Bouncing/Vibration at 45mph

[rrb6699]

originally I found my drivers side left tire belt seperating. I replaced both front tires thinking that had to be the cause.
of course the ride is better now, but, at 45mph I still have a bouncing. my new tires were balanced so that shouldn't be an issue. I replaced the passenger side inner and outer bearings, but not driver side yet.
it feels like the front end is bouncing. after 45 it stops and below 45 there's no noticeable bounce. I haven't been to any higher speeds over 60 to see if the bounce vibrates at any other speed. I'll do that soon.
any ideas? the bearings are easy enough to replace so planned on doing that anyway.
thanks in advance for ideas.

 

[dodge dude94]

Good luck. I never was able to find mine after 8 years.

 

[Nick_rp]

not a suspension guru but as far as i know bouncing is mostly associated with bad/failing dampeners

quick check to determine

"Standing in front of your vehicle and apply pressure to the sides of the car, where the wheels are located. When you apply this pressure in a downward motion, there should be only minimal movement in your car. If you detect too much movement, it is a sign of weak struts/ shocks."

Method sourced from google

 

[rrb6699]

ok assuming I find this to be an issue, I still need to find the source of the vibration. fortunately, a few things I'm gonna do are cheap and I was going to do them anyway.
is there an adjustment for camber & caster? I aligned the wheels, but, only the adjusters. no pull in the steering now at least. (it's what I did on my 2nd Gen today, lol)
I do notice a slight lunging when I brake. I know the rotors are not warped. new beake pads as well.

thx,

rr

 

[Nick_rp]

did a quick search on bad shocks/struts and found these symptoms

• Badly cupped tires and/or noticeable tire shaking, wheel shimmy or vibration after hitting a bump.
• Suspension bottoming on rough roads or when backing out of a driveway.
• A bouncy ride.
• Body sway or rocking when cornering or driving in strong crosswinds.
• Nose dive when braking hard.
• Fluid leaking from a strut or shock.

 

[rrb6699]

thanks for that info. I'll have to look to see how these parts in being worn cause vibrations. I can't Envision it in my mind right now. Would these worn Parts have play in them? Would that cause this symptom?

 

[Nick_rp]

also check this link
https://www.ericthecarguy.com/faq/d...ignment-loose-suspension-parts-and-vibrations
i subbed to his YT channel like 6 years ago, he can be very informative

i dont have enough experience to give advice on brands. hopefully someone can answer that for you

 

[rrb6699]

thanks. I am familiar with his Vids. your link did not work though.

 

[Nick_rp]

weird worked for me just now, maybe you have to make an account on his web page

if not ill write a quick "file path"

ericthecarguy.com-
Troubleshooting FAQ-
determining the causes of vehicle vibrations-
Wheel Alignment, Loose Suspension Parts, and Vibrations

heres the gist of it:

"It's a common misconception that a wheel misalignment or loose suspension parts can cause a vibration. This is false. Your vehicle’s alignment is the angle at which the wheels hit the road. It's not really possible for these angles to cause a vibration. If the alignment is way out, your tires will wear badly. This tire wear can get bad enough to make a vibration begin to develop, but understand that it's the tire that's causing the vibration at that point, not the alignment.

Loose suspension parts are another frequent suspect. People sometimes ask me if they have a loose ball joint or some other component causing the vibration they're feeling. The answer is always, "Loose suspension parts can aggravate a vibration, but they are not the cause of the vibration." Remember, vibrations are caused by rotating assembles, not necessarily loose parts. In fact, when a wheel is up to speed it acts like a gyroscope. This means that even with loose suspension parts, at speed, you may not notice the loose parts at all. Vibrations can actually create loose parts, sure, but that misses the point. Vibrations are almost always the result of something spinning that's out of balance. This imbalance is what causes the vibration. I've seen vehicles with very loose suspension parts drive smooth as glass down the road. I've also seen one wheel weight come off a wheel and it felt like the front end was about to fall apart.

The moral of the story is that you should put loose suspension parts and alignment at the very bottom of the list of things to check when dealing with a highway-speed vibration. They are very rarely, if ever, the cause of such things. Just to be thorough, I’m going to post a video here on how to inspect your suspension."

Source- ericthecarguy.com

theres 11 other sub topics on vibrations too

 

[dodge dude94]

Been through 2 sets of shocks my self all the way around, 4 up front. Same thing. lol
Seen guys go entirely through their suspension and ball joints only to have it not be fixed. My solution is just drive above 45. lmao

 

[rrb6699]

it's funny that's the only speed 40+ to 45 (particularly 45) is the most noticeable vibration. I checked lugs, made sure rotors were set properly and regreased, and packed bearings on the right wheel. I have yet to do the left since I recvd the wrong outer bearing. once I get that I'll go through it down to the spindle and lube everything after cleaning.
if I could figure out the rotor rpns at 45 mph, I could spin it just to notice any imbalance.
the truck 5.2l 2wd has 275k miles on it. I expect wear. my guess is the driver side bearing (probably inner) may be the culprit. looks like my bearing set will arrive Thursday so if rain, Friday I can do it.

I haven't checked, but are there inner/outer bearings on the rear of these trucks? RockAuto didn't list any.

speaking of drive train, I'll get to asking about the amount of whine I hear when driving. should I change differential fluid? probably never been serviced. if so, how much would jiffy libe charge or should I diy that one too?


tia

 

[Nick_rp]

275k yea id expect some issues. i looked at your post history and saw there is front end damage, are those the same wheels it had on when it happened? rims could be bent, suspension components bents, etc etc. after you get those bearings replaced get a professional alignment from a shop, and maybe even get the tires balanced again from a different shop as ask them to look for rim warping.

after that is when you start looking at the rest of the suspension

 

[gofishn]

Death Wobble?

 

[rrb6699]

not that bad. lol

 

[dodge dude94]

Death wobble only affects 4x4. It appears the OP has a 2WD.

 

[rrb6699]

I'm mostly worried about tire wear. I think shocks are a good idea, but, it doesn't solve the cause of the problem only masks it.

rr

 

[dodge dude94]

I haven't noticed any abnormal tire wear other than the trademark 4x4 tire chop.

 

[Nick_rp]

just read a post in a forum about mystery bouncing and thought of this thread. 90% of the suspension was replaced, tried multiple sets of balanced wheels and tires and in the end it was the rotors. a little more digging and its very possible to have rotors/drums so unbalanced it creates vibrations/hopping but braking to feel absolutely fine.

i said before, im not a suspension guru, but i do like having more affordable/maint friendly options to troubleshoot first, like rotors, before digging into drive line, u-joints etc

something else to look at anyway, hope it helps

 

[Yeret]

Does your "wobble" start just after overdrive engages? Have you tried driving your truck with the overdrive turned off?

Years back when my intake plenum was leaking, anytime my overdrive engaged, the truck would start shaking so bad that I swear it would fall apart. However, disengaging the overdrive eliminated the problem until I had the actual problem (leaking intake plenum) fixed.

I have a theory as to why this may be but I'm afraid it would end up being a TL;DR post, not to mention I've got a bit of Beam in me so it would probably take a year to type it up and proofread to ensure that I don't digress. Bottom line is verify that your plenum isn't leaking and the truck has a fresh set of plugs/wires/cap/rotor. Barring that, things open up quite a bit...

 

[rrb6699]

yes all rotor plugs, cap, are new. complete check of wiring harness done. I did have a broken (hanging by a strand) crank sensor.

the wobble only occurs at 42-45mph approx. if I speed thru that range I don't feel it. I will try the OD off setting. my simple take on that is the electronic tyranny could shift into overdrive when it does not need to. It could be an effect like driving a manual transmission in 5th gear at 20mph. it shakes except an auto would shake differently but shake.

I notice when it shifts into OD it does not stay in the previous gear long at all.

on the other hand,, I don't think it is in OD every time it shakes. I don't have any leaks other than my tranny dipstick does not have a grommet on it and it loses some fluid. I have to fix it . I just check it every 100 miles or so to see if it's low.

I checked my alignment today and it does seem slightly off due to some potholes I hit. So I'm going to realign the truck as I have new tires on the front now.

I still have yet to repack and or replace my driver side front inner and outer wheel bearings. Perhaps that is the cause.

I'll update soon. feel free to reply anyone.

rr