I took a friend for a ride last Sunday. I hit it pretty hard, with TCS turned ON, I started from a stop with a soft launch at about 2500 rpm, and then accelerated basically as fast as I could work the gears until I hit about 100mph. What fun that is!

It all happened so fast, I'm not really sure where it happened, but somewhere around 3000-4000 in 3rd, I heard a really loud CRACK sound, Not a BANG, or a BOOM. Car seemed to be operating fine, handling fine, etc. I eased off right after I heard that sound. I thought it was maybe a cracked window in the rear but that's fine. I did not see any road debris. Seemed to handle fine afterward too

As an aside - Later on that excursion, as I was headed down the road, picked up some admirers who wanted to race, one on a cycle, one in a beat up nissan S-10 style mini-pickup. I let the cycle pass, but then this kid in the beat up truck tries to pass - I don't think so. I think the kid had fun trying to pass me, and I let him get close enough to try a few times. It was a fun ride to the Home Depot that I'm sure friend will not soon forget.

When I got home, I peeked under the rear end, and everything seems pretty good, no obvious damage that I could see.

Anyone else ever hear this noise before? Any suggestions? Dare I take to the dealer for an inspection? I doubt their mechanic has ANY experience working on one.

TD

Oh yeah - when you live in a smaller town, the car really stands out... especially when you're passing someone like they're standing still. I'm just waiting until I'm eating out and someone says something to me about it. I know its coming...

I took a friend for a ride last Sunday. I hit it pretty hard, with TCS turned ON, I started from a stop with a soft launch at about 2500 rpm, and then accelerated basically as fast as I could work the gears until I hit about 100mph. What fun that is!

It all happened so fast, I'm not really sure where it happened, but somewhere around 3000-4000 in 3rd, I heard a really loud CRACK sound, Not a BANG, or a BOOM. Car seemed to be operating fine, handling fine, etc. I eased off right after I heard that sound. I thought it was maybe a cracked window in the rear but that's fine. I did not see any road debris. Seemed to handle fine afterward too

As an aside - Later on that excursion, as I was headed down the road, picked up some admirers who wanted to race, one on a cycle, one in a beat up nissan S-10 style mini-pickup. I let the cycle pass, but then this kid in the beat up truck tries to pass - I don't think so. I think the kid had fun trying to pass me, and I let him get close enough to try a few times. It was a fun ride to the Home Depot that I'm sure friend will not soon forget.

When I got home, I peeked under the rear end, and everything seems pretty good, no obvious damage that I could see.

Anyone else ever hear this noise before? Any suggestions? Dare I take to the dealer for an inspection? I doubt their mechanic has ANY experience working on one.

TD

Oh yeah - when you live in a smaller town, the car really stands out... especially when you're passing someone like they're standing still. I'm just waiting until I'm eating out and someone says something to me about it. I know its coming...

I too experienced the same sound when I launched it before I modified the LCA and UCA. I assume it was the rear deck as I also experienced alot of wheel hop at the time. I too could not find any obvious damage but it sure got my attention. It did sound as though it came from under the car but with so much going on I could not be sure.

I too experienced the same sound when I launched it before I modified the LCA and UCA. I assume it was the rear deck as I also experienced alot of wheel hop at the time. I too could not find any obvious damage but it sure got my attention. It did sound as though it came from under the car but with so much going on I could not be sure.

shlbysvt

Ummm do you think it may have been second gear ? Just curious.

ILLEGAL

shlbysvt

Ummm do you think it may have been second gear ? Just curious.

ILLEGAL

ILLEGAL, I do not believe there is any connection between this and second gear, but you will know this sound when you experience it. It is a loud crack that definetely gets your attention. I have examined the whole under carage of the car and I have not been able to determine the cause of the noise. It almost sounded as though the black plastic side panels had given way. I had dismissed the sound as a stone lodged in a rear tire, but now that some one else has experienced this, it makes me wonder.:confused:

ILLEGAL, I do not believe there is any connection between this and second gear, but you will know this sound when you experience it. It is a loud crack that definetely gets your attention. I have examined the whole under carage of the car and I have not been able to determine the cause of the noise. It almost sounded as though the black plastic side panels had given way. I had dismissed the sound as a stone lodged in a rear tire, but now that some one else has experienced this, it makes me wonder.:confused:



This is a common problem that many people have after modifing.I too have it and have talked to many people.Still don't know the root cause.

This is a common problem that many people have after modifing.I too have it and have talked to many people.Still don't know the root cause.

Fred, my problem resulted before any modifications. Thought wheel hop was the root of the problem in my case. Are you still experiencing this dilema after the UCA and LCA change? What is the cause of this distinct sound?:confused: Something has to be happening to cause such a distinct CRACKING sound.

Fred, my problem resulted before any modifications. Thought wheel hop was the root of the problem in my case. Are you still experiencing this dilema after the UCA and LCA change? What is the cause of this distinct sound?:confused: Something has to be happening to cause such a distinct CRACKING sound.


Yes and it is very common.I have only heard it under extreme acceleration but it is there.I have heard everything from pinion angle(which is -2) to bad bushings.I dunno:confused: :confused:

yep.
i've got the crack too =(

but i've got a similar crack in my lifted '99 grand cherokee ??

Thanks for the responses - I've only heard it that one time. I was wondering if it could perhaps relate to the drive shaft? I know its a 2 piece unit - not sure what that means, but makes me wonder if its just one extra part to go bad. Has anyone with a 1 piece aftermarket shaft heard the noise?

Oh, and my car is stock (currently) though I am gathering a lot from the rest of the expenditures on the board. Someday I'll make my move, but its going to be a while for sure.

TD

Thanks for the responses - I've only heard it that one time. I was wondering if it could perhaps relate to the drive shaft? I know its a 2 piece unit - not sure what that means, but makes me wonder if its just one extra part to go bad. Has anyone with a 1 piece aftermarket shaft heard the noise?

Oh, and my car is stock (currently) though I am gathering a lot from the rest of the expenditures on the board. Someday I'll make my move, but its going to be a while for sure.

TD

I have a 1 piece driveshaft but that is not my issue.This is what I did.1-I took out the lower trailing arms,inspected the bushings and regreased with synthetic grease.No problems reinstalled.2-Retorqued lower trailing arms,panhard rod,panhard rod brace,uca mount,uca bushing bolts.Regreased the uca,bushings looked real good..3-My muffler was real loose on the drivers side.I had the same problem with the passenger side 1.5 months ago.It could have been slamming up to the bottom of the car when I got on it.:confused: I don't have the noise any more and boy am I happy.It could have been a combination of things but now when I nail it it just jumps and no noise.:D :D :D :D

Not sure if this is the same noise that you are describing but is scared the hell out of me.

I was at the track (drag strip) and left the TCS ON.(didn't know this at the time)

Burnout: 4k dump clutch 1st gear.= tires spin for about 1/2 sec. then Pow and felt something smack the floor board in the center of the car. Felt like a blown tranny or drive shaft. So I inch up to the line and it is still rolling. I said if it is broke we are about to find out now!

Light turns green and I do a soft roll out (street tires). Everything appears to be ok. I am thinking ok cool. Then here comes 2nd gear. I slam 2nd and "POW", I hear the same noise, but the car is still going and everything appears to be ok.

third gear everything ok

fourth gear everything seems fine there too. Now I am going about 100+ and I am thinking if the drive shaft lets go and spins me out it is a good thing I have this helmet on.:D

Once I picked up my time slip I finally figured it out, I had left the TCS ON. Not sure exactly how the TCS works but kinda have an Idea. What I think was happening in my case was the drive train was loaded up and then the TCS kicked it out and the was the recoil in the drive train.

Doubt this is the case for you but just one of my experiences.

Think I found the answer.

Told my cousin about this. He's a big muscle car nut/mechanic/mustang nut/racing nut... well sort of like a lot of guys on the board here...

Anyway, he told me that when you're rapidly loading and unloading the DS load during a rapid shift (probably screwing up his explanation) that this can produce flex or torque the Pinion (?) and then it lifts up, and smacks into a hard pinion stopper causing the cracking noise... He said its normal...if you're at a drag-strip..

I dunno if this all makes sense to me... I'm not even all that smart when it come to the basic mechanics of it all..


TD

Think I found the answer.

Told my cousin about this. He's a big muscle car nut/mechanic/mustang nut/racing nut... well sort of like a lot of guys on the board here...

Anyway, he told me that when you're rapidly loading and unloading the DS load during a rapid shift (probably screwing up his explanation) that this can produce flex or torque the Pinion (?) and then it lifts up, and smacks into a hard pinion stopper causing the cracking noise... He said its normal...if you're at a drag-strip..

I dunno if this all makes sense to me... I'm not even all that smart when it come to the basic mechanics of it all..

TD
He's correct in theory, but are you saying you hear this on your GT500? It should not happen on the GT500 unless you've made a drastic adjustment error on your adjustable aftermarket UCA. On older cars with single leaf springs this was common. The advent of multi-leaf springs, traction bars, ladder bars, and other suspension system enhancements virtually eliminated this. In addition, with an aftermarket adjustable suspension you can dial in a downward initial angle to the pinion to "preload" the pinion angle such that when you "hit it hard" you are running at zero pinion angle.

Dave

thanks a lot !you are lukely!

thanks a lot !you are lukely!

It looks like someone has an admirer!


I wonder if you remind her of Luke Duke from Dukes of HAzzard... I was always as Daisy duke fan myself.


TD