07 Silverado Bump/clunk

[Wolverine]

I know this has been discussed in other forums as I have tried a variety of searches but have noticed a couple of times when I brake and come to a complete stop and then hit the accelerator it feels as tho someone just gave my bumper a love tap. I have seen that many recommend lubing the slip yoke and was wondering if there was an official TSB on this issue for the NBS trucks????? Taking it into the shop tomorrow before my warranty is up in 1500 miles and wanted to make sure they focus there attention on what others have described.

 

Also gonna have them look at the oil usage of being a quart low with 28% engine oil life remaining and a dripping sound I heard last night on the passenger side but could not find any water....

 

thanks......

[Dbeto54]

I know this has been discussed in other forums as I have tried a variety of searches but have noticed a couple of times when I brake and come to a complete stop and then hit the accelerator it feels as tho someone just gave my bumper a love tap. I have seen that many recommend lubing the slip yoke and was wondering if there was an official TSB on this issue for the NBS trucks????? Taking it into the shop tomorrow before my warranty is up in 1500 miles and wanted to make sure they focus there attention on what others have described.

 

Also gonna have them look at the oil usage of being a quart low with 28% engine oil life remaining and a dripping sound I heard last night on the passenger side but could not find any water....

 

thanks......

 

did they fixed your problem about the slip yoke? Im having same problem with mine i also had water under the carpet on the passenger side. My a/c compressors clutch turnrs on even with the a/c off

[ajcain79]

I know this has been discussed in other forums as I have tried a variety of searches but have noticed a couple of times when I brake and come to a complete stop and then hit the accelerator it feels as tho someone just gave my bumper a love tap. I have seen that many recommend lubing the slip yoke and was wondering if there was an official TSB on this issue for the NBS trucks????? Taking it into the shop tomorrow before my warranty is up in 1500 miles and wanted to make sure they focus there attention on what others have described.

 

Also gonna have them look at the oil usage of being a quart low with 28% engine oil life remaining and a dripping sound I heard last night on the passenger side but could not find any water....

 

thanks......

 

Yes, there is a TSB on the issue. I've had mine in twice for that and the fix lasts about a month or two. I just keep taking it back. Maybe eventually they will really fix the problem.

[07blkchevyz71]

I know this has been discussed in other forums as I have tried a variety of searches but have noticed a couple of times when I brake and come to a complete stop and then hit the accelerator it feels as tho someone just gave my bumper a love tap. I have seen that many recommend lubing the slip yoke and was wondering if there was an official TSB on this issue for the NBS trucks????? Taking it into the shop tomorrow before my warranty is up in 1500 miles and wanted to make sure they focus there attention on what others have described.

 

Also gonna have them look at the oil usage of being a quart low with 28% engine oil life remaining and a dripping sound I heard last night on the passenger side but could not find any water....

 

thanks......

 

Yes, there is a TSB on the issue. I've had mine in twice for that and the fix lasts about a month or two. I just keep taking it back. Maybe eventually they will really fix the problem.

 

 

Can you post a link to the TSB? I'm having this same problem...

[Xtremski74]

2007 Chevrolet Silverado Power Train Complaints #10296301

Year: 2007

Make: Chevrolet

Model: Silverado

Complaint Number: 10296301

Manufacturer: General Motors Corp

Was Vehicle Involved in a Crash: No

Incident Date: September 29, 2008

Was Vehicle Involved in a Fire: No

Number of Persons Injured: n/a

Number of Fatalities: n/a

Specific Component's Description: Power Train

Consumer's City: Memphis

Consumer's State: TN

Vehicle Identification Number: 2GTEC13J771

Date Added to File: December 17, 2009

Date Complaint Received by NHTSA: December 17, 2009

Vehicle Mileage at Failure: 28000 Miles

Number of Occurrences: 1

Date of Purchase: n/a

Is Original Owner: No

Has Anti-Lock Brakes: No

Has Cruise Control: No

Number of Cylinders: n/a

Drivetrain Type: n/a

Fuel System Type: n/a

Fuel Type: n/a

Transmission Type: n/a

Vehicle Speed: n/a

Description of the Complaint:

Thump after coming to a stop. After about 24,000 miles. I started feeling a light thump from the rear, as if someone bumped me from behind. Over the next few weeks it became very noticeable, so I took it to the dealer for investigation. The 1st time, they said the rear-end had the wrong lube in it & they replaced it. This seem to work for the next several weeks. Then the thump returned lightly at 1st & gradually worsened to a major thump. I returned it to the dealer & this second repair was that the lubed the rear-end & replaced the yoke on the driveshaft. This repair worked for about a week & I started feeling the light thump again. I took it back in again, left it all day & they apparently drove it around the parking lot & couldn't duplicate the problem. One of the service managers rode with me, around the parking lot & the problem wouldn't show up. It has since worsened again & I will take it back in once the problem gets a little worse.

 

 

This is all I could find! Couldn't find a NSB!

[s10driver85]

I know this has been discussed in other forums as I have tried a variety of searches but have noticed a couple of times when I brake and come to a complete stop and then hit the accelerator it feels as tho someone just gave my bumper a love tap. I have seen that many recommend lubing the slip yoke and was wondering if there was an official TSB on this issue for the NBS trucks????? Taking it into the shop tomorrow before my warranty is up in 1500 miles and wanted to make sure they focus there attention on what others have described.

 

Also gonna have them look at the oil usage of being a quart low with 28% engine oil life remaining and a dripping sound I heard last night on the passenger side but could not find any water....

 

thanks......

 

Okay i too had the same problem with the rear end, this is what i did. beings how gm makes great trucks but buts garbage rear ends in there half ton truck theres only one solution. take it to a ring and pinon shop and REBUILD. start by throwing away the crap 3.23 or 3.55 gears and put 3.73s in, get all new tinkin bearings and a nice posi for it. take all the old parts and throw them into the front window of your local dealership. make sure you buy good quality usa parts. ive totally stoped the problem and got more performance but its spendy, about $1500 for my 2wd. o yea. that clunk it probably your pinion crush bearing mine had 1/8 of an inch woble to it!!!! okay and about ur oil. did you do the oil change? are you using synthetic? one of two things i can think of, a conventional small block uses 5 quarts, yours uses 6, some one might have screwed up. or if not using synthetic(when you should) you might have burnt a quart

[herkdriver007]

s10driver--I have the same problem...and its the 14BSF with 3.73...not the infamous 10 bolt...so I'm not quite sure your argument holds water

[brims]

I know this has been discussed in other forums as I have tried a variety of searches but have noticed a couple of times when I brake and come to a complete stop and then hit the accelerator it feels as tho someone just gave my bumper a love tap. I have seen that many recommend lubing the slip yoke and was wondering if there was an official TSB on this issue for the NBS trucks????? Taking it into the shop tomorrow before my warranty is up in 1500 miles and wanted to make sure they focus there attention on what others have described.

 

Also gonna have them look at the oil usage of being a quart low with 28% engine oil life remaining and a dripping sound I heard last night on the passenger side but could not find any water....

 

thanks......

 

Okay i too had the same problem with the rear end, this is what i did. beings how gm makes great trucks but buts garbage rear ends in there half ton truck theres only one solution. take it to a ring and pinon shop and REBUILD. start by throwing away the crap 3.23 or 3.55 gears and put 3.73s in, get all new tinkin bearings and a nice posi for it. take all the old parts and throw them into the front window of your local dealership. make sure you buy good quality usa parts. ive totally stoped the problem and got more performance but its spendy, about $1500 for my 2wd. o yea. that clunk it probably your pinion crush bearing mine had 1/8 of an inch woble to it!!!! okay and about ur oil. did you do the oil change? are you using synthetic? one of two things i can think of, a conventional small block uses 5 quarts, yours uses 6, some one might have screwed up. or if not using synthetic(when you should) you might have burnt a quart

 

 

How does greasing the slip yoke stop a clunk from the rear end?

 

As for the gear ratio, never heard of 3.55 in these trucks, and if someone wants 3.23 for gas mileage, no reason they should "just throw them away". Someone could say the same about the 3.73, what if you're towing, should get 4.56.

[nick3941sd]

I bought a 09 Silverado 5.3 with 3.73s in the rear in Dec. Should I be expecting this problem soon or is this something GM has worked out?

[brims]

I bought a 09 Silverado 5.3 with 3.73s in the rear in Dec. Should I be expecting this problem soon or is this something GM has worked out?

 

No, you're not immune, they've had this problem for years. The GMT800s had a TSB if I remember correctly, not sure if there were others. Get some marine grease and pack the slip yoke splines. The gear ratio has nothing to do with it.

[Wolverine]

I have not taken my ride in yet for the bump / clunk since it seems to have mysteriously gone away. Hate it when that happens. As far as the oil consumption goes I change the oil myself and always use Mobil 1 synthetic with ac delco filter and of course 6 quarts of it. As far as how many miles are on it since reset of oil life indicator I am not positive but guestimating around 5k....

[shocktrp]

I did some research & the suggested fix was a PCM/TCM re-flash.

 

I took it back to the dealer, they told me the same thing, & they did a re-flash.

 

I still have the same "bump" - big surprise, the dealer couldn't fix it.

[csheatz]

I bought a 09 Silverado 5.3 with 3.73s in the rear in Dec. Should I be expecting this problem soon or is this something GM has worked out?

 

No, you're not immune, they've had this problem for years. The GMT800s had a TSB if I remember correctly, not sure if there were others. Get some marine grease and pack the slip yoke splines. The gear ratio has nothing to do with it.

 

 

I had this issue, and this is how I fixed it, has lasted thus far (10k). I am going to check it come warmer weather, just because I will be bored not because its making noise again.

[Thurman]

May I share this: 1) I have an '07 GMC, NBS, CC, 5.3, Z-71 2-WD, 44K miles, and have had the infamous "bump" since new. 2) I work at an auto parts store part time and often deliver to get outside, this let's me talk to dealership tech's and independent shop tech's. 3) I have had my truck into three (3) different dealers about this "bump". I get two different stories as to the cause of the problem: 1) The slip-yoke was not adequately lubed (greased) at the factory, 2) I have the Eaton locking (not posi) rear and the plates in the locker are not releasing as the should-they wait until the truck is stopped. The answers I'm getting: For the slip yoke-1) Putting Marine grade grease in the yoke seems to be a good solution. I went/bought a tube of Marine grease, for outboard motor lower cases, so a shop would do mine for a trial. This lasted maybe 5K miles. Grease it again, and so far-so good. 2) Get a GM dealer to authorize the slip-yoke replacement with the "Nickel coated" yoke. But-I'm told these are not working any better. 3) For the Eaton rear Locker--NO known solution. There has been discussion with two dealer shops as to proper lube. Because they have nothing in print from GM, they don't want to try another lube and possibly void warranty-go figure. One shop ran a request with "Mitchell", computer program for shops, and found only the "grease slip yoke". NO TSB's. "How does greasing the slip yoke stop a clunk from the rear end?" Imagine a drag race car--when taking off there is "radial" torque applied to the rear axle, causing the top of axle to rotate forward. Wheelie bars prevent this. The same radial rotation happens when you apply brakes with your truck, pulling the slip yoke out of the tranny-slightly. Once you've stopped (even with your foot on the brakes) you will release the brakes slightly. At this moment the rear axle moves back into proper angle and the yoke moves forward, maybe 1/8. There's the "clunk/bump", caused by inadequate lube. It's not hitting, it's trying to slide-dry. This noise travels via the hollow drive shaft until it meets solid metal and resonates from the rear of the shaft. Not really the rear end. Unlike older tranny's (in truck's) tranny fluid does not lube the slip yoke today, due to a second seal within the tranny nowadays. Some of you may remember pulling a yoke without tilting the tailshaft housing up-instant fluid bath. My recommendation: Go buy a tube (maybe 4 oz.) of Marine grade grease, it's Green, remove the yoke, clean the inner splines good, lube with Green grease, and re-install. David

[brims]

There's no way I'm going to read that giant block of text.

 

I bought a 09 Silverado 5.3 with 3.73s in the rear in Dec. Should I be expecting this problem soon or is this something GM has worked out?

 

No, you're not immune, they've had this problem for years. The GMT800s had a TSB if I remember correctly, not sure if there were others. Get some marine grease and pack the slip yoke splines. The gear ratio has nothing to do with it.

 

 

I had this issue, and this is how I fixed it, has lasted thus far (10k). I am going to check it come warmer weather, just because I will be bored not because its making noise again.

 

 

I originally tried Mobil 1 grease, it didn't last more than a month. I went to marine grease based on this forum. It's been in there for 6,000 or 7,000 miles and it's good.