Rear Main Seal on F150 4x4 mfg 3/1983 in Canada

Trying to determine whether it is split rear main seal or one piece before  the disassembly begins while on the truck.  I just finished overhauling the valves and heads (due to a blown head gasket between cylinder 7 and 8) . Now that it is all back together the rear main seal is really leaking heavily now. Runs great if it wasn't for the oil seal.  The truck sat for about 2 months while I had the heads out for machining and valve job.  

Any advice to find the motor information before  trying to get oil pan out or drop the transmission or a better direction to go.  Don't want to pull the engine now that I have it all back together.

Thanks,

Mike

P.S. Saw this in the forum (question is the mfg date Before or After the nameplate on the drivers side?  which is 3/83 mfg in Canada on this F150 4x4

81/83 F100/250,U150 "Before 12/1/82" 1 *E1AZ 6009-A N.R. use details

83/84 E-F100/250.U150 "From 12/1/82" 1 * E3AZ 6009-A One piece crankshaft seal-N.R. use details

mikemcmahon wrote

Saw this in the forum (question is the mfg date Before or After the nameplate on the drivers side?  which is 3/83 mfg in Canada on this F150 4x4

81/83 F100/250,U150 "Before 12/1/82" 1 *E1AZ 6009-A N.R. use details

83/84 E-F100/250.U150 "From 12/1/82" 1 * E3AZ 6009-A One piece crankshaft seal-N.R. use details

Mike,

As you've found out, the 302 can be a real can of worms when you start working on them. If the info you pasted above is the changeover date for the 2pc to 1pc rear main seal, then you should have the 1pc seal. Gary may have to confirm from the parts book, but that sounds about right as I know the seal changed later in 1982.

Your truck was built in March of 1983, and the 1pc seal should be in all 302 blocks after Dec 1st 1982.

So the good news is that you should have a 1pc rear main seal. Bad news is that you can't change it by only dropping the oil pan.

Thanks for verifying, now for the hard part replacing it.

 Any words of wisdom from a sage who probably knows some tricks for one to do this with no car lift....just jacks and car ramps....Do I need to purchase a transmission lift?  Or is it best to pull the engine and disconnect all the ancillary items, power steering, alternator, air pump, ac and drain the coolant?
Thoughts?



Thanks

Mike

mikemcmahon wrote

Thanks for verifying, now for the hard part replacing it.

 Any words of wisdom from a sage who probably knows some tricks for one to do this with no car lift....just jacks and car ramps....Do I need to purchase a transmission lift?



Thanks

Mike

Well, when it comes to the 302, I don't know if anything is ever 100% verified, but an '83 built in '83 should have a 1pc rear main seal. I'd hate to be the guy to steer you wrong, but that's what it should have if the engine is original.

I've done several transmission swaps in my little home garage with no lift, and is usually not fun lol. Maybe I worded that wrong, but I don't have as much enthusiasm as I used to, and I'm definitely not as strong as I used to be lol.

I have one of these transmission jacks:

https://www.harborfreight.com/automotive/jacks-jack-stands/transmission-jacks/800-lb-low-lift-transmission-jack-60234.html

It works great...except once the transmission is on it, it's then too tall to roll in or out from under the truck while on stands (mine was a 2wd, so with a 4x4 you may have enough room). The bellhousing you can roll under the body through a wheel opening if it happens to not be removeable like with an automatic.

If you don't need to take the trans out from under the truck, you can just leave it on the jack and roll it backwards out of the way.

You can use a regular trolley jack in place of a transmission jack, but it's hard to balance the transmission on there. If money is tight, buy the transmission jack, and then sell it on Craigslist when you're done and you'll get at least 50% of your money back.

One time I built a little wood frame inside the cab of the truck and then lifted the transmission with a pair of ratchet straps through the opening in the floor. I then used the jack to roll it forward and attach it to the engine.

I don't know if that's any help or not, but that's what I've done.

I guess you could always pull the engine...sometimes that's the lesser of the two evils.

That jack looks like a fair (for Chinese) copy of my Walker one.

a little bit of caution. im aware of a couple things from what you have already said. how many miles are on this engine?? you had a blown head gasket. how much did the crankcase get contaminated?? im going somewhere with this. many times, i have seen a worn set of main bearings get finished off by bad oil or contaminated oil and once they are sloppy they over work the rear main seal. meaning that it may be telling you something! please do not assume the bottom end is sound because you dont hear knocking when knocking is usually a rod bearing issue. test your oil pressure cold and hot and really see if its losing oil through loose mains before you proceed. a good direction is far better than backtracking even if it means more up front investment.  

When the head gasket blew it was between cylinder 7 and 8, resulting in loss of compression but no contamination of coolant in the oil.   The miles are not fully known since the odometer reads 80,000, assume at least been around once.   You are right to point out that there could be significant wear, especially since the valves had to be replaced.  

I'll get a oil pressure gauge and see how the pressure looks..thanks again for the input..

Oil pressure checked out find...Pulled the engine and this what I saw.  Oil in the transmission housing..see below

One Piece Rear Seal

Repair sleeve on crankshaft.   ?? Should you use this if there is no scoring on the crankshaft?   The old rear seal seemed very loose.....able to pop out with pick easily...

What is the measurement for the crankshaft ID and the housing ID....??

Thanks in advance for feedback..

Mike - You tagged me, apparently looking for help.  But I had to read back through your thread to even find out what engine we are talking about.  In cases like this where I can't easily determine from someone's signature what the engine and year are I usually move on as I don't have the time to read whole threads just to find the necessary info.

Having said that, it looks like you have a 1983 302.  As Cory said that should have a one-piece seal.  And if a crank isn't scored it would be unusual to run a repair sleeve.

As for the specifications, you can find them in the factory shop manual section on those engines at Documentation/Engines/Windsor and then the Windsor Instructions tab.  You may have to wait a bit for it to fully download as it is a 46 page document and the specifications are at the end.

Matt,

 Question: I replaced the rear main seal and it is still leaking on the Ford 302.   The oil pressure reading seemed fine.  Questioning whether the crank bearings are worn.   Can you replace the crank bearings without removing the crank shaft?  Can one bearing cause the seal to leak?

Any advice would help..

Thanks,

actually, this was the point of the caution. i guess you could do it while you have the engine upside down on the stand, but you would be at the point of loosening the crank from its position and working it up out of the block and then removing the upper bearings then matching the cap side halves up. this is also when you would be able to inspect the crank itself. there is a real reason for doing this. it is to avoid the entire upper part of the engine rebuild. it may be a fair compromise to a rebuild since it seems that the upper half has been done already. but it leaves the cam, pistons, and timing chain to be addressed. scratch that... the timing chain WILL be off to do the bearings so pretty soon you will have an almost rebuilt engine. but to do those last couple bits you will have to do all of this all over again. I HATE DO OVERS!!

Question:  why if the bearings are worn or the crankshaft....does it show up in the rear seal area and not also in the front seal area?  Is the torque converter more apt to cause more movement in the rear seal than the harmonic balancer on the front of the engine with the belts?  Just trying to understand better..

there are a couple of idiosyncrasies. the simplest difference to explain would be that the rear main seal has pressure on it while the front main has the gap between it and the front cover. they both have fluid pressure yet the front has the crank timing gear to sling it away and some also have a slinger between the gear and the front seal. this keeps pressure from the front seal along with some small differences like the fact that the engine slants towards the back. these two things make the rear more likely to leak first

let me add one thing that I have seen overlooked more than once. on the 5.0 the flex plate/ flywheel bolts are drilled through to the crankcase and require a good cleaning and thread "sealer". many leak a bit through the bolts especially if the pcv  system is not keeping the crankcase pressure in check.