]

No reason to "hack up" a new axle housing. Putting is some factory radius arms, with or without caster bushings, will be an interesting comparison to see if it changes anything.

With the tires, have you verified they are balanced properly? If they are not balanced, swapping them side to side, or front to back won't matter. Not trying to talk down to you at all. I know you've tried a lot of different things to try to find the cause. I'm making suggestions in an effort to help as well. Good luck.

Adam, I know you're trying to help man and I really appreciate it. Also appreciate your guidance on my Facebook thread. I don't think you're talking down to me at all. To be honest this is how I am feeling about this whole thing haha.

This is a really odd issue for sure and it feels like it's unique to MY truck.

I really don't think it's the tires because a) the symptoms get worse/better with the same tires and different drive shafts. The symptoms go away entirely when there is no front DS in place. I would imagine if tires were causing this, the vibration would be happening at the same speed regardless of whether a front DS was in place or not. That has been my experience with all tire related issues in the past on other cars/trucks.

But It is something I am going to try if time allows this weekend - swapping a different set of wheels/tires from my Tundra.

 

[digitalmarker]

Do you know what event bent the axle? If you found this after buying the truck it might indicate an accident and possible bent frame. I worked with a guy and we found just this. The repair was done by relocating the front radius arm frame bracket. We found this by using a tape measure and measuring the distance between the front and rear bolts in those brackets.

And I wasn’t advocating to install caster plates, just the arms and stock driveshaft as a check as i wouldn’t expect it to vibrate.

No idea, bought the truck this way. The pull got a lot worse when I increased the lift, and I realized the camber was off when I took it in to get aligned after the lift. The pull is gone now that a new axle housing is installed, so I am almost certain there is no frame damage. But given all the s*** I've found and have had to fix/replace from the PO, I wouldn't be the least bit surprised.

 

[Box Rocket]

Adam, I know you're trying to help man and I really appreciate it. Also appreciate your guidance on my Facebook thread. I don't think you're talking down to me at all. To be honest this is how I am feeling about this whole thing haha.

View attachment 2337493

This is a really odd issue for sure and it feels like it's unique to MY truck.

I really don't think it's the tires because a) the symptoms get worse/better with the same tires and different drive shafts. The symptoms go away entirely when there is no front DS in place. I would imagine if tires were causing this, the vibration would be happening at the same speed regardless of whether a front DS was in place or not. That has been my experience with all tire related issues in the past on other cars/trucks.

But It is something I am going to try if time allows this weekend - swapping a different set of wheels/tires from my Tundra.

isn't your Tundra 5-lug?

 

[digitalmarker]

isn't your Tundra 5-lug?

It's a 2004 Limited, has 6 lugs. I believe they are the same measurements as other 6 lug Toyotas.

 

[digitalmarker]

Cautiously optimistic update:

This last weekend I installed my buddy’s stock front driveshaft (no CV/double cardan) and the 35-45mph pulsating vibration went away completely!

I now feel a very slight vibe at low speeds like around 10mph but suspect it might be the MT tires.

I am also now getting a metal sound coming from the front DS at high speeds (65-70mph) when I am off the gas. It doesn’t happen consistently but it does happen.

Not sure if other folks in this thread experienced this - I hope it’s not something long term damaging.

Other than that I am happy the pulsating vibrations are gone, and am stumped as to why it took a factory shaft to solve the problem... but definitely not complaining!

 

[Heckraiser]

Glad you finally found it!

In my case, grinding noise when you let off the gas was a worn slip yoke. Definitely not going to hurt anything in the short term (I let it get worse and worse for years), but the only cure is a new shaft or verified good used shaft.

 

[Box Rocket]

Cautiously optimistic update:

This last weekend I installed my buddy’s stock front driveshaft (no CV/double cardan) and the 35-45mph pulsating vibration went away completely!

I now feel a very slight vibe at low speeds like around 10mph but suspect it might be the MT tires.

I am also now getting a metal sound coming from the front DS at high speeds (65-70mph) when I am off the gas. It doesn’t happen consistently but it does happen.

Not sure if other folks in this thread experienced this - I hope it’s not something long term damaging.

Other than that I am happy the pulsating vibrations are gone, and am stumped as to why it took a factory shaft to solve the problem... but definitely not complaining!

Out of curiosity, what kind of driveshaft did you try before that was using single ujoints like the stock shaft? Did it have Spicer ujoints, or other aftermarket joints? Just curious what the differences were with that one and the STOCK driveshaft you put in.

 

[tacocat]

In speaking to @NLXTACY, he said noises generated from letting off the gas is a symptom of the need for a CV, but you’ve done that.

OP, take a pic of what the current front drive shaft looks like.

Thanks

Glad you finally found it!

In my case, grinding noise when you let off the gas was a worn slip yoke. Definitely not going to hurt anything in the short term (I let it get worse and worse for years), but the only cure is a new shaft or verified good used shaft.

 

[Box Rocket]

In speaking to @NLXTACY, he said noises generated from letting off the gas is a symptom of the need for a CV, but you’ve done that.

OP, take a pic of what the current front drive shaft looks like.

Thanks

From my experience it been more commonly an issue with the slip yoke. Needing a DC driveshaft can also cause it I'm sure. But I've been in trucks, including my own, with brand new front DC driveshaft and have had those noises on decel. A few of those were used driveshafts, but had been built with new OEM ujoints/DC joint. There was slop in the slip yokes that caused the noise. Quieted down with a little grease on the splines.

In my own truck even with a brand new (stem to stern) DC driveshaft using OEM parts the deceleration noise has been present. I've chased just about every possibility including spindle bearings, pinion bearings, ring and pinions, all without success. It hasn't been serious enough to cause me too much concern, mostly just a bit annoying since it only happens on decel when coasting and there is no load (throttle or slowing down) on the driveshaft and that is a very brief amount of time. My current theory is that the noise is from a worn output bearing in the transfer case. I hope to check that theory soon. I have a spare tcase that I'm planning to build with reduction gears and will use all new bearings when I build it. Will be curious to see if it eliminates the noise. If so, it would appear to confirm my theory.

 

[tacocat]

From my experience it been more commonly an issue with the slip yoke. Needing a DC driveshaft can also cause it I'm sure. But I've been in trucks, including my own, with brand new front DC driveshaft and have had those noises on decel. A few of those were used driveshafts, but had been built with new OEM ujoints/DC joint. There was slop in the slip yokes that caused the noise. Quieted down with a little grease on the splines.

In my own truck even with a brand new (stem to stern) DC driveshaft using OEM parts the deceleration noise has been present. I've chased just about every possibility including spindle bearings, pinion bearings, ring and pinions, all without success. It hasn't been serious enough to cause me too much concern, mostly just a bit annoying since it only happens on decel when coasting and there is no load (throttle or slowing down) on the driveshaft and that is a very brief amount of time. My current theory is that the noise is from a worn output bearing in the transfer case. I hope to check that theory soon. I have a spare tcase that I'm planning to build with reduction gears and will use all new bearings when I build it. Will be curious to see if it eliminates the noise. If so, it would appear to confirm my theory.

I'm the exact opposite. I have a slight noise between 70 and 75. It's dead silent on decel. My slip yokes are tight, and look like they are new.

I'm wondering if a DC would create noise on the decel. It's very, very slight and can only hear it if I turn off the radio, but I know it's there. It annoys me too, as I'm OCD on all things mechanical. It will be interesting to see what happens when you make the change. That said, almost every bearing I've pulled off my rig looks like there has been no wear.

I'm considering deleting the ABS, and running a part time kit, but the brakes function fine.

OP, are you running that stock shaft out of phase, and are the u-joints relatively new?

 

[digitalmarker]

I'm the exact opposite. I have a slight noise between 70 and 75. It's dead silent on decel. My slip yokes are tight, and look like they are new.

I'm wondering if a DC would create noise on the decel. It's very, very slight and can only hear it if I turn off the radio, but I know it's there. It annoys me too, as I'm OCD on all things mechanical. It will be interesting to see what happens when you make the change. That said, almost every bearing I've pulled off my rig looks like there has been no wear.

I'm considering deleting the ABS, and running a part time kit, but the brakes function fine.

OP, are you running that stock shaft out of phase, and are the u-joints relatively new?

The stock DS I am running now is out of phase - that's the way it came out of my buddy's truck, so I didn't mess with it.

My buddy replace all U-joints with brand new OEM units about 1000 miles before he pulled the DS and replaced it with a DC one from Landtank.

I drove the truck around some more this weekend, there is still some mild vibration around 40mph, but still a lot less of it than what I had with three different DC shafts.

The metal sound on deceleration is still there as well, especially at high speed above 65mph.

The rest of the time it is pretty smooth and quiet.

Not ideal obviously but still probably better than what was happening before with a single CV and double CV shafts I had.

 

[Marco Lau]

i have a 4 " lift as well, stock driveshafts, zero vibration at all speed...must be your tires..

 

[digitalmarker]

i have a 4 " lift as well, stock driveshafts, zero vibration at all speed...must be your tires..

What happens when you’re at high speed, 65-70, and you let off the gas?

 

[Marco Lau]

What happens when you’re at high speed, 65-70, and you let off the gas?

Nothing..no nose, no vib.

 

[digitalmarker]

So since I am sure all of you are losing sleep at night waiting for an update on my endless saga, here it is.

Since my last update, I drove around for a few weeks with the Delta 4" arms and the factory drive shaft. The noise I was getting from the driveline was too much - rattling, metal grinding noise, especially pronounced at high speeds. It sounded like the transfer case or the driveshaft itself were going to blow up.

My buddy let me borrow a set of factory radius arms with OME caster correction yellow bushings that he wasn't using. Since I was completely out of options, this was the next logical thing to try. I re-installed the Slee DC driveshaft at the same time time and replaced the factory DS.

Voila, the violent vibration 30-45mph I was getting with a DC shaft, and the rattling/grinding noises I was getting with the factory DS were gone completely!

In fact, the whole driveline felt smoother/freer, truck felt faster off the line, and felt a lot better driving it at high speed - as if the driveline binding was reduced/eliminated.

One thing I noticed immediately is that the angle of the front diff pinion was altered significantly - it was visibly pointed up much more aggressively toward the transfer case flange. I re-measured the angles and got the following:

• With delta arms, pinion was 6.5*, and driveshaft angle was 10.5* (operating angle difference of 4*)
• With the factory arms and OME bushings, pinion is now 11* and driveshaft is 8* (operating angle difference of 3*)

Not only did the operating angle improve by 1*, it seems that the biggest difference is in the angle of the front diff pinion which went from 6.5* to 11*.

My buddy warned me that the handling is going to suffer, especially at high speeds. I put 500 miles on the truck so far, including a long road trip this weekend. It definitely doesn't feel quite as solid as it did with the Delta or Slee radius arms, but didn't feel like as twitchy and jumpy as some folks have described. Perhaps the Delta rear panhard bracket helps stabilize the handling at high speeds significantly as well, which is what my buddy guessed.

So, at this point I guess I am going with the factory arms/OME bushings combo.

I heard from a couple of sources that Slinky/Blackhawk has developed a set of radius arms designed specifically for the 3" Slinky springs. I am waiting to hear what the front pinion angle looks like with those before upgrading, because at least in my case it seems to be the most important factor in addressing the vibrations.

 

[baldilocks]

Your castor is at minimum, if that. I think I said something like this before. Mine ran smoothly in AWD mode with Slee plates, stock arms and 3”, 4” and even 5” lift Wasn’t terrible but my castor was less than one degree positive. At your lift height, if she runs smoothly, with any type of drive shaft, the castor angle is not optimal. That’s just how it is unless you cut the knuckle balls loose and clock them to achieve agreat angular distance between the pinion and a line drawn down through the trunion bearings. Basically, you solved one problem but created another.

I thought my rig handled acceptably with .5* of castor angle but then I installed Delta arms, which put castor angle at the upper limit of stock spec and was surprised at the difference a few degrees can make.

Glad to here you driveline vibes are gone though.

 

[rcracin]

I'm installing a Slinky 70mm setup in a few weeks and was thinking to order the Delta radius arms. Did you determine that the Delta radius arms OVER corrected your caster introducing too much positive caster and thus causing your vibrations through a bad driveshaft angle?

@Lumpskie is running Slinky 70mm and corrected his caster via Landtank plates and a Superior Flex arm. I don't believe he has any vibration issues.