ADD Problems

shampoop · 08-07-2012, 11:07 PM

So my 4wd doesn't work. Worked perfect the last time I tried it during the winter. Click the 4wd button and the light does not come on. The transfer case is doing it's job perfectly and the front driveshaft spins properly.

When I press the button, I can hear the ADD solenoid engage just like the transfer case solenoid. I'm currently trying to find a vacuum diagram that depicts how the system is supposed to work, but every picture/diagram I find doesn't seem to match up with the system in reality. I would just manually apply vacuum with my hand pump, but it's inaccessible currently.

It's a 03 tacoma v6 5spd with push button 4x4. Anyone found a good vacuum diagram? Any Ideas?

jski · 08-08-2012, 06:23 AM

Are you sure the ADD system in your 2003 is vacuum actuated? I know my 2003 is electrically driven and the 2003 FSM shows electric only.

Perhaps the vacuum lines don't match anything because they are the vent lines?

vegaskurt · 08-08-2012, 10:23 AM

03 is all electric, no vacuum lines.

shampoop · 08-08-2012, 05:55 PM

That would make a lot more sense! All I could trace was one going to a vent. The FSM I was looking at showed a vent and a vacuum line, looked for some different pictures and found none that matched what I could see on my truck!

shampoop · 08-08-2012, 10:32 PM

Figured it out! Turns out it sounded like it was working because it kind of was working. Only problem was that the solenoid was only moving the fork about a millimeter or two instead of 1 inch+ like it should have. Took it apart and found that the gear teeth cut directly into the shaft that moves the fork had a tooth broken off!

Edit: Pics FTW!

Anyone have a dead ADD solenoid from a 01-04 I could salvage this part from?

ecp_1991 · 11-21-2012, 05:12 PM

Sorry to bring this back.. But, Was it the solenoid on the dif or transfer case? The motor on my dif doesn't even seem to be working.. Does anyone know where I can get a new motor? (02 Tacoma ext. cab 3.4 V6 ADD)

Harmonytaco · 11-21-2012, 08:08 PM

So do some ADD diffs use vacuum to actuate and others electric? I have an 03 2.7 with a lever to select and engage 4x4. I have not looked at it close enough to tell and am not familiar with this. I just purchased a diff off a 2000 that had ADD hubs, hope I can make it work.

DudeMan · 11-22-2012, 08:40 AM

Quote:

Originally Posted by Harmonytaco

So do some ADD diffs use vacuum to actuate and others electric? I have an 03 2.7 with a lever to select and engage 4x4. I have not looked at it close enough to tell and am not familiar with this. I just purchased a diff off a 2000 that had ADD hubs, hope I can make it work.

I'm a bit confused in what you are asking. The rear diff can have an actuator that engages the diff lock but that has nothing to do with how you engage 4wd. Engaging 4wd takes place in the transfer case...not diff.

Harmonytaco · 11-22-2012, 09:28 AM

There is an actuated mechanism to engage the front add diffs that is located in the diff itself. My question is if there are vacuum actuated and electrically actuated add diffs. I just bought one with the impression that they are all vacuum actuated (the vacuum moves the fork in the diff) with a electrical solenoid that switches the direction the vacuum pulls to either engage or disengage. I might be totally wrong though. Above others are saying theirs are totally electric. I haven't had time to pull the skid and look for myself as mine is my only transportation at this time.

DudeMan · 11-22-2012, 09:48 AM

Gotcha. I'm willing to bet it's electric but I'm not 100% sure about 2000's.

Hopefully someone else can chime in who is sure.

Harmonytaco · 11-22-2012, 10:41 AM

I would say you are right, I have two vacuum lines coming out of the diff, but the are capped behind the fuse box under the hood.

valon5150 · 11-22-2012, 11:30 AM

Quote:

Originally Posted by Harmonytaco

I would say you are right, I have two vacuum lines coming out of the diff, but the are capped behind the fuse box under the hood.

Those are just breathers.

Harmonytaco · 11-22-2012, 07:51 PM

That would make sense. I not real sure what I got guess I will have to take the skid plate off this weekend and do some more looking around.

valon5150 · 11-22-2012, 10:06 PM

You should be fine. Just pull your diff out swap tube onto the diff you got and stick it back in like the stock one was

08-07-2012, 11:07 PM	#1
shampoop Member Join Date: Dec 2011 Location: SW Washington Posts: 50	ADD Problems So my 4wd doesn't work. Worked perfect the last time I tried it during the winter. Click the 4wd button and the light does not come on. The transfer case is doing it's job perfectly and the front driveshaft spins properly. When I press the button, I can hear the ADD solenoid engage just like the transfer case solenoid. I'm currently trying to find a vacuum diagram that depicts how the system is supposed to work, but every picture/diagram I find doesn't seem to match up with the system in reality. I would just manually apply vacuum with my hand pump, but it's inaccessible currently. It's a 03 tacoma v6 5spd with push button 4x4. Anyone found a good vacuum diagram? Any Ideas?

08-08-2012, 10:23 AM	#3
vegaskurt Veteran Member Join Date: Dec 2005 Location: Reno NV Posts: 696	03 is all electric, no vacuum lines. __________________ 1997 4runner SC V6 \| URD 7th \| Stubbs Sliders \| SAS \| FROR FF Kit

08-08-2012, 10:32 PM	#5
shampoop Member Join Date: Dec 2011 Location: SW Washington Posts: 50	Figured it out! Turns out it sounded like it was working because it kind of was working. Only problem was that the solenoid was only moving the fork about a millimeter or two instead of 1 inch+ like it should have. Took it apart and found that the gear teeth cut directly into the shaft that moves the fork had a tooth broken off! Edit: Pics FTW! Anyone have a dead ADD solenoid from a 01-04 I could salvage this part from? Attached Thumbnails

11-22-2012, 09:48 AM	#10
DudeMan Veteran Member Join Date: Jan 2011 Location: Central Pennsylvania Posts: 1,115	Gotcha. I'm willing to bet it's electric but I'm not 100% sure about 2000's. Hopefully someone else can chime in who is sure. __________________ 2004 V6 Taco XCab TRD SR5 5-speed All-Pro Standards & Billies 5125 - 881 coils - LR UCA's - Skid Row Skids & Homemade t-case protection - Homemade Sliders - All-Pro Rear Bumper - Wheelers Steelies - 33's - Homemade Bed Rack - Inchworm Crawl Box

11-22-2012, 10:06 PM	#14
valon5150 Senior Member My Rig: 84 pickup Join Date: Nov 2011 Location: cottonwood CA Posts: 228	You should be fine. Just pull your diff out swap tube onto the diff you got and stick it back in like the stock one was __________________ 01 turd. all pro 3 inch, 33's, homemade everything, Aussie front locker. - dead and chopped the fuck up. 84 std cab 22r POS. home brewed sliders and bumpers. 63's/RUF .elocker rear/welded front. 4.7. 35 km2s.

08-08-2012, 06:23 AM	#2
jski Senior Member Join Date: Apr 2009 Posts: 126	Are you sure the ADD system in your 2003 is vacuum actuated? I know my 2003 is electrically driven and the 2003 FSM shows electric only. Perhaps the vacuum lines don't match anything because they are the vent lines?

08-08-2012, 05:55 PM	#4
shampoop Member Join Date: Dec 2011 Location: SW Washington Posts: 50	That would make a lot more sense! All I could trace was one going to a vent. The FSM I was looking at showed a vent and a vacuum line, looked for some different pictures and found none that matched what I could see on my truck!

11-21-2012, 05:12 PM	#6
ecp_1991 Newbie Join Date: Jul 2012 Posts: 2	Sorry to bring this back.. But, Was it the solenoid on the dif or transfer case? The motor on my dif doesn't even seem to be working.. Does anyone know where I can get a new motor? (02 Tacoma ext. cab 3.4 V6 ADD)

11-21-2012, 08:08 PM	#7
Harmonytaco Senior Member My Rig: 03 burrito Join Date: Mar 2012 Location: IN Posts: 106	So do some ADD diffs use vacuum to actuate and others electric? I have an 03 2.7 with a lever to select and engage 4x4. I have not looked at it close enough to tell and am not familiar with this. I just purchased a diff off a 2000 that had ADD hubs, hope I can make it work.

11-22-2012, 09:28 AM	#9
Harmonytaco Senior Member My Rig: 03 burrito Join Date: Mar 2012 Location: IN Posts: 106	There is an actuated mechanism to engage the front add diffs that is located in the diff itself. My question is if there are vacuum actuated and electrically actuated add diffs. I just bought one with the impression that they are all vacuum actuated (the vacuum moves the fork in the diff) with a electrical solenoid that switches the direction the vacuum pulls to either engage or disengage. I might be totally wrong though. Above others are saying theirs are totally electric. I haven't had time to pull the skid and look for myself as mine is my only transportation at this time.

11-22-2012, 10:41 AM	#11
Harmonytaco Senior Member My Rig: 03 burrito Join Date: Mar 2012 Location: IN Posts: 106	I would say you are right, I have two vacuum lines coming out of the diff, but the are capped behind the fuse box under the hood.

11-22-2012, 07:51 PM	#13
Harmonytaco Senior Member My Rig: 03 burrito Join Date: Mar 2012 Location: IN Posts: 106	That would make sense. I not real sure what I got guess I will have to take the skid plate off this weekend and do some more looking around.

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