4wd randomly disengages (1 Viewer)

Mikeybro

SILVER Star
Joined
Oct 30, 2011
Messages
136
Location
Spokane, Washington
OK so i have an 89 with the mechanical t-case for 4wd. I replaced the detent spring that was recommended on one of the posts here. It made it better and isn't slipping out as bad, but will still randomly disengage sometimes. When replacing spring, I didn't check to see if ball was still in there, would it engage at all if that wasn't there? Also the tip of the old spring was pretty rough and was bent. Any thoughts on this?

Any one looking for the spring the part number on the pic is correct but it won't come up in any searches even the parts guy at Toyota couldn't find it. You can find with the item description though.

1613945481139.png
 

OSS

Joined
Jun 30, 2017
Messages
3,277
Location
Oblivion
The engagement teeth on the front output shaft probably have rounded edges and no longer grip inside the sleeve - and pop out under stress. The engagement is less than 1/4" so it doesn't take much wear for the teeth to start slipping.

The poverty fix is just lash the transfer shift lever back when in 4wd to prevent it from popping out. The expensive fix is replace the worn parts
 

DFXR

SILVER Star
Joined
Nov 18, 2010
Messages
913
Location
Oakland, CA
OK so i have an 89 with the mechanical t-case for 4wd. I replaced the detent spring that was recommended on one of the posts here. It made it better and isn't slipping out as bad, but will still randomly disengage sometimes. When replacing spring, I didn't check to see if ball was still in there, would it engage at all if that wasn't there? Also the tip of the old spring was pretty rough and was bent. Any thoughts on this?

Any one looking for the spring the part number on the pic is correct but it won't come up in any searches even the parts guy at Toyota couldn't find it. You can find with the item description though.

View attachment 2592400

Are you sure you don’t have a broken engine mount? The driver’s front mount on my 60 was broken, and the movement under load would throw the t case out of gear. Pretty common. New mount fixed it. I replaced the detent balls and springs before figuring that out.
 

MoaByte

SILVER Star
Joined
Dec 13, 2014
Messages
1,233
Location
Moab
Also, the inner boot on the TC shifter gets stiff. It wants to pull the lever over to the left when the motor/drivetrain gets stressed. It's been mentioned that wintergreen oil will soften it up.
 

3_puppies

SILVER Star
Joined
Dec 2, 2002
Messages
14,668
Location
Helena MT
The engagement teeth on the front output shaft probably have rounded edges and no longer grip inside the sleeve - and pop out under stress. The engagement is less than 1/4" so it doesn't take much wear for the teeth to start slipping.

The poverty fix is just lash the transfer shift lever back when in 4wd to prevent it from popping out. The expensive fix is replace the worn parts



my issue was the fork was worn along with the slide collar
 

4Cruisers

Supporting Vendor
SILVER Star
Joined
Apr 2, 2015
Messages
6,444
I posted that TSB a few times in the past.

You can slip a thin washer inside the plug before installing the detent spring, adds a bit more force to keep the 4WD engaged. I had to add a washer in my '86 FJ60, even after installing the stiffer detent spring. BTW, I still see Part Number 90501-16115 as being available.
 

Mikeybro

SILVER Star
Joined
Oct 30, 2011
Messages
136
Location
Spokane, Washington
OK thanks all for the responses. I will get into it this weekend. What size washer were you using? It just seems strange that when I am wheeling it doesn't slip out. The common factor seems to be speed for slippage.
 

4Cruisers

Supporting Vendor
SILVER Star
Joined
Apr 2, 2015
Messages
6,444
I used the thinnest washer I could find that would fit inside the plug, just takes a little bit. Glad it was easy, and grateful for the tip from @CenTXFJ60.
 

4Cruisers

Supporting Vendor
SILVER Star
Joined
Apr 2, 2015
Messages
6,444
The FJ62 transfer case that's in my '86 FJ60 came from my '89 donor vehicle with about 165,000 miles, all I did was convert it to manual front drive engagement using new Toyota parts and install new Toyota seals and gaskets. Everything inside the transfer case looked pretty pristine.
 

Users who are viewing this thread

Top Bottom