Rear Locking Diff Question

Rear Locking Diff Question:

I just bought a 2000 Tacoma TRD 4x4, when I push the "RR Diff Lock" button, it just flashes Red on the cluster "RR Diff Lock", but I don't think it is actually engaging. Any suggestions, also it looks like it has a very slow drip from the differential case, could it be low on oil?

 

4x4's only engage the rear locker in 4lo, anytime you have a leak its a good idea to check the fluid level. There is a mod to make the locker engage in 2wd like the prerunners, its under the mods and tutorials section

 

Thank you,

Wow, so the diff lock button only works in 4wd lo? That's nuts! So the only way I could lock it in 2wd is by doing a mod?

 

Yeah it only works in 4lo, heres the grey wire mod http://www.customtacos.com/tech/index.php?article=10

 

Thank you so much,

Last question, what oil type/weight should I put in the rear diff? Any preferences?

 

According to the manual its either SAE 90 or SAE 80 or SAE 80w90
I usually get the cheap stuff since i dont tow anything so no real need for the expensive oil

 

I would suggest using synthetic. Amsoil 75W90 or 80W90, I forget what weight toyota recommends. At one time I had changes all the drivetrain fluids, front and rear diff, manual trans and transfer case on my 2000 tacoma and it made a difference. I picked up a mile per gallon or two and much smoother shifting. One other good thing is it's good for 100,000 miles or so