: 4wd not engaging


ike
05-12-2008, 10:19 AM
My buddy just picked up an 88 4runner with ADD, and the 4wd is not engaging. The light on the dash turns on and the transfercase will shift into low, but the front wheels do not get engaged. I searched alittle, but am feeling lazy. what are the normal culprits that cause this as i have never had this problem with a toyota before. Thanks in advance for any help.

ziggy428
05-12-2008, 11:49 AM
Thats why I love the manual hubs. :wiggle:

ike
05-12-2008, 11:53 AM
I know, i need to convert the taco soon. I just want to figure this out for my buddy so we have another yota out on the trails. He made sevenmile in 2wd this weekend, but he needed several pulls.

RedRunnertc
05-12-2008, 02:46 PM
If the light comes on, the ADD is actuating, and it's in 4WD. (The light is positively switched by the throw of the little collar)

If it's ADD, then he has splined flanges, not "auto" or any other kind of movable hub.

Most likely culprit is a broken CV and the open diff just sends all the power to that side. If you jack up the truck (both front and back or remove the rear driveshaft and jack up the front) is the driveshaft spinning?

cchark
05-12-2008, 02:47 PM
Does the T-case lock into 4wd? Have someone watch the front drive shaft to see if it spins while driving slow in 4wd... Dont run over his/her head ;)

ike
05-12-2008, 03:26 PM
Will do tonight. I will post up what i find.

ziggy428
05-12-2008, 03:31 PM
If you turn one drive shaft off the ground then both should turn if its in 4wd right? I would think a broken cv would be really noticeable but maybe I'm wrong. Then while its jacked up the wheels should turn in opposite directions.

ike
05-12-2008, 05:23 PM
yeah i didnt think cv either because it drives perfectly normal with no noises from the front end, but it doesnt hurt to look in that direction either.

cchark
05-12-2008, 05:46 PM
yeah i didnt think cv either because it drives perfectly normal with no noises from the front end, but it doesnt hurt to look in that direction either.
When you went wheelin, did you ever see a front tire spinnin?
Check the front DS thing... Having someone to watch it spinning while driving in 4wd is the simple way IMO... Should turn = to the rear
From there you either have-
Tcase linkage issues
Tcase is fukked
Broken CV- Could be at one of the shafts far inside or out. Even then, if the boot clamps are tight, it should have torn a boot open spilling grease. Maybe youre lucky :D
Front spider or ring/pinion gears went kaabooom. Pull the drain plug and look for fun chunks.

ike
05-12-2008, 05:58 PM
we noticed it when attempting a fairly easy hill. you would be in 4 low and sit there spinning one rear tire and no front tires.

ziggy428
05-12-2008, 06:57 PM
Are the 88's vacuum actuated? I would check vacuum and the solenoid too. Newer trucks the 4wd indicator is plugged into the actuator as well as t-case.

ike
05-12-2008, 07:14 PM
I believe it is vacum actuated. Those were my first two thoughts and still items i am going to look at. It doesnt look like our schedules will match up until sunday though, so i will have to wait until then to take a look at anything.

RedRunnertc
05-12-2008, 09:41 PM
Believe me - if the light comes on, the vacuum actuation is working. The other not unheard of failure is one of the stub shafts INSIDE the diff.

This might help - it's the FSM for a '93 truck, yours should be the same:
http://personal.utulsa.edu/~nathan-buchanan/93fsm/suspensionandaxle.html

thefatkid
05-12-2008, 09:59 PM
88 versions were not ADD. He has those crappy auto hubs. I'd look at those first.

RedRunnertc
05-12-2008, 10:20 PM
Well, there ya go ...

ziggy428
05-12-2008, 11:56 PM
check this page out
http://www.4x4wire.com/toyota/tech/autohub/
http://toyota.off-road.com/toyota/article/articleDetail.jsp?id=423991

sport4x4runner
05-13-2008, 09:00 AM
THose 88 some were transition model between add and auto hub. The auto hubs are notorious in the yota shops for being POS. best bet, go with warn or asin manuals...not too expensive but much more reliable.

ziggy428
05-13-2008, 02:07 PM
I've Heard that the Aisin oem hubs are the better than Warn. no personal experience though.

sport4x4runner
05-13-2008, 02:26 PM
I run warn hubs on my '90 V6, not a problem whatsoever... I have a friend with an 89 that we swapped the auto-hubs for the asin hubs, went nice and smooth, they work perfectly....

ToyRunner1
05-13-2008, 03:38 PM
My 87 was swapped to Superwinch hubs. I've had no problems at all, but I do prefer the Aisins for the offroad rig.

RedRunnertc
05-13-2008, 10:42 PM
I have Warns - only issue is they stick out further.

poorboyota26
05-17-2008, 04:06 AM
ASIN keep it toyota :D

ike
05-25-2008, 09:25 PM
Finally got under this runner. Everything works up to the hubs. Will the manual hub just replace the auto hub assembly, or will i have to change out anything else? Anyone want to help out in a week or so?

ziggy428
05-25-2008, 10:53 PM
from the looks of it you have to tear everything out of the spindle to the cv shaft.
http://www.yotatech.com/~corey/tech/matt_hubs/matt_hubs.htm (http://www.yotatech.com/%7Ecorey/tech/matt_hubs/matt_hubs.htm)

http://www.4x4wire.com/toyota/reviews/man_hub_conversion/manual_hub_kit.JPG

RedRunnertc
05-26-2008, 07:06 AM
from the looks of it you have to tear everything out of the spindle to the cv shaft.
http://www.yotatech.com/~corey/tech/matt_hubs/matt_hubs.htm (http://www.yotatech.com/%7Ecorey/tech/matt_hubs/matt_hubs.htm)

http://www.4x4wire.com/toyota/reviews/man_hub_conversion/manual_hub_kit.JPG

Ummm ... your link and the photo aren't for the same thing. The link is for a preTaco with ADD. Seriously, it takes longer to remove the wheels than it does to swap from the ADD plate to manual hubs.

The picture are the parts to convert a Taco or 3rd gen 4runner. All the extra parts are because the ADD on those is semi-floating and the manual hubs are full floating.

Unfortunately, this has limited use to the OP. His will be closer to what the link says, but I think he needs a few more parts than just the hubs to replace the automatic hubs.

ike
05-26-2008, 09:03 AM
I will start researching. In the meantime anyone who has done this to an 88 post up and let me know what you needed.

thefatkid
05-26-2008, 11:09 AM
You need everything ouside the bearings.

washer, nut, keyed washer, nut, then your new hub. Warn sells it as a kit or you could pick it up from toyota.

ike
05-27-2008, 06:32 AM
what would the damage be from toyota?

thefatkid
05-27-2008, 08:59 AM
I'm not at work today.

If your getting junkyard hubs you might as well get the nuts and washers there. Don't forget the big socket.

ziggy428
05-27-2008, 09:33 PM
Ummm ... your link and the photo aren't for the same thing. The link is for a preTaco with ADD. Seriously, it takes longer to remove the wheels than it does to swap from the ADD plate to manual hubs.

The picture are the parts to convert a Taco or 3rd gen 4runner. All the extra parts are because the ADD on those is semi-floating and the manual hubs are full floating.

Unfortunately, this has limited use to the OP. His will be closer to what the link says, but I think he needs a few more parts than just the hubs to replace the automatic hubs.
Wasn't sure if it was full or semi, which gen is an 88? 1st? So his should be pretty easy then.