HomeDashboardFAQSearchRiviera Questions & AnswersWrite-Ups IndexRegisterRelated LinksMemberlistLog in
Share | 
 

 short vibration at 25kmh?

View previous topic View next topic Go down 
AuthorMessage
jlaw
Member
avatar

Name : Jay
Location : Vancouver Island, Canada
Joined : 2011-04-19
Post Count : 70
Merit : 2

PostSubject: short vibration at 25kmh?   Thu May 12, 2011 10:10 am

I don't know if this is a real issue or not. I've noticed that as I accelerate slowly, as I reach 25kmh I can feel a vibration through the gas pedal for a second. It goes away immediately and does not seem to happen except when first driving. I can't feel it if I doa jackrabbit start. I don't think it's tranny/shift related, I put it in 1str this morning and drove and felt it.

I was under the car the other day and looked at the CV boots on the driveshafts, they look intact, but that doesn't prove anything - Worn CV joint maybe?
Back to top Go down
AA
Administrator
avatar

Name : Aaron
Age : 40
Location : C-bus, Ohio
Joined : 2007-01-13
Post Count : 18310
Merit : 239

PostSubject: Re: short vibration at 25kmh?   Thu May 12, 2011 10:33 am

Just a guess, but could be an engine mount going bad. The vibration might only be transmitted when the engine is shifting under torque. 1st gear happens to create a lot of torque response.

_________________
'98 SC Riviera 268k miles 298 HP/370 TQ 0-60: 5.79s ET: 13.97 @ 99.28 4087 lb 20.1 avg MPG Nelson Ledges Lap: 1:30
3.4" pulley AL104 plugs 180 t-stat FWI w/K&N 1.9:1 rockers OR pushrods LS6 valve springs SLP headers ZZP fuel rails
KYB GR2 struts MaxAir shocks Addco sway bars UMI bushings GM STB Enkei 18" EV5s w/ Dunlop DZ101s F-body calipers
EBC bluestuff/Hawk HP plus SS lines Brembo slotted discs DHP tuned Aeroforce Hidden Hitch


'05 GTO 49k miles 0-60: 4.8s 16.9 avg MPG Nelson Ledges Lap: 1:26
Because fun
Back to top Go down
http://www.cardomain.com/ride/657082/4
jlaw
Member
avatar

Name : Jay
Location : Vancouver Island, Canada
Joined : 2011-04-19
Post Count : 70
Merit : 2

PostSubject: Re: short vibration at 25kmh?   Thu May 12, 2011 11:17 am

Yeah, that was the first thing I thought of, but it doesn't happen at a shift, like I said I can keep it in first and hit that speed and it happens. Is thetre a way to check CV joints in the driveway?
Back to top Go down
AA
Administrator
avatar

Name : Aaron
Age : 40
Location : C-bus, Ohio
Joined : 2007-01-13
Post Count : 18310
Merit : 239

PostSubject: Re: short vibration at 25kmh?   Thu May 12, 2011 11:48 am

If the CV boots are not torn, they should be good. If the boot is bad, grease will leak out to surrounding areas in the engine bay. My original CVs are still holding strong at 225k miles. They really overbuilt them, imo.

A bad CV will "click, click, click" when you are rolling or turning. The CV can also growl when accelerating or decelerating. This would be noticeable at high speeds as well.

_________________
'98 SC Riviera 268k miles 298 HP/370 TQ 0-60: 5.79s ET: 13.97 @ 99.28 4087 lb 20.1 avg MPG Nelson Ledges Lap: 1:30
3.4" pulley AL104 plugs 180 t-stat FWI w/K&N 1.9:1 rockers OR pushrods LS6 valve springs SLP headers ZZP fuel rails
KYB GR2 struts MaxAir shocks Addco sway bars UMI bushings GM STB Enkei 18" EV5s w/ Dunlop DZ101s F-body calipers
EBC bluestuff/Hawk HP plus SS lines Brembo slotted discs DHP tuned Aeroforce Hidden Hitch


'05 GTO 49k miles 0-60: 4.8s 16.9 avg MPG Nelson Ledges Lap: 1:26
Because fun
Back to top Go down
http://www.cardomain.com/ride/657082/4
jlaw
Member
avatar

Name : Jay
Location : Vancouver Island, Canada
Joined : 2011-04-19
Post Count : 70
Merit : 2

PostSubject: Re: short vibration at 25kmh?   Thu May 12, 2011 2:00 pm

Hmmm I just don't know then. I get a little wobble in the steering wheel sometimes too but that feels more like a power steering thing, something I take to be common from reading this forum. Maybe its a tire thing? I'll try to drive at that exact speed and see if it keeps vibrating....
Back to top Go down
AA
Administrator
avatar

Name : Aaron
Age : 40
Location : C-bus, Ohio
Joined : 2007-01-13
Post Count : 18310
Merit : 239

PostSubject: Re: short vibration at 25kmh?   Thu May 12, 2011 2:19 pm

The steering wobble might be a tie rod end thing.

_________________
'98 SC Riviera 268k miles 298 HP/370 TQ 0-60: 5.79s ET: 13.97 @ 99.28 4087 lb 20.1 avg MPG Nelson Ledges Lap: 1:30
3.4" pulley AL104 plugs 180 t-stat FWI w/K&N 1.9:1 rockers OR pushrods LS6 valve springs SLP headers ZZP fuel rails
KYB GR2 struts MaxAir shocks Addco sway bars UMI bushings GM STB Enkei 18" EV5s w/ Dunlop DZ101s F-body calipers
EBC bluestuff/Hawk HP plus SS lines Brembo slotted discs DHP tuned Aeroforce Hidden Hitch


'05 GTO 49k miles 0-60: 4.8s 16.9 avg MPG Nelson Ledges Lap: 1:26
Because fun
Back to top Go down
http://www.cardomain.com/ride/657082/4
jlaw
Member
avatar

Name : Jay
Location : Vancouver Island, Canada
Joined : 2011-04-19
Post Count : 70
Merit : 2

PostSubject: Re: short vibration at 25kmh?   Thu May 12, 2011 3:06 pm

Yeah I know, I know, but if it is tie rod ends experience tells me I can let it get MUCH worse before I fix it ha ha.
Back to top Go down
jlaw
Member
avatar

Name : Jay
Location : Vancouver Island, Canada
Joined : 2011-04-19
Post Count : 70
Merit : 2

PostSubject: Re: short vibration at 25kmh?   Thu May 12, 2011 4:49 pm

After trying to drive around at athat speed it seems like a short jolt - and once it happens it won't happen again until the car is put in park and then driven again. Maybe it is a motor mount "settling" a bit at that level of torque in 1st. I'll try swapping them out once I put my Tahoe back together (doing brakes on it in a peicemeal fashion)
Back to top Go down
rocafella1
Rookie
avatar

Name : datdamnrivi
Location : saint paul ,MN
Joined : 2011-05-06
Post Count : 18
Merit : 0

PostSubject: Re: short vibration at 25kmh?   Thu May 12, 2011 6:28 pm

Back to top Go down
albertj
Guru
avatar

Name :
Location : Finger Lakes of New York State
Joined : 2007-05-31
Post Count : 6763
Merit : 124

PostSubject: Re: short vibration at 25kmh?   Sat May 14, 2011 2:29 am

first thing to do is get under the car and look at the mounts.

The under-car transmission mounts are nowhere near as robust as the top pass side unit.

Albertj
Back to top Go down
jlaw
Member
avatar

Name : Jay
Location : Vancouver Island, Canada
Joined : 2011-04-19
Post Count : 70
Merit : 2

PostSubject: Re: short vibration at 25kmh?   Sat May 14, 2011 1:11 pm

How do I tell if they are worn to the point where they need to be replaced? The only other time I needed a mount, it was snapped in half, so it was pretty easy to tell.
Back to top Go down
AA
Administrator
avatar

Name : Aaron
Age : 40
Location : C-bus, Ohio
Joined : 2007-01-13
Post Count : 18310
Merit : 239

PostSubject: Re: short vibration at 25kmh?   Sat May 14, 2011 5:43 pm

I took mine to a local mechanic and put it up on a lift. He took a long bar and shifted the engine, showing me the movement and metal/metal contact occurring from the failing rear mount. He also diagnosed a bad ball joint and cradle insulators needing replacement. Well worth the $40 for diagnosis, imo.

_________________
'98 SC Riviera 268k miles 298 HP/370 TQ 0-60: 5.79s ET: 13.97 @ 99.28 4087 lb 20.1 avg MPG Nelson Ledges Lap: 1:30
3.4" pulley AL104 plugs 180 t-stat FWI w/K&N 1.9:1 rockers OR pushrods LS6 valve springs SLP headers ZZP fuel rails
KYB GR2 struts MaxAir shocks Addco sway bars UMI bushings GM STB Enkei 18" EV5s w/ Dunlop DZ101s F-body calipers
EBC bluestuff/Hawk HP plus SS lines Brembo slotted discs DHP tuned Aeroforce Hidden Hitch


'05 GTO 49k miles 0-60: 4.8s 16.9 avg MPG Nelson Ledges Lap: 1:26
Because fun
Back to top Go down
http://www.cardomain.com/ride/657082/4
rocafella1
Rookie
avatar

Name : datdamnrivi
Location : saint paul ,MN
Joined : 2011-05-06
Post Count : 18
Merit : 0

PostSubject: Re: short vibration at 25kmh?   Sat May 14, 2011 6:09 pm

its nice to know good honest mechanics
Back to top Go down
albertj
Guru
avatar

Name :
Location : Finger Lakes of New York State
Joined : 2007-05-31
Post Count : 6763
Merit : 124

PostSubject: Re: short vibration at 25kmh?   Sat May 14, 2011 7:38 pm

jlaw wrote:
How do I tell if they are worn to the point where they need to be replaced? The only other time I needed a mount, it was snapped in half, so it was pretty easy to tell.

Get the car on jackstands or a lift and look at the mounts.

The trans mounts are basically rubber cubes with a rubber bar molded through surrounding a ferrule. Please do a search, there are pictures on this site. (look for "Filling mounts" or some such)

When you look at the installed mounts, if the rubber is cracking they are weak and it is time to replace. You have some time before they completely fail but during that time they give you all kinds of cr-p when they are weak because the nice high-torque Riv engine whacks against the limits of travel in the mounts. *all* the mounts have to be good for the engine to sit right in the subframe.


Most likely the rear transmission mount is wack. If it has been bad long enough the excess movement will take out the front trans mount.

bounce
Back to top Go down
 
short vibration at 25kmh?
View previous topic View next topic Back to top 
Page 1 of 1
 Similar topics
-
» short vibration at 25kmh?
» Short Shifter
» Anti-vibration bars
» Vibration Dampening Insert
» Front-end Vibration

Permissions in this forum:You cannot reply to topics in this forum
Riviera Performance ::   Supercharged 3800 Tech :: Series II Engine & Transmission-
Jump to: