Grinding noise coming from out back..............

[Mark]

As the title states, I have this annyoing grinding/rubbing type noise coming from out back. It only happens when I'm in 1st gear and going really slow <10mph or so. It is very evident while going over speed bumps in parking lots and while taking off from a stop sign. It's very very annoying and I have no idea what it is :crazy:

My Tahoe has very low miles, around 9200 and it's a 2004 2WD

Does anyone have any idea what this could be? I cannot for the life of me figure this out. I thought it could be the rear fender well plastic, due to my 305/45/R22s, but I trimmed them and it's still making this noise. I've had my Tahoe for over 4 years since new and it's never done this. It all started about this spring.

It doesn't do it all the time, but it does happen a lot.

I thought it could be the knocking noise I had before, but it doesn't feel the same and I've already had my intermediate steering column replaced.

I looked underneath the undercarriage and I didnt' see any rubbing whatsoever.


Also, my rear suspension is riding horribly. Everytime I go over a bump, it feels like it's bottoming out. Does this mean my shocks are done? The ride altogether sucks right now. I'm getting really annoyed with the ride. I want to put my 3'' DJM lowering springs in again, but I guess I'll have to get new shocks. Any recommendations?

 

[matt14]

i'm running the djm drop shocks on my truck with the 3/5 drop. i called djm themselves to get the part number cause the company that i bought the kit through kept on sending me the wrong stuff. so far i dont have any complaints with the shocks. the truck of course rides a lot more stiff cause of the drop, but thats it. as far as the noise, i did have a slight knocking noise when driving at slow speeds a whiel back and it ended up being the trailing arms i think. cant remember exactly what the noise sounded like, cause i had it repaired like three years ago. my noise also was not real frequent

 

[Mark]

i'm running the djm drop shocks on my truck with the 3/5 drop. i called djm themselves to get the part number cause the company that i bought the kit through kept on sending me the wrong stuff. so far i dont have any complaints with the shocks. the truck of course rides a lot more stiff cause of the drop, but thats it. as far as the noise, i did have a slight knocking noise when driving at slow speeds a whiel back and it ended up being the trailing arms i think. cant remember exactly what the noise sounded like, cause i had it repaired like three years ago. my noise also was not real frequent

Hmmm, I've been thinking about that......... the trailing arms that is.

I had some 3'' drop coils on mine (for about 6 months), then realized I needed shock extenders. I put my OEM coils back in late September and have been hearing the noises since? Any correlation here? Due to the fact I didn't have shock extenders on the rear for 6 months? Would this ruin my shocks? Cause I'll be honest, it feels like I have no shocks, every bump I go over feels like the rear is bottoming out.

 

[rockman20]

Another thing to just check is the Ujoints. I have had rubbing/grinding noises, squeaking noises, clunking noises, I even had one set that would make a slight squeaking noise but only if you let off the throttle.

Seems like every time I have a Ujoint go out on something, it is a new noise.

Just one more thing to check.

 

[Mark]

Another thing to just check is the Ujoints. I have had rubbing/grinding noises, squeaking noises, clunking noises, I even had one set that would make a slight squeaking noise but only if you let off the throttle.

Seems like every time I have a Ujoint go out on something, it is a new noise.

Just one more thing to check.

This isn't the first time I've heard this.

Don't make fun of me, but the U-Joints are on the drive shaft correct?

I'm not the best with mechanical stuff, I'm more of a cosmetic knowledgeable guy.

So what would I be looking at regarding this? What tools would be needed?
The last part of your post really hit the nail on the head........... I get the grinding noise when I release off the throttle. Say I'm coming into my circle, and I turn the wheel, as soon as I let off the throttle, I get the grinding type noise.

 

[05Yukon]

Does it sound like it could be the rear end? Could be the rear diff if its at low speeds. Might want to check to see if you have the G80.

 

[Mark]

Does it sound like it could be the rear end? Could be the rear diff if its at low speeds. Might want to check to see if you have the G80.

Yeah I have the G80

It only happens in 1st gear.

 

[05Yukon]

The G80 is only going to work in 1st gear it will only lock below 20 or 25. Its possible that it has an issue. That or the gears in there are making noise.

 

[matt14]

What 3" coils do you have? I was reading about the djm 2/3 kit and they had recomended that you have the trailing arm brackets. This is so the pinion angle will stay the same with the drop. If not, this can cause a bad angle on the pinion, and can cause a problem with the differential or the u-joints, like rockman20 had stated. And having no extenders for your shocks can cause the factory shocks go bad. there is no suspenion travel with the stock shocks with a drop. here is a pic of the stock rear shocks/ 3" drop shocks/ 5" drop shocks and you can tell the difference between the shocks and there travel.

 

[Mark]

What 3" coils do you have? I was reading about the djm 2/3 kit and they had recomended that you have the trailing arm brackets. This is so the pinion angle will stay the same with the drop. If not, this can cause a bad angle on the pinion, and can cause a problem with the differential or the u-joints, like rockman20 had stated. And having no extenders for your shocks can cause the factory shocks go bad. there is no suspenion travel with the stock shocks with a drop. here is a pic of the stock rear shocks/ 3" drop shocks/ 5" drop shocks and you can tell the difference between the shocks and there travel.

Thanks for that input.

I guess I'll be getting some new shocks for the rear then.

Do you recommend DJM?

So regarding the trailing arms, what do you suggest here? Are they messed up as well?

I will be ordering shocks ASAP.

One last question, because my pinion angle was messed up, would this ruin my front shocks as well?

 

[matt14]

Nah, you pinion angle will not affect the front shocks. i would recomend to run the djm shocks or some type of drop shocks if your planning on running a drop. if not, you can get some factory shocks if you want. if you plan on running the drop, you can get the shock extenders and run the stock shocks. Did you have the trailing arm brackets isntalled with your kit? You need to isloate the noise and repair that, then you can decide what you hant to do as far as a drop goes.

 

[Mark]

Well I ordered a pair of DJM rear drop shocks for the back of the Tahoe. I'll throw those 3'' coils back in there and take a look at the U-joints as well. Someone said just move the driveshaft with my hand?

What are my options as far as repairing them?


Also, when I dropped the Tahoe back in April, it was a 1/2'' lower in the back than the front and drove me nuts :mad3:

So because I have the right shocks now, does this mean it will no longer sit like that and now sit even? Or does this mean I'll still end up having to crank the torsion bars to lower the front end a 1/2'' to truly level it out?

Cause I want the leveled look, that's what I'm going for here.

 

[rockman20]

Sometimes Ujoints can be tricky to diagnose. The one that I had the slight noise after releasing the throttle, I actually had to take apart. I took 3 cups off and thought that I was nuts because they all had grease, all looked great. Got to the 4th cup and it was like dust in there. The seal must've gave way and all the grease went with it.

The hardest thing with a ujoint is getting it out. There are snap rings that hold them in and then a good vise and some sockets work great at pressing the joint out.

 

[Mark]

Nah, your pinion angle will not affect the front shocks. I would recommend to run the DJM shocks or some type of drop shocks if you're planning on running a drop. If not, you can get some factory shocks if you want. If you plan on running the drop, you can get the shock extenders and run the stock shocks. Did you have the trailing arm brackets installed with your kit? You need to isolate the noise and repair that, then you can decide what you want to do as far as a drop goes.

No, I didn't have the trailing arm brackets installed. I asked recently on this site about them and was told they were not needed if I got the shock extender brackets or the DJM drop shocks.

So in your opinion, are they needed? Do you have them?

What's your setup?

Sometimes Ujoints can be tricky to diagnose. The one that I had the slight noise after releasing the throttle, I actually had to take apart. I took 3 cups off and thought that I was nuts because they all had grease, all looked great. Got to the 4th cup and it was like dust in there. The seal must've gave way and all the grease went with it.

The hardest thing with a ujoint is getting it out. There are snap rings that hold them in and then a good vise and some sockets work great at pressing the joint out.

Damn, this is sounding out of my realm. I don't trust myself to "operate" on something like this. Especially when I'd be going freeway speeds later on :lol:

I might have to see what a mechanic would charge to look at this. I'm usually a do-it-yourselfer, but I'm also a visual learner and would need some type of how-to article with pictures.

 

[Mark]

Anyone know of any how-to articles on checking/fixing U-Joints in our rides?

 

[matt14]

I do recomend to install the trailing arm brackets. they do recomend them on djm's site, when performing a 2/3 drop.

 

[Mark]

I do recomend to install the trailing arm brackets. they do recomend them on djm's site, when performing a 2/3 drop.

Yeah I know they do, but another $160 isn't looking great right now.

I asked numerous times here and the consensus seems to be that rear hardware kit isn't needed.

What's your setup?

 

[matt14]

i would recomend the rear kit of your going to lower it. im running the djm front control arms with 5" rear springs. i have the trainling arm brackets and no shock extenders, running djm drop shokcs all the way around

 

[Mark]

Ok, well I find out what the noise was

The "grinding" type noise was actually a very irritating vibration noise caused by my Gibson exhaust pipe on the driver side. I have the dual extreme kit from them and what happened was the cheap bolt on hanger (that you're supposed to bolt the rear frame) was vibrating against the frame. Also, because I put my 3'' drop coils back on, with the new DJM shocks, the pipe would vibrate against the frame right behind the diff as well. I knew it had to be the exhaust last night, because I was parked in a parking lot, although the transmission was in Drive, I had my foot on the brake (thus not moving, just sitting), and the noise was worse than ever. However, when I put the Tahoe in park, the noise stopped. So I'm guessing when the engine is in drive, it caused the noise and when it was in park, it didn't.

Well to make a long story short, I went out earlier and removed the driver's side tail pipe and unbolted the crappy designed hanger. I'll be going to a muffler shop this week and having them weld a hanger onto the frame like the passenger side has. Hopefully this will stop the pipe from shifting so much and causing that irritating vibrating noise.

Thanks to all those who helped

Now I gotta lower the front of the Tahoe.

Any ideas where I can get some keys?
I need to lower 2'' up front to level out the Tahoe. I have some major Cali lean going on right now.

I've heard you can use Ford keys, but I also ran across these

Seem high?
I'm sure I can find a used pair somewhere.

Also, how hard is it to lower the front by yourself?
I know I need that 7 ton puller from Sears, which I'll get.

Is there a how to anyone knows of?