Transmission, TOD and hub questions.

[CatFish]

First let me tell you all that I have done many searches and found lots of threads about these items but there is so many pages to read and I have read them for hours and still not found the specific info I am looking for that is why I posted this thread.

I have been having a strange transmission glitch lately and from what I have found it might be the transmission pressure control solenoid, it shifts hard into second and then shifts hard from second to first when slowing down. It has only done this a couple of times and after I pulled over and shut if off it starts acting normal again. A few times, I have noticed the indicator on the dash has flashed from drive to neutral as I take off or when I am sitting at a light. I will try to see if I can get a code, I have a code reader.

With that going on with the transmission, I have been doing some research about the TOD, transmission, and hubs on the VX and I have some question about that too.

I have always wanted to have the 2-wheel drive option as being in full time 4-wheel drive uses more gas, wears out parts and it is just not necessary to have all the time. Here in the Denver area, it is dry most of the time and I would like to have the 2-wheel drive option if it did not have any adverse effects and there was a benefit to doing the manual hubs. So to all of you that have done the manual hub swap here are a few questions:

1. What benefits have you found having the manual hubs?

2. Have you had any issues with the drive train using them?

3. Do you know if it affects the TOD system in a good or bad way? Or does it not affect it at all?

4. If you leave them locked, does it just work like a normal stock VX?

5. Do I need the TOD off switch I have read about to do the manual hubs?

If so can you tell me what it is, how it works, do you make it, or can I buy one, and where it would be installed on the VX?

I did find this thread about the TOD but there is not much about how it worked out after they did it, and the pictures are gone too. In addition, if you have manual hubs why would you need the off switch?
http://www.vehicross.info/modules.php?name=Content&file=viewarticle&id=74

Please let me know how the manual hubs have worked for you and tell me any information I may not have thought of and asked about that might be helpful.

My VX has 60K, 16” wheels with new Dura-Track tires 245/75 R16, the torsion bars were cranked up about 1” on the left and 1.5” on the right as it was not even when I got it now both sides are at the same ride height.

Thanks,
Chris

[Y33TREKker]

I was going to suggest that you speak with Fizx regarding your TOD/Manual hub questions, but I see that you've already asked in his For Sale thread, so my only other suggestion at this point about the problems you're experiencing (especially what your trans indicator lights on the dash are doing) would be to remove and inspect your Mode Selector switch from the drivers side of the transmission to see if it's dirty and can be cleaned, and/or possibly just needs to be replaced.

[CatFish]

I was going to suggest that you speak with Fizx regarding your TOD/Manual hub questions, but I see that you've already asked in his For Sale thread, so my only other suggestion at this point about the problems you're experiencing (especially what your trans indicator lights on the dash are doing) would be to remove and inspect your Mode Selector switch from the drivers side of the transmission to see if it's dirty and can be cleaned, and/or possibly just needs to be replaced.

I will check out the Mode Selector switch and see if it is dirty, how do I tell if it is bad?

I was hoping to hear from Fizx as my fried was interested in his VX and I was hoping he would tell me about the hubs, maybe he is busy and will get back to me at some point. Until then I am hoping for some good info from the rest of the VX community.

Thanks

[Y33TREKker]

I will check out the Mode Selector switch and see if it is dirty, how do I tell if it is bad?
Unfortunately, from what I've seen in various threads, about the only way to tell for sure if it's causing the problems is to take it off, clean it, then reinstall it to see if the problem goes away. I've not had one apart myself to see how the electrical traces on it's circuit board are arranged, but being an electrical switch, it might be possible to following the traces on the board to determine which contacts should show continuity depending on what position the switch is in.

From some of the pictures of mode switches I've seen here in various threads, it looks like the switches sometimes just get built up with road grime and such, which then causes short circuits between adjacent contacts (which results in the erratic light displays on the dash board and the trans going into gears other than the ones that are currently selected).

[CatFish]

Unfortunately, from what I've seen in various threads, about the only way to tell for sure if it's causing the problems is to take it off, clean it, then reinstall it to see if the problem goes away. I've not had one apart myself to see how the electrical traces on it's circuit board are arranged, but being an electrical switch, it might be possible to following the traces on the board to determine which contacts should show continuity depending on what position the switch is in.

From some of the pictures of mode switches I've seen here in various threads, it looks like the switches sometimes just get built up with road grime and such, which then causes short circuits between adjacent contacts (which results in the erratic light displays on the dash board and the trans going into gears other than the ones that are currently selected).

Thanks for the info I will check it out this weekend and see what I find.

[tom4bren]

1. What benefits have you found having the manual hubs?

For me, the sole purpose of installing the manual hubs was so that I could tow the VX '4 down' behind the RV. Of course, I also had to install a quick disconnect on the rear driveshaft for that.

I seriously doubt that you'll see a significant increase in mpg after installing manual hubs. The jury is still out on that one but I didn't see any improvement. I didn't install the TOD 'off' switch'.

2. Have you had any issues with the drive train using them?

None at all. My TOD light was flashing before I put on the manual hubs ... & it still does.

3. Do you know if it affects the TOD system in a good or bad way? Or does it not affect it at all?

In my experience ... not at all (of course that's a statistical sample of 'one').

4. If you leave them locked, does it just work like a normal stock VX?

Yes

5. Do I need the TOD off switch I have read about to do the manual hubs?

I don't have the switch. Mebbe sometime in the future but so far it just wasn't worth the effort.

Please let me know how the manual hubs have worked for you and tell me any information I may not have thought of and asked about that might be helpful.

Thanks,
Chris

Chris,

I was worried about running the manual hubs with the TOD because I just didn't like the idea of power being applied to the front differential with no load. That ended up being an unfounded concern. So far it's worked out great for me. I think I did a How2 on the install. Lemme know if you need it.

Tom

[bartmanS4]

I have the TOD on/off switch with no manual hubs. The switch was installed by the previous owner and doesn't have the resistor mod so when the TOD is bypassed I get an error light under the TOD display. This doesn't bother me because it gives me an indication that I'm in 2WD, otherwise the only way I know is by rear wheel slippage. I don't see any reason to go with manual hubs unless you have a locker or plan on towing like Tom mentioned.
Scott

[CatFish]

Chris,

I was worried about running the manual hubs with the TOD because I just didn't like the idea of power being applied to the front differential with no load. That ended up being an unfounded concern. So far it's worked out great for me. I think I did a How2 on the install. Lemme know if you need it.

Tom


I have the TOD on/off switch with no manual hubs. The switch was installed by the previous owner and doesn't have the resistor mod so when the TOD is bypassed I get an error light under the TOD display. This doesn't bother me because it gives me an indication that I'm in 2WD, otherwise the only way I know is by rear wheel slippage. I don't see any reason to go with manual hubs unless you have a locker or plan on towing like Tom mentioned.
Scott

Thanks for the info guys, sounds like I can just install the TOD off switch and get what I want.

Scott, when you have the TOD off do the lights for the front wheels in the TOD display still light up?

[bartmanS4]

Thanks for the info guys, sounds like I can just install the TOD off switch and get what I want.

Scott, when you have the TOD off do the lights for the front wheels in the TOD display still light up?

No, the front wheel lights stay unlit but the auto and rear wheels are lit along with the Check light (I stated Error before but it is Check). If you add the resistor mod then I think the TOD computer is fooled into thinking everything is fine and the front wheel indicators light up normally even though no power is being routed to the wheels. The PO of my VX just put a toggle switch in under the passenger seat but I think I will wire it up to a 4WD switch that I have to make it a little more finished.

[CatFish]

OK so the front wheel lights stay off indicating they are not in use so I could get rid of the error the front wheel light not lighting would tell me the VX in in 2WD with out the error light. are you sure the front wheels light up with the resistor mod? I would think they would stay off?

I think I will use the blank slot next to the heated mirror switch on the console for the TOD off switch location. I am going to see if I can get one with a light in it so I will know when it is on or off.

Now to troubleshoot the trans issue and find a TOD off switch and learn how to install it it.

[bartmanS4]

OK so the front wheel lights stay off indicating they are not in use so I could get rid of the error the front wheel light not lighting would tell me the VX in in 2WD with out the error light. are you sure the front wheels light up with the resistor mod? I would think they would stay off?


Yes, with the resistor mod the error light will turn off but I think I read that the front wheel indicators light up as if the wheels are being powered. I don't know for sure though.



I think I will use the blank slot next to the heated mirror switch on the console for the TOD off switch location. I am going to see if I can get one with a light in it so I will know when it is on or off.


Exactly my thought too. I'll have to check my 4WD switch to see if it has a lamp in it.



Now to troubleshoot the trans issue and find a TOD off switch and learn how to install it it.


5 spd mod will fix it. :yesb:

[tom4bren]

Thanks for the info guys, sounds like I can just install the TOD off switch and get what I want.

Not Zakly.

If you're going for maximum mpg, then you'll still need the locking hubs. Without them, you're still spinning the 3rd member in your front diff & hence the front prop shaft. That'll eat up a little bit of your mpg.

[bartmanS4]

Not Zakly.

If you're going for maximum mpg, then you'll still need the locking hubs. Without them, you're still spinning the 3rd member in your front diff & hence the front prop shaft. That'll eat up a little bit of your mpg.

I think the spinning of the 3rd happens anyway due to drag in the TC. There is probably a little more drag at the wheels though without disconnecting the hubs.

[VXorado]

Thanks for the info guys, sounds like I can just install the TOD off switch and get what I want.

Scott, when you have the TOD off do the lights for the front wheels in the TOD display still light up?

I also run manual hubs/TOD off switch. Works well and I average 1-2 MPG better with TOD off and hubs unlocked. I did thorough testing last winter to check for MPG differences and it's always slightly improved with TOD off.

I have the resistor installed and I don't get a checklight, just some whacking illuminations on the front wheels. Typically, all three front wheel bars will light up and hold.

I ran just manual hubs for a while and I definitely recommend the TOD off switch. The t-case will still try to transfer power to the front wheels and you'll feel the loss of power if the hubs are unlocked. This was common for highway driving when accelerating... TOD would try to transfer extra power to the front wheels I would end up accelerating slower.

[tom4bren]

I think the spinning of the 3rd happens anyway due to drag in the TC. There is probably a little more drag at the wheels though without disconnecting the hubs.

When VX is in 'Toad Mode', I get 0 miles accumulation on the odometer. I'm interpreting that to mean that nothing is making it into the tranny from either the front prop or the rear (not even a negligable turning due to viscous coupling).

[bartmanS4]

When VX is in 'Toad Mode', I get 0 miles accumulation on the odometer. I'm interpreting that to mean that nothing is making it into the tranny from either the front prop or the rear (not even a negligable turning due to viscous coupling).

I was thinking that because the rear is being driven the front will be spinning too, even though it's not being sent power. I think someone confirmed this via a GoPro camera recently. In your toad mode both front and rear are disconnected so the TC shouldn't get any input from the output so to speak.

[CatFish]

I also run manual hubs/TOD off switch. Works well and I average 1-2 MPG better with TOD off and hubs unlocked. I did thorough testing last winter to check for MPG differences and it's always slightly improved with TOD off.

I have the resistor installed and I don't get a checklight, just some whacking illuminations on the front wheels. Typically, all three front wheel bars will light up and hold.

I ran just manual hubs for a while and I definitely recommend the TOD off switch. The t-case will still try to transfer power to the front wheels and you'll feel the loss of power if the hubs are unlocked. This was common for highway driving when accelerating... TOD would try to transfer extra power to the front wheels I would end up accelerating slower.

I like that the MPG improves a little, it is not real important but it would be nice to get a little better MPG. Where did you get the TOD off switch? How hard was it to install, how long did it take?


When VX is in 'Toad Mode', I get 0 miles accumulation on the odometer. I'm interpreting that to mean that nothing is making it into the tranny from either the front prop or the rear (not even a negligable turning due to viscous coupling).

So you have less miles on the odometer than you have driven? Strange that the odometer does not count miles when the TOD is off.

VXorado, does your VX do the same thing?

[CatFish]

I hooked up the scanner and got a code, P0705 Transaxle Range Switch Circuit. I am not sure what part this is but I am going to try an find what the malfunction is by doing some searches.

If anyone knows what the best course of action should be to correct this problem please do tell me. In the mean time I will be searching.

Edit:
I found this http://engine-codes.com/tsb/tsb.php?tsb_id=154353&tsb_code=p0705&tsb_make=isuzu
ISUZU Technical Service Bulletin for Code P0705

Bulletin Number: IB00S007 Bulletin - Date: 2000-02-01
Component: Unknown Or Other
Summary:
On suv vehicles with automatic transmissions, some remote starter installations may cause the malfunction indicator light to set and store p0705. American Isuzu motors does not sell remote starter kits and does not recommend any particular model.

Read more: http://engine-codes.com/tsb/tsb.php?tsb_id=154353&tsb_code=p0705&tsb_make=isuzu#ixzz2dz2Vq6rw

I also found this thread:
http://www.vehicross.info/forums/showthread.php?t=14908
It appears to be part 8-96017-511-0 "Neutral Safety Switch"
I can get it but I would like to know where it goes and how hard it is to replace. I tried to search the shop manual I downloaded on line but it is not searchable and is just hundreds of scanned pages. Does anyone know what pages have the repair procedure on it? or a good picture of it's location?

[bartmanS4]

My VX manual shows DTC P0705 Transmission Range Switch
(Mode Switch) Illegal Position . . . . . . . . . . . . 7A1 30

First thing I'd check is the 15A fuse (CB 15) in the engine compartment. According to the manual "This fuse can burn due to a short circuit in the backup lamp." Does your back up light come on?

Also, Tom's toad mode has the rear drive shaft disconnected which is why his odometer doesn't advance while being towed.

[tom4bren]

So you have less miles on the odometer than you have driven? Strange that the odometer does not count miles when the TOD is off.



Also, Tom's toad mode has the rear drive shaft disconnected which is why his odometer doesn't advance while being towed.

Yah, 'toad mode' = being towed (4 down).

I only pointed out the 0 miles accumulation on the ODO (when being towed) to stress the point that you should do both the TOD disconnect and the locking hubs for best results. It's all well and good to cut power going to the front but if the front end is still spinning, then you really aren't reaping the full benefits.

[CatFish]

My VX manual shows DTC P0705 Transmission Range Switch
(Mode Switch) Illegal Position . . . . . . . . . . . . 7A1 30

First thing I'd check is the 15A fuse (CB 15) in the engine compartment. According to the manual "This fuse can burn due to a short circuit in the backup lamp." Does your back up light come on?

Also, Tom's toad mode has the rear drive shaft disconnected which is why his odometer doesn't advance while being towed.

Thanks I checked the fuse and it looked fine but I replaced the fuse anyway. I cleared the codes last night, so if the code reoccurs I can then look at replacing a part.
FYI: the CB 15 fuse is in the side panel of the dash, the engine compartment fuses are EB #s so if you are looking for a fuse the CB fuses are in the dash and the EB fuses are in the engine bay.

Well on the way to work the indicator light started to flash between neutral and drive and the shifting started to slam from first to second and second to first on down shift, so I shut it off and when I restarted it is was normal again. I am want to order the part but code P0705 says it is the "Transaxle Range Switch Circuit" but when I go to the Isuzu parts page I do a search for Transaxle Range Switch Circuit and there is no such part shown under that name, but after doing a few searches I found it is also called the "Neutral safety switch" does this sound right to you guys? I was looking here http://www.stcharlesautoparts.com/ I did find the neutral safety switch but no picture showing location, is it in the same place as the Trooper?

Should I replace the switch or could it be something else causing the issues?

I did have to replace this same part in my 96 Trooper not long after I put in the remote starter in it too.

Code Page:http://www.vehicross.info/forums/showthread.php?t=2013&highlight=P0705
Other Code page: http://www.troublecodes.net/isuzu/iszuobd2/