torque converter shutter

[dcain]

I recently bought a 1997 Mark VIII, with 45,000 miles.It has what I believe is a torque converter shutter. When I drive the car after a cold start, there is a shutter, or rumble for about the first 10 miles. It is not a constant shutter, probably does it around 9 times. If I park the car for about 3 hours, and drive it again, I do not feel the vibration. There is also a pronounced downshift at 30 mph, which occurs all of the time, hot or cold. I had the transmission fluid changed, along with the torque converter fluid, and something called 3800 smart blend supplement was added. The transmission shop told me that this should cure my shutter problems, but he didn't know what to do about the pronounced downshift. The shutter is still there, and he now says I need a new torque converter, which he thinks will cure the problem. I hate to go with the expense of a converter, and still have the problem. If anybody has any suggestions, or has had a similar problem, I would truly appreciate the help.

[Antiburn]

My tranny has the same shutter at 35-40mph acceclerating. Also 1st gear is pretty shot on it to. Its a ford so eather expect a rebuild or a new tranny.

[Towncar]

Mine HAD the same problem but it was cured with the flush and additive. I used Lubegard instead of 3800 Smart Blend.

LOL ?

[Mark8denny]

It was common in those days to drain and refill the trans and converters with mercon 5 fluid. 5 is synthetic and at that time Ford did have their problems with the 4r70w trans untill 1999. If you buy a new converter make sure you get a good one , don't waste your money on a stock type , check precision industries or pro torque or even art carr. if your car is stock I suggest a 2800 stall lockup. The car will really have much more useable power+still have mileage the price , about 800$

[BlackiceLSC]

the stock torque converter lock-up solenoid is commanded to lock the TC at 37 mph. This will feel alot like an upshift into 4th gear due to the low engine rpm at that speed.

the other problem is, the additives your tranny shops are using DONT WORK. Think about it...they make a living off selling trannies/rebuilds. Why on earth would they sell/install an additive that was designed to prolong the life of your tranny?

use ONLY mercon V. period. it is a synthetic tranny fluid used in ALL 4R70W trannies since 1998. there have been several TSB's issued regarding this matter.

In simple english, the frictional plate material in your torque converter is prone to high heat damage due to fluid breakdown. Mercon V is synthetic, so it is more capable of sustaining its viscosity.

you cannot simply drain the tranny, or the torque converter. You MUST drain both, AND flush the heat exchanger as well. This is done by flushing the tranny cooling lines while they are connected to the radiator's side tank.

then pour in the correct amount of Mercon V fluid. Now drive the car. it can take upwards of 100+ miles to get the Mercon V fluid to saturate the frictional material in the torque converter clutches.

many of us have used this, along with a custom SCT-based computer chip to reprogram the stock TCC setting(torque converter lock up solenoid) through the ECU command. ideal torque converter lock-up is 50 mph.

think about this one-the 4R70W is a wide-ratio 4-speed automatic. when the torque converter locks up at 37 mph, the engine rpm is way too low, and below the proper torque curve of the engine. it feels alot like as if you were driving a manual tranny, and shifted into 5th, instead of 3rd gear, dropping the rpms too low to accelerate without harming the clutch. Same prinicple.

[tbmurphy]

I have owned several Mark VIIIs'! From 1993 to 1997. The shutter that you speak of can be eliminated by draining the tranny and torque converter of all of it old nasty fluid and installing either the merkron 5 or I used Amsoil Synthetic ATF. I have turned several people on to this and it g=has resolved the problem for all! There is a drain in the torque converter and the gasket for the pan is reuseable! Buy the fluid and a filter and your all set! This is the first thing I do when picking up a Mark VIII fron here on out! Good Luck!

[BlackiceLSC]

Originally Posted by tbmurphy

I have owned several Mark VIIIs'! From 1993 to 1997. The shutter that you speak of can be eliminated by draining the tranny and torque converter of all of it old nasty fluid and installing either the merkron 5 or I used Amsoil Synthetic ATF. Luck!

yes, yes yes. Amsoil is definately a known agent of cure as well. it like Mercon V is a synthetic.

when i said you cant just drain the TC or the trans, I meant...dont only do one....do them both. and yes, Thank Ford for installing a drain plug(bolt) in the torque converter.