LX470 AHC rear kicking when driving - new globes+springs (1 Viewer)

[Sargy]

Interesting Sargy, how much weight did you add?

I had someone bouncing on the tailgate today while I was under the car and it was off, I can hear the clunking sound coming from inside the hydraulic lines running from the control valve assembly to the actuator valve assembly.

I'm going to try a big flush again incase there is air trapped in the lines and I'll also switch the front globes to the back/back to the front - I can then rule out air and globes.

Bleed the rears, start in low idling, add 100-200 pounds to the rear then go to Normal height and drive around to see if the problems go away. The gas charge in the new globes can throw things off for the actuator valves and stiffer spring combo but it settles eventually. I'm running about 350-400lbs In the back of steel bumper, spare tire, drawer and fridge. The moment I have almost no gasoline in the tank and decide to pull the fridge out for cleaning I experience your symptoms.

 

[TheSquid]

Bleed the rears, start in low idling, add 100-200 pounds to the rear then go to Normal height and drive around to see if the problems go away. The gas charge in the new globes threw things off for for the actuator valves and stiffer springs but it settles eventually. I'm running about 350-400lbs In the back of steel bumper, spare tire, drawer and fridge. The moment I have almost no gas and decide to pull the fridge out for cleaning I experience your symptoms.

Much appreciated Sargy, may have saved me from a lot of diagnoses time, I'll give this a go.

 

[Justinmalone7]

Much appreciated Sargy, may have saved me from a lot of diagnoses time, I'll give this a go.

Did you ever solve this? Just replaced my globes and I’m having the same issue.

 

[Sargy]

https://www.lowes.com/pd/Sakrete-70-lb-Tube-Sand/3067709

 

[Justinmalone7]

https://www.lowes.com/pd/Sakrete-70-lb-Tube-Sand/3067709

Worth a shot

 

[Justinmalone7]

https://www.lowes.com/pd/Sakrete-70-lb-Tube-Sand/3067709

Didn’t grab the sand bag, but I work for a beer distributor so I threw a full keg back there and that solved it…now to figure out how I solve it permanently? Mine is all stock, just new globes.

 

[Sargy]

Try placing the keg inside, cycle through all heights, drop it to low, remove keg, close all doors and give it a few seconds before bringing it back up to Normal height. If its still there there could be other problems. Another idea is to slightly raise the rear height sensor to pump more fluid in the hydraulic rams when going to Normal height.

To sum that up in detail, If the problem is still there and you have OEM springs I would try bleeding it again and raising the rear height sensor a little. If you have aftermarket springs, you need more static weight for the system to work properly at all heights. (too much spring holding the truck, not enough hydraulic pressure to work, causing the "bounce" effect. Feel free to PM me if you are still having problems or message me on instagram @Sargy2 and we can dig further.

 

[Jack90210]

Clunking in the rear can also be caused by worn bushings on the rear control arms.

 

[Justinmalone7]

Try placing the keg inside, cycle through all heights, drop it to low, remove keg, close all doors and give it a few seconds before bringing it back up to Normal height. If its still there there could be other problems. Another idea is to slightly raise the rear height sensor to pump more fluid in the hydraulic rams when going to Normal height.

To sum that up in detail, If the problem is still there and you have OEM springs I would try bleeding it again and raising the rear height sensor a little. If you have aftermarket springs, you need more static weight for the system to work properly at all heights. (too much spring holding the truck, not enough hydraulic pressure to work, causing the "bounce" effect. Feel free to PM me if you are still having problems or message me on instagram @Sargy2 and we can dig further.

Great info, thanks man. I'll reach out if I have any issues.

 

[Justinmalone7]

Clunking in the rear can also be caused by worn bushings on the rear control arms.

Bushings look to be in pretty decent shape.

 

[Africaster]

Send full beer keg to me and I’ll send you magic AHC sandbags in return.

Back and front globes are NOT the same size (dunno about capacity) … can’t remember which is which but one of them fits both front and back and one only the other … took an hour of increasing frustration to discover this!

 

[Jack90210]

Bushings look to be in pretty decent shape.

How many miles/what year? If they are original, it's getting to be time even for the later year trucks.