I have a 2000 F150, 5.4, 4x4, auto with the 4R70W trans. It has 76.5K on the clock. I've been using a Superchips Microtuner 1715 on the 87 tune since about 62000 miles. A while ago I noticed that the trans would squeak a little when the torque converter (TC) locked up. Then it got to be sometimes when it shifted into 3rd. I changed the filter and fluid with new Motorcraft Mercon V about 800-1000 miles ago. It's filled to the correct level.

I just got back from a trip where I was towing 2 quads (~600lbs each) on a 12x6 single axle trailer (1200lbs tops?). So that's like 2400lbs. The terrain was some rolling hills, 70-75MPH. It usually didn't even have to shift out of OD, or I would have locked it out. The whole way it was squeaking during the 3-4-TC lock up. After the TC had locked, it would intermittenly squeak. More power made it squeak a little more.

The funny thing is that it didn't really behave like a trans slip. RPM didn't change, MPG was better than ever, and ECU shows no codes. I'm kind of lost as the only symptom is the sound.

I had my buddy tow the trailer home with 1 of the ATVs. I still had mine in the bed. It did squeak a little less, but it still did it plenty.

Mike


Edit: There is also no shudder or vibration with this. Just the noise.

 

Is Mercon V approved for use with your transmission?

Have you checked your transmission mounts?

Steve

 

If your truck has a limited slip differential, it may be due for LS additive to freshen up the clutch packs.

 

I thought the 5.4 liter engines had the 4R100 transmission. That's the tranny my 5.4 liter 1999 expedition had. The 4R100 uses Mercon, not Mercon V. They are not interchangable.

 

My `02 F150 KR 4x2 with a 5.4L has a 4R70W. Checked the door tag just the last week. Mercon V for the 4R70W and Mercon for the 4R100.

 

Just thought I'd add that my 1999 Expedition was a 4x4. Maybe that explains the 4R100? I don't know.

 

It's definitely a 4R70W. Trans code on the door sticker is U. AFAIK, the 4R70W is the most common F150 trans regardless of engine size.

I don't think that it's a mount problem as it's more of a mechanical squeak and it's kind of drawn out over about a second. It's not what a body or mounting bushing squeak sounds like.

It's definitely coming from the tranny area, not the diffs. I just serviced them and they are fine.

Is Motorcraft Mercon V any good? I figured that it would be being that it is Motorcraft. Are there any additives that I can add to it?

The mystery is that other than the sound, there is really no apparent problem. It shifts fine, does not rev like a slipping trans, doesn't throw a code, doesn't puke fluid, etc. It just makes this friggin sound.

Mike

 

Yeah i had the same prob with my 4r70w and the squeak got worse... i had the fluid changed and flushed... i changed the filter... i changed the solenoids inside... Then the OD light was blinking and the stupid thing i replaced it... not cheap!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! 1505.20 plus tax (that was a rebuilt swap) and the best thing you can do is to get a programmer and firm up the tranny when u get a new one (as told by the people that did my tranny) Anyway hope this helps
Marshall

 

At least someone else has had the same problem. Unloaded it hardly ever does it and even with the bed full of wood it didn't all day.

I'm going to be in a better position to buy a new truck next year so I hope it can hold out till then. Next truck is definitely going to be a 350 Diesel, 6speed, CrewCab, longbed, 4x4.

I'm sick of wanting more power, more room, and more reliability.

Mike

Edit: Was that 1500 installed? That's not really that bad.

 

no, that was not installed but just my luck i have a buddy whose dad was a ford tech/mechanic whatever they are called for 20 years and had a car lift in his garage the old tranny was out and the new one was in within 2 hours and damn its like a new truck again lol
marshall

 

I did a little search and some saw some threads on shuddering 4R70Ws. They said that tightening the valve body bolts cured the 3-4 shudder. Maybe this would help me as well. Does anyone know the torque specs for the valve body?

I'm also going to add some Lubegard to the trans. Is there a specific Lubegard that works with Mercon V, or is it universal. I know that additives are basicly a bandaid, but that's pretty much what I'm looking for if I have to.

Mike