oil pump gear exploded today...WTF

[aljordan]

While some 500 lb/ft isn't directly applied, much of it is. I suppose a little fatigue plus big ass torque eaquals boom.

I don't feel power isn't the problem here. i've been doing 500 lbs of torque for about 4 years or so. Something is binding in the shaft or the pump. The belt is still turning, and the force of the belt pulling on the gear shears it. It would be very interesting to have a place take a look at the gear and tell us what happened. I suspect that's realy the only way we'll find out the root cause.

One thing is for sure.. it sucks when it happens.

 

[MKIIINA]

very interesting problem. wish we could backtrack it some and figure out what caused the failure

 

[aljordan]

They make a billet gear for the 2jz...
Make one for the 7m arz, you know you want to.
eric

Wrong. The pump on the 2jz motor is meshed with the crank. There is not a gear as we have.

http://www.mkiv.com/techarticles/parts/oil_pump/index.html

 

[Stretch]

Ahaha thanks for finally proving me wrong someone. I just remembered some sort of gear being made out of billet for the 2jz that wasn't cam gears, so I figured it was this one. W/e make a billet one anyway damn it!
eric

 

[Joel W.]

If all the cracks were the same color, that would mean that it was a sudden failure..

Both of these guys said that the cracks were discolored which means to me that this gear has been weakened over time and it just finally let go imo..

 

[aljordan]

Ahaha thanks for finally proving me wrong someone. I just remembered some sort of gear being made out of billet for the 2jz that wasn't cam gears, so I figured it was this one. W/e make a billet one anyway damn it!
eric

That was a tensioner. Pretty sure it was for the serpentine belt.

A new gear would be nice. But I bet very expensive. Plus it doesn't solve the root problem. Just masks it.

 

[malloynx]

i will post pics tommorow. i don't know how my driveshaft would seize up.. doesn't make any sense

 

[mkiiSupraMan18]

^ Toyota is just trying to push those $40 a piece bearings for the oil pump shaft, I bet money on it... :icon_conf

 

[aljordan]

i will post pics tommorow. i don't know how my driveshaft would seize up.. doesn't make any sense

Nor do I. It's the only thing that makes sense.

I say put another one and let her fly. See if it happens again. Ensure your belt is done correctly as well.

Wouldn't be bad to ID common items that both of you (get that other cat in here too) have. Shaved head and block, blah.. blah. blah.

 

[quicksilver]

Same thing happend to me. I got to it intime that it just crack around the center section. I put another one on and it has been fine for over a year. I just contrubuted the failure to over tighting it when I put it on. I dunno...

 

[pb92supraturbo]

I wonder how the timing belt was tensioned on the two cars that had the failure. Was the TSRM tensioning procedure followed when the timing belt was installed? If the timing belt was too tight, could the weak link be the oil pump pulley? The cam pulleys seem to be more robust in thickness and the tensioner is steel. Something to think about . . ?