Hi,

I am new to "f150online" I own a 99 f150 4x4 with a 5.4L, I was just wondering how hard it would be to change a rear main seal in one of these trucks. Would you need to pull out the motor and change it ? Or is there another trick too it, With out having to go to the shop and pay a pretty penny of 1,200 bucks

I have tons of tools and a garage, just not much knowledge of the 5.4L motor

Thanks for your reading and your input, Wes

 

My experiance has been when those kind of seals start to go or the engine is on its last leg. You have to remove the tranny to replace that seal. How many miles are on your engine?

 

there is 381,562kms on it 1 owner my rents had it since bran new and gave it to me at 351,000 the seal went at 230,000 roughly and its jus starting to get worse, so im tryin to do somthing about it now

 

Almost 237,000 miles, that is some serious miles. If the truck runs great otherwise and the body is in good shape, it is worth the money. Sorry I can't advise you on the seal replacement. How much oil are you going through at this point.

 

The seal could just be dry. I've replaced one on a S10 Blazer which only had 83K on it. They'll crack when they dry out, or just from being worn away by heat. Sure thats a lot of miles, but whos to say that a maintained engine wont last that long?
As for my experience, given this is a different type of vehicle, it wasn't as hard as I planned. Removed a couple of support bars, and an idler arm, dropped the oil pan (nothing was in the way of it after removing a couple supports, and it was elevated above everything else, so axels or anything along those lines weren't a problem. As soon as it was dropped, took off the bolts furthest to the back of the crank shaft, attached to the Rear Main cap, and half of the seal came out. As for the other half, I just grabbed it with needle nose pliers. If you do decide to do this on your own, be careful when you put the upper part of the seal in. If your not careful, while sliding it in, the walls are sharp enough to shave the seal. I've heard of other people having to drop the transmission, I never had to touch it. But every vehicle differs. The seal should be dry when putting it back in, and while your putting it in the bearing cap.

 

the truck runs awesome and the body is in great shape its just got high kms, mostly highway. roughly about 500 kms to half a quart. it isnt a bad leak but its slowly getting there

 

Rear mains in newer fords are on the back of the crank. You HAVE to remove the tranny to access it. Again my experience has been this is an INDICATION of main bearing wear. A new seal will likely fail in a short time.
I would factor that in to any decision about repairing it.

 

Hespen- Most all rear main seals are 1 piece seals now. They are much more effective and long lasting than the 2 piece seals. Yep, the tranny has to come out, no other way to replace a 1 piece seal.

 

If my calculations are correct, that is a 1/2 quart every time you fill up + a little @ 310miles.
That's going through some serious oil. Time for a change IMO. Check around for some different quotes from some recommended shops, unless you feel confident you can tackle this on your own.

 

Yup,

Pull tranny back about a foot and a half. Remove torque converter and flexplate. Remove the seal retainer and remove the seal from the retainer. Install new seal and reinstall the cover. You have to clean off the sealer off the engine and the retainer and reseal it with silicone. That is not quite how the book says to do it but I didn't have the puller and installer so I pounded the old seal out with a hammer and flat screwdriver and pounded it back in using as 2x4 laid flat. Be very careful when installing the retainer as it holds the seal and it has to slide over the crankshaft and line up correctly for the 6 bolts to line up. Be sure to notice how deep the seal is installed before you remove it from the retainer so you can seat the new seal at the same depth.

EDIT
If you don't do it this way you have to remove the tranny in order to make room to swing the hammer to pound the seal back in to the retainer that was left attached to the engine.