2002 LC Vibration between 3-4k rpm on accel? (1 Viewer)

[beerock]

I have a 2 2002 Lc's one is perfect and the other I been getting a vibration between 3-4k rpm soon as i hit 3k it starts and once above 4k it goes away. it seems to be doing it in 3rd gear. I checked the front and rear drive shafts, they are tight. I did a lock to lock while driving forward and reverse with no clicking from the Cv's.
Also there is a bit of tranny slop when i go from park to drive and from drive to Reverse. it Bumps into gear.. If i get off the gas and get back on it I will also feel a bump.. I'm wondering if its engine tranny mounts that are causing all of this. Figured I would post here for some help as this forum seems to be very knowledgeable.

Anyone else have this particular issue and now the fix for it? (vibration between 3-4k rpm in 3rd)

 

[beerock]

any suggestions as what to check?

 

[BRob2756]

I had something similar and drove myself crazy. Took it to ACC and they found the culprit. My fan clutch was about to let go and go through the radiator - caused a heavy vibration, almost felt like we were driving over really rough pavement. Might be worth checking out?

 

[beerock]

I had something similar and drove myself crazy. Took it to ACC and they found the culprit. My fan clutch was about to let go and go through the radiator - caused a heavy vibration, almost felt like we were driving over really rough pavement. Might be worth checking out?

Just to clarify, did your vibration happen like i described between 3-4k rpm?

 

[2001LC]

Sounds like multiple issues at play.

Vibrations can be difficult to tack. If 3-4K RPM vibration is constants regardless of vehicle speed, fan clutch is a good place to start. But many other issue could be at play. i.e engine tune, harmonic balancer, torque converter, transmission, etc. all the way out to tire balance. You also mention "seem to be 3rd gear" which points to transmission issue. I assume your getting 3 to 4K RPM in D with OD off. Try 1st gear & 2nd gear OD off then on to confirm it always happen at 3 - 4K RPM.

N to D, N to R is typically axle hub flange teeth to axle teeth having play from wear (sawing action). Typical this is caused by wide hub flange snap ring gap and wheel bearing preload set to loose. Axle will move in and out of hub flange pounding on axle brass bushing, hub face, axle snap ring groove & snap ring ever widening the gap. A loose wheel bearing will chatter (vibrate) wearing claw washer, which loosens bearings further. This creates a sawing action on teeth of hub flange & axle. As you move from N to D you'll here a clunk as slack gets taken up in these teeth. Sooner or later this condition will either cause snap ring to fall off or teeth of hub flange to shear. There is some natural play with millage we live with throughout drive train, buy front drive shaft axle & hub flange is easy cost effective fix.

Worn axle hubs could also be the bump feel when letting on and off gas. But this is most often associated with slip yokes of forward & aft propeller shafts (aka drive shafts). Greasing yokes usually takes care of it, less often removal and cleaning is needed to stop Stiction - Wikipedia.

 

[beerock]

Sounds like multiple issues at play.

Vibrations can be difficult to tack. If 3-4K RPM vibration is constants regardless of vehicle speed, fan cluck is a good place to start. But many other issue could be at play. i.e engine tune, harmonic balancer, torque converter, transmission, etc. all the way out to tire balance. You also mention "seem to be 3rd gear" which points to transmission issue. I assume your getting 3 to 4K RPM in D with OD off. Try 1st gear & 2nd gear OD off then on to confirm it always happen at 3 - 4K RPM.

N to D, N to R is typically axle hub flange teeth to axle teeth having play from wear (sawing action). Typical this is caused by wide hub flange snap ring gap and wheel bearing preload set to loose. Axle will move in and out of hub flange pounding on axle brass bushing, hub face, axle snap ring groove & snap ring ever widening the gap. A loose wheel bearing will chatter (vibrate) wearing claw washer, which loosens bearings further. This creates a sawing action on teeth of hub flange & axle. As you move from N to D you'll here a clunk as slack gets taken up in these teeth. Sooner or later this condition will either cause snap ring to fall off or teeth of hub flange to shear. There is some natural play with millage we live with throughout drive train, buy front drive shaft axle & hub flange is easy cost effective fix.

Worn axle hubs could also be the bump feel when letting on and off gas. But this is most often associated with slip yokes of forward & aft propeller shafts (aka drive shafts). Greasing yokes usually takes care of it, less often removal and cleaning is needed to stop Stiction - Wikipedia.

It's in third gear, I did 1st second and third didnt do 4th yet. it only does it in third so far when im on the gas pretty hard. I'm guessing it may be motor mount/axle related i've had similar situations happen in other cars where installing a new motor mount fixed the issue due to the engine moving/angling with a worn mount and causing vibration through the axle. feels like its vibrating through the right side

i figured the slack in the r to n to d was usual for a LC with a fair amount of miles, My 04 does it too.

 

[2001LC]

In all gears does suggest it's not a transmission issue.

Be interesting to see how your motor mounts inspection goes. But, I can see how hitting 4K RPM vib would stop, unless RPM stops raising at that point.

 

[BRob2756]

Just to clarify, did your vibration happen like i described between 3-4k rpm?

My experience was that it showed these symptoms between these RPMs. However, mine would do this regardless fo what gear it is in - sounds like your may be more selective? Hope this helps

 

[beerock]

In all gears does suggest it's not a transmission issue.

Be interesting to see how your motor mounts inspection goes. But, I can see how hitting 4K RPM vib would stop, unless RPM stops raising at that point.

Stop scaring me lol mine only does it in third... but i thnk it does it in third due to the torqueing of the engine under hard accell that twists the engine and causes the axle to vibrate at least thats what im hoping

BOB, I'll look into the clutch fan... but i thnk that ould be more related in in any gear at the 3-4k rpm range..

 

[beerock]

Turns out the guy had the car in 4 low low low differentiallights. Just an airbag light. Which I believe is covered under the recall?