Funny Noise in the Silverado Diagnosis

[TRCM]

Try driving with the front driveshaft out...see if the noise goes away.....

also check transmission mount

if your front driveshaft has a bad u-joint or cardan joint centering ball, it can make your t-case/transmission vibrate/shake and give you a thumping noise like you describe, and will be felt in the pedals & floorboard

(doesn't hurt to check either)

[Have rod will travel]

200K, don't waste your time, get a new truck.

[Scottw]

The old bald guy at Freddie’s tires down on Reno will be able to diagnose it I bet,he been aligning trucks for 30 years,run it by there

[Arkyarcher]

Front cv axle .. had a bunch 07-14 that you would swear it’s a wheel bearing

You don’t have a leveling kit in it do you ?

This has my vote.

[Walkabout7781]

Changing the struts (coil overs would be correct term, IMO) on the front of the Silverado is a major PITA. I have an old Craftsman spring compressor and it was maxed out on the springs. I would suggest taking the old ones and the new shocks into an automotive machine shop to get the springs transferred or buy them with new springs installed.

I put Bilstein #4600's on mine and like them for the improved control and handling, but if you are looking for a plush ride, get something else. I've had Koni and KYB on other vehicles and like the Bilstein's best. Somebody will come along soon and suggest Bilstein #5100's, which are ride height adjustable, but unless your truck droops, you don't need that, IMO.

PS: I would also be looking at the front half-shafts and CV joints. Make sure there are no Senko's wrapped up in the CV boots.

[JerryT]

Another good theory....is there a way to check that without pulling everything?

You can sneak the axles out with out taking the ball joints apart ..problem being you can not run the truck down the road with a CV axle out .. wheel bearing will come apart

I actually have 1 inch thick bolt by 6 inches long and washers I throw in so I can drive them with the axles out

Axles only cost me 50 bucks.. most of the time it’s cheaper for me to just swap it than waste putting the bolt in and re driving it if i am pretty sure it’s the axle

[Mark Perry]

Maybe you have a bolt or rock etc inside one of the front pa mb else etc. Maybe something loose in engine compartment etc.

[John Br.]

pull the drain plug on your front differential and see how much debris on it

[SoonerFan]

pull the drain plug on your front differential and see how much debris on it

All fluids, transmission, transfer case, and both differentials were serviced just a couple months ago.

[twt]

Front drive shaft between transfer case and differential is my guess. If the u joint is bad at the differential, the shaft will hit the catalytic converter which may be the thump you feel on the floorboard since it would be under your feet.

[John Br.]

All fluids, transmission, transfer case, and both differentials were serviced just a couple months ago.

did you do that ?? notice excessive material on magnetic drain plug ??

[idratherbeefishin]

Broken motor mount those 07-12 model trucks are notoriously know to go out and could cause the vibration.

[hatcreek]

...PS...another clue I just thought of. I can lightly feel the thump in the floorboard and pedals. Nothing dramatic, but I can feel it.

You don't have a prankster buddy who has access to some large zip-ties, by chance?

[SoonerFan]

I appreciate all the suggestions and have consider them all. It was so bad when I pulled out of the driveway this morning, I came back home and took my wife's car for the little running around I had to do. I just came in from crawling around all under the truck.

The ONLY thing I found amiss was the left tie rod end...the rubber on top of the weird little plastic tower thing was cracked and missing a small chunk. I gave it a good hard shake and could barely get a rattle out of it...definitely not loose. With the weight of the truck bouncing around, it's conceivable that it could pop and that be transferred to the sound I'm hearing. IDK

I pulled and shook around on every component that made any sense...tie rod, sway bar, front drive shaft, front axles, boot, even the rear shocks that I put on a couple of months ago. Everything is tight as an army boot...barely a sound out of anything. I don't know if that means anything without digging into it or not. One of the really good things I noticed is my front shocks don't look bad at all...no oil build up on the side or anything. I may put the strut job off and concentrate on this non-factory noise.

I think I've decided to surrender and take it over to my old shop and have him drive it and put it on the rack. There's only so much I can do out in my sloped driveway. I can't be messing around with something like this. I got to get to work and it may stop raining some day and I can go to the lake.

Going off topic slightly let me get your opinion on this story...I referred to the shop I'm going to as my old shop. Back last year, I had a motor mount go bad. I went by the shop I had used for years and he hit me at $1200!! I couldn't believe it so I called around. The Chevy store was $1500 and this franchise chain place, Christian Bros. hit me at $950. They did the job and actually came in under the original estimate and even gave me the 10% discount for vets. Great! I'm a new customer. When my wheel bearing went out, that's where I took it. The old truck needs a lot of routine maintenance so over the months I got it in there for fluid changes and a diff pinion seal. Still have a to do list for it.

When the subject of shocks for the front came up, I wanted the same KYB Gas A Just shocks that I had put on myself on the rear. Rock Auto sells the KYB Gas A Just shock for about $74 with the mount around $30....O'Riley is around $165ea. I really didn't want to try to do the fronts with dealing with the springs and all that so I checked with my new found shop for an estimate. I realize that I'm pouring a lot of money into this old truck but I'd rather do that than buy an new one and not be able to retire until I'm 76 years old. Aware of how much I'm spending on this truck I even mention to the shop owner that I can get the shocks for $74 from Rock Auto. I didn't expect him to let me supply my own parts...just wanted to let him know that I wasn't totally uneducated. I was expecting him to hit me with the somewhere around the O'Riley price for the parts, knowing that he will get his wholesale prices well under retail to make his profit on the parts and then whatever his shop rate is. What he did was hit me at $946 for two shock absorbers and strut mounts. Quick math tells me that he took the retail price and keystoned (doubled) it. Add $425 for labor and $99 for an alignment, it all works out to $1500 for two coil over shocks. I'm no expert on theses things but that seems too damn high to me.

I may be wrong but I watched three or four You Tube videos on swapping those struts out on my Silverado and to me, it looks like taking the wheel off is the hardest part. Even a old shade tree like myself could do it in the driveway. The KYB Gas A Just isn't available as the entire strut assembly but it does come with the MonoMax shock which is one step above the Gas A Just. I think it'll work out fine and I'll be about $1100 or $1200 richer.

I still can't get over being a little butt hurt over the, IMHO, outrageous markup in his parts. I know...I know...he's got to make a profit, I fully understand but I just can not justify spending almost a grand for something I can buy for a little over $220. Or I can get the better shocks in a complete assembly with spring and all for $162 per side...top of the line KYB.

[Walkabout7781]

One of the brands I looked at was expensive but came with new springs installed on the struts. No idea what brand that was, but I promise you that finding/renting/buying a spring compressor that will do the job safely won't be easy. I also watched a bunch of videos on UTube. As I remember it, all the ones dealing with the Chevy truck installed shocks that came with the springs installed.

Also watched a video showing a guy using a spring compressor that he rented from AutoZone or someplace...NO WAY that spring compressor would have a prayer of doing the job safely on the truck springs...they are THAT MUCH stiffer. Messing with the springs can be a dangerous process, so I strongly suggest either buying shocks with springs pre-installed or take the old assemblies and the new shocks to an automotive machine shop and get them removed/installed there. I would NOT even want to watch them do it.

I've been working on my own cars and trucks since the late '60's...replaced clutches, transmissions, rebuilt engines, shocks, struts, lowering kits, so I figured shocks wouldn't be too bad. It sucked! Having the truck up on a rack would have helped some, but it would still suck. Just FYI.

[Lightningboy]

I'm betting CV joint. Had a mystery thump like you describe on my 02 AV. Turned out to be a CV joint.

Go to an empty parking lot. Put it in reverse, and back up with the wheels turned all the way to each side. If it's the CV joint, you should hear clicking on one side as you back up.

Easy test, worth trying before you throw money/parts at it.

[SoonerFan]

One of the brands I looked at was expensive but came with new springs installed on the struts. No idea what brand that was, but I promise you that finding/renting/buying a spring compressor that will do the job safely won't be easy. I also watched a bunch of videos on UTube. As I remember it, all the ones dealing with the Chevy truck installed shocks that came with the springs installed.

Also watched a video showing a guy using a spring compressor that he rented from AutoZone or someplace...NO WAY that spring compressor would have a prayer of doing the job safely on the truck springs...they are THAT MUCH stiffer. Messing with the springs can be a dangerous process, so I strongly suggest either buying shocks with springs pre-installed or take the old assemblies and the new shocks to an automotive machine shop and get them removed/installed there. I would NOT even want to watch them do it.

I've been working on my own cars and trucks since the late '60's...replaced clutches, transmissions, rebuilt engines, shocks, struts, lowering kits, so I figured shocks wouldn't be too bad. It sucked! Having the truck up on a rack would have helped some, but it would still suck. Just FYI.

I hear ya. I'm pretty much decided to use the strut assemblies. I was mostly concerned about the KYB strut having the base quality shock insert but once I did a little deeper research and learned that the strut can also be ordered with the top of the line MonoMax shock, that convinced me. I'm sure it will be harder than the You Tube guys make it look like. I'll probably take one day apiece to do each side. Sort of like the first time I replaced my hub bearings, races and seals on my trailer. I took all day to do one side and then the next day to do the other...now I can do both sides in an afternoon.

I used to work on my cars a lot when I was a teenager and young man. Did a clutch and stabbed a couple of transmissions, tune ups, brake pads. A pair of freeze plugs, outside in freezing weather was one of my greatest hits. As I got older and started making a little more money, I started letting the pro's do it. However, when I got my first boat and general maintenance, repairs, and upgrades fell on either myself or my wallet; I decided to roll up my sleeves and start expanding my tool collection. I still know my limits and don't get into something I can't back myself out of. For example, I don't even take the shroud off the Optimax except to admire the beauty of engineering.

I'm betting CV joint. Had a mystery thump like you describe on my 02 AV. Turned out to be a CV joint.

Go to an empty parking lot. Put it in reverse, and back up with the wheels turned all the way to each side. If it's the CV joint, you should hear clicking on one side as you back up.

Easy test, worth trying before you throw money/parts at it.

I'm thinking you might be right. I'll try your test. I sure like to know what's wrong with a car before I put it in the shop.

[billnorman1]

I changed the front struts on my 2007 Silverado 2 years or so ago. It took me 3 hours. I did have a friend with a drive-on lift. I'm 76. It isn't that hard.

[greenfshrmn]

I'm with Jerry on this. Axle shaft, (worn inner cv joint)...

[SoonerFan]

But wouldn’t a worn CV joint show some sort of looseness when I shook it?