A new to me 97 F150 4.6L auto overdrive 4x4.
I noticed on day 2 100+ miles into the new
truck that if I am slowly cruising up at 1500 RPM
that tere is a transmission driveline shutter immediately
after the upshift. If I keep on the pressure it will shift and
shutter again and again.

If I take the OD off it seems like it will do it under similar
rpms.

If I get on it a lot harder it does not seem to do it.

Wgat do you think it is?

And is there a better way to investigate it?

The trans fluid is clean and may be a little
on the high side. Dealer may have added some
as he topped off all fluids.
89 K on the odometer.
Thanks

 

Corvetteguy,

I have exactly the same thing - however I am overdue for a tranny fluid change and had assumed that the shudder might be related to the old fluid. But now I wonder - not that that is a reason not to go ahead and do the fluid change. Please post if you find out more.

 

I am driving the new (97) truck a little
more. I drove it the other day 100+ miles and
now am driving it a little more aggressively as
I get used to the handling. I did not notice
]the shutter (like riding over a speed bump strip)
at all. I think it is temperature of trans related as
yesterday my wife drove 200+ miles and she said
it did it on the way back going up an entrance ramp
right when the OD downshifted under light acceloration.

I almost get the feeling that the eec is telling the trans to
shift down only a few hundred rpm fron the shift up. And
that this ratio is not far enough apart to give a good shift.

I plan on using the 90 day 9K mile warrantee to complain to
the dealer. But I need to get it to happen regularly to show
him.

I'll let you know what he does....
Flash eec?
change fluid? (using Mercron V)
act dumb?
add "shutter stop"?
change torque converter? (yea that will happen)
change ignition? (ditto)
add oil cooler? (ditto)

ALL THESE FIXES HAVE BEEN SAID TO WORK

 

What's happening is torque converter clutch shudder. The EEC controls the torque converter clutch to a specific amount of slip during a shift. When the ATF gets worn out it's frictional characteristics change and the computer can't control the clutch properly. That shows up as shudder during a shift.

Change ALL of the fluid. Not just a pan drop, but the torque converter, too. The trans flush machines work GREAT for this. Use MERCON V. It was developed because of the shudder issue. MERCON fluid would shudder at very low miles, MERCON V will go quite a bit longer before shudder starts.

 

Your explanation makes a lot of sense. I will have
to convince the dealer it is the thing to do.
The temp issue also falls into this explanation.

Is this a problem that will leave me stranded?

 

No, it won't leave you stranded. If it goes on long enough the torque converter clutch will be damaged and new fluid won't stop the shuddering,

 

Whatever you do do not get the transmission flush. I have talked to at least 4 people who as soon as they had this service done had their transmission go completly out all at different milage so I believe it is due to this service. It cant be good to pump fluid under pressure through your transmission the wrong way. I have this same shudder and have ever since owning my truch for 50,000 miles,It is a f-150 lariet 4.6l auto with 114,000 miles now.Has always done this and know of two others with same problem.

 

There is a big difference between a flush and a machine fluid replacement. A fluid replacement uses the tranny pump with the engine running to suck up fresh fluid and pump the old stuff out.

 

It isn't possible to pump trans fluid through the trans the wrong way, unless you run the engine backwards while you're doing it. The trans pump acts as a one way valve and won't allow any fluid to flow backwards.

 

I am wondering if the people that had problems
get worse after the fluid exchange, may have used
regular mercron. I understand that mercron V is the only fluid
to use since it has friction additives missing in the earlier.

What about adding a product friction additive "shutter stop"
I would think it would beef up the fluid that you have in there.

Sure is easier than a flush.

 

I was just trying to prevent a failure of his transmission and am not aware of how they do the flush only of bad results.