A week or so ago I reported that after cleaning a bunch of undershield of my drive shaft my driveline vibration had gone away. Well the sucker is back again. I think I must have some evil little gremlins in my garage painting crap on to my drive shaft while I sleep at night.
Associated with this vibration are a couple of things, firstly the temperature in Buffalo has plumetted over the last few days from about 45F to 14F. The underlying vibration is accompanied by a rythmic thruming sound. This is not dependant on rpm and is also felt in neutral, so I am suspecting tires. The tires are almost new Pirelli 215 15inch winter tires from Tire Rack. The only other thing I did before the temperature nose dived was to adjust my tire pressures down from 36psi to the recommended 29/30psi
Any thoughts?
Vibration back to haunt me
-
Q45tech
- Moderator
- Posts: 14296
- Joined: Tue Apr 30, 2002 3:19 am
- Car: 1990 Q45 342,400 miles 22 years ownership with original engine
1995 G20t 5 speed 334,000 miles 16" 2002 wheels - 205/50/16 Sr20ve vvl
Have the tire wheels balanced measured on the Hunter do they exceed 14 pounds of excess radial force at 70 mph.
I try to get my tires down to 5 pounds to be vibration free.
The tires must not be allowed to sit on the ground after the warm up drive [15 minutes at 60 mph] for more than 5 FIVE MINUTES........get the car on the lift to relieve the sitting/deforming pressure IMMEDIATELY or the balance will be in ERROR!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
Almost impossible unless you pay them to keep a lift open and wait on you to warm the tires up. Then pull right on to the lift.
You will have less problems with Michelin Pilot H rated snow tires as the specs are better for shipped [allowed out the door] radial force imbalance........your wheels are surely not in spec by now!
I try to get my tires down to 5 pounds to be vibration free.
The tires must not be allowed to sit on the ground after the warm up drive [15 minutes at 60 mph] for more than 5 FIVE MINUTES........get the car on the lift to relieve the sitting/deforming pressure IMMEDIATELY or the balance will be in ERROR!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
Almost impossible unless you pay them to keep a lift open and wait on you to warm the tires up. Then pull right on to the lift.
You will have less problems with Michelin Pilot H rated snow tires as the specs are better for shipped [allowed out the door] radial force imbalance........your wheels are surely not in spec by now!
-
texasoil
- Posts: 875
- Joined: Mon Sep 02, 2002 3:18 pm
- Car: '92 Infiniti Q45A
'94 Infiniti Q45A
'94 Mercedes-Benz SL600
drumming and vibration
If you have not replaced the rear engine mount (actually the transmissiom mount located at the back of the transmission), it is highly suspect.
These sag over time until they touch the crossmember in a way you cannot see externally. Then you get vibration transmitted to the car body. The vibration often shows a peak at about 2400RPM.
You might try running the RPM's up and down slowly while not moving to see if an engine speed excites a resonance.
Likewise, when moving and experiencing the vibration, try slipping the transmission into neutral and letting the engine idle. A vibration that is only dependent on road speed is certainly driveshaft/wheel related.
If this is the case, your driveshaft may have developed stiff u-joints. They tend to get 'notchy' with age. Often they can be revived by either removing the aft end and rotating the joints to their full deflection several times to loosen them up. Be sure and also try and flex the center joint more than normal as well.(I think the grease work hardens at the ends of normal rotation and the extra deflection mixes it back up to smoothness. )Another way to loosen up the joints is too hit them with a 'calibrated hammer blow' perpendicular to the bearing cap/trunion being so hit so as to impart a shock load to the rollers in the trunion. This will usually accomplish the grease mixing. I am not able to adequately define a 'calibrated hammer blow' other than to say --using a 2# ball pein hammer, hit like you were trying to drive a 3" nail full depth in one blow.
Use a large soft drift (3/4" brass or stainless steel rod 4-6"long) on the bearing journal and hit on the end of the rod
These sag over time until they touch the crossmember in a way you cannot see externally. Then you get vibration transmitted to the car body. The vibration often shows a peak at about 2400RPM.
You might try running the RPM's up and down slowly while not moving to see if an engine speed excites a resonance.
Likewise, when moving and experiencing the vibration, try slipping the transmission into neutral and letting the engine idle. A vibration that is only dependent on road speed is certainly driveshaft/wheel related.
If this is the case, your driveshaft may have developed stiff u-joints. They tend to get 'notchy' with age. Often they can be revived by either removing the aft end and rotating the joints to their full deflection several times to loosen them up. Be sure and also try and flex the center joint more than normal as well.(I think the grease work hardens at the ends of normal rotation and the extra deflection mixes it back up to smoothness. )Another way to loosen up the joints is too hit them with a 'calibrated hammer blow' perpendicular to the bearing cap/trunion being so hit so as to impart a shock load to the rollers in the trunion. This will usually accomplish the grease mixing. I am not able to adequately define a 'calibrated hammer blow' other than to say --using a 2# ball pein hammer, hit like you were trying to drive a 3" nail full depth in one blow.
Use a large soft drift (3/4" brass or stainless steel rod 4-6"long) on the bearing journal and hit on the end of the rod
-
Q45tech
- Moderator
- Posts: 14296
- Joined: Tue Apr 30, 2002 3:19 am
- Car: 1990 Q45 342,400 miles 22 years ownership with original engine
1995 G20t 5 speed 334,000 miles 16" 2002 wheels - 205/50/16 Sr20ve vvl
Find a Lexus dealer or other shop with a vibration frequency meter..........measure the vibration/vibrations and give us the frequency and the speed it occurred.........is it 13-14 Hz or 25 or 26-27 or 33.3 Hz or 46 Hz at 60 mph [2000 engine rpm]..........may be multiple vibrations whose amplitude rises and falls and go in and out of phase.http://www.vibratesoftware.com...n.htmhttp://www.vibratesoftware.com...s.htm
Everything is simple when you have the correct test equipment and know how to use it!
Everything is simple when you have the correct test equipment and know how to use it!
-
rover3l
- Posts: 514
- Joined: Sat Oct 11, 2003 3:22 am
- Car: 1998 Q45, 2000Q45 Anniversary, 1965 Rover 3L,
Latest Vibration update
Took the Q45a to be evauated on a Hunter 9700. They got three of the wheel / tire assemblies in balance with a road force less than 10lbs. The fourth, the front drivers side would not go below 20lbs. The diagnosis reads
"ForceMatching will not bring assembly within limit"
Tire: Limit exceededRim: Pass
I noticed some improvement on the road but it is still not perfect. Also I may have other driveline problems as suggested by Texas oil and I need to try his ideas and also follow up with a vibration meter as suggested by Q45Tech.
The tires are all one month old Pirelli Winter Force tires mounted on steel rims and supplied by The Tire Rack
"ForceMatching will not bring assembly within limit"
Tire: Limit exceededRim: Pass
I noticed some improvement on the road but it is still not perfect. Also I may have other driveline problems as suggested by Texas oil and I need to try his ideas and also follow up with a vibration meter as suggested by Q45Tech.
The tires are all one month old Pirelli Winter Force tires mounted on steel rims and supplied by The Tire Rack
-
Q45tech
- Moderator
- Posts: 14296
- Joined: Tue Apr 30, 2002 3:19 am
- Car: 1990 Q45 342,400 miles 22 years ownership with original engine
1995 G20t 5 speed 334,000 miles 16" 2002 wheels - 205/50/16 Sr20ve vvl
With 20 pounds of radial force you will see a serious vibration at 13 Hz and 26 Hz, as it will be pushing up the body by 0.136" every revolution. This tire should be always on the rear as the rear subframe will absorb some and the softer rear shocks will react better........not much better but some better.
Again my personal spec is 5 pounds and only Michelin has a chance in Hell of getting close.
Again my personal spec is 5 pounds and only Michelin has a chance in Hell of getting close.
-
rover3l
- Posts: 514
- Joined: Sat Oct 11, 2003 3:22 am
- Car: 1998 Q45, 2000Q45 Anniversary, 1965 Rover 3L,
UPDATE AND QUESTION FOR Q45TECH
The Tire Rack agreed graciously to replace my defective Pirelli tire so hopefully I can get all 4 of my tire / wheel assemblies in balance on the Hunter machine.
I suspect this isn't the end of my vibration issues though as I have at least one or maybe two other sources I am trying to track down. Today for example when the car was cold there was a distinct vibration to be felt even when stationary in Park at about 1600-1700 rpm. The next stage I think is for me to get the vibration analysis done as Q45Tech suggests. My question is exactly what to ask for and the approximate cost.
For example can I just ask for a diagnosis report and say 1 hours worth of labor?
I suspect this isn't the end of my vibration issues though as I have at least one or maybe two other sources I am trying to track down. Today for example when the car was cold there was a distinct vibration to be felt even when stationary in Park at about 1600-1700 rpm. The next stage I think is for me to get the vibration analysis done as Q45Tech suggests. My question is exactly what to ask for and the approximate cost.
For example can I just ask for a diagnosis report and say 1 hours worth of labor?
-
rover3l
- Posts: 514
- Joined: Sat Oct 11, 2003 3:22 am
- Car: 1998 Q45, 2000Q45 Anniversary, 1965 Rover 3L,
Definately very elusive these vibrations. I couldn't reproduce the 1600 rpm vibration later on today during another test. I think it may have been engine running related as it was only when cold and did give a slightly uneven running. The vibration was quite severe but once fully warm it disappeared.
Other vibrations felt on the road are still there so I will reapraise once the new tire is fitted and Hunter balanced.
My alignment must also be out again because the car is pulling to the right and it is slightly worse after the Hunter treatment. When the new tire is fitted I was also get the alignment done. As it is an "Active" I think this needs to be done with the car running?
Other vibrations felt on the road are still there so I will reapraise once the new tire is fitted and Hunter balanced.
My alignment must also be out again because the car is pulling to the right and it is slightly worse after the Hunter treatment. When the new tire is fitted I was also get the alignment done. As it is an "Active" I think this needs to be done with the car running?
-
Q45tech
- Moderator
- Posts: 14296
- Joined: Tue Apr 30, 2002 3:19 am
- Car: 1990 Q45 342,400 miles 22 years ownership with original engine
1995 G20t 5 speed 334,000 miles 16" 2002 wheels - 205/50/16 Sr20ve vvl
I think you are wasting your time with "snow tires" and below 60F temperatures........as far as trying to get vibration free by balancing the tires.
As to vibration analyser few people know how to use it correctly.I would think a few hours labor [to start].........one would really need to be an experienced engineer or factory specialist to interpret the numbers and intensity.
Errors creep in when the device need the EXACT speed or rpm.As different brand tires in the same size will have different rolling diameters.
Measuring the steering wheel vibration is tricky, Few [only the factory] have the $10,000 special seat sensors that measures your back and bottom vibration with you sitting in the seat.
Years of experience has taught me to just start with NEW Michelin premium [top of the line] tire models [even snow tires] on new or completely tested wheels........the radial force minimize the assembly...........while the wheels are off check EACH rotor for specs.....as rotors can be a problem.
Make sure the motor mounts are new and check each rotating accessory [AC compressor, fan, alternator, ps pump and all the belt tensioners for noise [free rotating feel].Then a new transmission rear mount and a new drive shaft [or measure the frequency of the drive shaft].
Engine oil level is critical as overfilling will allow the crankshaft weights to whip the oil.
As to vibration analyser few people know how to use it correctly.I would think a few hours labor [to start].........one would really need to be an experienced engineer or factory specialist to interpret the numbers and intensity.
Errors creep in when the device need the EXACT speed or rpm.As different brand tires in the same size will have different rolling diameters.
Measuring the steering wheel vibration is tricky, Few [only the factory] have the $10,000 special seat sensors that measures your back and bottom vibration with you sitting in the seat.
Years of experience has taught me to just start with NEW Michelin premium [top of the line] tire models [even snow tires] on new or completely tested wheels........the radial force minimize the assembly...........while the wheels are off check EACH rotor for specs.....as rotors can be a problem.
Make sure the motor mounts are new and check each rotating accessory [AC compressor, fan, alternator, ps pump and all the belt tensioners for noise [free rotating feel].Then a new transmission rear mount and a new drive shaft [or measure the frequency of the drive shaft].
Engine oil level is critical as overfilling will allow the crankshaft weights to whip the oil.
-
rover3l
- Posts: 514
- Joined: Sat Oct 11, 2003 3:22 am
- Car: 1998 Q45, 2000Q45 Anniversary, 1965 Rover 3L,
Tire Rack supplied me a new tire to replace my out of balance one and got it fitted today. Road Force was now under 10lbs and the vibration is definately less. I also had the intake system and fuel system service using Run-Rite. This was added together with air under pressure into the intake system while the engine was run at 2000 rpm for 15 minutes. A second stage of the treatment was a Run-Rite fuel additive added to the gas tank.
The result is a much smoother idle and general performance. Before the treatment there was a slight lumpy feeling during acceleration and now it feels much smoother and quieter. I think this has also helped reduce the vibrations I was experiencing at 1650 and 2500 rpm
The result is a much smoother idle and general performance. Before the treatment there was a slight lumpy feeling during acceleration and now it feels much smoother and quieter. I think this has also helped reduce the vibrations I was experiencing at 1650 and 2500 rpm
-
Q45tech
- Moderator
- Posts: 14296
- Joined: Tue Apr 30, 2002 3:19 am
- Car: 1990 Q45 342,400 miles 22 years ownership with original engine
1995 G20t 5 speed 334,000 miles 16" 2002 wheels - 205/50/16 Sr20ve vvl
10 year old motor mounts [even 7 year old ones] will allow a lot of abnormal vibration. Maintaining that as new feeling is expensive.
Every company that doesn't test radial force before shipping from factory hates the Hunter machine.........but they bank on less than 5% of the owners willing to pay for testing.
The $20 additional per tire test goes along way towards paying for the Michelins in the first place.........since they pretest all the MXV4 and Pilot series and most others if they are at least H rated.
Every company that doesn't test radial force before shipping from factory hates the Hunter machine.........but they bank on less than 5% of the owners willing to pay for testing.
The $20 additional per tire test goes along way towards paying for the Michelins in the first place.........since they pretest all the MXV4 and Pilot series and most others if they are at least H rated.
-
rover3l
- Posts: 514
- Joined: Sat Oct 11, 2003 3:22 am
- Car: 1998 Q45, 2000Q45 Anniversary, 1965 Rover 3L,
ok now I am really getting frustrated. The last post I reported smoother and quieter running after having my unbalanced tire replaced and also getting the intake system cleaned with run-rite. It really was very smooth on the return from the autoshop with pick up being better, general running quieter and most of the vibration gone.
Well I couldn't believe it but today when I started it up it seemed I noticed a very distinct vibration at 1600- 1700 rpm in neutral. I can feel it through the whole car, seats, steeing wheel and the interior mirror vibrates. If I rev the engine through that rpm level the vibration peaks. Also I noticed a couple of further odd things. The engine seems lumpy when accerating and there is also some rumbling noise which seems to be associated with the Power steering (I had the fluid changed at the weekend).
I am finding this totally frustrating as I do one thing then seem to have a new source of vibration and noise.
I am thinking of getting a power balance test carried out but shoud I check anything else. There is some hesitation when accelerating from rest but after a second or so it seems to really fly.
i still have to check transmission mounts and other stuff but it is too cold up here to do any significant work outside
Well I couldn't believe it but today when I started it up it seemed I noticed a very distinct vibration at 1600- 1700 rpm in neutral. I can feel it through the whole car, seats, steeing wheel and the interior mirror vibrates. If I rev the engine through that rpm level the vibration peaks. Also I noticed a couple of further odd things. The engine seems lumpy when accerating and there is also some rumbling noise which seems to be associated with the Power steering (I had the fluid changed at the weekend).
I am finding this totally frustrating as I do one thing then seem to have a new source of vibration and noise.
I am thinking of getting a power balance test carried out but shoud I check anything else. There is some hesitation when accelerating from rest but after a second or so it seems to really fly.
i still have to check transmission mounts and other stuff but it is too cold up here to do any significant work outside