Towing with 2001 Sienna

We were unexpectedly given a pop-up camper. We'd love to start camping
again, but I think we're pushing the limits of what we can safely tow
with our 2001 Sienna. We do not have the towing package, so 2000 lbs
is the limit. Are there any modifications that we can do now to
increase the van's towing capacity?

"New Camper" <burkefamily48@fuse.net> wrote in message
news:1147406089.297509.111970@i40g2000cwc.googlegroups.com...[color=blue]
> We were unexpectedly given a pop-up camper. We'd love to start camping
> again, but I think we're pushing the limits of what we can safely tow
> with our 2001 Sienna. We do not have the towing package, so 2000 lbs
> is the limit. Are there any modifications that we can do now to
> increase the van's towing capacity?
>[/color]

There is no easy way to increase a vehicle's towing capacity after the fact.
I don't know what the towing package entails, my guess is that the biggest
difference is a larger transmission fluid cooler. The limiting factors in
trailer capacity are transmission capacity, braking ability, and suspension.

An aftermarket transmission cooler and air bags for the rear suspension may
help, as will getting surge brakes installed on the trailer if not already
equipped with them.

I still would not tow more than the factory recommended maximum trailer
weight.
--

Ray O
(correct punctuation to reply)

On Thu, 11 May 2006 23:11:09 -0500, "Ray O"
<rokigawa@tristarassociatesDOTcomn> wrote:[color=blue]
>"New Camper" <burkefamily48@fuse.net> wrote in message
>news:1147406089.297509.111970@i40g2000cwc.googlegroups.com...[/color]
[color=blue][color=green]
>> We were unexpectedly given a pop-up camper. We'd love to start camping
>> again, but I think we're pushing the limits of what we can safely tow
>> with our 2001 Sienna. We do not have the towing package, so 2000 lbs
>> is the limit. Are there any modifications that we can do now to
>> increase the van's towing capacity?[/color]
>
>There is no easy way to increase a vehicle's towing capacity after the fact.
>I don't know what the towing package entails, my guess is that the biggest
>difference is a larger transmission fluid cooler. The limiting factors in
>trailer capacity are transmission capacity, braking ability, and suspension.
>
>An aftermarket transmission cooler and air bags for the rear suspension may
>help, as will getting surge brakes installed on the trailer if not already
>equipped with them.
>
>I still would not tow more than the factory recommended maximum trailer
>weight.[/color]

(Cue standard trailer towing primer now. I should bookmark this...)

Most "tow packages" consist of bigger radiator, more powerful
cooling fan and a slightly more aggressive thermostatic clutch if it's
a mechanical fan, an external automatic transmission cooler, more
powerful alternator and a higher capacity battery.

The automatic transmission cooler should always be added if you tow.
You can change the other items as needed, one at a time.

If you plan to charge the lighting battery in the trailer or run a
12V powered refrigerator while driving, you will probably need the
larger alternator. If you plan to drive it hard while towing in hot
weather, you may need the larger radiator.

Some tow packages come with heavier rear springs - but they will
ride like a buckboard when the tow vehicle is empty. Rather than
overload springs, it is much better to attach airbags on the rear
suspension like the Firestone Ride-Rite if they are available for your
car. Then you can infinitely adjust the suspension from no load to
full load. (Read the instructions - 10 PSI minimum, they can't be
left at zero.)

The brakes on the tow vehicle are the biggest limitation - even with
the "Tow Package" they do not beef up the braking system. And when
you need to stop in 150 feet, you /need/ to stop in 150 feet.
Especially if 155 feet is where the collision starts.

If the loaded trailer weight is anywhere near the trailer towing
weight limit of the tow vehicle, get brakes installed on the trailer.
They make brake kits for small pop-up trailers with 8" or 10" rims,
and any good RV Supply or mechanic can install them - it takes a bit
of welding to change the coupler to the surge brake (master cylinder)
version.

Hydraulic "surge" brakes are the simplest overall because they do
not require an electric brake controller on the tow vehicle - antilock
brakes on cars do not allow tapping into the hydraulic circuit to
sense the brake application needed.

There are other non-hydraulic sensing methods for electric trailer
brake controllers but they have their drawbacks, like adjusting a
pendulum sensor (a knob that kids like to spin and play with whenever
left unattended) or getting used to a brake pedal extender with a
force gauge inside.

The other thing you need is a secure place on the body to attach a
bridle ring for the breakaway actuator cable. You do NOT connect the
breakaway cable to the trailer hitch, hitch receiver, or hitch bumper
- if the receiver or bumper physically becomes detached from the car
(and it does happen) the emergency brakes will not actuate. Your car
goes left, the trailer goes right, and it gets REAL messy.

--<< Bruce >>--

--
Bruce L. Bergman, Woodland Hills (Los Angeles) CA - Desktop
Electrician for Westend Electric - CA726700
5737 Kanan Rd. #359, Agoura CA 91301 (818) 889-9545
Spamtrapped address: Remove the python and the invalid, and use a net.

New Camper <burkefamily48@fuse.net> writes:
[color=blue]
> We were unexpectedly given a pop-up camper. We'd love to start
> camping again, but I think we're pushing the limits of what we
> can safely tow with our 2001 Sienna. We do not have the towing
> package, so 2000 lbs is the limit.[/color]


How much does the pop-up trailer weigh? I thought tent trailers[*]
(I gather that's what you're referring to) were pretty light, and
could be towed by cars that conventional travel trailers couldn't.
Indeed, I always thought that was one of their selling points.

[*] [url]http://tinyurl.com/e7byp[/url] (although this one is bigger and more
elaborate than most)



Geoff

--
"If I underfed a janitor, would he cling sucker-mouthed to the
surfaces of my cube, slurping up paper algae?" -- C J Silverio

Bruce L. Bergman <blPYTHONbergman@earthlink.invalid> writes:
[color=blue]
> Rather than overload springs, it is much better to attach airbags
> on the rear suspension like the Firestone Ride-Rite if they are
> available for your car.[/color]


There are also air *shocks* available. My father's Mercury station
wagon is equipped with those, for trailering a boat. They can be
filled as needed from the air hose at any gas station.



Geoff

--
"If I underfed a janitor, would he cling sucker-mouthed to the
surfaces of my cube, slurping up paper algae?" -- C J Silverio

On 12 May 2006 06:07:13 -0700, [email]geoffm@u1.netgate.net[/email] (Geoff Miller)
wrote:[color=blue]
>Bruce L. Bergman <blPYTHONbergman@earthlink.invalid> writes:[/color]
[color=blue][color=green]
>> Rather than overload springs, it is much better to attach airbags
>> on the rear suspension like the Firestone Ride-Rite if they are
>> available for your car.[/color]
>
>There are also air *shocks* available. My father's Mercury station
>wagon is equipped with those, for trailering a boat. They can be
>filled as needed from the air hose at any gas station.[/color]

Right - but there are two reasons I deliberately did not mention
them: (A) they're not nearly as available now as they were 25 years
ago, and even back then there were not too many choices. You had to
guess and try, and with a limited selection the valving of the shock
section was not always a good match to the car.

And (B) Air shocks are only suitable if you are willing to make
custom beefed-up mounts for them, otherwise you WILL have problems.
Shock mounting points have never been up to the task of carrying a
load, and they make them even lighter now because with normal shocks
they hold up just fine. But add air shocks and put a bunch of miles
on the vehicle, and broken shock mounts are normal, even expected.

Then you find out just how expensive odd parts like that are, and/or
you have to interrupt your vacation trip while they air-freight in a
replacement and then find someone to crawl under there to change them,
or to weld it back together temporarily.

--<< Bruce >>--
--
Bruce L. Bergman, Woodland Hills (Los Angeles) CA - Desktop
Electrician for Westend Electric - CA726700
5737 Kanan Rd. #359, Agoura CA 91301 (818) 889-9545
Spamtrapped address: Remove the python and the invalid, and use a net.

Replace the rear springs with progressive springs, I did on my 01 Sieena and
they're great. The stock springs are mush. The progressive springs rides
pretty much normal at light loads, but stiffen up as the van is loaded.
Call around and find a spring shop that knows what they're doing,
LT

Bruce L. Bergman <blPYTHONbergman@earthlink.invalid> writes:

: There are also air *shocks* available. My father's Mercury station
: wagon is equipped with those, for trailering a boat. They can be
: filled as needed from the air hose at any gas station.

[air shocks aren't as available as they once were]
[color=blue]
> And (B) Air shocks are only suitable if you are willing to make
> custom beefed-up mounts for them, otherwise you WILL have problems.[/color]
[color=blue]
>Shock mounting points have never been up to the task of carrying a
>load, and they make them even lighter now because with normal shocks
>they hold up just fine. But add air shocks and put a bunch of miles
>on the vehicle, and broken shock mounts are normal, even expected.[/color]


Hmmmm, interesting. My experience with the things is admittedly
limited. However, my father never had any problems with his. More
to the point, there are loads and there are loads. It seems to me
that the additional stress placed on the shock mounts by the weight
of a typical small boat like my father's 16-foot runabout, or a
modest travel trailer, or particularly a tent trailer like the
original poster mentioned, would be minimal. Hell, people pick
up the tongues of such trailers without difficulty in order to
lift them onto the hitch ball.

That being said, I'd never heard of air bags until you mentioned
them, and they do strike me as a more sound approach.



Geoff

--
"After several minutes of utterly dull conversation I began to think
of her not as a woman but as a human, then not as a human but as an
animal, then not as an animal but as a source of high-grade protein."
-- Mark. Gooley