It would be advisable to determine exactly where the vibration is coming from. As set of chasis ears would allow you to do that and you wouldn't be chasing the vibration ghosts. It could also save you a bunch of money.
Help me diagnose a driveline vibration - Slinky 3" lift (1 Viewer)
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- Thread starter
- #102
Done this, actually. Running a stock shaft is a non starter - terrible grinding noises and rattling coming from the shaft when I am off the gas pedal.
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- #103
My vibration comes from the front drive shaft, for sure. If you read up the post, I have tried multiple drive shafts (DC, double DC, stock), leading arms, etc. Vibes come from the front shaft.
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- #104
Alright folks, gather round - it's story time!!
Seeing that I am out of options besides for lowering the truck altogether to a < 3" lift, I am trying to work with what I have to see if I can retain the lift I have now.
In an earlier post, I talked about adding weight to the front of the truck to lower it a bit and improve the diff/TC pinion angles.
So, I strapped 80lbs worth of salt bags to the front of the truck, and went driving around the neighborhood. The 80 lbs lowered the front end by about .5" (measured from bottom of flare to center of the wheel cap.
I didn't go into the spots where I could test all of the speed ranges because I was worried about the bags falling off, but I did go through one of the ranges (30-35mph) and felt a reduction in the severity of the vibration. I didn't get a great feel for the other part of the range where I get vibes (50-55mph) but may try it again this weekend.
So, I think my best bet at this point is to get a heavier bumper (I have always liked the ARB better than the slee), and have been planning to get a 2nd battery for some accessories. Between those two I may just add enough weight (80-100lbs) to help lower the front end just enough to address the vibes.
Literally feels like a "game of inches" at this point. I will still maintain that I should have stayed with my 4" slee lift and matching trailing arms - I did not have any vibes with that setup.
Seeing that I am out of options besides for lowering the truck altogether to a < 3" lift, I am trying to work with what I have to see if I can retain the lift I have now.
In an earlier post, I talked about adding weight to the front of the truck to lower it a bit and improve the diff/TC pinion angles.
So, I strapped 80lbs worth of salt bags to the front of the truck, and went driving around the neighborhood. The 80 lbs lowered the front end by about .5" (measured from bottom of flare to center of the wheel cap.
I didn't go into the spots where I could test all of the speed ranges because I was worried about the bags falling off, but I did go through one of the ranges (30-35mph) and felt a reduction in the severity of the vibration. I didn't get a great feel for the other part of the range where I get vibes (50-55mph) but may try it again this weekend.
So, I think my best bet at this point is to get a heavier bumper (I have always liked the ARB better than the slee), and have been planning to get a 2nd battery for some accessories. Between those two I may just add enough weight (80-100lbs) to help lower the front end just enough to address the vibes.
Literally feels like a "game of inches" at this point. I will still maintain that I should have stayed with my 4" slee lift and matching trailing arms - I did not have any vibes with that setup.
Road Apple
SILVER Star
Surprised that 1/2” made the difference!! Hope this puts an end to your problems. Been feeling your pain chasing down a solution. I applaud your tenacity. Thanks for sharing. I’m right behind you having just install a 3” Slinky lift, but haven’t test driven yet. Your info has been enlightening.
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Bludozer
SILVER Star
"Honey why do we need multiple batteries?"
"Uhh uhh I don't know my truck is vibrating sh-shut up!!"
"Uhh uhh I don't know my truck is vibrating sh-shut up!!"
I’m sure you’ve done this, but my suggestion with the spacers was to use the dual cardon. I think I screwed that up.
Definitely a game of inches and balance. I went from Dobinsons 3.5” 144VT back to OME850. It’s smooth as silk on the stock shaft and the truck fits in the garage. If I were to change springs, it would be to the 146VT. It would retain the nice geometry of the OEM springs, but allow the extended droop found on tapered springs.
Salt bags. Keep em on there. I’m partial to the look.
Definitely a game of inches and balance. I went from Dobinsons 3.5” 144VT back to OME850. It’s smooth as silk on the stock shaft and the truck fits in the garage. If I were to change springs, it would be to the 146VT. It would retain the nice geometry of the OEM springs, but allow the extended droop found on tapered springs.
Salt bags. Keep em on there. I’m partial to the look.
Nice work, until you step back and notice the stinkbug it caused.. gives you something else to chase after tho!
I too applaud your tenacity and am hopefull for you! I went through it as well, you can see my 5 page thread!
A couple things to mention:
I think he meant a single double cardan shaft, with the double cardan joint at the tc end. .....but the problem is not the front shaft itself, it is the angles it is working at....(@baldilocks nailed it in post 9).
Also maybe take these two measurements (should take 2 min) and post them up to help us:
DC-Shaft pinion check
I've had a few questions about vibrations and whether or not a DC shaft is the solution/problem. So I decided to post up how I evaluate the pinion angle to confirm if the pinion is aligned correctly for a DC shaft to operate without any vibrations. The technical aspect of this is that a DC...
forum.ih8mud.com
Compiling/comparing lift and caster data
The question has been raised over and over again: How do I fix my caster after installing "x" springs and having "y" lift? Well, how much lift do you actually have? How much weight do you carry around? What is the distance from center of wheel to fender? These are all questions that get asked...
forum.ih8mud.com
and finally, the ARB bumper I'm pretty sure is lighter than the Slee. adding more weight to the front is going to give you diminishing returns. Depending on what your measurements above yield, your best bet is to either
-swap to lower springs (not that expensive as you can sell yours) + single double cardan shaft + dvs arms. done.
or
-return to stock arms with stock bushings and landtank or slee 4" plates + single dc shaft. done.
Edit: keep the landtank longer rear lca, as they will only help keep the rear shaft happy.
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- Thread starter
- #110
Funny you say that. With the slinky kit and the hardware I have on the truck (slee bumper up front and 4x4 labs bumper in the back), without any gear in the truck, the front is a hair slighter than the rear. When loaded up with camping gear and all of my family's stuff, it's like reverse stinkbug where the front is about an inch higher. To a point where I actually was going to install a 10mm spacer in the back to raise it up slightly. So lowering the front end will actually help level it out. Here is a picture where you can see it when it's loaded - even though it's not on level ground you can see the rear is a lot lower than the front. It is way more pronounced when it's on level flat ground.
- Thread starter
- #111
I too applaud your tenacity and am hopefull for you! I went through it as well, you can see my 5 page thread!
A couple things to mention:
I think he meant a single double cardan shaft, with the double cardan joint at the tc end. .....but the problem is not the front shaft itself, it is the angles it is working at....(@baldilocks nailed it in post 9).
Also maybe take these two measurements (should take 2 min) and post them up to help us:
DC-Shaft pinion check
I've had a few questions about vibrations and whether or not a DC shaft is the solution/problem. So I decided to post up how I evaluate the pinion angle to confirm if the pinion is aligned correctly for a DC shaft to operate without any vibrations. The technical aspect of this is that a DC...
Compiling/comparing lift and caster data
The question has been raised over and over again: How do I fix my caster after installing "x" springs and having "y" lift? Well, how much lift do you actually have? How much weight do you carry around? What is the distance from center of wheel to fender? These are all questions that get asked...
and finally, the ARB bumper I'm pretty sure is lighter than the Slee. adding more weight to the front is going to give you diminishing returns. Depending on what your measurements above yield, your best bet is to either
-swap to lower springs (not that expensive as you can sell yours) + single double cardan shaft + dvs arms. done.
or
-return to stock arms with stock bushings and landtank or slee 4" plates + single dc shaft. done.
Edit: keep the landtank longer rear lca, as they will only help keep the rear shaft happy.
Thanks for the post, always appreciate input from folks who chased this before. Few points to clarify:
- I ran both a single DC shaft, and a double DC shaft - as in a DC joint on both ends of the shaft. A local shop made it for me, but didn't make me keep it since it didn't solve my issue. Also tried two types of single DC shafts, the slee one I am running now and my buddy's Landtank one.
- Everything I have read on these boards, the ARB bumper is about 50lbs heavier than the Slee. Unfortunately neither manufacturer posts the weighs on their sites, so I am going on what I have found on this site.
- Not a fan of correction plates because they essentially do the same thing as arms without pushing the front wheel back closer to factory position, and require you to cut up the front axle. I have a brand new axle housing I installed last year that I am not going to chop up for something I may have to swap out in the future. Plus there is no guarantee that they will work since they will also affect the angles and may not get it right.
- Definitely thought about getting lower springs, but would have to get shocks as well since the slinky kit is matched springs and shocks. So this is still an option.
I think he meant a single double cardan shaft, with the double cardan joint at the tc end. .....but the problem is not the front shaft itself, it is the angles it is working at....(@baldilocks nailed it in post 9)
Also maybe take these two measurements (should take 2 min) and post them up to help us:
DC-Shaft pinion check
I've had a few questions about vibrations and whether or not a DC shaft is the solution/problem. So I decided to post up how I evaluate the pinion angle to confirm if the pinion is aligned correctly for a DC shaft to operate without any vibrations. The technical aspect of this is that a DC...
forum.ih8mud.com
Compiling/comparing lift and caster data
The question has been raised over and over again: How do I fix my caster after installing "x" springs and having "y" lift? Well, how much lift do you actually have? How much weight do you carry around? What is the distance from center of wheel to fender? These are all questions that get asked...
forum.ih8mud.com
roger. sounds like a plan. Plus a new bumper and dual battery!
But man, I had the ARB, and there is not much to it. My arm scales weighed the ARB only slightly heavier that then stock bumper I took off.
anyway, good luck and keep us updated. Always good to see how members solve these issues.
Are you absolutely sure it isn't the bearing in the nose of the transfer case. I thought I was having drive shaft issues and it wound up being the bearing in the rear nose of the transfer case. We changed it out and the problem was solved. Only found it with chassy ears.
I'll echo @Surfdc in echoing @baldilocks ... before you invest in anything else, just check your pinion angle and post a photo over here. I'd also want to make sure there are no other contributing factors, like the T-case bearing mentioned above.
(I'm sure you listed it... but what is your fender to hub measurement?)
If it turns out that nothing else can be done, you can cut 1 dead coil from your front springs and reinstall to reduce your front height. I would do this as a last resort rather than swapping in new springs or shocks. Even with a dead coil missing, the Slinky setup will have a taller free height than the OMEs. (which only matters if you actually need the "long travel" style flex of a tapered dual rate spring)
(I'm sure you listed it... but what is your fender to hub measurement?)
If it turns out that nothing else can be done, you can cut 1 dead coil from your front springs and reinstall to reduce your front height. I would do this as a last resort rather than swapping in new springs or shocks. Even with a dead coil missing, the Slinky setup will have a taller free height than the OMEs. (which only matters if you actually need the "long travel" style flex of a tapered dual rate spring)
Box Rocket
SILVER Star
Few thoughts from me (peanut gallery) in response to this post....
Caster plates. Yes, there's no guarantee they would fix your specific problem. But, they do effectively correct/change caster and are the least expensive way of doing it. The low cost alone makes it worth attempting IMO. If they didn't help or you don't want them as a final solution, they could easily be sold. You're not wrong that aftermarket arms also correct/change caster so I get your point there. My only argument for the plates is because of the significant difference in cost between the plates and arms.
I don't think caster plates are as invasive as you think. The cutting required is literally a small piece from the radius arm bracket that is maybe .5" x 1" and it doesn't have any permanent or irreversible affect. Any radius arm, stock or otherwise, can still be used with or without the caster plates (although I don't recommend combining the two). The plates also don't "require" welding them to the axle. I know most plates recommend that, but it's for redundant safety if the plates are a long term solution. I ran a set of Slee plates that were never welded to the bracket for several years. If they are welded, it's only a very short weld that is easily removed/reversed if you need to remove the plates.
**For the record, I'm not trying to convince you that caster plates are a better solution than a set of good aftermarket radius arms. I'm just describing how they can be another way to inexpensively try something that changes the variables slightly to see if there is any improvement. The difference between arms and plates may be very minor but as you said, you're down to a game of inches at this point, so a small change might make all the difference.
If you were to get lower springs, which would be an option, you would NOT need to change shocks. You're using the 75mm Slinky coils and they have 50mm (2") coils too and the same shocks are used in combination with both shocks.
If you find that your solution is to just add weight to the front, an ARB bumper will add a little compared to the Slee bumper, as will a second battery. I don't remember what your winch setup is, but you could also use a steel winch cable instead of a synthetic winch rope to add a little weight as well.
I still am scratching my head as to why you are having such a difficult time with this issue. From the beginning this has been a very odd and uncommon issue as it relates to the Slinky suspension. There are literally hundreds out there running the exact same suspension you have that do not have this issue. It makes it all the more strange. I wish you were closer and we could compare and measure all the different components between our two trucks and figure out what differences there may be.
I am having this exact problem on my 80 but with a 4" Dobinsons Lift and caster plates. Almost a "grinding" sound when I let off the gas and it gets slightly better when I am on the gas. Stock driveshaft up front with new joints and a Tattons double cardan in the rear. Completely goes away when I remove front DS. But then I am left with a slight vibration from rear but no grinding! Had a 2.5 OME lift before the Dobinsons and never had any vibration or noise with that setup.
You need a DC shaft up front and if you get a vibration from the rear, either the shaft is worn somewhere, it’s not balance, or the pinion is out of position.
Have you measured hub to fender so you know what actual lift is? Your plates are from Dobinson as well as the springs?
If you rebuilding the rear you might as well fix the pinion angle with upper rear arms or you will be rebuilding the rear soon again. It’s just as important as far as I’m concerned unless you have a loud sound system and believe your driveline issues are fixed with caster plates and the front dc. The rear is cheaper to tackle and more options out there.
All most all the after market spring are designed around a built Reg ( Armor, winch,dual batteries , roof rack, roof top tents etc etc ) so with out all of that you are going to get more lift then advertised.
Across the board people have reported that they are get more lift from Dobinsons springs even built out with all that hardware. I am running a 2.5 dobinson front springs and I am getting 31/4" of lift fully built out.
Basically each Reg is going to achieve a different lift with the same springs base on weight.
Not sure why one would run a DC shaft in rear these Regs
Across the board people have reported that they are get more lift from Dobinsons springs even built out with all that hardware. I am running a 2.5 dobinson front springs and I am getting 31/4" of lift fully built out.
Basically each Reg is going to achieve a different lift with the same springs base on weight.
Not sure why one would run a DC shaft in rear these Regs
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