Flex Plate broken on 100series (LX470) (1 Viewer)

[PrimeFJ]

Anyone have issues with their flex plate (flywheel) breaking? Pics attached
Broken at the bolts.

My vehicle is a 2006 LX470 with 160k
Runs strong and no leaks. Timing and pumped and seals have been changed.

I don't even wheel it. Mostly highway miles. Still building it for some overland trips.

Back in June 2017 it broke while driving.. meaning motor was still running when it broke. Rpm revved when I applied throttle. It was not engaging. Vehicle coasted to a stop on the highway.

Put in park and then back in drive and reverse I get nothing. Turned off and tried to restart and the motor does not turn but I can hear the starter turning.

Had it replace with oem flex plate and torque converter while we were in there. Made sure the pins were aligned and torqued per oem manual.

Keep in mind I have the five spoke stealthcustomseries wheels 16" with 285 tires (nitro trail grapplers)33"

So I get my car back and it breaks again in July 2017.

Driving the family home and it breaks Again!. I was cruising at 50-60mph when it did the same thing again. (Rpm revving and not engaging)

So now it's in the shop to make sure everything was installed properly.

Anyone have the same issues or any suggestions? Searched everywhere and there's not much on it besides make sure the bolts are torque right and pins are aligned correctly..

Is it possible I have the wrong torque converter or flex plate?
I'm lost here guys. Really love the truck and don't want to sell it.

 

[jerryb]

that's just weird. My rms is leaking, so I'm paying attention.

 

[dogdaysindurham]

I found these FSM for the A750 transmission, hope this is helpful.

e457d_2010_4_all.pdf

A750E Automatic Transaxle.pdf

A750.pdf

A750E.pdf

 

[nissanh]

Is your starter OEM? I see some flex plate damages in the 4runner forum and some find non-oem starter as the issue.

 

[ajax1]

Saw one that had cracked from holes out, replaced it never heard him have issue again. That was the one and only one I saw in year of working cruisers

 

[seanz0rz]

Possibly a very stupid question, but is it possible to install it in the incorrect orientation? I see an offset from the center to the outer of the flexplate. Is it possible this is installed backwards and causing a sheering or punching force in the plate? Again, I feel silly for asking, but I usually start with simple stuff. "Is it plugged in?"

 

[FLWookie]

It happened on my 06 tundra a few weeks ago, it has the same engine as your lx. It started as a loud banging and heavy vibration. I tend to think it has more to do with the torque converter.

 

[planomateo]

It happened on my 06 tundra a few weeks ago, it has the same engine as your lx. It started as a loud banging and heavy vibration. I tend to think it has more to do with the torque converter.

I was thinking someone posted a similar issue recently.

 

[spressomon]

Fortunately caught mine in time courtesy of Robbie while in Denver a little over 2-years ago.

#555

 

[PrimeFJ]

It happened on my 06 tundra a few weeks ago, it has the same engine as your lx. It started as a loud banging and heavy vibration. I tend to think it has more to do with the torque converter.

Yea it's the same motor and tranny I believe. What was your resolution? Replaced with OEM flex plate and torque converter??

 

[PrimeFJ]

Possibly a very stupid question, but is it possible to install it in the incorrect orientation? I see an offset from the center to the outer of the flexplate. Is it possible this is installed backwards and causing a sheering or punching force in the plate? Again, I feel silly for asking, but I usually start with simple stuff. "Is it plugged in?"

No not at all. Going to double and even triple check with install again. A friend of mine who works for toyota/Lexus knows these vehicles so we will go through it again with the 2nd flex plate. It was warranty through Lexus so we will see...

Just wondering if it's the wrong flex plate or wrong torque converter.

We're thinking something is misaligned maybe?? Transmission to output shaft?
It's frustrating. Thx in advance guys.

 

[PrimeFJ]

Hm so just to update, we got a new oem flex plate and torque converter from the dealer. But my mechanic is saying the problem might be caused due to the pressure in the line causing the torq c to push into the flex plate.. anyone else experience that or heard anything like that?

This is the second time we are replacing the flex and torqC and don't want a third time.. mechanic says we can install everything back and "turn down" the line pressure..???

Changed the gasket and he said the pump is good. Or should I change the transmission pump too??
Really want to figure this out... if not we have to call the junk yard for an '06 tranny..ughh

 

[PrimeFJ]

Above is the broken flex plate in less than a month..

Above here is the 2nd new oem flex plate

Oem starter still good.

 

[PrimeFJ]

Am I the only one experiencing this?? I haven't even wheeled this cruiser and it's breaking..

 

[FLWookie]

Is there something on either the block or the TQ-C that's scoring the center ring, causing it to fail?
Is your TQ-C working properly? You're not getting cyclic failure cracking at the outer diamter mounting holes like all the other failures seem to exhibit, its localized to the center depression in the flex plate.

In the first picture of post #13 i looks like the stamped area is almost polished like something has been rubbing on the metal.

 

[PrimeFJ]

The polished area is where it broke off.. the bent metal (attached to motor) still spinning when it broke scoring metal giving that polished finish.

Okay so update. Located an 07 transmission with about a 100k miles. Installed it with new gaskets/seals filter and tranny oil. And still creating that same vibration grinding noise.. my mechanic now suspect it’s crank walk...

Anyone deal with crank walk on their 100 series?? WTH?!

 

[sdnative]

Maybe I missed it, but what was the history between new and when the plate first broke? How long have you had it? Any info from the PO that may help? Assuming the first time it broke was the one you mentioned above, it seemed to have made it 10 years and ~160k miles without issue? Now twice in a month. What changed?

 

[PrimeFJ]

I’ve had it for almost 3yrs now. Bought it from Lexus preowned. Clean car fax with one owner who were elders and had a dog. Signs of dog hair inside and all stock and no accidents. All maintenance done by dealer. No leaks, and clean and dry under body when inspected.

Before the flex plate broke I added 16” wheels (19lbs/ea) with Nitto Trail Grapplers 275/75/16 muds. And did a ahc suspension lift. Very minor lift..I do oil and transmission / diffs and other diy changes myself. Have been for the past 15+ years and try to use oem toyota filters and oils..etc

To remind you the wife mainly drives it. So we’re talking about groceries and hauling two babies..

However we did tow my other project vehicle back home. About a 3 hrs drive. We tow dollied a 1985 Toyota pickup. (Marty McFlurry xtra cab) SMALL HILUX. The lx towed it without issues.. or so I thought.

Once home and tow removed of course..I noticed a vibrating/knocking sound from under the engine. Drove it around town and would only notice the clicking and knocking noise when under load.

Driving back home to family 3hr drive. The flex plate broke. Was able to coast it to a gas station and had to tow it the rest of the way home.

And here we are car-less ... seriously, Im like the only one with this issue while ever other 100 series owner is bashing theirs.

Never seen dirt or off-road. Had plan on getting this vehicle for its reliability and 4x4... my mechanic is now suspecting “bent rod, crank walk”

He says he bolted the new transmission back up and still hears a vibration from underneath. Sighhhhhhdjsishdhduwushd

Pls help. Anyone?

 

[FLWookie]

It could be that. Could always start it up with the transmission off and see if you can notice the crank moving, or drop the pan to inspect the crank journals and rods.

 

[2001LC]

Flax plate failure is rare indeed. To have two in a row means one of three things.

Defective part.

Or

Installed wrong!

Or

Something else is going on. "Most likely"

You can also do static test on crank, by putting pressure on one side as measurement taken from other. Oil pressure test of engine is a must. But really these lower ends are about as strong as they come, it's the hall-mark of the 2UZ-FE.

A break in this spot looks like either vibration issue, or something stop TC as engine still turned just ripping TC apart. If vibration I would think you'd notice something while driving, that got progressively worst over time. I can understand mechanic at Lexus thinking pressure with transmission issue since TC was replaced. Did he test pressures of transmission? Again to have two TC bad in row, not likely.

Sorry I can't be of more help, but this is strange.

BTW:
What was total weight of tow?
Was towing done before first failure also?