LX470 shakes pretty violently when letting off the gas? (1 Viewer)

[smwmustang]

Hey guys, my son told me his LX was shaking at around 40 mph and it was due for an oil change and tire rotation so I figured I would have them look at it. Of course, kids don't always tell you exactly what is going on.

Driving to the shop this morning their is a slight vibration while driving but when you let off the gas at about 40 to 45 mph it really shakes a lot. Once you apply the brakes it calms down but something is off somewhere.

We are still battling the check engine from the cats being stolen but I have new cats coming in today to install. This seems more motor mount or suspension related than just no power or shaking under load from a misfire.

I tried to search but was really not sure what to search for. Any suggestions or anyone had the same issue.

Thanks in advance!

 

[Toyoland66]

I would start with checking the driveshaft bolts and u-joints. Also check for pinion play. If you put it in park and have someone rock it forward and back while you observe from the side you can see the driveshaft jumping around if something is loose.

 

[Patron100LC]

If you didn't install new cats after criminals took them, the car will drive like crap. It'll be noisy and very shaky. It'll drive like a badly made V8 dune buggy.
When mine were taken I drove maybe a mile to the muffler shop, but it felt like a LOT more.

Wait till you deal with that issue first, then take it for a spin to check for other stuff.

 

[excessive]

what @Toyoland66 said , my first suspicion would be bad u-joints

 

[smwmustang]

I would start with checking the driveshaft bolts and u-joints. Also check for pinion play. If you put it in park and have someone rock it forward and back while you observe from the side you can see the driveshaft jumping around if something is loose.

The U-joints in the rear were making some noise a couple of weeks ago and I greased them and the noise went away so I am sure they are ready to be replaced as well. I will check the driveshaft as well.

 

[smwmustang]

If you didn't install new cats after criminals took them, the car will drive like crap. It'll be noisy and very shaky. It'll drive like a badly made V8 dune buggy.
When mine were taken I drove maybe a mile to the muffler shop, but it felt like a LOT more.

Wait till you deal with that issue first, then take it for a spin to check for other stuff.

Well I think they were stolen during the purchase of the truck and the guy I bought it from just had pipes welded in. It actually ran really well for about 5 months and then the problems started. They will arrive today and I think I can do them myself but I have not gotten up under to see how hard the front bolts are to get to.

 

[Patron100LC]

Thought you were driving with shorty's (no muffler), sorry.

Besides those listed above, check for rear control arms, maybe a bushing that ended falling apart recently, specially if you feel it under deceleration, like the car's ass is trying to get away when you let off the accelerator.

 

[smwmustang]

Update: drove it some more after oil change and tire rotation and it definitely was not an out of balanced tire. Upon further inspection when I got home both drive shafts do not have any play in them best I can tell, however I will probably replace both since u joints have been making noise. I turned the front wheels where I could get a better look at the front suspension as this appears to possibly be where the shuttering when you brake might be coming from. The left front CV boot has a huge tear in it and it is possible it is completely dry and worn out.

For those that might know, will a bad CV axle cause this same type of issue? Waiting for a quote from the shop on getting in to be checked out and replaced if that is what it is.