Hello community - Welcome post. I also need to fix a fully broken flexplate. (1 Viewer)

[Bugoutuniqueaux]

Hello IH8MUD! New member here - First post. I drive a 1999 4Runner Limited 4wd Auto Transmission.

So this is my welcome post and also asking what is your experience with flexplate replacement.
Just recently reached 310k miles and due for some maintenance.

Long story short I bought the truck in 2021 and it had a ticking sound shortly after I bought it.
After doing some research and inspecting under the bell housing cover I knew it was a cracked flexplate but decided to just drive on it.

Fast forward to October 2023 and it finally broke on the highway... Accelerating up the Sierra Nevada Mountains and... BOOM it pops and
luckily I was right by an exit. Got it towed.

So I drove with a cracked flex plate for just a little over two years.

NOW, the challenge of fixing it.

I had a shop quote me $1,400 for 8 hours labor at $175/ hr.

That price is a little steep for me. I called a mobile mechanic and he said he doesn't have the equipment.

SO, that brings me to my series of flexplate questions for your expertise. Your knowledge is much appreciated and I thank you in advance.

1. Is the job something that's not out of the picture for one person to do in a driveway under an awning? I have basic mechanic skills and have removed an engine before.
(Also I see Timmy the Toolman's video on Auto Transmission removal - I assume it would be the same steps for replacing the flexplate. Correct me if I'm wrong.)
(I might try to fix it myself unless anyone strongly suggests otherwise. I like knowing what exactly is going on with every part of my vehicle.)

2. Is a used flexplate an ok option for replacement vs a brand new one? A mechanic friend of mine (who is too busy to take on side work) gave me a used flexplate for free from a 3.4 motor with no cracks. He told me it's fine to use since it has no cracks but I wanted to ask here for a second opinion.

3. Would you recommend doing this job by pulling the engine or by pulling the transmission? Keep in mind the truck is now just over 310k miles and I am
thinking to myself does it need any other maintenance. (probably needs steering rack.) I have blocks to put the tires on.

IS there any other maintenance you would recommend doing while transmission or engine are out?

Thanks in advance to this great community.

 

[gnob]

other than the 27 plugs on the AT, it's pretty straightforward. i recommend two jacks, i use a floor jack and HF trans jack.
i would be a little hesitant to put in n another used plate as this seems like a pretty common issue.
wouldn't hurt to do the rear main while you are there.

 

[Bugoutuniqueaux]

other than the 27 plugs on the AT, it's pretty straightforward. i recommend two jacks, i use a floor jack and HF trans jack.
i would be a little hesitant to put in n another used plate as this seems like a pretty common issue.
wouldn't hurt to do the rear main while you are there.

Yeah you're totally right. I just watched all 3 transmission removal videos on Timmy the Toolmans YouTube channel. Great info on there. It doesn't look difficult to do with the right equipment and enough time. I'll probably order a brand new flexplate and do the rear main at the same time. Thanks

 

[vipergrhd]

Rear main seal would be good to replace while your there, not sure if the bolts are torque to yield so it might be a good idea to just install new bolts.

 

[Bugoutuniqueaux]

Rear main seal would be good to replace while your there, not sure if the bolts are torque to yield so it might be a good idea to just install new bolts.

Fantastic idea. I'll add that to the tab. Would not have thought of that otherwise. Are you talking all the bolts? Or just the ones on the rear main

 

[vipergrhd]

Fantastic idea. I'll add that to the tab. Would not have thought of that otherwise. Are you talking all the bolts? Or just the ones on the rear main

The bolts that holds the flex plate to the crankshaft and a little loctite should be good.

 

[splitshot]

How does your truck shift when in cruise control and you hit a grade? This should be the thing to ask if there is a deeper issue
going on which caused the plate to break.
My 2001 was (how do I describe) "bone jarring harsh". I replaced the flex plate and a year later had to do it over again and found
I needed a new torque converter and front pump.

 

[Bugoutuniqueaux]

The bolts that holds the flex plate to the crankshaft and a little loctite should be good.

Will do

 

[Bugoutuniqueaux]

How does your truck shift when in cruise control and you hit a grade? This should be the thing to ask if there is a deeper issue
going on which caused the plate to break.
My 2001 was (how do I describe) "bone jarring harsh". I replaced the flex plate and a year later had to do it over again and found
I needed a new torque converter and front pump.

Hmm that's a good question. Before the flexplate broke, I don't remember any shifts being too rough but never payed close attention to it. Maybe once or twice it was a little hesitant to shift into 3rd or whatever gear it was shifting into but not really too bad. Never noticed anything while in cruise control either. But the fact that it actually finally broke While going up a grade in the Sierra Nevada Mountains. Could that mean it was also the torque converter?

Is there any other way to tell whether the torque converter needs replacing? (ie visual inspection)

What actually happened after it failed - I coasted to a freeway exit and pulled on to the shoulder. Sat there for about 20 minutes with engine idling and then turned it off while looking for my emergency flares. Then I actually started it back up and it drove a little bit. It drove fine for a while at low speeds 20-30 mph. But once I got back on the highway again, boom, it failed again. After spending a night at a hotel the next day it completely did not start up or work anymore, even at lower speeds. It seems that it failed when going uphill above 40ish mph and probably when trying to shift into 3rd gear. So i donno. Maybe that in it of itself is reason that it could be a bad torque converter? I dont know. Never had this happen before. (I do hope it's not bad because the Toyota parts department seems to think those torque converters are made of gold.) However if absolutely necessary I would fork out the $1000 for a new one so I don't have to redo the job again.

 

[Bugoutuniqueaux]

How does your truck shift when in cruise control and you hit a grade? This should be the thing to ask if there is a deeper issue
going on which caused the plate to break.
My 2001 was (how do I describe) "bone jarring harsh". I replaced the flex plate and a year later had to do it over again and found
I needed a new torque converter and front pump.

Actually now that I think of it, it did shift a little harshly a few times, but again not an earthquake or anything, just a little bump.

Btw, which pump are you reffering to?

 

[splitshot]

Front pump on the transmission.
You would notice an uncomfortable like I said bone jarring "blam" shift that feels totally wrong.
Sounds like you are not there, I would just replace the plate. Not a fun job, but if you have access to a
transmission jack and wobbley sockets, various extensions, not to difficult.

Also a couple of drain/refills for the trans after.

 

[Bugoutuniqueaux]

Front pump on the transmission.
You would notice an uncomfortable like I said bone jarring "blam" shift that feels totally wrong.
Sounds like you are not there, I would just replace the plate. Not a fun job, but if you have access to a
transmission jack and wobbley sockets, various extensions, not to difficult.

Also a couple of drain/refills for the trans after.

Cool. I have the tools. Almost got the transmission pulled. Accidentally may have pulled the wires out by a millimeter when removing the t-case. Does it look like it's at the point where it needs replacing? If necessary I'd want to replace it now while it's out rather than later

Also, the cable from the transmission to the throttle. Kick down cable? Not sure what its for but I didn't see it in the youtube video. I'm assuming the easiest way is to disconnect it is from the throttle rather than the transmission itself?

T-case to transmission input seal

 

[Bugoutuniqueaux]

The bolts that holds the flex plate to the crankshaft and a little loctite should be good.

Yeah I removed the flex plate now. Noticed the bolts that hold the flex plate to the crankshaft go back in only a thread or two and then stop. I assume that means they're torque to yield. The ones that hold the flex plate to the transmission are not like that.

 

[vipergrhd]

Yeah I removed the flex plate now. Noticed the bolts that hold the flex plate to the crankshaft go back in only a thread or two and then stop. I assume that means they're torque to yield. The ones that hold the flex plate to the transmission are not like that.

View attachment 3484330

I just looked up the torque specs. for the flex plate, it is not a TTY bolts and torque is 55 ft/lbs while the M/T flywheel is a TTY and a two stage torque process.

 

[Bugoutuniqueaux]

Officially at the halfway point.

Is there any reason to remove the torque converter for inspection or anything like that?

Or does it look OK to keep the torque converter in place and proceed with installing new flex plate?

I noticed a red dust on the torque converter and some dirt in the bell housing.

Flex plate replacement checklist:
Replace:
- Flex plate
- Flex plate bolts
- rear main seal
- transmission rear input shaft seal
Inspect:
- torque converter
- transmission front pump

 

[Bugoutuniqueaux]

I just looked up the torque specs. for the flex plate, it is not a TTY bolts and torque is 55 ft/lbs while the M/T flywheel is a TTY and a two stage torque process.

Ok. That's surprising it's not TTY as it doesn't feel like it fits but ok. I can save some money on the bolts then.

Is that FSM or source accessible online somewhere? I actually need all the torque specs for putting everything back together haha. It's actually a '99 4runner Limited Auto transmission

 

[vipergrhd]

Ok. That's surprising it's not TTY as it doesn't feel like it fits but ok. I can save some money on the bolts then.

Is that FSM or source accessible online somewhere? I actually need all the torque specs for putting everything back together haha. It's actually a '99 4runner Limited Auto transmission

What else do you need ? I work for a fleet so we have access to factory specs. Do not remove torque converter make sure to push it all the way back towards bell housing.
Don't forget the rear main seal.

 

[Bugoutuniqueaux]

Nice. I was actually thinking of replacing the transmission fluid in the torque converter and doing a full flush since it's at 310k + miles.

I could use torque specs for bolts flexplate to crank, flexplate to torque converter and transmission to engine

 

[Bugoutuniqueaux]

What else do you need ? I work for a fleet so we have access to factory specs. Do not remove torque converter make sure to push it all the way back towards bell housing.
Don't forget the rear main seal.

Actually I found specs online

 

[Bugoutuniqueaux]

Is it bad there's so much dirt/mud on the engine / transmission? / could that be a reason why the flexplate failed?