Bad motor mounts? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

ShowSS12 · 01-29-2010, 02:58 AM

I am trying to figure out a problem with my 87 C-10, When i shift into reverse I get a bad clunk. I thought it was just the trans mount so I changed that, but its still doing it. Plus I do get allot of vibration while i am on the brake and the trucks is in drive (i.e like waiting at a stop light) So my next thought would be possibly bad motor mounts? or something internally wrong with the trans?

spinem · 01-29-2010, 05:51 AM

take the hood off and drive aggressively and see if the engine hops. it that noise is indeed a motor mount, she'll "be-a-hoppn"

andrewmp6 · 01-29-2010, 09:02 AM

Have a friend get in it hold the brake put it in drive and rev it up and reverse too.If the engine bounces around your mounts are shot.

**old Rusty C10** · 01-29-2010, 12:23 PM

if the motor mounts check out check the U joints next then the center bearing if equipped

ShowSS12 · 01-30-2010, 02:50 AM

I have a one piece shaft and have already replaced the u-joints when I got the truck. I am just trying to figure out why it SLAMS into reverse

f.monroe · 01-30-2010, 01:48 PM

How high is the idle set ? What trans is in it ? Depending on the trans another thing is that if the trans has been rebuilt , the rebuilder may have left the anti-clunk spring out . It is designed to control the noise when shifting from a forward gear to reverse etc .
Frank

mickman77 · 02-01-2010, 02:48 PM

Have you checked the fluid level and condition? May be low or time for a fluid change if it is a trans problem..

01-29-2010, 02:58 AM	#1
ShowSS12 Registered User Join Date: Apr 2008 Location: Sugarland,Tejas Posts: 356	Bad motor mounts? I am trying to figure out a problem with my 87 C-10, When i shift into reverse I get a bad clunk. I thought it was just the trans mount so I changed that, but its still doing it. Plus I do get allot of vibration while i am on the brake and the trucks is in drive (i.e like waiting at a stop light) So my next thought would be possibly bad motor mounts? or something internally wrong with the trans? __________________ Adam M STX Designs Motorcycles \| Choppers \| Hotrods

01-29-2010, 05:51 AM	#2
spinem haha, ford guys... Join Date: Feb 2007 Location: Visalia, CA Posts: 576	Re: Bad motor mounts? take the hood off and drive aggressively and see if the engine hops. it that noise is indeed a motor mount, she'll "be-a-hoppn"

01-29-2010, 09:02 AM	#3
andrewmp6 Registered User Join Date: Jan 2009 Location: Louisville,Ky Posts: 5,811	Re: Bad motor mounts? Have a friend get in it hold the brake put it in drive and rev it up and reverse too.If the engine bounces around your mounts are shot.

01-29-2010, 12:23 PM	#4
old Rusty C10 Robert Olson Transport Join Date: Oct 2002 Location: recent transplant to NC USA Posts: 20,277	Re: Bad motor mounts? if the motor mounts check out check the U joints next then the center bearing if equipped __________________ Bob 1951 International running on a squarebody chassis "If a man's worth is judged by the people he associates himself with, then i am the richest man in the world knowing some of the fine people of this board" http://67-72chevytrucks.com/vboard/a...t.php?f=25&a=9 (you can review the site rules here!) PM Me for your vehicle/parts hauling needs in the North East US or see my Facebook page Robert Olson Transport Live each day to the fullest.. you never know when fate is going to pull the rug out from under you... I hate cancer!!

01-30-2010, 02:50 AM	#5
ShowSS12 Registered User Join Date: Apr 2008 Location: Sugarland,Tejas Posts: 356	Re: Bad motor mounts? I have a one piece shaft and have already replaced the u-joints when I got the truck. I am just trying to figure out why it SLAMS into reverse __________________ Adam M STX Designs Motorcycles \| Choppers \| Hotrods

01-30-2010, 01:48 PM	#6
f.monroe Senior Member Join Date: May 2004 Location: Caldwell,Tx. Posts: 3,648	Re: Bad motor mounts? How high is the idle set ? What trans is in it ? Depending on the trans another thing is that if the trans has been rebuilt , the rebuilder may have left the anti-clunk spring out . It is designed to control the noise when shifting from a forward gear to reverse etc . Frank __________________ Born and proudly residing in a Red State !

02-01-2010, 02:48 PM	#7
mickman77 Registered User Join Date: Nov 2008 Location: The land of fruits and nuts, Kingsburg CA Posts: 44	Re: Bad motor mounts? Have you checked the fluid level and condition? May be low or time for a fluid change if it is a trans problem.. __________________ '77 K20 LWB 454, NV4500, NP205, 4.10's rollin on 33's passin everything but a gas station.



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