Vibration after transmission swap
Thread Starter
Le Mans Master
Joined: Feb 2011
Posts: 5,943
Likes: 61
From: Southern NH
Vibration after transmission swap
So I got my automatic to Richmond 5 speed swap done, But I get terrible vibrations from the engine now. I was thinking my flywheel maybe be bad, but I can feel the vibration in the car, but revving the engine from the outside with my hand on the engine it feels smooth.
I had poly engine mounts already, but installed a poly trans mount and poly front snubber bushing at the same time as the trans. Is it possible the new mounts are transmitting that much vibration though the chassis that it feels like it's shaking the car apart?
I had poly engine mounts already, but installed a poly trans mount and poly front snubber bushing at the same time as the trans. Is it possible the new mounts are transmitting that much vibration though the chassis that it feels like it's shaking the car apart?
Thread Starter
Le Mans Master
Joined: Feb 2011
Posts: 5,943
Likes: 61
From: Southern NH
I accelerated pretty hard once and it felt like the car was coming apart in all gears. I'm thinking I need to check my driveshaft angle also.
I'm using an Energy Suspensions poly trans mount, I've read online a few places that it may be taller then the stock mount, if so that could be putting my drive shaft out of alignment.
I'm not sure if I have one problem or a combination of problems, I'm just trying to look into anything I can before pulling the trans back out.
I think tomorrow I'm going to start by putting a stock rubber bushing in, since they're only $7 at NAPA
Le Mans Master
Joined: Nov 2003
Posts: 5,772
Likes: 694
From: Maryland
St. Jude Donor '05, '09, '15
As you probably realize a vibration while stationary at idle or in neutral just reeving the engine up, drive-shaft angle would not come into play. I would start by tying to pinpoint the source of that vibration first.
Drifting
Joined: Mar 2011
Posts: 1,347
Likes: 121
From: Kernersville NC
Does it have a new driveshaft? If not, is it indexed to the diff like it was removed? If you feel it while in motion but not while stopped I would suspect the driveshaft, either balance or angle, or a forzen u-joint.
Melting Slicks
Joined: Dec 2009
Posts: 3,233
Likes: 657
From: Thunder Bay
You need to figure out where the vibration is coming from before you do anything. Does the car need to be moving for the vibration to be present? If so, its driveshaft or transmission. Does it vibrate in neutral when you rev the engine? If so its clutch assembly or transmission. Does it vibrate with the clutch depressed and the transmission in gear? If so its flywheel or pressure plate. A little logic and some experimentation will tell you where the problem is coming from before you start throwing parts at it.
Thread Starter
Le Mans Master
Joined: Feb 2011
Posts: 5,943
Likes: 61
From: Southern NH
I can try rotating the drive shaft on yoke or even get new u joints for my old driveshaft and try that also.
I'm going to bring it into work and check my driveshaft angle tomorrow on the alignment rack. I did have to modify my stock crossmember, so it's very possible something is off.
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Team Owner
Joined: Oct 2004
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From: altered state
St. Jude Donor '05
BTDT get rid of the poly trans mount and get a rubber one in there
Trans cant be too rigid mounted it has to have some give or youll tear things up. Switched mine out night and day difference.
Make sure nothing is touching your floorboard either it canb transfer some harmonics through the floorboard depending on what gear youre in., engine load etc.
Also make sure your Ujoints are properly seated in theri spots it can be decieving
Trans cant be too rigid mounted it has to have some give or youll tear things up. Switched mine out night and day difference.
Make sure nothing is touching your floorboard either it canb transfer some harmonics through the floorboard depending on what gear youre in., engine load etc.
Also make sure your Ujoints are properly seated in theri spots it can be decieving
Last edited by cv67; Apr 14, 2012 at 09:18 AM.
Melting Slicks
Joined: Sep 2004
Posts: 2,655
Likes: 19
I've seen a few threads on trans swaps. Pretty much everyone ends up with the trans down in the back. My Richmond 6 speed was 3 degrees down and could not be moved up any higher. From the factory, both the trans and diff are about 0 degrees. I rotated the front of the diff up by thinning the front diff rubber mount.
Thread Starter
Le Mans Master
Joined: Feb 2011
Posts: 5,943
Likes: 61
From: Southern NH
I didnt dial in the bellhousing, I'm using a stock GM bell and I've never read anyone who has had an issue with a stock one, but who knows, I could be the one. I used a new throw out bearing. I went with the hydraulic style.
I drove the car to work this morning. 50 miles. I didn't seem as bad as it was before. the clutch chatter is getting better. maybe I just need to break it in more?
But i definitely have a vibration from 2700-3500 rpm when accelerating or driving steady at those rpms.
I drove the car to work this morning. 50 miles. I didn't seem as bad as it was before. the clutch chatter is getting better. maybe I just need to break it in more?
But i definitely have a vibration from 2700-3500 rpm when accelerating or driving steady at those rpms.
Race Director
Joined: Feb 1999
Posts: 19,659
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From: Lenoir City Tennessee
Ci 6, 8 & 10 Veteran
St. Jude Donor '05-'06-'07-'08-'09-'10-'11-'12-'13-'14-'15
My 70 had vibration after I put a Keisler in. I wound up having to shim the rear of my trans up in order to make the vibration go away. Runs nice and smooth now. I used flat washers between the trans and mount to raise the rear of the trans. Check the drive line angles and see if that doesn't help.
Drifting
Joined: Nov 2003
Posts: 1,874
Likes: 7
From: l In
What engine are you running ? I would double check the part number on the flywheel. I am running a 383 and used a Hays billet 400 cid flywheel with a 5 speed Richmond. They might have sent you an external balanced flywheel, if you are running a 350, it should be internal balanced fly.
Just my $ .02 worth
Just my $ .02 worth
Last edited by Phil Zell; Apr 15, 2012 at 10:02 AM.
Thread Starter
Le Mans Master
Joined: Feb 2011
Posts: 5,943
Likes: 61
From: Southern NH
I'm running the stock engine. I called Paul at American Powertrain and he verified the correct flywheel was ordered. there were no part numbers on the box or anything, but I didnt see any external weights or holes drilled in it so i'm guessing its a zero balance wheel.
I'm going to see if NAPA has a rubber trans mount in stock right now.
I'm going to see if NAPA has a rubber trans mount in stock right now.
Race Director
Joined: May 2003
Posts: 10,956
Likes: 409
From: California
I didnt dial in the bellhousing, I'm using a stock GM bell and I've never read anyone who has had an issue with a stock one, but who knows, I could be the one. I used a new throw out bearing. I went with the hydraulic style.
I drove the car to work this morning. 50 miles. I didn't seem as bad as it was before. the clutch chatter is getting better. maybe I just need to break it in more?
But i definitely have a vibration from 2700-3500 rpm when accelerating or driving steady at those rpms.
I drove the car to work this morning. 50 miles. I didn't seem as bad as it was before. the clutch chatter is getting better. maybe I just need to break it in more?
But i definitely have a vibration from 2700-3500 rpm when accelerating or driving steady at those rpms.
and not the throughout bearing,..... did you put in your pilot bearing?
http://forums.corvetteforum.com/c3-t...o-still-5.html
Burning Brakes
Joined: May 2008
Posts: 1,116
Likes: 5
From: Middleburg Florida
I'd bet the drive line angle is off. Happened to me when I swapped to the 2004R, and it was a pain to figure out. Looked at everything, ujoints, driveshaft, even the harmonic balancer. Started shimming the trans....vibrations went away...
Thread Starter
Le Mans Master
Joined: Feb 2011
Posts: 5,943
Likes: 61
From: Southern NH
Yes, I put in a stock GM bronze pilot bushing.
vibration is the same RPM in every gear.
NAPA just delivered my trans mount. as soon as it slows down in here I'll get the mount in and check driveline angle.
vibration is the same RPM in every gear.
NAPA just delivered my trans mount. as soon as it slows down in here I'll get the mount in and check driveline angle.
Team Owner
Joined: Oct 2004
Posts: 81,241
Likes: 3,063
From: altered state
St. Jude Donor '05
That mount will help
May solve all of it might not. But it will help period.
Your Ujoints are new so thats out.
Check pinion angle as you said.
Driveshaft may need to be balanced but doubt youd have the same vibes in every gear. Is the trans touching the underside of the body anywhere under accelration?
May solve all of it might not. But it will help period.
Your Ujoints are new so thats out.
Check pinion angle as you said.
Driveshaft may need to be balanced but doubt youd have the same vibes in every gear. Is the trans touching the underside of the body anywhere under accelration?