F sport shock swap to standard shock
#1
Pit Crew
Thread Starter
F sport shock swap to standard shock
Anybody else swapped their rear f sport shocks for standard non f sport shocks for better ride comfort?
Swapped mine out yesterday and must say the difference is there and ride is more comfortable now. The only concern I have is that in the non f sport shocks, the top bolt is non serrated and the f sport shocks are serrated. Please see attachment for the difference.
Anyone else that had already swapped and know if that is of any concern ???
Thanks
Swapped mine out yesterday and must say the difference is there and ride is more comfortable now. The only concern I have is that in the non f sport shocks, the top bolt is non serrated and the f sport shocks are serrated. Please see attachment for the difference.
Anyone else that had already swapped and know if that is of any concern ???
Thanks
The following users liked this post:
YKLim (09-09-24)
#2
Moderator
That difference in the bolt holes is of no significance. They are likely from different manufacturers, of if the same, it may be a quick way to tell the 2 models apart. It will not affect anything. Enjoy your smoother ride!
#3
Moderator
The serrations bind the shock center to the sides of the mounting when torqued down. This is the very reason that suspension parts are tightened in laden position. Stiffer suspension benefits from serrations. The down side is that the mounting will already have the serrations marks transferred. I would re-torque after a week of driving.
Salim
Salim
#5
Pit Crew
Thread Starter
The serrations bind the shock center to the sides of the mounting when torqued down. This is the very reason that suspension parts are tightened in laden position. Stiffer suspension benefits from serrations. The down side is that the mounting will already have the serrations marks transferred. I would re-torque after a week of driving.
Salim
Salim
I did see that the mounting bracket had indents of the serrated marks on the inside but wasn’t sure if they made it like that at factory or it was imprinted on by the torqued down shock. Makes sense now. I will retorque it after some driving- I think it was 75 ft pound for the top bolt and 65 on bottom right ?
#6
Moderator
Yes, or in other words, close enough that they will not get loose.
#8
Moderator
No.
When I suggested re-torqueing, it was simply because I would expect the ridges formed on the mounting get flattened a bit. If they do then when you torque the bolt would spin a bit more. If you put locktite, it will be counter productive.
In modern vehicle assemblies, the bolt heads and nuts have a larger surface [eliminating the use of washers] and when torqued right, provide a larger surface to bind together. I follow the book and the only place I have seen any mention of locktite (or equivalent) has been on moving parts where the tension is low. At the same time, I am **** about using the torque wrench.
Salim
When I suggested re-torqueing, it was simply because I would expect the ridges formed on the mounting get flattened a bit. If they do then when you torque the bolt would spin a bit more. If you put locktite, it will be counter productive.
In modern vehicle assemblies, the bolt heads and nuts have a larger surface [eliminating the use of washers] and when torqued right, provide a larger surface to bind together. I follow the book and the only place I have seen any mention of locktite (or equivalent) has been on moving parts where the tension is low. At the same time, I am **** about using the torque wrench.
Salim
#9
Moderator
I actually replaced the leaking original rear shocks with the sport package shocks used from 2010-2012 and do not recall such knurling on them. When recently servicing my brakes and inspecting stuff it all appeared as tight as when I installed & torqued them down a couple years ago. A bit stiffer ride but a bit less body roll.
#10
I also just finished replacing the stock F Sport shocks with KYB 349203. I noticed the non-serrations as well but was not concerned. Ride is much better. I had a terrible time removing the lower bolts. They were rusted into the shock bushing. I had to remove the lower bracket along with the shock on one side and use the torch to heat the bolt to get it free. I put never seize on the bolts/bushings when I installed the new shocks.
#12
Moderator
I am sure that physically the F Sport and regular front struts look the same. So the removal and replacement procedure would be the same. The F Sport struts are just stiffer.
#13
Pit Crew
Thread Starter
thanks
#14
Moderator
Many years ago Lexus got into 'L Tuned' stuff and that package was shorter springs and stiffer and shorter shocks.
Lets see what we find out. My feeling is the 'F sport' is now with same springs but stiffer shocks + other tire/wheel size and appearance + modes.
Salim
#15
Moderator
I thought we covered this a few years ago and determined that the struts/shocks were the only suspension change. That the springs and sway bars were the same on all RX350 models. Easy enough to check the OEM parts sellers lists.
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salimshah (11-01-18)