Shifting noise when I stop and then go??? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

RunTMCfan · 08-14-2006, 12:30 PM

When I firmly press the brakes at say 10mph everything stops great. But I feel a shifting somewhere under the driver seat and towards the the fender well. It shifts again when I take off.

Is this a clue to the ultimate demise of my Rockers???

tom71 · 08-14-2006, 11:23 PM

run i would jack it up with jack stands under both the axles , start it up and put your foot firmly on the brake and then put it into drive let the brake out and slightly press the accelerator and then press the brake again and try to feel if it is still shifting , you could have a buddy look around down there while doing this to see if anything seems irregular. check your motor mounts and trans mounts too as well as spring perches . but really its hard to tell with out driving the vehicle 1st hand

cdowns · 08-15-2006, 12:12 PM

i'd check the cab mounts could be rusted or broken or the rubber mounts have rotted to nothing causing the cab to shift

RunTMCfan · 08-15-2006, 01:09 PM

Motor is tight. I could be the cab mounts. I have not done the fronts yet.

tom71 · 08-16-2006, 10:04 PM

oh i saw one of your posts about body mounts i thought you did all of them so i ruled those out .

Huck · 08-17-2006, 07:21 AM

HOld your foot hard on the brake while the truck is in gear, then rev it enough to torque the engine and trans. Do this a couple of times and the problem will become obvious when the thing comes apart!hehehehehe--Don't do this in a garage or while parked behind your local police car. I suspect motor mounts, trans mount or spring mount issue. Was a common problem way back when.

RunTMCfan · 08-17-2006, 10:08 PM

Thanks guys. Good advice huck.

Chris_T · 08-18-2006, 06:13 PM

Sounds a lot like mine at one point - a bad trans mount that eventially led to a loose crossmember

Mark Mazzanti · 08-21-2006, 04:15 PM

Check your upper control arm shims. I have seen many of come out and have that exact problem

08-14-2006, 12:30 PM	#1
RunTMCfan Registered User Join Date: Oct 2005 Location: San Diego, Ca Posts: 251	Shifting noise when I stop and then go??? When I firmly press the brakes at say 10mph everything stops great. But I feel a shifting somewhere under the driver seat and towards the the fender well. It shifts again when I take off. Is this a clue to the ultimate demise of my Rockers??? __________________ Rob "RunTMCfan"

08-14-2006, 11:23 PM	#2
tom71 what happened to flint mi Join Date: Oct 2005 Location: san diego Posts: 437	Re: Shifting noise when I stop and then go??? run i would jack it up with jack stands under both the axles , start it up and put your foot firmly on the brake and then put it into drive let the brake out and slightly press the accelerator and then press the brake again and try to feel if it is still shifting , you could have a buddy look around down there while doing this to see if anything seems irregular. check your motor mounts and trans mounts too as well as spring perches . but really its hard to tell with out driving the vehicle 1st hand __________________ 71 swb 2wd fleet frame off in progress 72 4x4 blazer daily driver 70 olds cutlass s mint condition owned by a grandma 56 gmc 2wd project waitng 97 fiance mobile

08-15-2006, 12:12 PM	#3
cdowns Senior Member Join Date: Jan 2003 Location: daytonabeach Posts: 22,956	Re: Shifting noise when I stop and then go??? i'd check the cab mounts could be rusted or broken or the rubber mounts have rotted to nothing causing the cab to shift __________________ 71c-10 350/2004r/4:11 lowered3/4 longbed/dead by hurricane MEANING OF DEATH::::: SOMEBODY ELSE GETS YOUR STUFF DONT BELIEVE EVERYTHING YOU THINK TAKE MY ADVISE;I DON'T USE IT ANYWAY

08-15-2006, 01:09 PM	#4
RunTMCfan Registered User Join Date: Oct 2005 Location: San Diego, Ca Posts: 251	Re: Shifting noise when I stop and then go??? Motor is tight. I could be the cab mounts. I have not done the fronts yet. __________________ Rob "RunTMCfan"

08-16-2006, 10:04 PM	#5
tom71 what happened to flint mi Join Date: Oct 2005 Location: san diego Posts: 437	Re: Shifting noise when I stop and then go??? oh i saw one of your posts about body mounts i thought you did all of them so i ruled those out . __________________ 71 swb 2wd fleet frame off in progress 72 4x4 blazer daily driver 70 olds cutlass s mint condition owned by a grandma 56 gmc 2wd project waitng 97 fiance mobile

08-17-2006, 07:21 AM	#6
Huck Senior Member Join Date: Jun 2001 Location: Shelbyville, KY Posts: 3,269	Re: Shifting noise when I stop and then go??? HOld your foot hard on the brake while the truck is in gear, then rev it enough to torque the engine and trans. Do this a couple of times and the problem will become obvious when the thing comes apart!hehehehehe--Don't do this in a garage or while parked behind your local police car. I suspect motor mounts, trans mount or spring mount issue. Was a common problem way back when.

08-17-2006, 10:08 PM	#7
RunTMCfan Registered User Join Date: Oct 2005 Location: San Diego, Ca Posts: 251	Re: Shifting noise when I stop and then go??? Thanks guys. Good advice huck. __________________ Rob "RunTMCfan"

08-18-2006, 06:13 PM	#8
Chris_T Registered User Join Date: May 2003 Location: Saskatoon, SK Posts: 44	Re: Shifting noise when I stop and then go??? Sounds a lot like mine at one point - a bad trans mount that eventially led to a loose crossmember

08-21-2006, 04:15 PM	#9
Mark Mazzanti Registered User Join Date: Oct 2002 Location: California Posts: 27	Re: Shifting noise when I stop and then go??? Check your upper control arm shims. I have seen many of come out and have that exact problem



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