drpdmazda

This is going to be a little longer of a post, cliff notes at the end.

About a year ago my fiances 97 4runner started making a ticking noise, that seemed to be coming from the lower end of the engine, and it only did it once the truck was warmed up. We took it to two different mechanics neither of which could tell exactly what the noise was but one was certain it was inside the engine. I searched all the forums i know hoping to find a post about this weird ticking noise to no success. I found a good deal on a used motor from a member on here and went forward with the motor swap. We picked up the truck and on the way home heard the ticking noise once again.

We turned around, and took it right back to the mechanic who was very appologetic and pulled it into the bay right away to see what was going on. The mechanic decided it was the fan and replaced it with no success. the ticking noise kept ticking. The next step was to take it to the dealership and have them diagnose the noise. I had initially stayed away from the dealership due to the high cost of getting this issue fixed.

The dealership had a "master mechanic" look at it, and he diagnosed it as the flex plate within 15 minutes. The dealership only charged me for the 15 minute diagnose and gave me a quote of over $2k to replace it. i gained a new trust for dealerships with that minimum charge, figuring i would get hit for a few hours work with no solution.

back to the original mechanic to let him know its the flex plate. mechanic replaces the flex plate for a nicely discounted price, and installs my new radiator and trans cooler for free which was great. Take the truck home, run it for a few days and all seem great. WRONG the ticking comes back, and back to the mechanic we go. he takes the trans down, and the flex plate is cracked again?? and again he replaces it. He ensures he is using the correct "allignment bolt" on the flex plate and that he has no idea why it went again so soon.

about a week later, i hear another noise, similar to the original one but slightly different. I call him to tell him its doing "something" again but am too frustrated to deal with it again and will come back when his appointments slow down a bit and he has more time to dedicate to the truck.

Can anyone steer me in the right direction as to why this truck keeps going through flex plates? i trust the mechanic as he is a friend of mine, and has always done good work for me and my family, and dont feel he is giving me a run around, i just think he is as frustrated with it as i am.

CLIFF NOTES:
97 4runner 3.4 auto trans had ticking noise

two mechanics werent sure exactly what it was, but one was certain it was in the motor.

had the motor swapped and still had the ticking

went to dealership and got a diagnose of bad flex plate

had flex plate replaced 2 times, and it keeps cracking

now making a slightly different noise, but still from same general area of flex plate

is my truck possesd?

truck is genearlly only driven 80 miles a week.

thanks for any help offered

Jason

FourStroke

Crazy, I'm pretty sure my flex plate is on the way out as well. Just ordered a new one and waiting on a time to pull the old one out. From what I've read up on you might want to stop by the dealership, get new bolts for the torque converter and flex plate and have the mechanic pop off the torque converter and reseat it with new bolts and then reinstall the flex plate with new bolts.

If the torque converter isn't torqued down properly it can cause the issues you're having. Since he's going to have to replace the flex plate again anyways I'd say it's worth a shot making sure the torque converter is properly in place. Also look up a FSM and get the proper torque specs for the TC bolts and flex plate bolts and give it to your mechanic just to be sure he's doing it right. There's still plenty of mechanics out there that use the "gut feeling" approach rather than a proper torque wrench.

DeathCougar

iTrader: (23)

Make sure the flexplate is indexed the correct way, and the shims are in there. Without the shims, its going to ruin the flexplate fast. Also, the shims are NOT the same. So, you need to have the correct shim on the correct side of the flexplate.

drpdmazda

thanks to both of you for the advice. im going to call the dealership monday and get price and availability on the parts and take it from there.

FourStroke

Are the shims replacement parts as well? I'm planning on doing my flex plate sometime this week. I've done quite a bit of work myself, never anything transmission related however.

aowRS

Wow, that's frustrating.

Out of curiosity, how many miles on your original motor, where are you located, and are you interested in selling it?




Andreas

drpdmazda

andreas i am about 3 hours north of ellicott city md (that time includes stopping to eat, and then stopping to pee). i am in allentown pa. the motor that pulled and replaced from this flex plate issue was another low mileage replacement from about 3 years prior. i still have all the paperwork from when i carfaxed it before purchasing it. it had around 86k on it, and was serviced religiously by the previous owner. the timing belt was done about 3k miles before it was totaled. i would say at most that we put 15k miles on it in the time we had it in the truck.

it was out of a 99 runner. i am pretty sure i still have the computer and harness from it. it is missing a few small odds and ends, the timing cover, i believe a pulley, and a fitting on the bottom end on the drivers side that a coolant hose is connected to. and it has no accesories. power steering pump, ac pump etc.

the engine had no issues when it was pulled, it was pulled due to the flexplate noise. its in my garage so i could get you some good pics if you are interested. just pm me your email address and i will get some by monday. i believe when we bought the motor we paid $1k for it, and they still sell for around that price range as far as im aware. i would like to get $650 for it? but will listen to some reasonable talk about the price. am also possibly open for trades if its firearms related.

pm me if you want to talk more.

J

aowRS

PM sent.


Andreas

terminator

iTrader: (1)

When I bought my 4Runner about 4.5 years ago it had a bad motor so I had one swapped in. When they removed it they noticed the flexplate was cracked so it was replaced. About 4 months ago I had the slight tick that turned into a knock. A few mechanics thought motor but I said hell no.

We found a few missing flexplate bolts and some loose. Put new bolts in and a couple of days later the noise came back. I had the trans pulled and found this:



New flexplate in, new hardware and all is good now.

aowRS

Oh Holy Hell! That was a close call.

I know my truck inside out, but have never sniffed around to see if there is an access plate that would allow one to actually see the flex plate. Is there, or would the flex plate be obscured by the torque converter?


Andreas

terminator

iTrader: (1)

There is an access plate, PITA to get to all of the bolts though. You can remove the starter which is easier. May need some type of boroscope or something to get in there and see though b/c you'll only be able to see the teeth and the bolts on the flexplate. Not near the center where they typically crack.

vital22re

iTrader: (2)

This is a common problem with auto 4runners now. Sometimes the thrust bearings go and cause excessive movement to the crank. Sometimes the bolts come loose or do to an imbalance it fails. Best thing to do is get oem new flex plates and have it installed by the book.

MLiebal

Wow, now I'm worried. I replaced the flexplate on my 96 Ltd V6 at 300k miles. Looked like the pics above, but broken. I never saw any shims. The cracking seems like it should come from alignment of tansmission to engine. The flex would occur on the alignment of the centerline of engine to tranny. That being at an angle would flex the plate every revolution and shiming on the plate would not fix that. Are there shims for the trans to engine? Btw I put a newer transmission in my truck, so I may not get another 300k out of mine if the alignment is worse.

aowRS

I'm tempted to pull my tranny and take a look-see...


Andreas

myersja6

2002 4Runner 137,000 - 10 months/10,000 miles ago my flex plate completly broke like the pic above, but a full circle. Out of the blue, though afterwards I could admit to hearing some ticking noises prior. BF replaced it for me with a new flex plate, sounded great, worked great until now. Ticking noise is back in a bad way and the mechanic is sure it is the flex plate based on his listen. If the flex plate is cracked again, the problem is bigger. What would cause 2 flex plates to crack in less than a year? Didn't use Toyota parts last time, but still a flex plate should last more than 10,000!

drpdmazda

I forgot to come back and update this post. after having the flex plate replaced for the 3rd time, the starter seemed to crap out at the same time. I had the starter replaced and have yet to have the flex plate crack again. I noticed shortly before the flex plate noises started, the starter seemed to "over engage" occasionaly when we started the runner. It would crank a little longer and make a "pinging" noise really loud. My mechanic said that the plate may have kept cracking due to the starter staying engaged? I know it sounds like an odd ball story, but since the new plate and starter were installer, the issue has not come back. (knock on wood)

ncsugrad2006

Hopefully I have a little better luck.

Just picked up a '99 3.4 Limited 4wd that the previous owner said had rod knock. I bought it cheap enough to replace the engine and still come out way ahead..

After listening to it and reading some threads on the flexplate issues, I really believe that is my issue. The noise just isn't consistent with a bearing knock (i.e. not directly RPM dependent). It sounds EXACTLY like this:

http://www.stevesite.us/images/crack...246k-miles.mp3

I'll pull the starter /inspection cover off this weekend and see what I got myself into

Also attached a couple of pictures--looks to be in decent shape overall for it's age. 200K miles though, so hopefully I don't have too many issues with it!

4Tard

If this problem is indeed a result of the bolts backing out, then there's a simple solution. Red Loctite 271 on all drive plate bolts. Seen many morons not take this advice when helping them with clutch jobs, only to have to yank of their transmission and clutch just to put a drop of Loctite on the flywheel bolts.

I lost 3-4 teeth on my flex plate when a starter grenaded itself. Started just fine for another 2 years with a new starter, though it would skip a few teeth. When I swapped engines, I was sure to get a good, used flex plate and Loctite 271 all the crank to plate, as well as the torque converter to plate bolts when I installed it. Never had a problem with any noise, and the flex plate can take a lot of abuse and keep on working just fine from my experience.

If this problem is because of excessive crank thrust, which seems very unlikely on a 5VZ or 3RZ, then you're pretty screwed and have bigger issues to fix.

Mtn Mike

iTrader: (1)

Hmm, my 4R seems to be developing the same symptoms/noise. What parts are needed from the dealer to do this job? Can I have the dealer install the flexplate onto the TC, or is that something that needs to be done with the flex plate attached to the engine?

terminator

iTrader: (1)

The flexplate attaches to the engine, not the t/case. The trans needs to be separated from the engine to do this so it's labor intensive, not so much for parts. You'll need a new flexplate and new bolts, that's pretty much it. Oh yeah, and about $500+ in labor, more if you go to the dealer! What you want is for somebody that has a borescope or something like that so they can use that little camera to look through the inspection plate and look for cracks on the flexplate.