buckz6319

what are the signs of a bad torque converter?....will a bad one have anything to do with grinding under a load?...sorry

Tubbyfatty

Shifting hard and/or late, if you pull your pan and there is a bunch of friction pad, which is in the converter and getting pumped throughout the tranny.

But if it is going out, it will randomly shift hard or late.

buckz6319

Thanks for the info..all I have is some gear dust on the magnet and the tranny shifts fine I have some post of my tranny problems your welcom to read them and comment thanks.....here's the thread I started
https://www.yotatech.com/forums/f120.../#post50879433

abecedarian

Depending on what is wrong with the converter, it may give you some head's up.

If you let of the gas pedal in a low gear and don't feel the 'engine brake effect', the converter may be going out.
If you hear random 'grinding' noises when accelerating, the converter may be going out.
(wow, this is starting to sound like a "Jeff Foxworthy- the redneck mechanic" post)
If everything is fine when you put it in gear, but somewhere just above idle you hear a rattle, your torque converter may be going out.
If your transmission fluid temperatures have suddenly gone off the chart, your torque converter may be going out.
(yeah, now it sounds like a "foxworthy" post)
If your truck never goes into overdrive, it may be your torque converter going out.

(okay, I quit... sound's too much like foxworthy)

buckz6319

After all I have been through on this 4runner and all the parts I have replaced I have found out that the grinding is worse when the O.D. is off and lets up some when O.D. is on.I can tell you this also when I put some strain on the tranny I can feel the grinding and when I set at idle I can here a faint bearing noise or something bumping just under the console in the area under the ECT button.I have replaced the whole rear t-case and rear output shaft bearings thinking my problem was in that area of the t-case but the problem still exist.The tranny shifts smooth and on time so I think it's either in the hydraulic part of the t-case or the T.C. but not sure.I don't have any codes and my fluid is clean and well I'm just driving it until it breaks then I'll know where the problem is at that point...I also have a lot of slack in the tranny when letting off the gas in O.D. I have replaced all the u-joints also ect ect any rolling part I have replaced it or checked it at some point and one more thing my tranny never has run hot so as Jeff Foxworthy would say here's your sign LOL.....

abecedarian

having the OD on, could relax some of the shift points in the trans making it shift sooner.
are you sure the trans fluid is of the proper type and you are filled properly?
have you properly adjusted the detent cable (the downshift or kick-down cable as some like to call it)? if you look at the throttle body, the pedal cable comes up on one side, and the transmission detent (or kick down) cable comes off the other.

buckz6319

I have adjusted the detent cable per the FSM and still have a problem.I took the 4runner to 2 local shops here in town (tranny shops) and they both said I don't know where your problem is coming from in the tranny but it's some in that area.
I will tell you this that I have went through all the diagnosis I know of and replaces parts some I needed and some I didn't need.I now no that the problem is in the front of the tranny between the t.c. and the hydrulic case that houses the park prong.I think maybe it's my overdrive planetary and maybe I have some thing like this going.... on but not sure

I have jacked up the front axles with tires off the ground rear drive shaft removed and put it in 4H and let it free spin and there is a lot of vibration and grinding going on from speeds from 0-full range and when I stop the tranny from spinning and got under the 4runner and could here the noise making grinding.....

buckz6319

Well does any one else have some advice on how to diagnosis a bad torque converter? or maybe it's the bearing on the transmission pump....I do have something going on between the rear of the engine and the transmission area I can feel the grinding in my automatic shifter and the console area that houses the shifter...I also hear a whoo whoo sound like a bearing going bad in the same area but it will smooth out at different speeds and when I come to a stop I really don't feel it unless I put it in park and raise the rpms really high, I can feel the grinding vibration and when driving but when I cut the engine off but not the electrical the grinding vibration stops.... and starts as soon as I turn the ignition switch back on and the engine is operating...any suggestions
Dwayne

FredTJ

There is more friction material inside the tranny then in the 'itty bitty lockup clutch that's in the torque converter.
Just because there is friction material in the pan doesn't mean that the TC is bad.
Usually friction material in the pan is from some of the friction components (clutches, band, etc) inside the tranny and not from the lockup clutch in the TC.



Fred

FredTJ

Actually is pretty uncommon for the torque converter (other than the lockup clutch) to go bad.
If the lockup clutch has failed the tranny fluid will get very, very hot and burn quickly.
You'll be able to notice that by just checking the tranny fluid level frequently.

The check and see if the lockup clutch is working, drive the vehicle at a steady speed, say around 50 miles per hour.
Without letting off the gas, GENTLY apply the brakes (keep your right foot on the gas and use your left foot to apply the brakes.), just enough to cause the brake lights to come on. You don't have to apply the brakes hard enough to actually feel the vehicle slow.
The RPM's should increase 200 ~ 300 rpm or so as the lockup clutch unlocks.

BTW, the tranny shops are correct in that there is really no way to check all that's wrong and see what needs replacing other than to pull the tranny apart.


<EDIT>
If the lockup clutch is bad, the friction material from it, in the pan, is different looking than friction material from the other frictions in the tranny.
It'll look like fine, black sand.


Fred

buckz6319

Thanks for the input...and I'll do the test you mentioned and see what is happening with the t.c.

buckz6319

FredTJ. just wanted to update this post.....you asked me to do a test the lock up clutch is working?
Yes it is working I did the test as you described and the t.c. locked up and the rpms raised with out hesitation...
I just replaced a bad rear transmission mount today and what a pita it was took me all day to do it... GOSH!...it is hard to get to the lower screw on the passenger side of the tranny
any way I replaced it because a AAmco tech said they he thought the tranny rear mount was bad causing the vibration he called it not a grinding like I call it.
Well the old tranny mount was not vary good there was a lot of movement to the rubbers and my auto shifter handle always moved around while driving so I thought the new mount would solve that issue
The newly installed rear tranny mount did make some difference in the shifting from park to reverse and from park to drive it is a softer bump now.The 4runner feels like it rides better maybe just me being tired from the install.
However I still have the vibration (but I think it's a grinding but what do I know I'm just a shade tree mechanichere but been doing it for a while so I don't know nothing)..I tried to tell the guy from AAmaco( btw the 3rd shop I have been to in sense I purchased this runner)..that when I drive highway speeds 45,50,55,60,65 ect that I get a grinding(it is worse when the O.D. is off and accelerating) and some times I get a whoo whoo sound like there is a bearing under the tranny tunnel just under the console that the shifter in sitting into next to the 4x4 lever.The whoo whoo I here is like a starting to spin whoo whoo and it will catch up to speed at some point and it will not be so bad.
The AAmco tec said that he thinks it is a vibration from a bad rear tranny mount so I replaced it today and yet another miss diagnosis some what but he tried because the new mount did help some...
Well sorry for the long post but I think my t.c. is ok but something else is still not giving up the ghost yet. I guess that is a good thing because it is getting me back and forth to work
Thanks
Dwayne

buckz6319

Up date.........Maybe a bad flex plate?....I did this test...
I have jacked up the front axles with tires off the ground and rear drive shaft removed... and put it in 4H and let it free spin.I started to accelerate there is a lot of vibration going on.. more noticeable at speed of 30 and above... and I can feel the vibration in the shifter so maybe I have a bad flex plate?...
I was going to check it this past weekend but didn't have much time to do so.....

FredTJ

Well, you haven't ruled out the front drivetrain.
Why don't you drop the front driveshaft also and then repeat and see if you're still getting vibes.



Fred

buckz6319

FredTJ....how have you been? good to see that your still around and thanks for the input!

Fred...I haven't removed the front propeller shaft because it doesn't rotate until I put in 4H correct?

My vibration is going on even at idle in park I can feel ever so lite and when I start driving and accelerating I can really feel it.I can sit still in park and raise the rpms up above 2000 and start to feel the vibrations and when I get to 4000 it's really bad...I can drive down the road at speeds and when the vibration is at it's worse I cut the engine and the vibration goes away...turn the ignition back on and the vibration is back..
I don't think my problem is in the shafts any more?...I'm thinking maybe the T.C. or flex plate?
Thanks
Dwayne

buckz6319

I did another test this evening trying to find out where the vibration is coming from in this 4runner...and maybe this will help better diagnosis my vibration

I got home from work this evening and put the 4runner in park and with the engine running normal temp I start to slowly raise the rpms.I went from idle up to 1500 rpms and started to feel a little vibration in the auto shifter like usual.I proceeded to keep climing rpms slowly went to 2000 and the vibration started to get a little worse and I feel it in the auto shifter and the console that the shifter is housed in.I slowly get to 2500 and a little miss is in the engine and the vibration is getting worse.I go to 3000 and I think I get passed the miss but the vibration is still getting worse. I can here something that is making a noise and the shifter is vibrating at this point really bad.I go to 4000 and the noise is so loud and the vibration is so bad in the shifter and when I cut the engine it all goes away....what is up with that ......
input shaft bearing?...torque converter?....flex plate...something else?
I'm at my whitts end on this
Dwayne