Hello all,

I just recently went on a nice two week holiday and discovered a weird transmission problem with my 4R70W.

I have a 2000 F-150 with the 5.4 and a 4R70W.

The first problem occured when I drove up a steep hill (it was soft gravel) in 4WD HI, couldn't make it up any farther and parked the truck, basically the rear hitch was just touching the ground on the back. I left the truck parked for about 20 minutes, then jumped back in expecting to be able to back down no problem and found out the transmission would not go in gear, neither in reverse or drive, it would act like it went in (you would see the RPM dip when first engaging) but when you stepped on the gas you could not feel the truck even trying to move, it was like the transmission was just slipping in 1st. I wasn't real impressed, had to get my buddy in his 99 Chev 1/2 ton to pull me down off the hill, then everything was immediately fine as soon as the truck was level.

The next problem occured when pulling about 3000 lb's up a small incline out of the campsite and the transmission would slip, the motor would rev to about 1500 rpm's or so and then the transmission would engage fairly hard, this too was while moving slowly, this time in 2WD and in 1st gear.

I have since been able to duplicate the problem just by raising the front end of the truck about 3 feet higher than the back, or just so the hitch bairly touches the ground, the transmission will completely let go just like you put it in neutral, and then when you hit around 1500 rpm's will engage hard.

I have checked the transmission fluid, it is slightly over full actually, and does smell slightly burnt, so I am going to change it and the filter in the next day or so.

The weird part is pulling the trailer through the mountains in BC in second and third gear pulling hard the transmission is solid, driving normaly it is solid no problems at all.

Any ideas?

Also I found this sticker on the side of the transmission, any idea what it meant at the time? Do I have some experimental transmission that this problem could be a bug?

http://members.shaw.ca/cgartly/4R70W.jpg

Sticker reads:

US & CANADIAN DEALERS ONLY
2000 4R70W EXCHANGE PROGRAM

PRIOR TO REPAIR
SEE TSB 99-14
PLEASE CALL 1-800-551-0692
VOID AFTER AUGUST 31, 2000

Any ideas?

Thanks,

Chad

 

Sounds like you may be sucking air in the tranny. Either 1)the angle of the pan is too much and the pickup tube is sucking air or 2) The fluid is too low and when you get on an angle etc... 3) The pickup tube is not installed right(very common problem) and you are sucking air or 4) Someone put on a deep tranny pan but is still using a regular pickup tube and sucking air.

Make sure you follow the instructions on measuring tranny fluid level. Most makers are very specific on the procedure, timing and temperature and levelness of the truck.

Why is your hitch almost touching the ground? That is bad for the truck and usually unsafe. You either are overloaded, or have a mechanical problem with the springs or you need a weight distributing hitch. Dragging the trailer can lead to failure(of many things including the tranny) over the long run.

Drop the pan and take a peak at the contents at the bottom. You want to see Red or maybe dark red fluid. Not pink, brown or black. You also should not see a lot(more than one or two) of metal pieces the size of rice or bigger. You also don't want to see a lot of "pepper" flakes, maybe a teaspoon is OK.

You really don't want to smell burnt fluid, that usually means trouble, especially if you also see the other things I mentioned above.

As far as the sticker goes on your tranny, I would guess the tranny has blown up before and your tranny is a replacement.

Good Luck,

Jim Henderson

 

The hitch touching the ground was just in reference to the type of slope the vehicle was on, the front tires in the air until the hitch was dragging up the hill.

The hitch was well above the ground on level ground <g>!

The fluid is a little pink looking I thought, not at all brown though with a slight burnt smell not really bad.

How do you tell if the pickup tube is installed correctly do you have a picture or a diagram?

I also read on a website something about 4R70W being famous for the valve body bolts coming loose, where are these located and what are the torque specs?

Thanks a bunch!

Chad

 

Don't know specifics on your model so I can only make general comments...

The pickup tube often has an O ring that is deep inside the valve body. The tube just pulls out and is replaced with a new tube/filter assembly. Usually you are supplied a new O ring to replace the old one.

Two things often happen... 1) When you remove and replace the old O ring, you damage the new ring or god forbid you munge up the valve body hole. 2) You did not seat the tube into the hole until the tube kind of "snaps" in place. Either cause will create air leaks on the pickup side of the pump.

Alternatively, some pickups are bolted in and if the bolts are not snugged to the proper torque and sometimes with a gasket, you will develop air leaks.

Valve bodies are usually bolted in with several small bolts. They sometimes will vibrate loose. They need to be torqued to spec, look in a shop manual. Typically we are talking inch pounds, I vaguely recall something like 40-50 inch pounds, but like I said this can be different for each model. Most trannies and valve bodies have aluminum parts and aluminum strips way to easy. You might need a thread sealant, check the manual. The shop manual or Haynes or Chiltons should have enough diagrams and pictures to get you there.

The valve body is right inside the pan on the underside of the trann. Most are a bit bigger than your hand spread out flat. They will have what looks like lots of humps and ridges in the metal. These are fluid passages in the valve body. They will also usually have some solenoids and pistons at various places. They are pretty obvious and not much looks like a valve body on the under side of the tranny.

Hope someone with specific experience with your model speaks up. Sorry I don't have any pictures.

Good Luck,

Jim Henderson

 

4R70W transmissions have a seal on the tube at the top of the filter, as others above have said it must fit snugly into the proper opening in the valve body. On 4x4 models there is also a tube on the bottom of the filter that reaches into the bottom of the pan. If the filter is for 4x2 applications it wont reach the bottom of the pan and will suck air on extreme angles.

 

As for the sticker,

That was the Ford mother ship trying to get their techs to run what is called an OASIS to see if there were any TSB's or special service messages(quick fixes) before they stupidly start tearing apart a transmission that may not need it. It does not mean that your transmission has ever been worked on or replaced before.

 

I did the fluid/filter change tonight and found out what the problem was.

The filter had come out of the valve body, the seal was still inside the valve body, so I guess the o-ring seal slipped off the filter, so it must have been sucking air on extreme angles.

Thanks a bunch for all of your advice, what a messy job!

and boy is Mercon V expensive! $5.27 per liter wholesale from Ford in Canada.

Oh also just for everyones information there is a difference between a 2 wheel drive and 4 wheel drive if you have the 4R100, but if you have the 4R70W the filter is the same.