OK, so I know I'll proabably have to pull the tranny to replace the Rear main seal. my question is, Is this a difficult thing to do??? What else is involved? AND if I decide it's too difficult for me, how much will some shmo at Aamco (or any other place on average) want to charge me?

 

Read thru the procedure in a Haynes - it's not technically hard, but it is physically. A transmission is heavy & bulky.

 

I just did this on my 86 F150 302 w/ AOD transmission today. It took me and a friend from work all day (of course, we ran into more than our fair share of problems to deal with). We started at 9am, finished about 1am, with a couple of meal breaks in between. no single aspect of it was particularly difficult to understand or do, but when you add up everything that you have to do, it'll wear you out by the time you finish! Yes, the tranny is bulky, and stabbing it back onto the engine was probably the hardest part of the day. I also spent a lot of time cursing Ford's F-Series engineers back then, because there were several terrible designs that wasted a lot more time and effort than they should have. BUT.....so far the leak at the rear main is gone, so hopefully it will have been worth it! Hope this helps with your decision!

TM

 

You don't state which motor you have. The 460 does not need to have the trans remove for replacement of the rear main seal. Invest the $12 in a Hyanes manual and you will have all the instruction you need. It will be the best $12 you have ever spent on a repair!

Good luck,

Mark

 

sorry it's an ol' 351w

 

I was in a similar situtation years ago. When I first encountered a leaking rear main seal on my 351W (in my 85 F250), I had to pull the manual transmission back, remove the clutch assembly, and then remove the flywheel. After all this and about 2 hours, I had access to the rear main seal. For the original engine in my '85 the rear main seal was a one piece seal. The seal is about $20 at your local FORD parts store.

But it was a different story with the 351W I now have in my pickup. With the older 351W, the rear main seal is a two-piece set up. To replace the rear main seal, in this set up, it did NOT require removal of the transmission. I just dropeed the oil pan a few inches, removed the last main bearing cap and replaced the rear main seal. This took me about 4 hours to do. Just make sure you install the rear main seal in the right direction. If you don't it will leak. Also make sure you replace the oil pan gasket.

Have a good time in the shop.

85FordTruck guy

 

I was headed there too with my 86 460, but after I changed my PCV valve, the oil leak went away. I have suggeested this to several guys and have saved some some big work. You would be surprised how much pressure a bad PCV valve can cause, and from where oil will leak out with a bad valve.

Worth a try first.

 

First, I'd like to say that I'm a new member and that I'm not a mechanic....My truck is a straight 6, 4.9L. I need to replace my rear main seal obviously. I've heard a couple ways to do it, but I need to know how I can get this done by myself. What kind of things will I need to look out for.

 

What year 351w did they go from a 2 piece to a 1 piece seal? I have the 351w HO in a '85 F150, and my seal leaks.

 

If thats the original engine I'm pretty sure its a 1 piece, look it up on autozone,com and look at the pic.

 

according to chilton's 1976-86 manual, the 330-6 and diesel use a one piece, all others use a two piece, after 86 it may be different, but for those years that's what it says.

 

03-11-2003

 

Yea, it's a 1 piece seal. Now I need to read up on it and see how much trouble it is to replace. According to my Chilton book, this is a early summer job.