trying to pin point a front end clunck

Posted by: mikemee1331

trying to pin point a front end clunck - 10/03/17 03:44 PM

69 B-body with 440.
i recently re-bushinged (is that a word?) the front end of my Road Runner. everything was pretty much shot. i also replace the original torsion bars with the next heavier (GTX) ones. all the bushings were replaced with poly except the lower control arms and there i used rubber(to avoid the dreaded squeek)and at the suggestion of the machine shop that replaced them. all the 'hard' parts have less than 3000 miles on them and all seemed good.

now heres the issue. when i got everything back together i didn't have to mess with ride height too much as i re-installed the adjusters to the same location they were in when i pulled it apart.
the back end of the car sits high (re-sprung spring) to clear my tires, 29x15x15 fatties, and i wanted to level out the front some so i wasn't going down the road like this - \. i raised up the front via the torsion bars but now i have a clunk i didn't have when it was lower. i have searched and searched and retightened everything but i can't isolate it. everything is nice and tight. the noise has nothing to do with cornering or hitting bumps. it's like a popping/flexing noise like the shocks are loose in the front.

ANY suggestions would be helpful as i'm at a loss. just please no negatives about the ride height as i like the way it looks.

thanks guys!
Posted by: Andrewh

Re: trying to pin point a front end clunck - 10/03/17 04:10 PM

but can you consistently reproduce the clunk, and if so when do you get it.
Posted by: 5spdcuda

Re: trying to pin point a front end clunck - 10/03/17 04:12 PM

The first thing I would do is to look for any shiny spots that would indicate a point of contact. You can also try putting a small amount of grease on anything that looks like it might be close clearance as the suspension moves through it's full range of motion and see if you get a grease smear. As for ride height all I am going to say is that any new spring or re-arched leaf spring will tend to settle or take a set over the next few months. This is true for coils, torsion bars or leaf springs so don't be surprised if the car sits a little lower in time. In so far as squeaks are concerned I've found that you're much more likely to get squeaking from polys in the UCA's than you are in the lowers. I still use rubber in the lowers myself, but I have used poly on the lowers before and didn't have any problems with them.
Posted by: dvw

Re: trying to pin point a front end clunck - 10/03/17 04:37 PM

Have a helper grab the roof and rock the car left to right. Grab each suspension point while it is being rocked. You will feel any point that is loose.
Doug
Posted by: FurryStump

Re: trying to pin point a front end clunck - 10/03/17 04:43 PM

K frame bolts tight? Don't ask me how long I chased that little annoying sound!!!! Put the wife in the car and had her steer left then right. The k frame was moving just the slightest bit. Clunk! You could barely see it! Cinched them down alls quiet!!
Posted by: autoxcuda

Re: trying to pin point a front end clunck - 10/03/17 04:59 PM

Sounds like you installed poly strut bushings. The lip that fits into the k-member can make a snapping sound when the front suspension articulates up and down a bunch like into and out of driveways.

Try loosening them, put grease around that area and bushing and re-tighten up with suspension at ride height.
Posted by: RapidRobert

Re: trying to pin point a front end clunck - 10/03/17 06:14 PM

you rebushinged it & it was good then you right away lowered it & it clunked OR you rebushinged it/lowered the ride height at the same time & now it clunks? As said I would loosen everything (as needed) & lube the needed areas then retighten.
Posted by: Challenger 1

Re: trying to pin point a front end clunck - 10/03/17 06:30 PM

Got a Go Pro camera?
Posted by: mikemee1331

Re: trying to pin point a front end clunck - 10/03/17 06:35 PM

all good stuff!
1)"can you consistently reproduce the clunk, and if so when do you get it." it seems to be on area of the road that make no sense what so ever. stepping on or letting off the gas does make it happen though.

2)"The first thing I would do is to look for any shiny spots that would indicate a point of contact" tried this and couldn't readily find any.

3)"any new spring or re-arched leaf spring will tend to settle or take a set over the next few months. This is true for coils, torsion bars or leaf springs so don't be surprised if the car sits a little lower in time." it's been 1 1/2 years since the springs and front were redone.

4)"Have a helper grab the roof and rock the car left to right" yep, hopefully this weekend if my son doesn't have to work.

5)"K frame bolts tight" never thought of that as i didn't have it off but it is certainly worth looking at.

6)"Try loosening them, put grease around that area and bushing and re-tighten up with suspension at ride height." i really like the sound of this. i was never really happy with the fitment and it seems like the noise is when the rode is unevenish and not really when it's bumpy. not related to bumps at all actually.

Robert - all was well until i raised the car up a few inches in the front. i never lowered it. the issue started this summer (a year after the rebuild) when i raised the front to try and level it some.




Posted by: RapidRobert

Re: trying to pin point a front end clunck - 10/03/17 06:41 PM

I don't know where I go the "lowering" from. I would do #6
Posted by: stumpy

Re: trying to pin point a front end clunck - 10/03/17 06:48 PM

If it happens when you get off and on the gas I would look at the motor mounts and trans mount. Just because it happened after you redid the front end doesn't necessarily mean it's front suspension related.
Posted by: 71GTX471

Re: trying to pin point a front end clunck - 10/03/17 07:03 PM

Once you decide where you want your ride height loosen the upper & lower control arm bushings preferably on a drive on lift,jounce the front end up n down & retorque the bushings at that static ride height & reevaluate it.Also retorque the K-frame bolts.
Posted by: ahy

Re: trying to pin point a front end clunck - 10/03/17 07:13 PM

As mentioned, it is important to loosen everything up when significantly changing ride height. Otherwise the bushings can be pre-loaded and overload on bumps.

I would add to the suggestions, careful inspection of all bushings for any tears.
Posted by: mikemee1331

Re: trying to pin point a front end clunck - 10/03/17 07:15 PM

Originally Posted By 71GTX471
Once you decide where you want your ride height loosen the upper & lower control arm bushings preferably on a drive on lift,jounce the front end up n down & retorque the bushings at that static ride height & reevaluate it.Also retorque the K-frame bolts.


i like this too. it has to be realigned anyway.

stumpy, all 3 are newish but i did check them any way up
Posted by: Andrewh

Re: trying to pin point a front end clunck - 10/03/17 08:45 PM

other thing that it might be sounds like u joints.
giving it gas and letting off makes me wonder about that too.
Posted by: Frankenduster

Re: trying to pin point a front end clunck - 10/03/17 10:55 PM

Originally Posted By stumpy
If it happens when you get off and on the gas I would look at the motor mounts and trans mount. Just because it happened after you redid the front end doesn't necessarily mean it's front suspension related.


Boy, aint THIS the truth...
Many times in the past I have had something conk out moments after doing something else unrelated.

I rotated the tires, now I have bad breath. I should have left the tires where they were.
Posted by: JonC

Re: trying to pin point a front end clunck - 10/03/17 10:57 PM

Did you grease the Torsion bar sockets, they can clunk if they are dry.
Posted by: NANKET

Re: trying to pin point a front end clunck - 10/03/17 11:39 PM

Originally Posted By JonC
Did you grease the Torsion bar sockets, they can clunk if they are dry.


This right here is your noise. Factory packed them with grease. They need that to be quiet.
Posted by: John_Kunkel

Re: trying to pin point a front end clunck - 10/04/17 01:26 PM

Originally Posted By mikemee1331
i also replace the original torsion bars with the next heavier (GTX) ones.


Did you grease the hex ends of the T-bars?
Posted by: mikemee1331

Re: trying to pin point a front end clunck - 10/04/17 04:00 PM

Hmmm... i can not say with 100% certainty that i greased the front t-bars. i know i did the back but i'll have to double check the front.

U-joints i did think about and will check but they too are newish and the clunk is most definitely in the front. i can feel it in the steering wheel.
Posted by: GMP440

Re: trying to pin point a front end clunck - 10/04/17 05:01 PM

Check the bolts that hold the steering column to the firewall.
For years I always had this front end clunk. Was not the shocks. Was not any of the suspension components.
One day I was working on the steering column to pull it back for removal
of the power steering gear. Went to loosen the bolts that hold the lower steering column plate to firewall and found some of the bolts were loose.
Tightened them and there was no more front end clunk.
Posted by: Andrewh

Re: trying to pin point a front end clunck - 10/04/17 09:28 PM

since you can feel it in the steering it probably isn't driveline.
But can you try shifting from reverse to drive and see if you get any clunks?
It would either eliminate or point to the drive line/ motor mounts / trans mounts etc..
Posted by: Frankenduster

Re: trying to pin point a front end clunck - 10/05/17 12:48 AM

Originally Posted By John_Kunkel
Originally Posted By mikemee1331
i also replace the original torsion bars with the next heavier (GTX) ones.


Did you grease the hex ends of the T-bars?
Posted by: mikemee1331

Re: trying to pin point a front end clunck - 10/05/17 08:05 AM

Originally Posted By Frankenduster
Originally Posted By John_Kunkel
Originally Posted By mikemee1331
i also replace the original torsion bars with the next heavier (GTX) ones.


Did you grease the hex ends of the T-bars?





YIKES! i will, i will!!i just am not looking forward to sliding them back out!

Andrewh - the clunk is very definitely a suspension issue. just not looking forward to the task!
Posted by: stumpy

Re: trying to pin point a front end clunck - 10/05/17 12:19 PM

Have you got a hand grease gun with a needle tip. That might make it easier to get grease around the T bar end. You can get the tip at any parts store. It just plugs into the gun like a grease fitting.
Posted by: RapidRobert

Re: trying to pin point a front end clunck - 10/05/17 12:47 PM

If you do have to slide em out, restore the height to the same exact distance on both sides (not sure where the best reference point would be) so you dont alter your alignment (not sure how close it needs to be but I'd get it real close) but I would for sure try the needle, its cheap.
Posted by: dvw

Re: trying to pin point a front end clunck - 10/06/17 04:54 PM

Did you rock it as I suggested? With over 30 years as a dealer tech specializing in suspension I had many difficult noises to locate. The method mentioned found 95% of them.
Doug
Posted by: bboogieart

Re: trying to pin point a front end clunck - 10/06/17 05:07 PM

Originally Posted By mikemee1331
i raised up the front via the torsion bars but now i have a clunk i didn't have when it was lower.


This changes the relationship of all the alignment components.

Lots of good advice above.

Look for signs of wear.
Should be easy with all new parts.
Tighten everything up, and get the new set-up properly aligned.
Posted by: mikemee1331

Re: trying to pin point a front end clunck - 10/08/17 10:47 AM

Originally Posted By dvw
Did you rock it as I suggested? With over 30 years as a dealer tech specializing in suspension I had many difficult noises to locate. The method mentioned found 95% of them.
Doug


i will be doing this first!

yes, tons of good advise here and i really appreciate every bit of it! i will update this when i get a chance to work on her. before i do anything i have to get the ride height, back and front, where i want it. the back is a little too high now that i put the 'extended reach' KYB's on there. i was hoping they would settle down some but no dice. i'll put those where they belong, on my sons Ram pickup and just go with the regular KYB's. that should work as i have the springs where i want them. then move to the front.

thanks again all!