Oldssupreme

I know this is an old thread but great instructions for the installation of the neoprene rear main seal. I wanted to ask if there is currently one specifically for an 72 Olds 350 or if is still need to ask for the ford 460 seal? I have been unable to find one- i only see the rope one. Eric had told me that I can install the neoprene one with the crank loosened a bit.

Oldsmaniac

I believe the small block uses a Ford 292 seal not the 460.

MDchanic

Yes, the big blocks have 3" main bearings, and so need the larger 460 Lima block seal.

The small blocks use the F_rd Y-block seal.

- Eric

Oldssupreme

Thank you. Any particular year I that ford 260?

joe_padavano

The Y-block is a 292, not the 260 Ford. Also the AMC 258 neoprene seal works as well.

Oldssupreme

Ok. What years ford 292 or amc?

joe_padavano

One more time, it's NOT a "Ford 260"...

If you go to Google and type in ford 292 rear main seal, you'll get them.

MDchanic

ANY F_rd 292. They all used the same seal.

As noted in this thread:

Rear Main Seal -- BS6141 -- Small Block Neoprene Ford Type (Y-Block 239, 256, 272, 292)
Rear Main Seal -- BS13879 -- Small Block Neoprene AMC / Jeep Type (196, 199, 232, 258)

- Eric

joe_padavano

Considering that the old thread was for a BBO, I moved these posts to the SBO forum.

olds 307 and 403

I have used the AMC seal in an Olds 350 and an Olds 403 without issue. It is a nice tight fit, once the ears are trimmed off.

coppercutlass

Are the rope seals really that bad. i have never had one leak in the 10 plus years i have been messing with small block olds.

Oldsmaniac

Ease of installation has it all over the rope seal.

olds 307 and 403

Don't forget ease of removal for a running motor that you are not pulling out the crank.

Oldssupreme

Great! Thanks for all the Info. I'll be tackling this next week so I'm going to buy this seal tomorrow and get this baby buttoned back up. I believe you guys pointed me to a thread of how to remove the rope and install the neoprene seal with the crank installed correct? Thanks again!
Chris

olds 307 and 403

It is a challenge but can be done, good luck.

Oldssupreme

Just to make sure here are two links to 6141 and 13879. Just want to make sure they look right. The 6141 is actually listed as a small block olds 64-90.
http://m.ebay.com/itm/FelPro-BS6141-Rear-Main-Seal-Oldsmobile-Small-Block-307-330-350-403-1964-1990-/191656373571?hash=item2c9f9c2d43%3Ag%3A5aUAAOSwLVZ VxRT6&_trkparms=pageci%253A86878a74-542d-11e6-8c99-74dbd1806314%257Cparentrq%253A2dc23a431560a357c0fe 6d66fffc75cb%257Ciid%253A1 and
http://m.ebay.com/itm/Fel-Pro-BS-13879-Engine-Rear-Main-Bearing-Gasket-Set-Rear-Main-Seal-Set-/361320633518?hash=item54206354ae%3Ag%3ALl4AAOSwl8N VfSAt&_trkparms=pageci%253Ac10adc3e-542b-11e6-abac-74dbd1e0600d%257Cparentrq%253A2db69e4c1560a2abd3f8 bddefffc8466%257Ciid%253A1

joe_padavano

Yeah, but it really is the Ford Y-block seal. Those straight pieces seal the sides of the rear main cap on the Ford motor, since it's a deep skirt block design. The Olds doesn't use them.

Oldssupreme

Thanks Joe!

Oldssupreme

Ok. My seals should be coming in the mail tomorrow. If I'm doing this with the crank in place do I have to remove the oil pump to "lift" the crank to remove and replace with the neoprene seal? Anyone have any pics of doing this with the crank in? Also I've seen discussion about having the seams of the upper and lower seal meet in the block instead of horizontally. Thoughts?

MDchanic

The oil pump is attached to the rear main bearing cap, so, yes, it has to come out.

And, Yes, you have to offset the seams of the seal slightly from the block's machined surface.

- Eric

Oldssupreme

Thanks Eric. Is there a specific way that the oil pump and it's drive gear needs to be installed?

MDchanic

No. It just attaches pretty easily.

And there is NO GASKET.

- Eric

Oldssupreme

Ok. So no gasket. I didn't know that. Thank you.
Also does anyone have a photo or diagram of exactly where the "ears" should be cut off of the amc seal? Thanks!

Oldssupreme

So i removed the oil pump and rear main cap, turned the engine rightside up again in hopes that the crank would drop enough for me to remove the rope seal and install the neoprene but the crank didn't Appear to move at all. Thoughts?

MDchanic

Did you loosen all of the other caps?

- Eric

joe_padavano

Even after loosening all the caps, you still need to push or pull the pistons down in the bores to move the crank. Friction will make this difficult.

Oldssupreme

No i didn't loosen the others. I was a little worried about doing that that I would miss align the crank. I'll do that and see how that works.
Thanks

MDchanic

I seem to recall that I use one or two long pry bars on appropriate surfaces to get the crank up the required distance in a gently and controlled manner.

- Eric

MDchanic

You can't misalign the crank because the #3 bearing is a thrust bearing.

That being said, be nice and be gentle - don't gum up the bearings.

- Eric

Oldssupreme

What would be an appropriate surface to use to pry? And just to make sure I DO want the engine to be rightside up correct?

MDchanic

I think you can get decent leverage and control by lifting at the flexplate flange and/or at the flexplate bolts.

It will be easier to work looking down at the engine than looking up at it.

- Eric

distributorguy

You can try to pound the rope seal in its groove, but be 110% careful not to hit anything in the process. Then grab the exposed end with a pliers and pull it out. Installation is similar, but I like to "jog" the seal ends so they don't line up 100% with the main cap parting line. Generously lube the crank contact area of the seal with engine oil.

MDchanic

I had no problem pulling out the rope seal with long, fine needlenose pliers, with the crank in place.
I just reached in and started pulling, and it all came out after a few tries.
There is also a special barbed wire tool made for this.

You can practice "rotating" the neoprene seal into the groove on the main bearing side before you do it on the block side.

- Eric

Oldssupreme

So I loosened all the main caps. The bolts were loose but I could not loosen the caps with the gentle pressure I was applying with a large pry bar between the flex plate mounting piece and the engine stand. I'm wondering if i should jut replace replace the 1/2 on the main cap and leave the block seal? I'm not one to do things halfa** but I don't know if I'm going to really mess something up...

MDchanic

Yeah - you kind of have to whack the caps with a hammer to get them off.

A plastic hammer or wooden mallet is recommended, but I haven't heard of anyone damaging anything with a few civilized taps from a ball pein.

- Eric

Oldssupreme

And I'm not going to damage the bearings by removing the caps? Thanks guys!

distributorguy

Only if you get dirt and dust on them before reinstall. They need to be surgically clean and well oiled at install.

MDchanic

I should clarify that you tap the corners of the bearing caps from side to side, with diagonal blows that go in toward the center of the crank, and upward, away from the block.

You don't tap in a front-to-back axis.

- Eric

Oldssupreme

Eric and distribute guy, thanks so much. This is all new to me as I have never been this far Into this engine before. Your help is much appreciated!

Chris