Instant Shudder Fixx

[V-8]

Had a part throttle transmission shudder between 1000 & 2000 rpms in a high mileage '95. Bought the Instant Shudder Fixx off Amazon and am pleasantly surprised by the result.

 

[1997ThunderbirdLXV6]

Formerly known as "Dr. Tranny". Yes, it does work; however, you achieve the same result by changing the fluid. There are differing opinions about that on higher mileage cars with unknown maintenance history.

There are also Technical Service Bulletins on the subject which are an interesting read.

 

[KevinVarnes]

I also used the Lubegard in our '97 and it worked well after a complete trans fluid change made little improvement. It is surprising how four ounces can have any impact, but it did. I just bought mine at NAPA since I cannot stand supporting Amazon.

 

[theterminator93]

The main cause of the shudder is the breakdown of the fluid and burning up of the friction modifiers due to prolonged (over)heating. The best fix is an aux trans cooler and fresh fluid (or more frequent fluid changes) but if it's never been serviced before and the clutches are toast, the bottle is just as good as anything else if it staves off a rebuild.

 

[Kidd-7]

A rebuild…

 

[racecougar]

Transmission shudder fix products are mainly friction modifier that increase slip to prevent clutch chatter (shudder). They can absolutely eliminate the symptom for awhile, but they are not a permanent fix for failing TCC friction material.

 

[1997ThunderbirdLXV6]

I think the big question is: how long was the period between A. the first time the shudder occurred and B. when the issue was addressed in whichever way (additive, or fluid change, or whatever else).

Because when you hear the torque converter clutch shudder, you likely also incur excessive wear. If that continues for one week, or one month, or one year...makes a difference.

If you just bought the car, and it shudders, you have no way of knowing how long the previous owner lived with the noise. With my car, the first time the shudder occurred, I had already owned it for several months; I was pretty confident it was a new problem. Then I immediately addressed it with Dr. Tranny, followed by a flush with Mercon V maybe a month later, and a full drain and fill another year later.


It also matters where the car is owned. The TCC shudder primarily occurs when locked up, at speeds just fast enough to lock up, under load (going slightly uphill), accelerating mildly. So if the vehicle is owned in an area with a lot of mild hills and driven ever so gently, that doesn't help.
In my opinion, that's another reason to be deliberate in the use of the O/D off feature; the powertrain just feels happier when there's no lugging (or lugging-adjacent low-rev acceleration).


Just my entirely unprofessional opinions.

 

[MadMikeyL]

At some point (1998 maybe?) Ford upgraded the torque converter to have a larger clutch with more friction material, and that combined with the updated MerconV fluid was enough to completely fix the problem. In the earlier transmissions, keeping clean fluid helps, but once the shudder starts, it always comes back. It doesn’t really hurt anything though, so unless it bothers you enough to drop the trans and change the converter, I wouldn’t worry about it.

 

[1997ThunderbirdLXV6]

once the shudder starts, it always comes back.

Mine has never returned after those initial few instances, some 25,000 miles ago. Knock on wood.
But I see your point. The wear can't be unworn.

 

[Grog6]

At this point, even the 2002 trans upgrade needs a rebuild the seals are hard; and not sealing.

 

[MadMikeyL]

Mine has never returned after those initial few instances, some 25,000 miles ago. Knock on wood.
But I see your point. The wear can't be unworn.

The 3.8s seem to be less problematic with it than the 4.6s. I don’t know if it’s because of less torque, or different programming, or what. In my experience the first fluid change will fix it for about 30k miles. Then when it returns, the next one goes about 20k, then 10k, and then it stops helping. It sounds like you got to it pretty quickly though and didn’t let it get too bad before changing the fluid, so hopefully between that, and being a 3.8 and lower mileage, hopefully you’ll be fine for a long time. I would still change the fluid every 30k though just as a preventative measure. If you get the Dorman trans pan, it has an actual drain plug in it, which makes changing the fluid no more difficult than changing oil.

 

[1997ThunderbirdLXV6]

If you get the Dorman trans pan, it has an actual drain plug in it, which makes changing the fluid no more difficult than changing oil.

I actually prefer the siphon method. The handpump is <$5 at Harbor Frieght, and you easily get 4 quarts out of the pan, plus 7 quarts from the torque converter drain plug.

. I would still change the fluid every 30k though just as a preventative measure.

That's definitely the plan.

 

[White Lincoln]

I also used the Lubegard in our '97 and it worked well after a complete trans fluid change made little improvement. It is surprising how four ounces can have any impact, but it did. I just bought mine at NAPA since I cannot stand supporting Amazon.

You hate "the jungle site" as much as I hate "eBate".