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Hey guys, I have just finished installing the set of Hinson engine/trans mounts, and after putting everything back together, and going through a test drive I noticed a very pronounced grinding/scraping sound, that seems to be coming from the torque tube tunnel, and starts when I engage the clutch and continues as long as I'm accelerating. Coming off throttle or in neutral doesn't make this sound. The sound also increases in loudness the higher the gears, but does not do anything in reverse.
I am completely stumped and I don't know what it could be. I tried checking all the things I bolted together, and everything is tight, exhaust doesn't contact anything that I see.
Hey guys, I have just finished installing the set of Hinson engine/trans mounts, and after putting everything back together, and going through a test drive I noticed a very pronounced grinding/scraping sound, that seems to be coming from the torque tube tunnel, and starts when I engage the clutch and continues as long as I'm accelerating. Coming off throttle or in neutral doesn't make this sound. The sound also increases in loudness the higher the gears, but does not do anything in reverse.
I am completely stumped and I don't know what it could be. I tried checking all the things I bolted together, and everything is tight, exhaust doesn't contact anything that I see.
HELP!
Grinding/scraping sound? Do you mean vibrations? Does the sound get louder the higher the rpms are getting? Seems logical if your going with stiffer mounts, these mounts in turn will send vibrations and noises through out the car but in turn wont allow the drivetrain to wobble around.
I have a hoosier trans brace diff mount with stock engine mounts and everytime I go above 3000+rpm I have alot of noise and vibrations going through out the car, though the benefit I got was I no longer have wheel hop like I did with the stock mount. Performance parts have its positives and negatives.
This is not a normal noise. Vibrations are one thing there are not any that are out of the ordinary. This is a sort if metallic scraping sound, that gets louder with speed/engine rpm, and only happens with throttle, not in neutral, or just free revving. Its only on power in a forward gear.
Last edited by Lemansz06fan; 03-20-2016 at 11:56 PM.
Reason: Video
That noise definetly isnt normal I wouldnt even drive it for the mean time until you figure it out, I would put the car on a two post lift turn it on, turn off traction control put the car in gear spin the rear wheels and have some guys on the side and underneath the car with lights pointing underneath to see where the noise is coming from.
Also how did u remove the rear cradle to install the new mount? If you can't pin point the noise in the rear, put in the oem differential/trans mount and see if the noise is gone. For the mean time I wouldnt get on the car hard or you'll start breaking parts.
That noise definetly isnt normal I wouldnt even drive it for the mean time until you figure it, I would put the car on a two post lift turn it on, turn off traction control put the car in gear spin the rear wheels and have some guys on the side and underneath the car with lights pointing underneath to see where the noise is coming from.
Also how did u remove the rear cradle to install the new mount? If you cant pin point the noise, put in the oem mount and see if the noise is gone for the meanwhile I wouldnt get on the car hard or you'll start breaking parts.
So I did get the car up in the air and tried running the engine in gear and was unable to find the sound from outside the car.
I did not remove the cradle to install the mounts, only the exhaust and unbolted the brackets.
I have the LS7/ZR-1 exhaust manifolds and xpipe and I think I may have put it back together incorrectly causing an exhaust leak. On this exhaust I put new OEM dounut seals between the cat pipes and the x pipe. Was there any sealant that was supposed to go on these?
The only other thing I did was remove the clutch inspection cover to see if I could see anything in the clutch/flywheel area but everything seemed secure and looked good.
Last edited by Lemansz06fan; 03-21-2016 at 09:20 AM.
So I did get the car up in the air and tried running the engine in gear and was unable to find the sound from outside the car.
I did not remove the cradle to install the mounts, only the exhaust and unbolted the brackets.
I have the LS7/ZR-1 exhaust manifolds and xpipe and I think I may have put it back together incorrectly causing an exhaust leak. On this exhaust I put new OEM dounut seals between the cat pipes and the x pipe. Was there any sealant that was supposed to go on these?
If you couldnt find a noise and their isnt any vibrations feeling out weird, it might be true that it is manifolds/exhaust did you install them after the motor mounts went in? Also did they bolt in place where the stock mid pipe hangs from and sit fine? I dont have any knowledge with the ls7 manifolds, but one thing about the ls1/ls6 with the stock cam everytime you go above 3.5k rpm the tone and sound of the engine changes remarkably like it wakes up, in your video when you roll on it hard it makes the noise, it also makes the noise on the downshift. But thats also the case you dont have any noise durint free reving? This is tricky.
If you couldnt find a noise and their isnt any vibrations feeling out weird, it might be true that it is manifolds/exhaust did you install them after the motor mounts went in? Also did they bolt in place where the stock mid pipe hangs from and sit fine? I dont have any knowledge with the ls7 manifolds, but one thing about the ls1/ls6 with the stock cam everytime you go above 3.5k rpm the tone and sound of the engine changes remarkably like it wakes up, in your video when you roll on it hard it makes the noise, it also makes the noise on the downshift. But thats also the case you dont have any noise durint free reving? This is tricky.
A few more observations of this noise on my way to work (took it really easy). First is that the speed of the car does not matter. in 6th gear at 65-70mph there is no sound. As the RPMs rise, or anything above 20% throttle or so, you can hear that roar. Sounds kind of like the new mustangs and their sound tube. The weird thing is it seems to skip over bumps when the gas is applied (part throttle steady state).
There are no out of the ordinary vibrations or harshness, and actually the new mounts may have relieved some of the vibrations I was having at 4k rpm like described in another thread.
The exhaust all *seems* to be put together properly, but I will loosen everything up and try to re align the connections. If I had to pinpoint the sound, it sounds like its coming from the tunnel behind the flywheel (around the shifter), which is about where the mid-pipe to X-pipe connection is.
Looks like a mgw lower shifter box, and from the looks of it, its sitting higher in the rear, hopefully OP knows that the Urethane in the hinson mounts won't compress down like the OEM oil filled mounts.
Looks like a mgw lower shifter box, and from the looks of it, its sitting higher in the rear, hopefully OP knows that the Urethane in the hinson mounts won't compress down like the OEM oil filled mounts.
^this
the front mounts measured correctly compared to the uncompressed engine mounts, however the rear transmission mount measured 1/8" taller uncompressed. this lead to the increase in hight of the rear of the drivetrain. I replaced the diff mount with the OEM GM mount (about 4000mi new) and everything has gone to normal, except when getting the rear to hop . I will contact Hinson and see what I can do about this mount. Is there some reason I shouldn't go with the 3/8" lower mount (or is that only the engine mounts they have lower?)?
Originally Posted by LoneStarFRC
No.
Thankfully this is a good thing, it means I couldn't have messed up the install as I removed the brackets to remove the mounts.
03-20-2016, 08:40 PM
Grinding/scraping sound after motor mount install
