P71 Shudder

NYSpeed Automotive
1

I am getting a shudder on my 1998 P71 when shifting from 4th to 3rd. Kinda feels like driving on a rumble strip for a moment.

A few other searches yielded doing a transmission fluid flush and filter change as it is most likely a torque converter slip/lock issue and its the fluid that is the problem.

I dont want this to get from bad to worse, and the dealer wants $180 dollars to “vacuum the system, run cleaners through it and replace the 14 quarts with new Mercon V fluid” does not change filter

I wanted some the viewpoints of the ford crew, and the wise people here, since i dont trust any internet yahoo talking about shit.

Has anyone else had this issue, do you think that a tranny flush will fix it?

And can anyone do that work at a better price, I can go get the fluid and filter as i think the filter should be change, dealer disagrees.

I dont mind traveling to buffalo, prefer rochester area.

Thanks again.

2

bump

3

$180 doesn’t seem like too far fetched of a price

4

No personal experience with a P71, but when trying to clear up some hard shifting on the Ford 4R100 in my Expedition I decided to go the pan drop, filter change route over a flush. Forcing fluid backwards through the system just seems like asking for trouble on an older trans, especially since it also gets flushed backwards through the filter meaning any contaminants the filter has trapped will likely end up floating around. Hopefully they all come out in the process but more likely they end up securely wedged in some small passageway in your trans.

I was lucky with the Expedition in that it has a 2nd drain on the torque converter that you can access by slowly turning the motor over by hand so you can actually get most of the fluid out by draining the pan and the converter. From what I’ve read these drains are quite rare though.

5

I was reading a tutorial on a ford forum that instructed taking the hose off of the transmission cooler, and putting that in a bucket, starting the engine and letting it all get pumped out with the car in neutral. The system holds like 14 quarts. Draining it that way doesnt sound that safe, and i was going to still drop the pan and change the filter.

I just dont know if i feel comfortable letting it get pumped dry essentially, i suppose it would get all of the fluid and the pan drop would ensure that but. Its a bit more complicated than an oil change lol

6

off topic, but does this car really take 14 qts of tranny fluid?

7

Everywhere im reading says the 4r70w and the cooling system takes a total of 14 quarts.