Jump to content

Rear End

Josephhunt27

By Josephhunt27
in Ask A GM Technician

Recommended Posts

Josephhunt27 Enthusiast

Josephhunt27

Posted
Posted

I'm experiencing some play in the rear axel on my '05 Sierra Crew Cab, which is causing a "thump" every time I make a turn. I took it in to a Big O shop and was told it was normal. I didn't notice this until after I had them machine the rotors.

 

Is it normal to have some play in the axel? I had them jack the truck up and shook the wheels back and forth and heard the same sound as when I drive.

 

Thanks.

GM-Tech Senior Enthusiast

GM-Tech

Posted
Posted

If the rear wheels are off the ground and you grab one and shove it in and out, you're going to have some play and associated noise. This is NORMAL.

pm26 Senior Enthusiast

pm26

Posted
Posted

It is impossible to manufacture a differential without play between gear teeth (backlash). If they built one like that , it would not last very long. The key is to be within the permissible specification. Too much or too little backlash is not good and it will manifest itself either as rapid gear wear or excessive play and /or whining noise in the differential.

lesZ71 Enthusiast

lesZ71

Posted
Posted
Thanks for the replies.  What is within "specifications"?  How is it corrected?  The thump is pretty prominent.  Thanks.

 

 

 

 

I have a 2004 Chevrolet Z-71 with just under 20k miles. I am also experiencing a clunking/thumping noise from the rear end. It occurs whenever I am going over uneven surfaces such as speed bumps, entering the driveway, etc. The noise occurs mainly whenever I go over these surfaces at an angle. It also occurs sometimes when going around corners. This noise was not present until about a month ago.

 

I have taken it to two different dealers and they both have told me that it is due to "free-play" in the rear axle and that this is a normal condition. They also stated that they could not do anything to make the clunk go away.

 

GM-Tech, I read on this thread where you also stated that this is normal. What concerns me is that the noise was not present until recently and I want to make sure there will be no long term damage to worry about as a result of it. Is this anything more than an annoyance?

GM-Tech Senior Enthusiast

GM-Tech

Posted
Posted
GM-Tech, I read on this thread where you also stated that this is normal.  What concerns me is that the noise was not present until recently and I want to make sure there will be no long term damage to worry about as a result of it.  Is this anything more than an annoyance?

 

 

 

 

I can only tell you that some freeplay in the axles is normal and if you raise the wheels off the ground and shove the axles in and out, they'll go "clunk clunk." I have NEVER heard this noise while driving under any conditions.

 

So without knowing what the actual source of the noise is, I can't tell if you if whatever it is is anything more than an annoyance.

lesZ71 Enthusiast

lesZ71

Posted
Posted

When I took it to each dealer, I had the service manager ride with me so that they could know exactly what noise I was talking about and how to create it. After having their respective technicians drive the vechicle, they came back and told me that the noise was normal and was a result of having a semi-floating rear axle.

 

I have a friend who has a 1999 Z-71 with 115k miles and his does not make this noise. Another friend has a 2002 Z-71 with 56k miles and his does not make this noise either.

 

I am going to try and find a reputable axle/supsension shop and get them to take a look at it. Thanks for your input!

  • 2 weeks later...
Norseman Senior Enthusiast

Norseman

Posted
Posted

Hey guys! My Z71 (153, 000 miles) has started to make that noise that you were describing. I took it to the best drive train shop in town (if there is somthing wrong they can fix it). They said there is a bushing that can be placed close to where the "C" clip goes in and that will eliminate the clunk noise. I'm gettin' it done in a couple of weeks. I'll have more info when I get it done. The guys said it (the noise) was a normal occurrence, but it didn't have to be. Man does it pay to know great mechanic's!! :crackup:

lesZ71 Enthusiast

lesZ71

Posted
Posted

I just got my truck back today from a third dealer in my area...they also stated that this was a normal condition for these trucks...very frustrating experience to say the least.

 

Glad to hear that you are having some luck! Let us know how this works for you when you have it done.

  • 4 weeks later...
billy65 New Member

billy65

Posted
Posted
I just got my truck back today from a third dealer in my area...they also stated that this was a normal condition for these trucks...very frustrating experience to say the least. 

 

Glad to hear that you are having some luck!  Let us know how this works for you when you have it done.

 

 

 

:) well fellers with clunks in your rear ends,i have a gmc 2000 z71 that was aggrivating me to curse words every time i turned a corner,stopped and started,backed up or anything,i jacked it up grabbed the rear wheel,pulled it out and pushed it back and it made the noise i had been hearing,iremoved the diff cover measured the distance bewteen the axle end and the pin with a feeler guage and got 35 thousands,i used some old pinion shims in equal thickness behind the c clip and fixed the problem,but the problem is simply wear in the c clips i did this when the parts stores were not open or i would have just replaced the clip ,passenger side was the culprit,driver side was ok...

  • 1 month later...
lesZ71 Enthusiast

lesZ71

Posted
Posted

Well, the noise described above started happening when going around corners at low speeds (<20mph) so I took it back to the dealer. The heard the noise and decided to replace the passenger side axle shaft and c-clip. Unfortunately this has not fixed the problem. :gmc: This past week, I had some co-workers riding the in the back seat and when the noise occurred while entering a parking lot, both guys indicated that the noise seemed like it was somewhere between the rear axle and the back of the cab. They also said that they felt something in the floorboard...like a quick pop. I have also felt something like a pop in the driver's side floorboard a couple of times and my wife felt something in the passenger floorboard about a week ago. Each time we were either turning a corner or going over an uneven surface. Anyone else experiencing this? Are there any recalls or TSB's on something like this? Could it be my leafs springs flexing and causing a vibration in the frame ?

icecoldtexan Enthusiast

icecoldtexan

Posted
Posted
Well, the noise described above started happening when going around corners at low speeds (<20mph) so I took it back to the dealer.  The heard the noise and decided to replace the passenger side axle shaft and c-clip.  Unfortunately this has not fixed the problem. :gmc:  This past week, I had some co-workers riding the in the back seat and when the noise occurred while entering a parking lot, both  guys indicated that the noise seemed like it was somewhere between the rear axle and the back of the cab.  They also said that they felt something in the floorboard...like a quick pop.  I have also felt something like a pop in the driver's side floorboard a couple of times and my wife felt something in the passenger floorboard about a week ago.  Each time we were either turning a corner or going over an uneven surface.  Anyone else experiencing this?  Are there any recalls or TSB's on something like this?  Could it be my leafs springs flexing and causing a vibration in the frame ?

 

 

 

 

I had a noise like you describe on my 2001 2500HD. It was the leafspring isolation pad on the bottom leafspring, it was missing. This spring dosen't touch the others until a load is on the truck, so when driving over a speed bump or into a driveway it would hit the other leafspring and would be a metal on metal clunk. I replaced the isolation pads and the problem went away. GM part number is 15247030 it's a round plastic/rubber pad that attaches to the bottom leafspring, two on each side.

lesZ71 Enthusiast

lesZ71

Posted
Posted

Thanks for the response. I just checked and all four of the isolation pads are still there...two each on the bottom helper spring. I have also checked the tightness of all body mounts and bed mounts that I could find. I also checked to make sure that the leaf spring mounting bolts were tight (at the shackles and the U-bolts holding them on the axle). Again, thanks for the feedback...if you or anyone else had any more suggestions I welcome them. Thanks!

  • 5 months later...
  • 2 weeks later...

Archived

This topic is now archived and is closed to further replies.

Go to topic listing

  • Latest Articles

  • Posts

    • Erfar
      Oil Change

      By Erfar · Posted

      have you stuck with dealer oil changes since then? I made the same switch after getting tired of crawling around under the truck, but I’ve found some dealers are way better than others about getting you in quickly. Curious if yours has been good about scheduling or if you’ve had to look elsewhere for quicker turnaround.
    • cherryred21duramax
      Can anyone decode a VIN to determine if this truck has had emissions issues or a recall?

      By cherryred21duramax · Posted

      Thank you.   I am set on a 3.0 Duramax as my previous truck with a Ford Ecoboost had just as many, if not more, "common" issues.  Cam phasers, timing chain issues, 10-speed valve body and CDF drum, emissions issues, etc.  So I figured, why not get 2x the fuel mileage (these things got 27+mpg on every mixed city/highway test drive I put them through) and better towing capability with resale value to boot?   My minimum, shortest trip will be 50 miles 1-way and I regularly go out of state with a travel trailer.  I'm planning on using this for a marketing/event promotion business also, which would require regular towing of trailers for bands, DJs, sound and lighting gear, along with my personal camera gear for filming events.   Looked at other trucks in the $30k+ price range but the issues seem to be everywhere, plus too many with gaudy mods.  I'm literally sticking with RWD trucks because they tend to be actually used as trucks, vs. the 4x4 models I've seen with unsafe lifts, huge tires, and general mods that would affect reliability (I'm wondering if some of them were tuned, hence the aggressive throttle response and hard shifting).   So my goal is to find a stock, 3.0 with 1 or 2 owners, in good physical condition, and decently well maintained.  Can't seem to find that up here, everything in the $27-30k range has had multiple owners, smoke smell, issues, or body damage.  Or the ridiculously modified trucks with 80k miles for under $27k but lots of problems...
    • KARNUT
      OCI, not when but why?

      By KARNUT · Posted

      That’s pretty tough Grumpy. I reread the previous few posts. They all reference oil changes. Much like your last thread. In my humble opinion it keeps things interesting.
    • Grumpy Bear
      OCI, not when but why?

      By Grumpy Bear · Posted

      Engine Wear and ISO 4406   1.) Cold Starts. 2.) High Particle Count. 3.) Low operating temperature viscosity and high low temperature cranking viscosity. 4.) Depleted AW, Friction and Acid packages.  5.) High engine load.    https://me.caltexlubricants.com/en_me/home/learning/from-chevron/heavy-duty-diesel-vehicles-and-equipment/The-Importance-of-Clean-Engine-Oil-and-Its-Impact-on-Equipment-and-Business-Performance.html   High particle counts have five sources. 1.) They are manufactured within the engine. Both wear debris and amalgamation of degradation products and combustion driven soot (worse in GDI). 2.) They are ingested via intake air. Ever hear the best oil filter is a good air filter? 3.) They are entrained in the fuel. 4.) This one is insidious. They are introduced in 'fresh oil'. 5.) They are introduced during the oil change.   ISO 4406 is the test that measures and quantifies the combine effects of all of the above particle related issues. You can mitigate your way into multiples of engine life by being attentive to them all.    https://www.hyprofiltration.com/blog/is-new-oil-clean   (from the link above)    [Quote] What Is the Recommended ISO 4406 Cleanliness Code for New Oil?   A good upper limit for new oil cleanliness is 16/14/11 (ISO 4406). Typical new oil usually has ISO codes of 19/17/15 or worse, which is far too dirty for sensitive components. This can be a major cause of degradation and premature failure. [Close quote].     Source of graph: Machinery Lubrication (GM Study)  
    • Diamond817
      WTS: Pulsar LT 22451 GM Silverado/Sierra 5.3 & 6.2

      By Diamond817 · Posted

      Make me an offer!

  • GM-Trucks.com Clubs

  • Popular Contributors

×
×
  • Create New...