2nd Gen Non-Engine/Transmission Thump in R/F is back !%&*#!

[Joe Mc]

I've been trying to figure this one out (sorry to admit) since shortly after I bought it some 65k miles ago. A constant thumping under the right floorboard and bouncing as speed increases. I've replaced wheels, tires, spent countless $ on different methods of balancing (road force etc) all to no avail. Then one day not too long ago I thought I found the nuisance. By taking a small pry bar and placing between the lower R/F shock doughnut and spring I was able to wiggle the whole shock base. Tried the left front to see if it was the same - it was snug and unable to be moved. I took a breaker bar & tightened the p*ss out of the R/F lower shock bolt and took it for a ride. No more thump Oo. Yes! I got new bottom bolts for both sides, purchased 4 Bilsteins and thought all was well especially when I found a loose top shock bolt on the R/L. And all was well . . . at least until the weekend before last when the thump was once again noticed during a short trip to Englishtown, NJ to the FAST drags :{ . The most frightening part of the trip was my wife's comment "I don't know why you put so much $$$ into this piece of *^@# it rides horrible" and then "if it wasn't for that thumping it would actually be a nice truck". Words that rang all too true. The thumping is only noticeable at speeds around 60 or above. It's very similar to a balancing issue as it almost disappears under 40 mph - however since I've fought this fight before and ended up rather pleased with dynabeads doing the constant balancing, and have new shocks and tires and wheels - I'm 99% certain it's not in the balancing. However it's in the rotating mass (I think) and is definitely narrowed down to coming from the R/F.



I've re-checked everything I can think of: both front bottom & top shock bolts are tight, I've re-torqued the (newly installed with the shocks) leveling spacers, checked R/H ball joints (less than 3k miles since new), track bar joints, sway bar joints, alignment was done after ball joints, everything under the front on both sides is tight. I'm very frustrated #@$%!, at wits end and almost ready to put a brick on the go pedal, point her towards a cliff and drop her into gear



Someone please help before the men in the white coats come to take me away, hee, hee, haw, haw to the funny farm where life is beautiful all the time and all Dodge trucks run wonderfully fine, hee, hee, haw, haw . . . .

 

[Steve St.Laurent]

When you installed your shocks did you install a steel sleeve in the bushing? Many shocks you have to reuse the sleeve out of your stock shocks (if they don't include them) and I've seen a lot of people neglect to put one in. When you do that there is a lot of play in the bushing to bolt connection and can cause a thump just like that. The other thing I have seen is the track bar causing that. Have your wife get in the truck and turn the wheel lock to lock back and forth and lay in front of the truck and watch the front end. I had a worn track bar that I couldn't sense any play in the track bar but when I did this you could see the whole front end "pop" left to right (the pop was on the right front btw).

 

[Joe Mc]

Yes the new shocks came with the steel sleeve. I'll give the track bar a try. It's a Lifetime Moog so if it's bad I'll swap it out. I guess if the bushing in the track bar (axel end) was bad it could produce what I'm experiencing? At this point anything is possible / worth giving a try. Thanks Steve.



Any one else have another idea?

 

[THUREN]

One more thing to try... .



I HATE how Dodge uses SUPER coarse thread bolts. It really makes you have less clamp force for the torque compared to fine thread bolts... The lower shock and track bar axle bolts are 14mm which can be swapped out to 9/16" grade 8 FINE THREAD bolts which really helps clamp things down...





Don Thuren. .

 

[Mhannink]

following your rotating mass idea might think about it being wheel bearings not saying it is just food for thought

 

[Joe Mc]

following your rotating mass idea might think about it being wheel bearings not saying it is just food for thought

OK let me show my 4X4 front end ignorance - How to check wheel bearing I have Dodge Shop Manual - haven't looked in it yet for this - can anyone give an idea. I found the bad ball joint by the tried & true "bar placed under front wheel while raised and hold top of tire while lifting the bar" method. Same way to check wheel bearing? Or is it more of a "take things apart to see" ordeal?

 

[DNewell]

When you installed your shocks did you install a steel sleeve in the bushing? Many shocks you have to reuse the sleeve out of your stock shocks (if they don't include them) and I've seen a lot of people neglect to put one in. When you do that there is a lot of play in the bushing to bolt connection and can cause a thump just like that. The other thing I have seen is the track bar causing that. Have your wife get in the truck and turn the wheel lock to lock back and forth and lay in front of the truck and watch the front end. I had a worn track bar that I couldn't sense any play in the track bar but when I did this you could see the whole front end "pop" left to right (the pop was on the right front btw).

Just make sure that she doesn't pop it into gear and then sell the truck! Do you beat on the truck(4x'ing and all), as this may be signs of a bent axle. I'm just making stuff up as I'm not an ASE certified mechanic. Just do the brick thing in worst case scenario and claim it was an act of god.

 

[JesseJ]

I have the same problem! There has been a thump felt/heard in the pass. floor since I bought my truck 70k ago. My axle shaft seals were leaking and I had cracked rotors so I went through the whole front axle. Seals, axle U-joints, hub/rotor assys. , upper & lower ball joints, track bar, shocks, tires, calipers, pads, EVERYTHING! Unfortunately, that really annoying noise is still there. Like you, I have tried everything and it hasn't gone away so I have resorted to the tried and true method of turning up the radio. The loud exhaust and turbo whistle has helped too, and I told my wife to consider it a foot massager. However, if anyone has the fix, I would love to hear it!

 

[Joe Mc]

Just make sure that she doesn't pop it into gear and then sell the truck! Do you beat on the truck(4x'ing and all), as this may be signs of a bent axle. I'm just making stuff up as I'm not an ASE certified mechanic. Just do the brick thing in worst case scenario and claim it was an act of god.

:-laf I like it! thanks. As far as the beating it - I rarely go off road and when I do it's very gingerly as it's a heavy stock suspended truck - not my ol little Toyota thrasher. And, your point on a bent axel is a good one as the truck was in a right front hit prior to me owning it. I only realized this as it had non-stock ball joints w/zerk fittings on the right side and new caliper & rotor (singular). In addition it was panel painted where damage was repaired. I think the brunt of the hit was r/f wheel as I had one of the stock "potato chip" wheels that was un-ballancable. I'll have to yank the axel and see if I can dial it for trueness??? I guess?

 

[Joe Mc]

It's not a noise it's the agravation of driving the "vibra machine". Other than that it's a sweet machine. Any ideas on how to check the wheel bearing and axel?

 

[DNewell]

My only thought there is to take it to a machine shop and have them chuck it in a lathe to spin and see if it's out of balance. Either that or taking an industrial type straight edge and seeing if it's bowed. I like the option of taking it to a machine shop as the spinning method will really pronounce if it's bent. I'm just pulling things out of my butt, but it seems as though you've already done a majority of things to check the balance. The only other thing that I can think of is that the tire has a high spot that only will show up at higher speeds. At lower speeds, the weight of the truck will keep it spinning relatively round, but as the rotational mass increases with speed, this will be pronounced as a wobble or bounce at a certain speed. As you spin the tire faster, it will go away as when spun fast enough, the centrifical forces will equalize and the wobble will stop. Does this sound like I'm a scientist or something? I'm actually a finance guy.

 

[Joe Mc]

DNewell - No not a scientist but, it is similar to a balance issue. And everthing you've mentioned makes sense. It's not balance as it's always done this, with the tires that were on it when I bought it 265/80/16 Steeltex, 305/70/16 Coopers and the 301/70/16 Nittos. I'm also running balance beads, and previously treid RoadForce balancing all to no avail. "Long live the vibra machine". If nothing else taking the axel to a machine, or drive shaft shop will at least rule out the bent axel theory if it's not bent.



Thanks guys - keep those ideas coming - seems like I'm not the only one with a 4X4 that vibrates the r/f.

 

[Nate]

Mine does as well. Feel to me like the driver's front though. It feels like a tire is egg shapped, thats the best I can describe it. Really only notice over 65mph.

 

[jkeyes]

I had a similar issue with mine a while back. Here is a description of my process to fix my problem.



Noticed that track bar had way too much play at the axle end.



bolt had wallowed out hole in bracket.



deamed hole larger and machined my own bushings from 17-4 ss with a . 005 clearence for the bolt and a press fit into the newly reamed holes in the bracket.



also noticed that the bushing in the track bar allowed about . 02 in. clearence for the bolt. This seemed to be way too much for me and I cut a piece of . 005 stainless shim stock and rolled it up andt stuck it in the bushing.



end result was a much tighter fit for the track bar on the axle end of the assy. and consequently my "knock" went away.



-J-

 

[RAJohnson]

I've been trying to figure this one out (sorry to admit) since shortly after I bought it some 65k miles ago. A constant thumping under the right floorboard and bouncing as speed increases. I've replaced wheels, tires, spent countless $ on different methods of balancing (road force etc) all to no avail. Then one day not too long ago I thought I found the nuisance. By taking a small pry bar and placing between the lower R/F shock doughnut and spring I was able to wiggle the whole shock base. Tried the left front to see if it was the same - it was snug and unable to be moved. I took a breaker bar & tightened the p*ss out of the R/F lower shock bolt and took it for a ride. No more thump Oo. Yes! I got new bottom bolts for both sides, purchased 4 Bilsteins and thought all was well especially when I found a loose top shock bolt on the R/L. And all was well . . . at least until the weekend before last when the thump was once again noticed during a short trip to Englishtown, NJ to the FAST drags :{ . The most frightening part of the trip was my wife’s comment "I don't know why you put so much $$$ into this piece of *^@# it rides horrible" and then "if it wasn't for that thumping it would actually be a nice truck". Words that rang all too true. The thumping is only noticeable at speeds around 60 or above. It's very similar to a balancing issue as it almost disappears under 40 mph - however since I've fought this fight before and ended up rather pleased with dynabeads doing the constant balancing, and have new shocks and tires and wheels - I'm 99% certain it's not in the balancing. However it's in the rotating mass (I think) and is definitely narrowed down to coming from the R/F.



I've re-checked everything I can think of: both front bottom & top shock bolts are tight, I've re-torqued the (newly installed with the shocks)leveling spacers, checked R/H ball joints (less than 3k miles since new), track bar joints, sway bar joints, alignment was done after ball joints, everything under the front on both sides is tight. I'm very frustrated #@$%!, at wits end and almost ready to put a brick on the go pedal, point her towards a cliff and drop her into gear



Someone please help before the men in the white coats come to take me away, hee, hee, haw, haw to the funny farm where life is beautiful all the time and all Dodge trucks run wonderfully fine, hee, hee, haw, haw . . . .

Mine did this after leveling spacers were added. I took it back to the installer who had to reset the camber. Been great ever since

 

[Joe Mc]

This has been going on since 75k I just put the leveling spaces on @ 144k. It's not them it did it before I put them on.

 

[Nate]

Can't adjust camber on a 4wd... well unless you use offset balljoints.

Mine did this after leveling spacers were added. I took it back to the installer who had to reset the camber. Been great ever since

 

[Joe Mc]

Good point Nate - When I had the alignment done at "supposedly" the best shop in my area they installed degreed upper balljoint spacers on both sides, I think one was +1. 5* and the other was -1. 0* (I think). I was disappointed as I brought it in complaining of a pull to the right (all brake stuff was checked first), they called me stating tires were bad and needed to be rotated so the better one's were on the front (should have known then - alignment is mechanical yes? tires are expendable), and that the steering box was in need of adjustment (too sloppy). I told as long as it would straighten things out and stop the pulling situation to go for it, for like $260 total not bad - right? So, tire rotation, box adjustment, ball joint spacers and alignment done. I picked it up and it pulled to the left *&$#($* not as bad as it did to the right but it still pulled. I took it back later in the week after I had a chance to fully observe the pull. They called me and said all was in spec and it "had" to be the tires. When I picked it up I asked if they were sure it was tires - the story changed with "actually all oversize tires will make a vehicle pull". What a load - 4 new Nittos later - take it back cause it still pulls left - this time they could only reply "everything is in spec". Basically, what I heard them say is, "we're 'supposedly' the best shop in the area but, we don't really know what the problem is because we only claim to be the best shop in the area and now that we have your money we could care less about your problem, so stop bothering us with your ' :{ my truck pulls and you said it wouldn't BS', as we have more customers to rape - now go away. " Ah, yes the great American way!



Sorry bout that - this still doesn't solve my "what the heck is bumping on the right front" question. I'll be looking into the suggestions made earlier in the post, this weekend with hopeful results and will report back. But another question arose after a suggestion early on to check the wheel bearings - I asked how to check front wheel bearings on 4X4? Any one have an easy suggestion or is it a look in the shop manual? Thanks for keeping this post alive. Man is this bumping a nuisance... . it's no consolation but at least I'm not the only one w/this PIA thump. Maybe I should chance my handle to "Thumper" . . . .

 

[Joe Mc]

Eyy Haww I hope - slack 1/4" in track bar to housing mounting bushing. Will be swapping out "Lifetime" Moog # DS1413 Track Bar today.

 

[Joe Mc]

still doing it#@$%!. New Moog Trackbar in tightened the pi*s out of it, greased it up and took for a ride. It's still there Next guess is . . . If I remove the front shaft that will eliminate it. But if the diff is not "locked in" (4 hi or low) the shaft shouldn't be turning . . . right?

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