Can a 2005 Sienna be changed from 7 to 8 passenger seating?

wrote in message

> I'm thinking of buying a used late model AWD Sienna. Unfortunately, 7
> passenger seating was the only option you could (or can) get with AWD.
> I'm wondering how hard it would be to replace the second row captains
> chairs with the 3-person second row. It looks like the mounting system
> on the floor is different for the the two configurations, so some kind
> of custom adapter would be have to be made. Does the AWD have a hump
> on the floor for the driveshaft? Any thoughts on this hare brained
> idea appreciated. Thanks.
>

My guess is that there is either a weight limitation or interference between
the seat mounting system/seatbelt anchors and the drivetrain for the rear
wheels.

I would not attempt a home made mounting system. Seats must remain anchored
to the floor during a crash, and there is no simple way to be sure that a
home made system will conform. Also, the seat belt anchors are different
for bench seats than for the captains chairs so seat belts probably wouldn't
work. Lastly, that middle bench seat may not be available as an assembly
and if you buy it part-by-part, it is probably close to $1,000.

If you routinely carry 8 people, you may wish to check out the Sequoia -
the third row seating is actually pretty comfortable.

One other thing to be aware of on the AWD Sienna is that it does not have a
spare tire unless the previous owner opted for the spare tire carrier.
Instead of a spare tire, the standard tires are "run flat" which allows the
driver to drive a limited distance until the tire can be repaired.

--

Ray O
(correct punctuation to reply)
 >> Stay informed about: Can a 2005 Sienna be changed from 7 to 8 passenger seating? 

Ray O wrote:
> wrote in message
>
> > I'm thinking of buying a used late model AWD Sienna. Unfortunately, 7
> > passenger seating was the only option you could (or can) get with AWD.
> > I'm wondering how hard it would be to replace the second row captains
> > chairs with the 3-person second row. It looks like the mounting system
> > on the floor is different for the the two configurations, so some kind
> > of custom adapter would be have to be made. Does the AWD have a hump
> > on the floor for the driveshaft? Any thoughts on this hare brained
> > idea appreciated. Thanks.
> >
>
> My guess is that there is either a weight limitation or interference between
> the seat mounting system/seatbelt anchors and the drivetrain for the rear
> wheels.
>
> I would not attempt a home made mounting system. Seats must remain anchored
> to the floor during a crash, and there is no simple way to be sure that a
> home made system will conform. Also, the seat belt anchors are different
> for bench seats than for the captains chairs so seat belts probably wouldn't
> work. Lastly, that middle bench seat may not be available as an assembly
> and if you buy it part-by-part, it is probably close to $1,000.
>
> If you routinely carry 8 people, you may wish to check out the Sequoia -
> the third row seating is actually pretty comfortable.
>
> One other thing to be aware of on the AWD Sienna is that it does not have a
> spare tire unless the previous owner opted for the spare tire carrier.
> Instead of a spare tire, the standard tires are "run flat" which allows the
> driver to drive a limited distance until the tire can be repaired.
>
> --
>
> Ray O
> (correct punctuation to reply)

I was thinking of something like a steel plate that would bolt into the
existing 7-passenger floor and contain a 'replica' of the 8-passenger
bolt/track pattern on top. So the seats would end up elevated a bit.
I think something like this would be as strong as the orginal design.
But the drivetrain might be an issue if it creats a hump in the floor.
And you have a good point about the seatbelts, that's not something I'd
be comfortable 'adapting'.

Thanks for your thoughts, very helpful.
 >> Stay informed about: Can a 2005 Sienna be changed from 7 to 8 passenger seating? 

badgolferman wrote:
> , 7/17/2006, 1:00:50 PM,
> wrote:
>
> > I'm thinking of buying a used late model AWD Sienna. Unfortunately, 7
> > passenger seating was the only option you could (or can) get with AWD.
> > I'm wondering how hard it would be to replace the second row captains
> > chairs with the 3-person second row. It looks like the mounting
> > system on the floor is different for the the two configurations, so
> > some kind of custom adapter would be have to be made. Does the AWD
> > have a hump on the floor for the driveshaft? Any thoughts on this
> > hare brained idea appreciated. Thanks.
>
> How would you get passengers into the rearmost seat?

The Sienna is sold in both 7 and 8 passenger configs, so the mod I'm
contemplating shouldn't limit access (I'd have to replace the entire
3rd row, not just add a middle seat).
 >> Stay informed about: Can a 2005 Sienna be changed from 7 to 8 passenger seating? 

, 7/17/2006, 1:00:50 PM,
wrote:

> I'm thinking of buying a used late model AWD Sienna. Unfortunately, 7
> passenger seating was the only option you could (or can) get with AWD.
> I'm wondering how hard it would be to replace the second row captains
> chairs with the 3-person second row. It looks like the mounting
> system on the floor is different for the the two configurations, so
> some kind of custom adapter would be have to be made. Does the AWD
> have a hump on the floor for the driveshaft? Any thoughts on this
> hare brained idea appreciated. Thanks.

How would you get passengers into the rearmost seat?
 >> Stay informed about: Can a 2005 Sienna be changed from 7 to 8 passenger seating? 

wrote in message

> Ray O wrote:
>> wrote in message
>>
>> > I'm thinking of buying a used late model AWD Sienna. Unfortunately, 7
>> > passenger seating was the only option you could (or can) get with AWD.
>> > I'm wondering how hard it would be to replace the second row captains
>> > chairs with the 3-person second row. It looks like the mounting system
>> > on the floor is different for the the two configurations, so some kind
>> > of custom adapter would be have to be made. Does the AWD have a hump
>> > on the floor for the driveshaft? Any thoughts on this hare brained
>> > idea appreciated. Thanks.
>> >
>>
>> My guess is that there is either a weight limitation or interference
>> between
>> the seat mounting system/seatbelt anchors and the drivetrain for the rear
>> wheels.
>>
>> I would not attempt a home made mounting system. Seats must remain
>> anchored
>> to the floor during a crash, and there is no simple way to be sure that a
>> home made system will conform. Also, the seat belt anchors are different
>> for bench seats than for the captains chairs so seat belts probably
>> wouldn't
>> work. Lastly, that middle bench seat may not be available as an assembly
>> and if you buy it part-by-part, it is probably close to $1,000.
>>
>> If you routinely carry 8 people, you may wish to check out the Sequoia -
>> the third row seating is actually pretty comfortable.
>>
>> One other thing to be aware of on the AWD Sienna is that it does not have
>> a
>> spare tire unless the previous owner opted for the spare tire carrier.
>> Instead of a spare tire, the standard tires are "run flat" which allows
>> the
>> driver to drive a limited distance until the tire can be repaired.
>>
>> --
>>
>> Ray O
>> (correct punctuation to reply)
>
> I was thinking of something like a steel plate that would bolt into the
> existing 7-passenger floor and contain a 'replica' of the 8-passenger
> bolt/track pattern on top. So the seats would end up elevated a bit.
> I think something like this would be as strong as the orginal design.

As I mentioned before, there is no easy way to test the crashworthiness of
the modification and if it were my vehicle, I would not feel very
comfortable doing this modification.


> But the drivetrain might be an issue if it creats a hump in the floor.
> And you have a good point about the seatbelts, that's not something I'd
> be comfortable 'adapting'.
>
> Thanks for your thoughts, very helpful.
>

You're welcome!
--

Ray O
(correct punctuation to reply)
 >> Stay informed about: Can a 2005 Sienna be changed from 7 to 8 passenger seating? 

It's kind of a moot point now because the sea tbelt issue has nixed the
whole idea. But just to be argumentative, the fact that Toyota doesn't
offer 8-passenger seating with AWD doesn't *necessarily* mean there's a
structural issue. Japanese car companies limiting configuration
options for business reasons. Perhaps Toyota thought there wasn't
sufficient demand for this configuration to warrant manufacturing and
importing it.

As far as the law suit thing goes, you see people driving around with
all kinds of mods that could potentially affect safety. Non-stock rims
and tires are an obvious one. And you see these on expensive cars
where presumably the owner has (A) insurance and (B) something to lose
in a lawsuit. I'm not saying there's no liability issue, but insurance
companies seem to have some tolerance for mods, which I don't think
would be the case if liability issues were out of control. Again, I'm
not going to do this because of the seatbelt thing, and I'm looking at
other vehicles including the Sequoia. Thanks again.

Jeff Strickland wrote:
> What Ray said.
>
> If the standard model can have the 8 seat option, but the AWD can not, then
> there are structural considerations that must be thought about. The Sequoia
> sounds like maybe you should give it a look.
>
>
>
>
>
>
> wrote in message
>
> > I'm thinking of buying a used late model AWD Sienna. Unfortunately, 7
> > passenger seating was the only option you could (or can) get with AWD.
> > I'm wondering how hard it would be to replace the second row captains
> > chairs with the 3-person second row. It looks like the mounting system
> > on the floor is different for the the two configurations, so some kind
> > of custom adapter would be have to be made. Does the AWD have a hump
> > on the floor for the driveshaft? Any thoughts on this hare brained
> > idea appreciated. Thanks.
> >
 >> Stay informed about: Can a 2005 Sienna be changed from 7 to 8 passenger seating? 

wrote in message

> It's kind of a moot point now because the sea tbelt issue has nixed the
> whole idea. But just to be argumentative, the fact that Toyota doesn't
> offer 8-passenger seating with AWD doesn't *necessarily* mean there's a
> structural issue. Japanese car companies limiting configuration
> options for business reasons. Perhaps Toyota thought there wasn't
> sufficient demand for this configuration to warrant manufacturing and
> importing it.

IMO, the most likely reason that the AWD versiosn is only offered in a 7
passenger configuration is weight. Among the factors when calculating EPA
fuel economy is weight, and it is possible that the 8 passenger configuratio
puts the vehicle into a different weight category. Weight is the reason why
certain options like sunroofs used to have limited availability, and why
even some upscale vehicles have space saver spares.

>
> As far as the law suit thing goes, you see people driving around with
> all kinds of mods that could potentially affect safety. Non-stock rims
> and tires are an obvious one. And you see these on expensive cars
> where presumably the owner has (A) insurance and (B) something to lose
> in a lawsuit. I'm not saying there's no liability issue, but insurance
> companies seem to have some tolerance for mods, which I don't think
> would be the case if liability issues were out of control. Again, I'm
> not going to do this because of the seatbelt thing, and I'm looking at
> other vehicles including the Sequoia. Thanks again.
>

Aftermarket wheels and tires must meet the same safety standards that OEM
wheels and tires do, and as long as the offset, tire circumference, bolt
pattern, etc. are the same as stock, they are not inherently less safe than
OEM wheels and tires.
--

Ray O
(correct punctuation to reply)
 >> Stay informed about: Can a 2005 Sienna be changed from 7 to 8 passenger seating?