thump sound/ jolt after stopping

[jpinoy]

I've been going between this site and the 'old' site trying to find a clue on my concern/issue. the old site has good info, but feels like a ghost town....

I just picked up a 2006 TB LS 4.2 I6, about a month ago, got it with 107K/ miles... plan on doing a tranny filter/fluid change soon... along with plugs, air filter change... already cleaned throttle body and tightened the intake manifold bolts, couple of them were loose and I was getting the p107 code... anyways...

What I notice sometimes, after stopping at a light, after a few seconds, it would seem that the engine disengages... that's what it feels like anyways...

I feel a little thump, feels like it's coming from under middle/rear of the vehicle... it's happened maybe 6-9 times?... it's not consistent....

Anyone experience this before? any insight would be appreciated....

 

[Playsinsnow]

Welcome! That place is a ghost town. More will chime in soon, Sorry Wooluf!
http://gmtnation.com/f5/welcome-gmtnation-com-heres-story-226/


Have you checked the tranny fluid? How about the differentials? With 4wd, should exchange the transfer case fluid every 50k. Here is some info I came across... Might need more info on what is going on. Some have reported draining and refilling TC fluid solved THEIR issue...

http://gmtnation.com/f79/feels-like-i-get-rear-ended-when-sitting-red-light-2430/

 

[AtlWrk]

on changing the transfer case fluid. Needs to be done anyway. While you're under there you might as well grease the splines of the output yoke too. Fairly easy job.

 

[The_Roadie]

Welcome. I agree with the tactic of greasing the slip yoke. Worked for me. Huge thread on trailvoy titled Feeling of being bumped while stopped.

 

[jpinoy]

Welcome. I agree with the tactic of greasing the slip yoke. Worked for me. Huge thread on trailvoy titled Feeling of being bumped while stopped.

Thanks everyone! I had a feeling that was going to be the case and was thinking along the same lines as your guys suggestions. @the roadie, yes, as you stated, it does feel like getting bump while at a stop, I'll search that thread as well.

http://gmtnation.com/f5/welcome-gmtn...res-story-226/[/url]


Have you checked the tranny fluid? How about the differentials? With 4wd, should exchange the transfer case fluid every 50k. Here is some info I came across... Might need more info on what is going on. Some have reported draining and refilling TC fluid solved THEIR issue...

http://gmtnation.com/f79/feels-like-...ed-light-2430/

@Playsinsnow, tranny fluid level is good, but was going to change filter/fluid this coming weekend or next anyways The car fax on this TB only shows oil changes, but you never know if the owner(s) themselves did anything else to it, as it's had 5 different owners.... Thanks for the link, will check it out during my lunch break today

Thanks for the input guys, appreciate it!

 

[The_Roadie]

Here's where the grease goes:

 

[jpinoy]

Here's where the grease goes:

Thanks! It looks like I'll be spending about a day doing all the maintenance/tune-up work, gives me an excuse to skip some yard work

 

[deepblue]

Sounds like the "bump/clunk" thing... Do you have the rear air bag leveling suspension ?

 

[jpinoy]

Sounds like the "bump/clunk" thing... Do you have the rear air bag leveling suspension ?

I don't have the air bag levelling suspension.. and from reading the OS thread that was linked, there was a lot of debate on the air bag leveling suspension as being the culprit and it seemed that whether you had it or not, it didn't make a difference as others that didn't have the air bags, like me, is experiencing the same thing.

I did find it funny as one of the members, believe he had an 03 Envoy, was very persistent on it being the airbag leveling suspension, and how he got rid of the problem, was to sell his 03 and buy an 05(06).. haha.. which he eventually chimed in later that his 05 was also now doing the same thing..

Drove around town for a while yesterday after work, and it didn't happen once. Tried doing the hard stops and slow stops... didn't get the bump/clunk.... Mine is not consistent, it's only happened a couple times in the month I've had it..... but I'll be under there doing a tranny fluid/filter change soon and will look at the other things mentioned already


Thanks for the input

 

[deepblue]

this is what solved the bump/clunk for me.... I believe it was a problem on trucks without the leveling suspension too...


The Bump/Clunk fix involves replacing output shaft and drive shaft yoke in the transfer case.

Technical Service Bulletin #07-04-17-001C: EI07148 - Bump/Thump Noise Heard/Felt from Driveline or Rear suspension After Braking (Replace Output Shaft/Drive Shaft Yoke) - (Aug 25, 2008)

Condition

Some customers may comment on a bump or thump noise heard from the rear suspension or felt in the floor. The information below will affect vehicles with G67 Automatic Level Control rear suspension. This noise will typically occur at traffic lights after rapid stops. This noise is due to a combination of the rear electronic suspension attempting to level the vehicle and the driveline becoming unbound after these rapid stops.

Correction

Contact your DVM (District Service Manager) for approval prior to making any repairs. 4WD Vehicles - Replace the Output Shaft of the Transfer Case and the Drive Shaft Yoke and grease with P/N 12345879 (in Canada, use P/N 10953511) . Reinstall and evaluate operation. 2WD Vehicles - Replace the Output Shaft of the Transmission and Drive Shaft Yoke. Reinstall and evaluate operation.

 

[jpinoy]

this is what solved the bump/clunk for me.... I believe it was a problem on trucks without the leveling suspension too...


[/I]

Yeah, I saw that TSB as well, I think in the OS. That would have to be my last resort if the cheaper alternatives that's been suggested doesn't work out. Seem some people are seeing/experiencing the bump/clunk way more than others.. for me, it's not consistent and can't reproduce it at will...

Glad yours got resolve