Torque binding when turning a sharp corner

[johnnyapollo]

If I'm not mistaken the wheel speed sensors are at each wheel and feedback to the TOD ECU to determine when "slippage" is occuring - the TOD compensates by adjusting more power to front (back is always at "full"). The TOD speed sensors that went out on mine are both on the TOD unit itself - one in front and one behind the transfer case - these measure the speed the internal gears are running and also feedback to the TOD ECU so that it can adjust power to front.

-- John

[mrlegoman]

If I'm not mistaken the wheel speed sensors are at each wheel and feedback to the TOD ECU to determine when "slippage" is occuring - the TOD compensates by adjusting more power to front (back is always at "full"). The TOD speed sensors that went out on mine are both on the TOD unit itself - one in front and one behind the transfer case - these measure the speed the internal gears are running and also feedback to the TOD ECU so that it can adjust power to front.

-- John

Are you talking about the VSS?
There is no listing of 'TOD speed sensor' in the shop manual. Of course a search on TOD brings up about 1000 results......

[mdwyer]

TOD Speed Sensors
Are these the same "Wheel Speed Sensors" noted in the shop manual?

I'm pretty sure that the answer to that is 'no'. There are Wheel Speed Sensors at the wheels, but they are used for the ABS system. The TOD speed sensor is located on the prop shafts, if I recall correctly. It is closer to the tranny than the wheels.

[johnnyapollo]

Makes sense.

-- John

[mrlegoman]

I've located the Front and Rear Speed sensors.
4B2-4 in the shop manual.
But I cannot find a part number in the 'part list' for them.
We don't have an official local dealership. Where else can I look?

[rocket man]

It sounds to me like what Johnny Apollo and other's have had including me (bad speed sensors)...

I just posted earlier today my transmission and t/c odessey. If I were you, I would check the wiring leading to these sensors first they get really close to the exhaust pipes.

I had a major transmission failure but I also had the symptom of what the manual calls "tight corner braking". This felt like a binding to me too... I lived with this for abount 6 months. I also had a "check TOD" light. Without out a code reader (special one from Isuzu) you are SOL. A dealer will read the code for around $85. I never got to the dealer to diagnose, I just swapped out a transmission and transfer case and the problem went away.

The front and rear sensor's are on the "Transfer case". These sensors are approx. $235 a piece, from Isuzu. In my travels on the net looking for a transmission, I found lots of transfer cases for the Trooper 2 99-2001 and VX 99-2001(these are interchangable and mirror image of themselves). I found one for $125.00 + $25 shipping and it had both sensors! They (transfer cases) ranged in price from $75-$350. That trims the cost from $470 to $150, plus you get a transfer case core in return to use for parts or exchange if you ever trash your present transfer case

The rear sensor is pretty easy to replace the one at the front is on top of the TC in a tight area. I did a straight r&r on trans and tc which entailed dropping the rear crossmembers and front and rear propellar shafts. Access to these places would be easy then. Try car-parts.com and follow the prompts and see whats out there. Dealers charge a lot to replace these, but its really easy especially if you have little hands.


Good lucK

John

[Wylderon]

I have the same problem....turn sharp and starts binding.....tod light freaking out and sometimes you can hear a "Thump" in the rear end.......I am totally lost on this TOD thing.....sometimes it's working fine then sometimes its freaking Haywire!!! Have Read the threads on TOD but still lost......

[rocket man]

"Tight corner braking" is a term the factory manual coined.

It best describes a malady that is associated with the function of the speed sensors. There are 2 of them and they are on the transfer case. One is up high on the right side of the case and is held in place with a nut and retainer there are wires leading from it to the ECM that controls the TOD. The same is true with the speed sensor in the rear to the TC (transfer case). Don't confuse this with the speedometer sensor that is on the right side also but looks way different and is adjacent to the propellar shaft.

But before, I suggest you run this test. Go into a market parking lot, or better yet a a place with nice shiney cement floor like an underground parking lot. Now while going very slow forward turn the wheel left or right to "full lock" does the car act like or feel like your applying the brakes? Also do you feel any sensation of "hard steering" that seems to let-off when the wheels straighten out?? Then does it relase with a "thud only to start braking again?

Okay that is "hard Corner braking". The popping or the "thud" is the "clutch pack" binding up and then releasing in the transfer case. We have full time 4 wd so it is necessary we syncronize the speed and distance that the front and rear wheels travel. For example, when you make a sharp right turn your right front wheel (inside)is traveling a much shorter distance that the left front wheel (outside). The same is true for the rear wheels. Those sensors syncronize the power to the front propeller shaft.

I you have any mechanical ability I would climb under the car with a high intensity led lite attached to your forhead and realy scrutinize the wiring and connectors that lead to your transmission and TC. Since your problem is "intermittant" and not constant....that could be a very real possibility. I would especially check the wiring area around the converter housing on teh left side of the transmission as it passes very close to the exhaust manifold, the wiring should go behindthe heat shield. Check that area real close.

Also, you didn't mention this but you should be seeing a "check TOD" lite in RED that is under the TOD meter. This will reset each time you turn the car off, but then show up again after driving a short distance. If you are not getting a "check TOD lite" your problem may be elsewhere??

If all else fails take it to a dealer that has the computer to shoot the "trouble codes". This is a different diagnostic computer than you can get at Kragen or at your local shop and from what I have been told it is only availble at a Isuzu dealership. BTW the sensors are around $235 each. (no labor) although they are not difficult to install I have heard quotes of around $600 labor.

You could solve this problem by purchasing a TC from a wrecking yard and scavaging the sensors ($125-$350) and instdalling them in your unit. Make sure before you buy that the sensors are there. Check: car-parts.com go the home page and follow the prompts.

Good luck

John
ps...download or purchase the CD manual for this car, available on this site, if you do not already have it. It will help you alot.......

[psychos2]

have you checked the tire pressure? and how worn are your tires? shawn

[mrlegoman]

The front and rear sensor's are on the "Transfer case". These sensors are approx. $235 a piece, from Isuzu. In my travels on the net looking for a transmission, I found lots of transfer cases for the Trooper 2 99-2001 and VX 99-2001(these are interchangable and mirror image of themselves). I found one for $125.00 + $25 shipping and it had both sensors! They (transfer cases) ranged in price from $75-$350. That trims the cost from $470 to $150, plus you get a transfer case core in return to use for parts or exchange if you ever trash your present transfer case

John

I've spent the entire morning searching the net and have not had much luck finding anything. The closest I've come to is parts.com:
Electrical - Powertrain control - Vehicle speed sensor $146

Does anyone have the Isuzu part numbers for these sensors? I cannot find them in the parts catalog.

But the 99-2001 Trooper 2 used the same transfer case and sensors as the VehiCross?
There are some VehiCross cases for sale on car-part.com. Lowest price seems to be in the $400 range. Not sure how much their going to charge for shipping.

So my choices basically are to either spend 300$ on two new sensors or spend $500 on a used transfer case with used sensors that might be ok?

[rocket man]

So my choices basically are to either spend 300$ on two new sensors or spend $500 on a used transfer case with used sensors that might be ok?[/QUOTE]

You just searched under Vehicross....go back to car-parts.com and search under, 2001 Isuzu, Trooper 2. transfer case, then look for "with torque on demand" or w/TOD. It is the exact same tranny, transfer case, and sensors as your car.... all wrecking yards may not know this. I think the price goes up when they get in a car like the VX and they think its rare. I just visited the site and there were many t/c's in the $200 range with one listed for $150and another for $175. They were both in California, but these places will ship via truck cheap!

Revisit the site and you'll see....be sure to confirm that the sensors ands connector wires are still in place...

[mrlegoman]

^ Thank you!! I appreciate the help!

[rocket man]

Your very welcome Legoman:

BTW. I might not have made it clear in my post but the transmissions, t/c and sensors on the Trooper 2 with TOD are the same in 1999-2002.

[evillecutter]

ran across this old thread and thought i would input - this is what mine did when the chain in the transfer case stretched and the clutches went bad - according to borg werner our transfer cases are completely unique to the vehicross

[Leon R]

"Unique" - as in: it has a different part number, but otherwise can be easily interchanged or...

As in: do not even consider substituting them!

A lot of people (aka manufacturer's reps) like to do things "by the book".