Hello everyone. I'm new to the forums. I've recently gotten myself into fixing up a 77 highboy (F26SR029927). Being somewhat mechanically inclined, but never really having worked on cars much, I thought I'd start easy and one of the first things I did was give it an oil change.

I bought some 10w40 and drained the goo that had been in there for who knows how long. I had purchased a new drain plug bolt thinking with so many things to do to the truck why not put in new when I can. The bolt I got was a standard one with the light blue plastic washer. The threads didn't fit exactly and that's when I realized that the plug that was in the truck was a self-tapping oversized type. You could still see some brownish gunk on the threads that I assume was some kind of sealant.

So I went and picked up a different new plug bolt with the same thread size. This bold snugged up tight to the 20-25lbs torque the Haynes book says but I was still getting a pretty steady leak.

I read around a bit and it seemed like metal washers are preferred, so I went and got one of those and some more oil… I'm sure it was happy with an oil flush anyway!

I put back in the original plug bolt and the new metal washer and that seemed to get me the best seal, but the truck still leaks. A lot.

The good news is that the engine starts much easier, the truck shakes less -- all in all the engine seems a lot happier with fresh oil. The bad news is that it is leaking profusely. Obviously a faster leak when it's hot and then it slows down to a slow drip when it's been sitting. I'm afraid by draining out the old sludge I've doomed myself to buying a new oil pan.

I've read that you have to undo the motor mounts and lift the 400 up to swap in a new pan. Is that true?

I'm also having a tough time finding a new pan on the internet. If you have to start pulling the engine to get to the pan, the junkyard doesn't seem like a viable option.

I've found this:
Milodon Oil Pan 351M - 400-Broncograveyard.com

The Milodon site says to use part # 30520
Milodon 4 x 4 Truck and Offroad Oil Pans

I can only find the front sump version on RockAuto.com and LMC.

Here's a picture of the old beast: First project vehicle - Ford Truck Enthusiasts Forums

Thanks for any advice!

 

If it has a rear sump oil pan on it now, then you need to go back with a rear sump. Other wise the oil pick up tube will need to be changed and then maybe a possible hitting of the pumpkin on the front sump part....

As far as the leaking pan plug, if you stripped the current threads, you can and will need to retap up a size and then use a new matching pan plug size wise to the tap.

That Mildon pan is a aftermarket, large sump, increased capacity, more for high performance eng oil pan. Look for a stock pan, maybe Tmeyer inc.

http://www.tmeyerinc.com/

 

Just weld the nut on it'll be fine

 

Thanks for the reply! I don't think I stripped the bolt. It wasn't in very tight when I first removed it and I never felt like I was cross threading anything and it does tighten up. But who knows…

Maybe I should take away the washer? There was no washer between the plug and the pan from the previous owner.

If the pan has already been tapped out to a larger size by the previous owner, can I do it again? Should I?

Tmeyer has this Oil Pan but it doesn't really look like what's on the truck now. The "belly" of the pan is towards the rear right before the transmission and the drain plug is right above where the stock exhaust pipe makes its way across the width of the truck left/right.

 

there are no aftermarket pan options as OEM 4x4 replacement for 351M or 400.

You will need to source one from a JY or buy the $350 Milodon one with matching pickup.

 

If it is not stripped, try it with NO washer as the Po had it and if that does not work maybe try a copper crush washer?

 

After you weld the nut on you might as well weld the bolt to it too otherwise it could leak

 

Thanks for the confirmation on the (lack of) availability somethingclever.

I will try without a the washer and see what happens. Certainly a lot easier than replacing the pan.

Do you guys know the steps to remove/replace the pan? Is it true that you have to lift the engine?

Willz74 I was assuming you were joking, but now you've come back so I'll bite and say I don't understand how welding the drain plug to the pan would help.

Thanks again for the advice everyone.

 

The first one wasn't a joke the second one was

 

If you use a tapered pipe plug and white Teflon paste it won't leak

 

Just pull the pan and buy 1 of these.
NAPA AUTO PARTS

 

I would certainly pursue the advice given on how to stop your leak without pulling the oil pan, but if those methods fail, here is what the manual says for pan removal.
It doesn't mention the size of the wood blocks to shim the mounts with on the 400, but for the 460, blocks of 1 1/4 inches are specified.





David

 

You could go to a +2 oversize drain plug if you suspect the threads.

Mysef, I stopped using plastic or aluminum drain plug sealing washers ...... I use the kind that has the O-ring molded inside a metal outer .... the O-ring seals, the metal limits compression of the rubber so it doesn't get torn.

On my '77 F150 there is no cross member under the pan, I just raised the truck and dropped the track bar and pulled the dip stick and dropped the pan when I did bearings and oil pump years ago. I don't recall taking the starter loose but I did undo the batter connection at negative side. That was 1992, it's still hanging together with good oil pressure.

If I dropped the pan, I'ld get a new nut welded in place unls the pan is eat up with rust ..... even then, I'ld fix it.

 

Wow rougeriver that is outstanding! Thank you so much for sharing those pages from the service manual.

I will definitely try some of the non invasive solutions first. I thought there was risk of teflon or some other sealant getting into the engine which is why it was discouraged? Maybe the rubber/metal combo washer that tbear853 suggests is the hot ticket. I think I may try that first.

Thank you to everyone for the good ideas (I need to start a new thread about my steering column woes with such a positive response as this).