Coil springs for AHC (17 Viewers)

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The colors are just paint dots on one of the coils.

My rear height is ok, I think. 20.5" back and 19" front from center of wheel to fender lip.

I forgot to measure the overall length of the new springs. I was going to, just to confirm the measurement numbers above where the LC springs are 40mm longer than LX springs. I did take a quick snap of the springs side by side. I would have thought that the extra length is like having a 40mm spacer.

1441974172946.jpg
 
Looks like the coil on the left (LC AHC) has a full extra turn over the LX coil, I wonder what the LC coils' wire diameter is because you'd have to think that both coils have a very similar/the same design load rating if LCs and LXs weigh about the same and the AHC systems' provide the same lifting force to the same height?
 
Looks like same number of turns per coil to me.
 
Yeah, there are 6 or 7 turns in each spring, pending on where you want to start counting. The thickness of the springs look pretty close too. I can measure them with calipers tomorrow.

I suppose itnis possible that the two springs are rated to manage the same weight at a level ride height. If the LC spring has a lower spring constant but is compressed more... I don't know what the practical benefit of that would be though. (Not a suspension expert by any stretch.) A lower spring constant but longer spring perhaps allows the axle to flex more over rough terrain???

In any case, I didn't seem to get any additional load capacity out of the LC springs. Oh well. I am back in spec at least.

Next up is inspecting the air bags. Either one of the hoses piped loose, or I burst one of the bags when trying to characterize the neutral pressures, ie dropping down to Low with inflated bags.
 
Looks (to me at least) that the LC coil is 6.5 turns and the LX coil is 5.5 turns, total turns counted end to end. The wire diameter is important to the rate as a 1% change in diameter changes the rate by 4%. But whatever.
 
Could it be possible that one spring is taller because it is for the drivers side. Just want to make sure we are comparing apples to apples. :hmm:
 
Yep, not sure if we're talking apples to apples. As a point of reference the standard LX springs are 460mm long for the drivers side (LHD) and 445mm for the passengers side.
 
Both springs in the pic are for LH side. Measured the cross sectional diameter of the springs and the LX springs are thicker by 0.013 (.472 vs .485). Using Paddo's 4:1 ratio, the LX spring is 10% stiffer than the LC.
I can see the extra turn in the LC spring now. The LC springs are approximately 10% longer. So further confirming the idea that the LC and LX springs have the same load carrying capacity on level ground.

Air bags are fine, but I the hoses popped loose from the bags fitting. I need to open up the hole in the spring perch more. I made the 3/4" hole in the instructions, but this isn't enough. The axis changes as suspension articulates. It lloks like a slot is the right kind of pass through. Will have to wait until I have a few hours free to get in there to gerrymandering rig a slot with another hole and probably a few dremel wheels.
 
I replaced the rear springs on my 2000 LX470 with the Lexus parts springs. I had towed a heavy boat for a few years, and that, along with 14 years of use, wore the originals out. After replacing the springs, I tightened the torsion bars following some excellent directions here on the forum. The ride is back to "excellent" on my LX470 after this work.
 
I have an 07 LC with 160k miles. I replaced the AHC fluid at 120k miles. And I am getting about 9 on the graduation test. Figuring out the techstream software and adjusting torsion bars and all that isn't in the cards for me, I just don't have the knowledge and time as a busy single dad. But I found another LC member that has done it before that is willing to help me out, or I'll just take it to the dealer to get checked.

My question is, should I go ahead and replace the rear springs so I can just do the check and adjustment once? My thought is that if I don't, I am likely to have to check/adjust once before and after new springs. Thanks for your thoughts. Also any confirmation on the part numbers for the 07 springs would be appreciated. Thanks!
 
So has anyone done LC coils on a LX?
I wouldn’t know how to do the tech stream if I change out my LX coils to LC coils.
Getting a good deal on LC coils but don’t know if anyone’s done it.
 
I have LC coils. My pressures weren't great so i went this route. I had a shop do it so the T Bars, rake and alignment could all be done at the same time. Ride is great when loaded or full tank of gas. Gets bouncy once I get to 1/4 tank.
 
DanInDenver said:
I have LC coils. My pressures weren't great so i went this route. I had a shop do it so the T Bars, rake and alignment could all be done at the same time. Ride is great when loaded or full tank of gas. Gets bouncy once I get to 1/4 tank.
Click to expand...

Did you buy new or used ones?
I am thinking about 30mm spacers.
 
Free from a friend, no spacers. Not sure if they were used, looked pretty clean.
 
What's the best place to order LX springs? Is the discount at Lexus at Dominion (San Antonio) still active?
 
Is there a definitive agreement on when coil springs should be replaced? And would one expect new coil springs to raise the neutral height of a ahc equipped vehicle with worn out springs? Or would ahc just compensate, and pressure would fall in spec.

Also, correct oem part numbers for a lx470 rear spring replacement would be:
RH: 48231-6A730
LH: 48231-6A740

Correct?
 
When I changed my 16 year old rear springs (with less than 100k miles) my pressures didn't really change. Adding a 30mm spacer after the new springs got my pressure's in spec. When I tried to order the two springs above, I was told they were discontinued (this was at a online Toyota dealer). I had them substitute Land Cruiser AHC coils.
 
trdcorolla said:
When I changed my 16 year old rear springs (with less than 100k miles) my pressures didn't really change. Adding a 30mm spacer after the new springs got my pressure's in spec. When I tried to order the two springs above, I was told they were discontinued (this was at a online Toyota dealer). I had them substitute Land Cruiser AHC coils.
Click to expand...

Did you notice a ride quality difference with the new springs?
 
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