What does a bad torque converter feel like, symptoms??

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xLURKxDOGx

xLURKxDOGx

"An angel fat, at satan's feast"
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Just put a 360 magnum in my valiant, took a long minute to sorted out an oil pressure problem but now ive got a rotten vibration coming up in the rpms after idle. This leads me to believe its the converter but cant find a definite answer. I used a weighted balancer and b&m flexplate and from what i saw/recall a neutral balanced converter. I attempted to take it for a spin and it drove like ****, wouldnt shift and had zero power so that leads me to believe it has to be the converter. Any insight/experience would be appreciated.


Thanks.
Jake
 
Jake,

There is a lot that can go wrong with a converter. I cannot speak about the magnum 360's and if the converter is balanced or neutral balanced.
If a converter goes bad for certain reasons, here are a few of the symptoms I have found over the years. I know there are more but it is a start.
Converter clutches lock up all the time- car wants to stall and kill the engine when in gear at a stop sign.
Converter is slipping- when you hit the converters desired rpm range- factory converter lets say is 1300-1700 rpm. When you start to drive and hit that rpm the tach should climb even to the MPH. If it revs higher than the converter, it is slipping. Hard to describe as it is seat of the pants feeling. you feel it engage and the car starts pulling. Its like a clutch slipping feeling.
If the converter is out of balance it vibrates thru the floor and the faster you go (MPH and RPM) more stuff starts to vibrate. First is is the dash then you cant see thru the rear view mirror shaking so bad until you cant even see thru the side mirrors. sometimes its a harmonic vibration and cycles in and out like a rummm, rummm, rummm as you drive.
Sometimes its that in idle and you never even put it in gear.
Foaming of the trans fluid, or oil pumping out of the vent hole.
Is it possible the converter AND the flex plate are both balanced when it should be one or the other?
OKAY,
Others chime in.
Good luck,
Joe
 
xLURKxDOGx said:
I attempted to take it for a spin and it drove like ****, wouldnt shift and had zero power so that leads me to believe it has to be the converter.
Click to expand...

If the engine tune is known to be good, and if the rear end is anything but 2.45 or less,and it's a non loc-up; Then it sure sounds like there is no torque multiplication going on in that TC

But before you yank it, this problem could be as simple as the tranny being stuck in 3rd gear,lol.
 
AJ/FormS said:
If the engine tune is known to be good, and if the rear end is anything but 2.45 or less,and it's a non loc-up; Then it sure sounds like there is no torque multiplication going on in that TC

But before you yank it, this problem could be as simple as the tranny being stuck in 3rd gear,lol.
Click to expand...

Hmmmmmmmmm. Well, ive shifted manually from 1st to third and get the same result. I have 3.23 gears, engine is tuned, guess all thats left is the transmission or converter.

Thanks!

Jake
 
Syleng1 said:
Jake,

There is a lot that can go wrong with a converter. I cannot speak about the magnum 360's and if the converter is balanced or neutral balanced.
If a converter goes bad for certain reasons, here are a few of the symptoms I have found over the years. I know there are more but it is a start.
Converter clutches lock up all the time- car wants to stall and kill the engine when in gear at a stop sign.
Converter is slipping- when you hit the converters desired rpm range- factory converter lets say is 1300-1700 rpm. When you start to drive and hit that rpm the tach should climb even to the MPH. If it revs higher than the converter, it is slipping. Hard to describe as it is seat of the pants feeling. you feel it engage and the car starts pulling. Its like a clutch slipping feeling.
If the converter is out of balance it vibrates thru the floor and the faster you go (MPH and RPM) more stuff starts to vibrate. First is is the dash then you cant see thru the rear view mirror shaking so bad until you cant even see thru the side mirrors. sometimes its a harmonic vibration and cycles in and out like a rummm, rummm, rummm as you drive.
Sometimes its that in idle and you never even put it in gear.
Foaming of the trans fluid, or oil pumping out of the vent hole.
Is it possible the converter AND the flex plate are both balanced when it should be one or the other?
OKAY,
Others chime in.
Good luck,
Joe
Click to expand...

Thanks for the response Joe. The transmission fluid is new, not foaming and not leaking from anywhere. The thing about the b&m is there is only one way it can go on so im guessing its not that either but my gut feeling is that the converter is bunk. I was going to try to get a know good one this weekend and give it a shot but i might wait and save to get one thats better suited for the application.

Jake
 
You haven't mentioned what year the transmission/converter or the year of the engine is. This might help:
Non-Lockup 360 converters: to 1976: 11" Model, with a wide (1") ring gear, 2 weights welded to the front(engine side) of the converter.
1977 on: 11" model with a single 120 gram weight

Lock-up 360 converters: 1978 on: 12" model with a narrow( 1/2" ) ring gear. No weights on the converter front.

It could be that the one-way roller clutch (sprag) inside the converter is the issue as far as a lack of pulling power, if it is a converter problem.
 
Try do a stall test. If the revs go up and stay there it should be good. If they go up then start coming down u have a converter problem. Kim
 
some 360 magnums need the factory flex plate????
 
transman said:
You haven't mentioned what year the transmission/converter or the year of the engine is. This might help:
Non-Lockup 360 converters: to 1976: 11" Model, with a wide (1") ring gear, 2 weights welded to the front(engine side) of the converter.
1977 on: 11" model with a single 120 gram weight

Lock-up 360 converters: 1978 on: 12" model with a narrow( 1/2" ) ring gear. No weights on the converter front.

It could be that the one-way roller clutch (sprag) inside the converter is the issue as far as a lack of pulling power, if it is a converter problem.
Click to expand...

This transmission is a 68 904 and the converter was a used "know" good converter. The engine was a 98 360 magnum from a dodge ram. I rebuilt the transmission over the course or 3 days, watching and rewathcing instructional videos and i felt like i did it right but that could be the problem as well. It goes into all gears without issue. Do you suppose that if the converter was bad it wouldnt shift at all or in the correct way because it isnt converting the torque like its supposed to? Ive got it back out again, im sending to someone to have it looked over, if its good than ill have to look at the transmission next.

Jake
 
Torque multiplication happens inside the TC. It is only a small amount and is fleeting.
Generally it is 5% to perhaps as much as 10%, and only lasts long enough to get the car moving.
With a soft engine you might get 10 to 20ftlbs for something like 5 feet. Then dropping as speed increases. More input equals more multiplication .
Going from a teener type cam to a 268 without an accompanying stall increase or still with the same gears out back would certainly make the combo feel like crap.

Post #1 says it wouldn't shift
Post #4 says you manually shifted it with no different results.

Are you saying it wouldn't upshift out of first? This would normally point to a faulty governor circuit.And the combo pulled like crap in first gear?
With the engine tuned and 3.23s, and the above situation,namely crappy pull in first gear,there can only be one of four things wrong.
1) the TC is not working, or
2) the tranny is trying to get two gears at once, or
3) the brakes are tight, or
4) the engine is way down on torque.
Since you have already pulled the tranny down, we cannot prove a problem in the oil circuits,nor can we check the cylinder pressure. And so,we will have to adopt a wait and see approach. Unless you want to check the brakes, while you wait.
 
AJ/FormS said:
Torque multiplication happens inside the TC. It is only a small amount and is fleeting.
Generally it is 5% to perhaps as much as 10%, and only lasts long enough to get the car moving.
With a soft engine you might get 10 to 20ftlbs for something like 5 feet. Then dropping as speed increases. More input equals more multiplication .
Going from a teener type cam to a 268 without an accompanying stall increase or still with the same gears out back would certainly make the combo feel like crap.

Post #1 says it wouldn't shift
Post #4 says you manually shifted it with no different results.

Are you saying it wouldn't upshift out of first? This would normally point to a faulty governor circuit.And the combo pulled like crap in first gear?
With the engine tuned and 3.23s, and the above situation,namely crappy pull in first gear,there can only be one of four things wrong.
1) the TC is not working, or
2) the tranny is trying to get two gears at once, or
3) the brakes are tight, or
4) the engine is way down on torque.
Since you have already pulled the tranny down, we cannot prove a problem in the oil circuits,nor can we check the cylinder pressure. And so,we will have to adopt a wait and see approach. Unless you want to check the brakes, while you wait.
Click to expand...

Thanks for the response! I half forgot i had wrote asking for help so i didnt check it before i opted to pull it. It felt like it wasnt changing gears right but it was hard to tell because the vibration was absurd, i didnt want to go to far driving it. It felt like it shifted but not how it should. I cycled through manually and all the gears worked but was way way down on the power. The cam isnt really big by anymeans so i dont think its a dog like that. My 273 with a 260/268 .444/.444 had way more power than this did/does. The brakes are good, KH swap 2 months ago, so im going to say thats out. Im looking at contacting a converter company and seeing what i can do, i feel like maybe i should have done that months ago but thats a bit too late. I might just bite the bullet and pull the trans and go through it again, im just not sure what to look for.

Jake
 
You're not getting it; Saying something is good doesn't necessarily mean it is so.
>If you have been driving the car with the KHers and have not experienced any binding brakes, ok then they must be good. I get that. Otherwise testing may be required.
> If you have been driving the 98 for several miles with no power issues then it must be good, I get that. But if this is a maiden voyage, then testing may be required.
>With no oil pressure tests on the tranny prior to pulling it down, you are at your own mercy, in having a look-see. I fear if the new TC does not solve your problem, you will need to take it down yet again. The pressure test is the only way to prove the tranny is any good, and if you don't have a test bench, then the tranny has to be engine driven,ie;reinstalled.
>I get that there were vibration issues,but others have addressed that.

> so just what cam went into the 98? Was it degreed in? You got any unusual noises? Were there other changes at the same time? Like ignition timing? or a 4bbl set-up?
>Is that old 904 a stocker? Was the KD mechanism hooked up and correctly adjusted? Was the cooler line flushed prior to being hooked up?Did you preform an air-test on it before the VB went on? Since it is now on the floor, this would be a good time to remove the rear extension and verify that the governor is correctly installed. Or did you install a shift kit with a governor bypass?
> what rearend is in it; an 8.75 with tapered bearings?You probably know that if the bearings on these are loose, then the drum can be caused to rub on the shoes. Or something with ball bearing axle-bearings?
>How about the exhaust? Is it known to be free-flowing?

Jake
I know you are a smart man, I have seen a lot of your posts.But sometimes we tend to move a little too fast, and might miss some little thing.
So, honestly. I'm not trying to be a dick.Sometimes it just happens all by itself,no trying involved.
Hopefully it really is as simple as a failed sprag ,in the TC.
 
xLURKxDOGx said:
This transmission is a 68 904 and the converter was a used "know" good converter. The engine was a 98 360 magnum from a dodge ram. I rebuilt the transmission over the course or 3 days, watching and rewathcing instructional videos and i felt like i did it right but that could be the problem as well. It goes into all gears without issue. Do you suppose that if the converter was bad it wouldnt shift at all or in the correct way because it isnt converting the torque like its supposed to? Ive got it back out again, im sending to someone to have it looked over, if its good than ill have to look at the transmission next.

Jake
Click to expand...
Without cutting a converter open, there is no KNOWN way if a used converter is good or not. Yes you can stick an input shaft in it to see if the sprag rotates one way or both ways, and yes if YOU'VE driven a car with said converter in it and it functioned fine then, then it should be fine, otherwise it falls into the "just another used converter" category.
 
transman said:
Without cutting a converter open, there is no KNOWN way if a used converter is good or not. Yes you can stick an input shaft in it to see if the sprag rotates one way or both ways, and yes if YOU'VE driven a car with said converter in it and it functioned fine then, then it should be fine, otherwise it falls into the "just another used converter" category.
Click to expand...
I'm taking the converter over to have it looked at/opened up. If it turns out it's bad then I'll start looking at the transmission. I'm just trying to understand what the severe vibration would be coming from and why I was curious the signs of a bad converter would cause a vibration like that. Thanks for your input.

Jake
 
xLURKxDOGx said:
I'm taking the converter over to have it looked at/opened up. If it turns out it's bad then I'll start looking at the transmission. I'm just trying to understand what the severe vibration would be coming from and why I was curious the signs of a bad converter would cause a vibration like that. Thanks for your input.

Jake
Click to expand...
Your 98 360 engine will need the properly balanced converter.
For a non-lockup style transmission it should have a converter with a single tri-angular shaped weight welded to the front of the converter.
For a LOCK-UP style transmission it will have the same weight as the non-lockup.
You never said what the problem converter was out of or what engine it was originally behind, so it might be totally out of balance for the '98 360 engine.
 
transman said:
Your 98 360 engine will need the properly balanced converter.
For a non-lockup style transmission it should have a converter with a single tri-angular shaped weight welded to the front of the converter.
For a LOCK-UP style transmission it will have the same weight as the non-lockup.
You never said what the problem converter was out of or what engine it was originally behind, so it might be totally out of balance for the '98 360 engine.
Click to expand...
Thanks! That would make sense. I just realized that the b&m flexplate I order said 72-93 360, I never noticed that before. It's the flexplate that is missing a corner, should I have the regular one and a weighted converter? The converter is neutral balanced.


Jake
 
Magnums are balanced differently than the LA engines. U can go with a regular flex plate and a weighted converted for the magnum. Or does b&m make a f/p for the magnum so u can run a neutral converter? Kim
 
oldkimmer said:
Magnums are balanced differently than the LA engines. U can go with a regular flex plate and a weighted converted for the magnum. Or does b&m make a f/p for the magnum so u can run a neutral converter? Kim
Click to expand...
I was under the impression that if you used the B&M that you could use a neutral balanced converter and thats why i chose that flexplate its #10239

Jake
 
oldkimmer said:
Magnums are balanced differently than the LA engines. U can go with a regular flex plate and a weighted converted for the magnum. Or does b&m make a f/p for the magnum so u can run a neutral converter? Kim
Click to expand...
I think you have hit the nail on the head Kim. I did a quick search, and the B&M flexplate is shown only for the older 360's. A further search did not show up any flex plates other than the stock on for the 98 360, either by ATP or Pioneer. If I was you Jake, I'd maybe contact B & M directly to see if they can help you, but right now, it would appear that you'll need to go with the OEM style flex plate and the weighted converter.
 
318willrun said:
some 360 magnums need the factory flex plate????
Click to expand...
oldkimmer said:
Magnums are balanced differently than the LA engines. U can go with a regular flex plate and a weighted converted for the magnum. Or does b&m make a f/p for the magnum so u can run a neutral converter? Kim
Click to expand...
Thats what im using. Its a b&m flexplate that is used with a neutral balanced converter. Im balanced in the front with a weighted balancer and weighted in the back with a b &m flexplate. Do people make their magnums internally balanced? If so, im wondering if thats whats going on? Is there a way to tell on a crank the difference between an internal and external balance?

Jake
 
U have the wrong flex plate for a magnum. Apparently b&m doesn't make a f/p for the magnums they are weighted differently. Kim
 
oldkimmer said:
U have the wrong flex plate for a magnum. Apparently b&m doesn't make a f/p for the magnums they are weighted differently. Kim
Click to expand...
So, im going to need to weight the converter and run a stock or b/m neutral balanced flexplate?

Jake
 
xLURKxDOGx said:
So, im going to need to weight the converter and run a stock or b/m neutral balanced flexplate?

Jake
Click to expand...
The TC will need to be weighted for the Magnum. You can buy the weights separately, and weld them on per the Magnum instructions,and
You could mod your current flexplate to neutral balance by cutting a matching scallop out of the other side,180* out of phase.
 
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