LX450 vibration issue with A/C (1 Viewer)

[fresnoLC]

Basic issue: Vibration in cab when AC is on transmission in drive, foot on brake. Goes away as soon as you take off, put trans into nuetral, or turn off the AC. Also doesn't seem to do it when first warming up.

Rebuilt engine, new AC compressor (not done by me), new engine and trans mount.

Just wondering where to start with this one. Checked that the compressor was torqued down, belt seemed tight. Can't seem to identify the source of the vibration, my next check was going to be the flex plate bolts, I remember torquing those down but figured it would be worth checking.

Any ideas?

 

[Fj80oregon]

Have you watched the ac pulley/dampener when the ac is on and off? It could be delaminated like the crank pulley does and causing the t motor to vibrate.

 

[LongDuck]

Change your belts with Toyota OEM and go from there. The set of 3 is only about $25, and more than likely by doing that you'll touch whatever has a harmonic vibration and change it, and then your noise goes away and you have new belts!

My 80 runs so much smoother and quieter with new belts.

 

[fresnoLC]

Have you watched the ac pulley/dampener when the ac is on and off? It could be delaminated like the crank pulley does and causing the t motor to vibrate.

I need to check this.

Change your belts with Toyota OEM and go from there. The set of 3 is only about $25, and more than likely by doing that you'll touch whatever has a harmonic vibration and change it, and then your noise goes away and you have new belts!

My 80 runs so much smoother and quieter with new belts.

Not a bad idea, this was the second 80 and I don't recall at this point whether it got Toyota belts or not. But might identify something that's loose

 

[Kernal]

Check your exhaust system hangers. the rubber isolator blocks may look good at first glance but they can crack in half from age. Push up on the (cold) pipes while looking at the isolator blocks to see if they separate in the middle. The pipes won't droop (maybe an inch) due to the interlocking "L" design of the hangers but if the isolator blocks have fallen apart it can cause a vibration/rumble most noticeable like in the OP's scenario (foot on brake, transmisison in drive, AC idles up,---).

PM # 17: check your exhaust system cushions

Been discussed in the past and just recently so thought I'd post this up for those that haven't seen it yet. My 97 model FZJ80 recently started getting a new vibration for example while idling in drive, foot on brake, more apparent when the engine idled up with the AC compressor coming on...

forum.ih8mud.com

 

[robnicko]

Change your belts with Toyota OEM and go from there. The set of 3 is only about $25, and more than likely by doing that you'll touch whatever has a harmonic vibration and change it, and then your noise goes away and you have new belts!

My 80 runs so much smoother and quieter with new belts.

WOW - in Melbourne Aus the OEM belts are around $120 for the 3 last time I asked at Toyota. $60 for the two ALT and $60 for the AC

 

[Rusty Marlin]

Proud of them!

 

[LongDuck]

I'll send ya some for $100+$20 to cover shipping (*USD)!