4R70W Tranny rumble (?)

robertplattbell · #1 05-23-2005, 03:28 PM

I have a 1995 F150 XLT Supercab Lariat 4x4 that I've had since new. I've changed the tranny fluid every 20-30K miles. The tranny is a 4R70W (I thought it was an E4OD but it's not). I just changed the fluid and put in a new filter. Most other times, I had it done using one of those flushing machines.

The truck has 112,000 miles on it and runs great. We tow some pretty large trailers with it (5,000 to 8,000 lbs) so it has been well-used over the years.

Recently, I notice an intermittent rumble in the driveline when in 3rd gear doing like 35 mph. It sort of comes and goes in a harmonic fashion and almost feels like driving over a mild rumble strip. Most of my passengers don't even notice it. It's like, "thrummmmm....(2 second pause) thrummmm" but sometimes it goes away.

The U-joints seem pretty tight. I can't get any slop out of it when I turn the shaft by hand.

If I stomp on it, the vibration goes away. It does not do it in 2rd or 4th gear. The tranny works great if you are flooring it or if it is under heavy load. It seems like when it is lightly loaded is when I get this rumble.

Torque converter clutch chattering? Worn clutch pack? What?

When I dropped the pan, the magnet inside had a good amount of very fine filings on it, and there was a very, very small piece of *metal* in the pan. Ouch.

Also, there is a small amount of fluid dripping through the rubber plug at the bottom of the torque converter housing (front seal going?).

The truck generally gets about 3,000 miles a year on it at this point, used mostly for launching and retreiving a 27 foot boat. I am planning on towing the boat from Florida to NY next month, and I'm a little worried the tranny might be ready to go.

From what I read, though, these are pretty robust transmissions. There a lot of websites offering performance rebuilds for these, but most seem to be Mustang-oriented. Any sources for rebuilt HD versions of this tranny (for a truck?).

TIA.

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robertplattbell · #2 05-23-2005, 06:06 PM

Metal in the pan says it all. I guess I should start saving for a new tranny. I just hope the old gal has a few thousand more miles in her until the inevitable.

dirtyd0g · #3 05-23-2005, 06:19 PM

Sounds like your converter failed,but by now I would just build a later model tranny for the truck especially if you tow alot on it.
Alan

noirluispher · #4 05-24-2005, 04:06 AM

I was getting a rumble / shudder; that I percieved to be coming from the transimission. It ended up being cylinder 6s' boot had worked itself free of the spark plug.

pushrod · #5 06-03-2005, 05:35 PM

The pan magnet is normally covered in metal "dust". That's why it's there. If you've got a lot of hard miles under load, you should have a good amount of gorp collected. My guess is either ignition or u-joints. Worst case would be a bad t/c.

E.D. · #6 06-05-2005, 01:57 PM

"Metal in the pan says it all. I guess I should start saving for a new tranny. I just hope the old gal has a few thousand more miles in her until the inevitable."

Some fine metal powder on the pan magnet is normal. The key is, how did the fluid that you drained look? When looking into the drain pan, did it have that metallic "glimmer"? If it did, that means the fluid is full of suspended metal. That would be bad news, and a sign of impending doom for the transmission.

If the fluid did not have any "glimmer", then there may be hope for it, for a while yet. You could try adding a bottle of that Lucas Trans stop slip and sealer, it's the only product that I would recommend to add to a tranny, other than the factory recommended fluid. I have used it, and it seems to help when the tranny is on it's last leg.

E.D.