Wheel Spacers

[RXREY]

I am thinking about putting spacers on the rear wheels to widen the stance of the narrow footing my RX400h is on now. Has anyone done this? I saw the type that are pretty wide and to ensure safety they have their own bolts. Also, I know I can look this up but since I'm here, what's the bolt pattern on the RX400h? If anyone can give me any insight,I would really appreciate the advice or opinion, Rey Bustos, happy with my Lexus

[w@ntonsoup]

I don't like messing with suspension geometry that a 100-million dollar vehicle project chose :)

[Jim Nazium]

I am thinking about putting spacers on the rear wheels to widen the stance of the narrow footing my RX400h is on now. Has anyone done this? I saw the type that are pretty wide and to ensure safety they have their own bolts. Also, I know I can look this up but since I'm here, what's the bolt pattern on the RX400h? If anyone can give me any insight,I would really appreciate the advice or opinion, Rey Bustos, happy with my Lexus

Discount Tire offers 0 plus options where they list a 255/55-18 tire. I called and spoke with a representative and he stated that the 255/55-18 tire size was an option offered by Lexus for RX 350 & 400H owners. I am only reiterating what the Discount Tire Representative informed me. Personally, you have alot more tire choices for the plus zero option, than for the factory 235/55-18. I have also read by a fellow RX 330 owner who installed 255/55-18 tires on the factory Lexus 18" wheels and he stated that the only drawback to NOT installing 5mm spacers is the possible touching of the front tires to the inner fender well plastic housing. That being said, he did install spacers on all the wheels and the 5 mm offset was within spec to the factory wheel nuts (the alternative would be drastically more expensive).

Personally, I think given the weight of the vehicle, and all the complaints of premature tire wear, I would prefer opting for 255 instead of 235 as a factory tire. Also, please note that not all tires that are 255 mm are all the same width with respect to one tire manufacture to another.

Cheers,

MadloR

[skyfish400h]

I am thinking about putting spacers on the rear wheels to widen the stance of the narrow footing my RX400h is on now. Has anyone done this? I saw the type that are pretty wide and to ensure safety they have their own bolts. Also, I know I can look this up but since I'm here, what's the bolt pattern on the RX400h? If anyone can give me any insight,I would really appreciate the advice or opinion, Rey Bustos, happy with my Lexus

Spacers are a bad design. They but bending stess on the bolts which will shorten their life and lower there capacity. And I would not change bolts from the factory supplied bolts because you are never certain of the material strength.

If you want a wider stance spend the money and buy new wheels that have a deeper center location. That way you will have the reputation of the wheel mfg that they have done the correct stress analysis on the wheel design and you should be able to use your exiting bolts. Plus you may be able to move into a wider tire as well.

Avoid aftermarket spacers and quick fixes that may cost you or a loved one thier lives... it's not worth it.

[RX400h]

Surprisingly, there are quite a few wheel and tire choices here:

http://www.tirerack.com/upgrade_garage/Whe...mp;autoModClar=

Still, I'm going with the Bridgestone Alenzas (if they EVER) come in! (still waiting).

Dave

[jkatsoudas]

I am thinking about putting spacers on the rear wheels to widen the stance of the narrow footing my RX400h is on now. Has anyone done this? I saw the type that are pretty wide and to ensure safety they have their own bolts. Also, I know I can look this up but since I'm here, what's the bolt pattern on the RX400h? If anyone can give me any insight,I would really appreciate the advice or opinion, Rey Bustos, happy with my Lexus

Spacers are a bad design. They but bending stess on the bolts which will shorten their life and lower there capacity. And I would not change bolts from the factory supplied bolts because you are never certain of the material strength.

If you want a wider stance spend the money and buy new wheels that have a deeper center location. That way you will have the reputation of the wheel mfg that they have done the correct stress analysis on the wheel design and you should be able to use your exiting bolts. Plus you may be able to move into a wider tire as well.

Avoid aftermarket spacers and quick fixes that may cost you or a loved one thier lives... it's not worth it.

I'm not sure I follow your argument. Are you claiming that wheel manufacturers have all done stress analysis and therefore wheels are safe, whereas no spacer manufacturers do stress analysis so all spacers are dangerous? Do you have proof of this claim? I'm sure that Eibach and H&R Spring (both manufacture spacers specifically for this vehicle) would have something to say about this.

[RXREY]

I don't like messing with suspension geometry that a 100-million dollar vehicle project chose :)

Thanks, that's exactly what I was looking for, great insights and equally good advice. I appreciate this very much,thanks. Rey

[skyfish400h]

I am thinking about putting spacers on the rear wheels to widen the stance of the narrow footing my RX400h is on now. Has anyone done this? I saw the type that are pretty wide and to ensure safety they have their own bolts. Also, I know I can look this up but since I'm here, what's the bolt pattern on the RX400h? If anyone can give me any insight,I would really appreciate the advice or opinion, Rey Bustos, happy with my Lexus

Spacers are a bad design. They but bending stess on the bolts which will shorten their life and lower there capacity. And I would not change bolts from the factory supplied bolts because you are never certain of the material strength.

If you want a wider stance spend the money and buy new wheels that have a deeper center location. That way you will have the reputation of the wheel mfg that they have done the correct stress analysis on the wheel design and you should be able to use your exiting bolts. Plus you may be able to move into a wider tire as well.

Avoid aftermarket spacers and quick fixes that may cost you or a loved one thier lives... it's not worth it.

I'm not sure I follow your argument. Are you claiming that wheel manufacturers have all done stress analysis and therefore wheels are safe, whereas no spacer manufacturers do stress analysis so all spacers are dangerous? Do you have proof of this claim? I'm sure that Eibach and H&R Spring (both manufacture spacers specifically for this vehicle) would have something to say about this.

While I would be more inclined to go with the mfg's you mentioned than any others due to their reputation in the suspension biz, I still contend that adding an addtional component to the powertrain is unwise. Especially considering there are other options that can avoid this.

Bolt bending in a bolted joint is one of the most common causes of bolt failure. Considering the large torque loads appled to the wheel on this particular vehicle, the bolts on your 400h are under more stress from shear loading than comperable vehicles. Adding a non-structural shim (spacer) to the bolted joint means that the opposing shear forces are now separated by the thickness of the shim and introduce bending forces on the bolt as well. Combined stress from shear and bending will put the bolts under greater stress than they were designed for.

The only way to compensate for greater stress is to either increase the bolt dia (thats out unless you get new hubs as well, or drill them out and re-thread them which introduces more stress issues...), or you go with higher strength steel for the bolts. The problem with higher strength steels in general is that they and tend to fatique and crack (stonger -> more brittle). That would be a BAD DAY.

Bottom line. Avoid spacers. Get new rims.

[Jim Nazium]

Changing the Rim offset, or adding spacers, would put EXACTLY the same amount of "stress" on the vehicles suspension. In essence, you are creating the same thing.

Extrapolating on your point, I too would prefer a wheel that has the offset vs using wheel spacers. BUT, I much prefer the factory look verses the aftermarket wheel choices. Hence I'leaning towards wheel spacers and I honestly believe the 5 mm addition will not cause a "risk". If you don't mind and having the occassional wheel hitting the inner wheel well liner (THAT of course, depends on the tire choice you make for the given 255/55-18, as not all wheels are the same width) then you don't have to go with wheel spacers.

On another note, the factory specs for lug nut torquing is.... 79lb/ft. Your kidding me, right? (that's what I thought). Nope, it's in the factory 2006 manual. I would be much worried about having my factory wheels torqued to 79lb/ft.

Cheers,

MadloR

[Gryphon]

Spacers also put additional load on wheel bearings.

Tom

[JIBBBY]

When using wheel spacers just make sure you have enough stud thread grab on all your lug nuts after installation....

Atleast 6 full threads.. I lost a rear tire with only 4 full turns years ago...

[Jim Nazium]

Spacers also put additional load on wheel bearings.

Tom

So do rims with 5mm offsets... no difference there hehe.

[skyfish400h]

Changing the Rim offset, or adding spacers, would put EXACTLY the same amount of "stress" on the vehicles suspension. In essence, you are creating the same thing.

Extrapolating on your point, I too would prefer a wheel that has the offset vs using wheel spacers. BUT, I much prefer the factory look verses the aftermarket wheel choices. Hence I'leaning towards wheel spacers and I honestly believe the 5 mm addition will not cause a "risk". If you don't mind and having the occassional wheel hitting the inner wheel well liner (THAT of course, depends on the tire choice you make for the given 255/55-18, as not all wheels are the same width) then you don't have to go with wheel spacers.

On another note, the factory specs for lug nut torquing is.... 79lb/ft. Your kidding me, right? (that's what I thought). Nope, it's in the factory 2006 manual. I would be much worried about having my factory wheels torqued to 79lb/ft.

Saying that offset vs spacers will put the same stress on the suspension (as a whole) is correct. The free body diagram of the load and moment arms for the whole car would be the same (assuming the same geometry).

But that is not what I was saying. I was specifically talking about the combined stress IN THE BOLT. With the spacers you are adding bold bending stress on top of the tension (from the 79 lb-ft torque) and shear (due to drivetrain forces). That additional stress is non-trivial and needs to be allowed for to maintain the same level of safety or margin. You can choose to believe whatever you want, but it DOES add risk.

Again. Avoid the spacers. Buy new wheels.

[stroked4.6]

Spacers also put additional load on wheel bearings.

Tom

I was just about to add that comment. Spacers will add to premature wheel bearing failure and it will put more stress on the studs. Not worth it IMO. You are much more likely to have problems down the road.

[JIBBBY]

It all depends on what size spacers he plans to use...1/8 inch spacers the car won't notice a difference...1/2 spacers then he may have problems down the road....

[jkatsoudas]

Changing the Rim offset, or adding spacers, would put EXACTLY the same amount of "stress" on the vehicles suspension. In essence, you are creating the same thing.

Extrapolating on your point, I too would prefer a wheel that has the offset vs using wheel spacers. BUT, I much prefer the factory look verses the aftermarket wheel choices. Hence I'leaning towards wheel spacers and I honestly believe the 5 mm addition will not cause a "risk". If you don't mind and having the occassional wheel hitting the inner wheel well liner (THAT of course, depends on the tire choice you make for the given 255/55-18, as not all wheels are the same width) then you don't have to go with wheel spacers.

On another note, the factory specs for lug nut torquing is.... 79lb/ft. Your kidding me, right? (that's what I thought). Nope, it's in the factory 2006 manual. I would be much worried about having my factory wheels torqued to 79lb/ft.

Saying that offset vs spacers will put the same stress on the suspension (as a whole) is correct. The free body diagram of the load and moment arms for the whole car would be the same (assuming the same geometry).

But that is not what I was saying. I was specifically talking about the combined stress IN THE BOLT. With the spacers you are adding bold bending stress on top of the tension (from the 79 lb-ft torque) and shear (due to drivetrain forces). That additional stress is non-trivial and needs to be allowed for to maintain the same level of safety or margin. You can choose to believe whatever you want, but it DOES add risk.

Again. Avoid the spacers. Buy new wheels.

You may want to take a minute and familiarize yourself with the spacer design- at least those of H&R (see link below). The larger (25mm and 30mm) spacers (DRM type) attach to the factory studs with special lugs and then have another set of studs attached to the spacer that are the same length as the factory spacers. Therefore, your concerns regarding added stress on longer bolts are not applicable.

As others have said, the stress to the suspension in general and the wheel bearings specifically is identical whether you use a spacer or a new wheel with the same amount of additional offset. If this was an issue in the real world there would be wheel bearing failing all the time, given how many folks have gone with aftermarket wheels with more spacing. IMHO the criticism of spacers in this thread is waaaaaay overblown. I'd buy a spacer from a reputable company and not worry about it any more than I'd worry about the effect of aftermarket wheels.

http://www.hrsprings.com/site/index.html

Disclaimer- I'm in no way afilliated with H&R. I jus think they have a nicely thought-out product.

[RXREY]

I am thinking about putting spacers on the rear wheels to widen the stance of the narrow footing my RX400h is on now. Has anyone done this? I saw the type that are pretty wide and to ensure safety they have their own bolts. Also, I know I can look this up but since I'm here, what's the bolt pattern on the RX400h? If anyone can give me any insight,I would really appreciate the advice or opinion, Rey Bustos, happy with my Lexus

I already said this before but I wanted to thank all of you for your insights. It's amazing how a thing that I thought would be so simple has such an impact on the total design and engineering of car. I am NOT going to mess with spacers! This is why I came to you,my friends at the club! Now others that may have been as naive as I was can learn from all of you. Thanks again to all of you, Rey

[wwest]

Shortly after purchasing my 2001 AWD RX300 I discovered that the suspension clearance at the rear was so tight that tire chains could be used on the front ONLY. Here in the beautiful Pacific NW I don't have need for tire chains very often but when I do I absolutely refuse to risk my life in the process. FWD or front torque biased AWD vehicle already have more traction on the front so adding the disproportionate level of traction at the front with tire chains could prove to be patently unsafe, just as stated in your owners manuals.

So I added 1.5" wheel spacers all around, upgraded to +1 wheels/tires, 17X8. Wider stance, more rubber on the road and I run Bridgestone Turanza summer only tires all year "round. Even more rubber on the road, and nice quiet and comfortable ride.

6 years and 60,000 miles and I have had tire chains on maybe 6 times, mostly only on the rear but a few times on all four.