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Old 10-08-2003, 03:57 PM   #11
Denny_A
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Default Re:Toyota 4Runner replaces Honda ODY

[quote author=Denny_A link=board=20;threadid=1379;start=msg9950#msg9950 date=1065577536]
I have my dealer's top mechanic in the process of getting a definitive answer from Toyota. Said it could take a couple of days.
Denny_A
[/quote]
Here's the answer, and they're sticking to it! It's from the manufacturer, via the local Toyota Service Manager.

"A load adjusting hitch (WDH) puts extra weight on the 4Runner. This can result in the *trailer having a tendancy to steer the tow vehicle*, reducing resistance to sway/instability". [Paraphrasing here. I had it repeated, so I'm sure I understood "what he said", but not why!]

He could not elaborate. As in, those words (as from a Parrot) stood on their own. No further logical investigation possible.

So, here's my interpretation of what that could mean.

IF the max tongue weight were 500 lbs, and if one were to use a 100 lb WDH, then the max "trailer tongue weight " has just been reduced to 400 lbs (500 lbs - 100 lb hitch). Use of a bar and a ball (maybe 15 lbs), would not reduce the useful "tongue weight" limit by very much. Therefore, if a WDH is in use, the hapless owner might overload the receiver, causing instability, and allowing the trailer to "steer" the tow vehicle. That's the closest I can come to something sounding logical.

If a really fancy, heavy WDH were used, the weight might be as much as 150 lbs (?). Then only 350 lbs of tongue weight is left for the trailer. Is a Reese really heavy? Don't know, or care.

The logic missing, from this simple analysis, is that a WDH transfers a portion of the tongue weight + hitch wt back to the wheels, while simultaneously providing a torque moment around the TV's rear wheels. That moment transfers some of the "hitch / tongue wt to the front wheels.

Here's how I will proceed from now on. Measure front and rear TV bumper distances from the ground w/o the WDH hitch (mine's 90 lbs) in the receiver. Install the hitch and connect the trailer. Hookup the springs bars. Measure the new front/ rear
bumper heights. If the front bumper is more than an inch higher (Delta "h" - height difference) than the rear bumper, then go back and drop another link and adjust, etc., until satisfied.

Now that the vehicle is close to level I can logically surmise the following. If the hitch + tongue weight were 540 lbs total (arbitrary #), then 2/3 , or 360 lbs is carried by the TV and 1/3, or 180 lbs. is carried by the trailer axle. At the very least, the issue of the trailer steering the TV is bogus if the TV is level, and the hitch is within load limits. That's because part of the load has been "redistributed".

I will continue to ignore Toyota's recommendation to not use a WDH. That's my story and ............

Denny_A

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Old 10-08-2003, 07:26 PM   #12
mjlaupp
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Default Re:Toyota 4Runner replaces Honda ODY

Mine ain't a Toyota or Honda but I do have a how to write up from my F250 Super Duty Owner's Guide. They are talking about a much heavier tow vehicle and trailer than most TM owners have but the principal is the same.
Quote:
Hitches

Do not use hitches that clamp onto the vehicle's bumper or attach to the axle. You must distribute the load in your trailor so that 10%-15% of the total weight of the trailor is on the tongue.

Load Equalizing Hitch

When hooking up a trailor using a load equalizing hitch, always use the following procedure:

1. Park the unloaded vehicle on a level surface. With the ignition on and all doors closed, allow the vehicle to stand for several minutes so that it can level.

2. Measure the height of a reference point on the front and rear bumpers at the center of the vehicle.

3. Attach the trailer to the vehicle and adjust the hitch equalizers so that the front bumper height is within 0-13 mm (0,5 in) of the reference point. After proper adjustment, the rear bumper should be no higher than in Step 2.

Note: Adjusting an equalizing hitch so that the rear bumper of the vehicle is higher than it was unloaded will defeat tha function of the load equalizing hitch and may cause unpredictable handling.
I haven't pulled the TM with this truck yet so I don't know how the combination will perform. I know! I know! I don't need a Super Duty to pull a Trailmanor. I just wanted one and it had to have 4 doors for the grandkids.
MJL
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Old 10-08-2003, 08:29 PM   #13
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Default Re:Toyota 4Runner replaces Honda ODY

Mike, I think you are going to love your new truck. Have a buddy with one and he raves about it. Only thing is that I've heard stories of folks blowing sparkplugs out when they really wrap the rpms. So don't you go drag racin' or runnin' 'shine now, hear?
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Old 11-17-2003, 11:06 AM   #14
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Default Re:Toyota 4Runner replaces Honda ODY

We have a 2000 4Runner and are considering trading it for a 1999 Odyssey. The reason is that we thought we would use a 2027SD as a mobile base camp then use the minivan to boondock over night in places where we would not trailer in. However, we keep hearing of so many precautions that must be taken with the Odyssey that it makes me hesitate. Edmunds folks report transmission problems and road clearance problems.

There is no other minivan we would consider. The Previa only has 4-cyl, the Sienna is only a front wheel drive, the USA minivans have terrible owner reports.

Maybe we should just stick with out terrific, dependable 4Runner?
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Old 11-17-2003, 06:14 PM   #15
Denny_A
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Default Re:Toyota 4Runner replaces Honda ODY

[quote author=fnjkpas link=board=20;threadid=1379;start=msg10816#msg1081 6 date=1069092386]
We have a 2000 4Runner and are considering trading it for a 1999 Odyssey. [/quote]
I had a 2001 Ody and traded for the 2000 4Runner SR5 AWD. I am very happy with my decision. Recall, the SR5 has a 183 HP, V6 engine. Some 2000 4Runners may have a 4 cylinder engine, which is likely underpowered. The Ody's front wheel drive is a negative. Slippery roads seem a LOT slipperier.
Quote:
However, we keep hearing of so many precautions that must be taken with the Odyssey that it makes me hesitate. Edmunds folks report transmission problems and road clearance problems.
The Ody has a 3500 lb tow limit. The Combined Gross Weight Rating (CGWR) of the Ody is 8160 lbs. If you limit the trailer to 3500 lbs max + 4300 lbs for the Ody - there's only 380 lbs left over for passengers and cargo in the tow vehicle. That can be one heck-of-a limit for longer trips.
Quote:
Maybe we should just stick with out terrific, dependable 4Runner?
I think you already have a winner. Horsepower (V6) is 183 compared to the Ody's 205 (87 Octane) and 217 lb-ft torque, vs 225. The 4Runner weighs in at 400 lbs less than the Ody, the tow limit is 5000 lbs and the GCWR is 9000 + lbs. Game, set, match!!l 8).

Also, on excursions where trailers won't go, 2 people (short ones) can sleep in the back of a 4Runner - if they're friendly. The Ody ain't going many places the 4Runner can go. IMHO, keep the 4Runner!

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Old 07-30-2004, 06:23 PM   #16
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Default Re:Toyota 4Runner replaces Honda ODY

Well, I have one answer regarding this question. A WDH is not recommended. It fools the antilock This could cause an acdcident or worse, failure of the braking system on a grade. I know I have that quiestion ansered. I was thinking about a TRD Turbocharger to add extra HP. I was told that fit the '85 through '88 only.

Will let you more as I can find out.

For ansers to this questionToyota Customer Service at 8003314331. This is not a techical tech, but the lady verified her informatio before passing ion.
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Old 07-30-2004, 10:00 PM   #17
Denny_A
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Default Re:Toyota 4Runner replaces Honda ODY

[quote author=SeeKae link=board=20;threadid=1379;start=msg15171#msg1517 1 date=1091233383]
Well, I have one answer regarding this question. A WDH is not recommended. It fools the antilock This could cause an acdcident or worse, failure of the braking system on a grade. I know I have that quiestion ansered.
[/quote]

My thoughts (based on a previous vehicle) ragarding fooling the antilock brakes.

Chances are(?) that as the 4Runner is loaded and the rear end settles, a mechanical device is used to increase proportional braking to the rear wheels. So if one were to load 500 lbs over the rear wheels, a panic stop would result in a bunch more braking being applied to the rear wheels. Regardless, the antilock *must* function based on time-rate-of-change of the angular velocity of the wheel. Normally the slip ratio (when antilock kicks in) will be such that the wheels turn at 90% of vehicle speed. If a wheel suddenly decelarates too quickly it's released until vehicle speed is regained, then reapplied.

If a WDH is used, the vehicle stays level. The proportional braking feature is defeated. However, it seems that a brake lockup would still be prevented by the antilock sysyem. Braking, from the rear brakes, would be less. Still, with the trailer brakes assisting, that shouldn't result in an unsafe condition. The only other problem I can see might occur if the weight in the rear of the 4Runner were several hundred pounds. If the WDH were cinched to the point that the additional braking needed to account for the heavy trunk load weren't available, and a heavy trailer is also attached, and the trailer brakes were not working well - the trailer could tend to destabilize the rear of the tv. The extra cargo weight, along with low braking could cause the rear of the tv break loose laterally. Antilock is not designed to deal consistently with both straight ahead AND cornering loads simultaneously.

Since I don't overload cargo in the 4Runner, and do adjust/test my trailer brakes, I plan to keep on "living dangerously"! 8)

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Old 07-31-2004, 09:29 AM   #18
RockyMtnRay
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Default Re:Toyota 4Runner replaces Honda ODY

[quote author=Denny_A link=board=20;threadid=1379;start=msg15180#msg1518 0 date=1091246405]

If a WDH is used, the vehicle stays level. The proportional braking feature is defeated.
[/quote]

With all due respect, I disagree with your conclusion. Although a WDH transfers part of the hitch weight to the front wheels, some (a third if the WDH is correctly setup) does remain on the rear wheels. Hence, although the tow vehicle remains level, the rear of the tow vehicle does indeed drop (by comparison to an unladen vehicle), and the brake proportioning valve does thusly increase the amount & percentage of brake force applied to the rear wheels. Therefore a properly setup WDH does not defeat the proportioning feature...although the increase in rear braking is not as large as if a WDH hadn't been used.

The real problem with the brake proportioning valve (BPV) comes not with a WDH, but rather with the use of air bag type rear suspension boosters to "level" the tow vehicle. If a WDH is not used, two things happen to the tow vehicle: the rear of the TV does drop and, equally importantly, the front of the TV rises (because of the teeter-totter effect of applying substantial down force well behind the TV's rear axle). In many cases, the front of the TV rises by 1 to 2 inches. If an airbag system is then used to raise the rear of the TV so that the TV is level, the overall ride height on both ends of the TV is now 1 to 2 inches above that of an unladen vehicle! Since the rear is now lifted by as much as two inches, the BPV is now almost entirely closed and the rear brakes are providing only 5 to 10 percent of the braking force of the TV instead of the 20 to 30 percent they normally provide (or the 50 percent they should be providing when the TV is loaded). I consider airbags as completely evil devices if they're being used to "level" a tow vehicle.
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Old 07-31-2004, 11:52 AM   #19
Denny_A
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Default Re:Toyota 4Runner replaces Honda ODY

[quote author=RockyMtnRay link=board=20;threadid=1379;start=msg15184#msg1518 4 date=1091287781]
[quote author=Denny_A link=board=20;threadid=1379;start=msg15180#msg1518 0 date=1091246405]

If a WDH is used, the vehicle stays level. The proportional braking feature is defeated.
[/quote]

With all due respect, I disagree with your conclusion. Although a WDH transfers part of the hitch weight to the front wheels, some (a third if the WDH is correctly setup) does remain on the rear wheels. Hence, although the tow vehicle remains level, the rear of the tow vehicle does indeed drop (by comparison to an unladen vehicle), and the brake proportioning valve does thusly increase the amount & percentage of brake force applied to the rear wheels.
[/quote]

Hmm..... it was late and I maybe had tunnel vision. That's the problem with thinking - it's really hard work. :P

Of course, if properly adjusted, 2/3 of the hitch load is transferred to the tv axles. Approx 1/3 to each. The tv then squats a uniform amount (front and rear).

Here's the question. Do folks adjust the number of dropped links based on the attitude of the vehicle when loaded with the hitch installed, or based on measurements taken when the tv is empty? I've done it both ways

I now measure bumper heights before loading the vehicle and installing the hitch. When the trailer is connected I drop the number of links needed to return it to approx the same attitude. Having done that a time or few, I don't bother to repeat often, since the approporiate number of dropped links rarely changes. The tv cargo is nearly always the same.

The 75 to 100 lbs hitch, hanging from the receiver, can appreciably lighten the load on the front axle.

If the attitude of the tow vehicle is determined with cargo loaded and w/hitch installed, the outcome will be different, but probably not very noticeble regarding handling. Assumes one establishes baseline cago + hitch attitude.

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Old 08-01-2004, 03:23 PM   #20
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Default Re:Toyota 4Runner replaces Honda ODY

The instructions that came with my DrawTite single-arm WDH said to measure fender to ground front and rear before hitching and return front to origional position only (measurement before hitching) unless rear sag is more than 1 inch. I avoided going to heavier bars for fear that they would transfer too much weight forward and back from rear wheels if I crossed a short, deep dip like is found some places in the SW. Picture your hooked up TV and TM with the TV's front wheels on one side of the dip and trailer wheels on the other with the TV's rear wheels off the ground if that helps explain my concern. I'm not at all sure my concern is justified and I think I'll find out my true tongue weight. I know the weight on each axle but not the tongue weight as that was not readily doable when I drove through the truck scales.
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