Torque converter shudder

Tempest · Mar 6, 2007

My knowledge of Automatics is limited, but I have a basic understanding of how they work. Shudder is a commonly reported problem, and many oils/additives advertise that they eliminate it. I also read on Allpar that ATF+3 was brought about to reduce occurrences as ATF+2 was allowing it to happen after ~30K miles.

I was wondering what exactly is shuddering and how can oil/additives help to prevent it?

Thanks.

Axe Man · Mar 6, 2007

I don't understand what T/Q shudder is either. I have a 2003 Ford Taurus that has minor shudder on occasion.

I think one of the reasons Ford went from Mercon to Mercon-V was to address shudder issues. And I also understand it wasn't totally successful. I can testify to that since my Taurus uses Mercon-V.

SteveD2 · Mar 6, 2007

Shudder is the clutches in the converter chattering during lockup. They are "jerking" (slipping) as they are clamping together during the lockup.

The additive prevents the chattering during lockup...much the same as LSD additive prevent chattering in an LSD differential. It either causes them to "grip" harder or to "slide" past each other without chatter.

steved

Dick in Falls Church · Mar 6, 2007

Tempest-
what kind of car are you talking about?

SteveD2 · Mar 6, 2007

Quote:

Tempest-
what kind of car are you talking about?

Just a guess at the +2 and +3 reference would be a chrysler/mitubishi???

steved

ford3liter · Mar 6, 2007

sounds like a job for lubeguard red

RedDart · Mar 6, 2007

Quote:

sounds like a job for lubeguard red

I second that recommendation. Great stuff - used by transmission shops and available at NAPA (at least in my area).

XB70 · Mar 6, 2007

Quote:

sounds like a job for lubeguard red

If it's a Mopar, just do a flush and refill with the recommended fluid.

unDummy · Mar 6, 2007

Yep, if you have shudder, definitely flush the ATF with OEM spec'd or equivalent fluid.

Incorrect fluid and excessive time on fluid will cause shudder. But, sloppy OEM transmission programming and trying to create perfect seamless shifts are also major causes. Always research if there are software or hardware updates via OEM TSB's.

If you already have fresh quality ATF, try one of these:
http://lubegard.com/automotive/trans_shudder_fixx.html
http://www.lifeautomotive.com/Products/ATFP3800.asp

Doc8404 · Mar 6, 2007

just don't take it to JL...i'm still fighting with them about the #@$%! they put in my truck...then again, it could just be fine in the long run.

Tempest · Mar 6, 2007

Thanks for the replies guys. Luckily, I don't have shudder, at least I don't believe I do. The one auto trans that I own (Jeep Liberty w/45FRE) seems to shift fine with Amsoil fluid. It's just that I have always seen many problems posted on this without an explanation as to what it is and what causes it.

I assume that if there is shudder, it will vibrate with force to feel/hear something in cabin of the car? I don't believe I've ever been in car with this happening. What are the symptoms? Do the additives realy work?...or are they just stop gaps?

Whitewolf · Mar 6, 2007

The additives work, but they are matched to the friction materials that are used in the clutch. Not all materials work well with all fluids and the other way round. That's why it is important to use the recommended products. Doing otherwise could result in damage to the clutch.

SteveD2 · Mar 6, 2007

Quote:

I assume that if there is shudder, it will vibrate with force to feel/hear something in cabin of the car? I don't believe I've ever been in car with this happening. What are the symptoms?

It will feel like shudder during the lockup of the converter...might feel like a chatter in the floor. Don't know how much else to explain it. It doesn't last long...and only occurs when the converter locks.

If you "feel" the shifts in a 4spd auto, you will feel the 1-2 shift, the 2-3 shift, the 3-4 shift, and finally the converter locking up (it feels like another gear shift in most trans, you will notice the tach drop if you can't feel it)...when the converter locks, it will have a "mid-speed" vibration (like a short-in-duration low buzz usually) sometime accompanied by a groan if shudder is present.

All I can say is you will know it when/if you experience it...

steved

Da Game · Mar 7, 2007

Use the LubeGuard in the red bottle. Their site list it as better than Smart Blend, and this site gives positive reviews on the LubeGuard products. Oh, below is the link with the chart..

http://lubegard.com/automotive/trans_atf.html

Whitewolf · Mar 7, 2007

Use whats recommended. The 'mousemilks' are basically contaminants unless you understand how they interact with whatever additive chemistry is in your original fluid.

PT1 · Mar 8, 2007

Quote:

Quote:

sounds like a job for lubeguard red

Click to expand...

I second that recommendation. Great stuff - used by transmission shops and available at NAPA (at least in my area).

I agree LG Red will definitely help.

Doc8404 · Mar 8, 2007

so i should just drain 10oz out of my tranny and add the 10oz lubegard red?

unDummy · Mar 8, 2007

It depends on the symptoms, the transmission/vehicle, and the ATF that you are using.

This is why I posted the above two links. You don't need to drain anything. Just add the shudder elimator to your ATF. If it works, use a better ATF during future maintenance.
Or, add an ounce of ATF additive(Smartblend, Run-rite, Lubegard, Gunk), to each new quart of cheap ATF to you use for future maintenance.

If you don't have shudder and just want to improve the shift quality or fluid performance a little, then feel free to drain some ATF and top off with one of the Red products.

Doc8404 · Mar 8, 2007

Quote:

If you don't have shudder and just want to improve the shift quality or fluid performance a little, then feel free to drain some ATF and top off with one of the Red products.

I'm trying to improve shift qualities and see if there's anything wrong with her....started the "replace parts until it's fixed mode" already.

desmonsm · Mar 9, 2007

Quote:

Quote:

If you don't have shudder and just want to improve the shift quality or fluid performance a little, then feel free to drain some ATF and top off with one of the Red products.

Click to expand...

I'm trying to improve shift qualities and see if there's anything wrong with her....started the "replace parts until it's fixed mode" already.

No offense, but I hate it when people do #@$%! like that. Why waste the time and money throwing random #@$%! on, when you could take your vehicle to a reputable shop who will diagnose and fix it correctly the first time? You now in the end it's going to cost more time, and probably more money, just throwing parts on the vehicle.

Torque converter shudder

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