Flex plate issues.

splitshot

Head cook, Bottle washer, and Peace keeper.
SILVER Star
Joined
Nov 17, 2006
Messages
7,504
Location
Rodent Central, Az
 
 
I haven't torn it down yet but sure I have lost the second flex plate in the (new to me) 2001. The PO just replaced the original with an aftermarket unit.
All the symptoms, slight ticking that gets louder, and total loss of (like dropping into neutral) function while climbing a grade and downshifting. After shutting the engine down, it will not restart because there is no ring gear for the starter to come in contact with.
Is this common? And if there is anything other than going OEM I should look for?
 
Joined
Jan 6, 2012
Messages
8,091
 
Use oem bolts and make sure they are tight. If their is any play it will ruin the flex plate.
 

splitshot

Head cook, Bottle washer, and Peace keeper.
SILVER Star
Joined
Nov 17, 2006
Messages
7,504
Location
Rodent Central, Az
 
 
All bolts were tight, never seen one shear like this. I have the tendency of blaming it on a weak point on the stamping process. Thoughts?
001.JPG
 

splitshot

Head cook, Bottle washer, and Peace keeper.
SILVER Star
Joined
Nov 17, 2006
Messages
7,504
Location
Rodent Central, Az
 
 
Looks like the welds broke. Poor welding of the aftermarket piece?
No welds visible, just a stamped plate. the bluing involved had to be caused buy the heat stress of what little held together before it went.
It least it has an OEM replacement.
 
Joined
Jun 10, 2019
Messages
21
Location
95128
When this happens, missing alignment dowels on the engine block is a common cause for the flex plate to break. The bolt holes in the bell housing will allow slight movement in the transmission unless there's alignment dowels to prevent it. With a little extra movement, that will put more strain on the flex plate and cause it to fatigue and crack. If you are sill breaking flex plates, check to make sure the alignment dowels are present on the engine block. Sometimes they will get stuck inside the old transmission somebody swapped out and they don't realize it until they start having flex plate issues.
 

splitshot

Head cook, Bottle washer, and Peace keeper.
SILVER Star
Joined
Nov 17, 2006
Messages
7,504
Location
Rodent Central, Az
 
 
Just a 3 year update, no problems whatsoever replaced with an OEM Toyota plate.
 

splitshot

Head cook, Bottle washer, and Peace keeper.
SILVER Star
Joined
Nov 17, 2006
Messages
7,504
Location
Rodent Central, Az
 
 
Now 3 years and 2 months later.....
Got another one going South.:bang:
I have it narrowed down to two things, since the previous owner installed a low mileage 5vz-fe from Japan, it has to be (#1) missing alignment dowels or
(#2), something I discovered while searching the Toyota parts catalog, missing front and rear spacers (granted it's been 3 years), but I don't remember those on the last job.:hmm:
 

splitshot

Head cook, Bottle washer, and Peace keeper.
SILVER Star
Joined
Nov 17, 2006
Messages
7,504
Location
Rodent Central, Az
 
 
When this happens, missing alignment dowels on the engine block is a common cause for the flex plate to break. The bolt holes in the bell housing will allow slight movement in the transmission unless there's alignment dowels to prevent it. With a little extra movement, that will put more strain on the flex plate and cause it to fatigue and crack. If you are sill breaking flex plates, check to make sure the alignment dowels are present on the engine block. Sometimes they will get stuck inside the old transmission somebody swapped out and they don't realize it until they start having flex plate issues.
Thought I'd post up just in case someone else comes across this. ^^^ spot on. The flex plate was not cracked (yet) but on the road to doing so. After getting things torn apart, the front and rear spacers were there and in the proper fore and aft places sandwiching the plate. The dowel alignment pin on the lower driver's side visible and intact. After getting the plate out of the way, it was easy to see the upper pin was missing....
Symptoms at the beginning are a whine while in gear at idle (forward and reverse) and continue when under acceleration, that will go away in park or neutral. This is due to the nose of the torque converter stress of being out of alignment with the crankshaft. Toyota built this at such close tolerances that over time it will stress the plate which will crack and fail.
I remember last time a 5 hour job, either my memory is failing or my wrenching stamina. 12 hour job for this. :doh:
alignment pin.jpg
 
Joined
Aug 22, 2015
Messages
1,432
Location
Ohio
Mine Taco is a manual trans - but thanks for posting this follow as it helps the whole community. Glad you got it figured out and put to bed.
 
Top Bottom