mjwalfredo

I was thinking about pulling off the inspection plate to check for loose torque converter bolts or a cracked flexplate on my 97 4Runner 4x4. I've got a some vibration and noise coming from that area.

My question is, is it a good idea to drop the steering rack to get better access? The skid plate is definitely in the way but it looked like the steering rack might also make for a cramped working area. What you ya'll suggest? Also, the flexplate/TC don't run in transmission fluid do they? Do I need to drain the transmission before taking the inspection plate off?

Finally, I am guessing this would be a good time to check for a leaky main seal too right? I saw some oil when checking out the inspection plate but I am hoping it is just spillage from the oil filter removal when I changed the oil a couple of days ago.

HighLux

I had a weird rattle on the 99 recently...wife said its buzzing and rattling...I knew exactly what it was...loose cat shield. Take a quick look...I think they all are susceptible to this..


No...no fluid....leave the rack alone...but check the shield on the cats first!

mjwalfredo

Thanks.

I swear there is something not quite right in the driveline with my truck. I've had it since I was a senior in high school in 2000 and it's been through hell and back.

In fact, read somewhere that an out of balance driveshaft could possibly cause damage to the flexplate. I feel like the vibrations and weird shifting started after driving back to Columbia, SC from New Orleans right after the dealership replaced a leaky water pump. Can you believe they didn't torque the crankshaft pulley bolt to spec and it came loose in rural Georgia? (Apparently this is a common scenario due to a misprint in the FSM) I didn't know WTF to do but I was able to get it back on and drive 60 miles at a time before it would come loose again. Needless to say, that was a long trip...

The dealership in Columbia said I should try to get a new engine from the dealership that did the work but they were total a-holes when I came back and asked them to review the work done to fix their mistake.

But I swear, ever since then, this truck has not been quite the same.

(Sorry for the long posts. It's my birthday and I am celebrating with a couple of Maker's Marks before the wife gets home from work )

HighLux

Happy birthday.

Ever checked the balancer?

mjwalfredo

My dad's buddy who is a well respected machinist vouched for the master tech at the local dealership who cleaned up the damage. But he also said that the end of the crankshaft was pretty scared up from the incident.

I just don't trust most mechanics enough anymore to really take the time to figure out what is wrong. Granted I do have 250K miles on the truck now but most just say, "Your truck is old, deal with it." Is it even possible to measure how balanced the engine is for the average mechanic?

This truck is just so awesome in every other respect. I'd love to be able to get it repaired.


Also, you said that the inspection plate area is dry. That means when I open it up, I should theoretically be able to tell if the main seal is leaking oil right?

HighLux

Yes on the rear main seal....if there is oil in there...its a leakin.

If they crank pulley and balancer came off becuase of the bolt coming out.....then it may have been damamged. Ive seen one so bad once, you could move the balancer around in place...

Its so hard to diagnose a car on a website...

Do you hear the vibration or feel it. Maybe some more description of how/when/speeds etc would help....

mjwalfredo

Definitely feel it more than anything. When the truck is in gear ( D or R ) and my foot on the brake is when it is worst. It also causes the exhaust to rattle which makes something (not sure what) in the cargo area rattle really bad. I replaced all the rubber exhaust hangers thinking they were worn out from all the mud runs I did when I was younger but it didn't make a difference.

Also replaced the driveshaft and transmission mount chasing the rattle down. I pulled the rear 3rd member and took it to a trusted mechanic who said it looked like it had some miles on it but nothing to worry about. He adjusted the gears and gave it back at no charge but that didn't seem to make a difference.

I am pretty sure there is some slack in the driveline somewhere. The truck also "thuds" when switching from reverse to drive or vice versa. Also, there is a noticable thud the first time I come to a complete stop every morning on the way to work. It happens ONLY the first time I come to a complete stop after sitting over night. This is a thud you can hear and feel from the seat of your pants.

mjwalfredo

Oh, and the local dealership put a new harmonic balancer on because they figured the old one was trashed.

mjwalfredo

So I got around to pulling the inspection plate yesterday. Things looked fine: The torque converter bolts were all tight. the flexplate seemed okay even though you can't really get a good look at the area where it would probably crack if it had.

The truck sounded about the same with the inspection plate off while in neutral and drive.

I am starting to get the feeling that the motor must not be very well balanced anymore after the harmonic balancer fiasco. Just curious if anyone has an opinion on possible damage from driving a few hundred miles on the interstate with a loose harmonic balancer. Maybe that was really hard on the crank bearings?

I am going to clean up the motor real good and take it over to the machinist/mechanic buddy of my dad and see if he has any thoughts. Until then, I am just curious what anyone here thinks.

Just to reiterate, the truck has a lot of miles and generally drives fine but once it warms up, it idles a little low ( ~500rpm ) which causes vibrations you can feel in the body and rattles the exhaust pretty good. Vibrations are very apparent when accelerating through 2000-3000rpm range in any gear. The truck doesn't feel nearly as smooth in the acceleration department as my buddy's 98 with same amount of miles. It's driven this way for several years and doesn't seem to be getting worse. Oh, and no trouble codes thrown in the last few years except for an O2 sensor which I replaced with the correct part from URD.

FogRunner

I've seen where this has happened several times because of either the dealership or the owner doing the work didn't torque the crank bolt down. When I do mine I always put some blue thread locker.

But to directly address your concerns in the 3 times I seen this happen none of them where able to resolve the vibrations without either a new crankshaft or in the case of the other two just replace the engine.

Its because of what happened to you that most of us here on Yotatech don't trust dealerships and do our own work.

FOG

mjwalfredo

Thanks for the info. Do you know if it was the crankshaft itself that bore the brunt of the damage in those cases? I think I remember reading that it is possible to replace the crank bearings with the motor still in the truck by removing the oil pan so I can't help but wonder if new bearings would help the problem at all.

Edit: Nevermind, replacing the bearings with the motor in the truck sounds like a lot of work that probably wouldn't even fix my problem. And if it did, who knows else might go next...