Name this part

[Hagen]

Hello! This part right here has given me some trouble. I was told this was a timing cover seal, yet the 2 that I've purchase that say fit absolutely do not! Before I order a 3rd whatIthinkitispart, will one of yall give it a shot please name the darn thing. Very green to the scene, first rebuild. It didn't look like this when I started pulling it out from around the crankshaft on the timing cover.

Thanks
63 305

[AZKen]

The guessing game is not the answer.
1. Where did you get this chewed up seal? Does it come close to fitting the timing cover?
2. What are the numbers on it? I see the word National. It WILL have a number.
3. What is the ID, OD, height? I have those dimensions but don't want to influence your measuring.
4. What part numbers did you order, from what vendor?

If you answer these question we will tell you what to buy...IF YOU NEED A TIMING COVER SEAL........ That's what it's called.

Rockauto and other vendors do mix up GMC part numbers. They give straight 6 and Chevy 305 V8 parts. ALWAYS buy from a place near you, if you can (no ship), and ALWAYS buy where returns are accepted when buying 60-66 parts. ALWAYS ask here first and check the search function. Jolly's legacy page has a "Known Good Parts" section. No one knows anything anymore about these motors but us. Parts guys just wing it.
CLICK

[Hagen]

Thanks for the response!
1)This seal came from behind the dampener? That sits in the end of the crank. It was flush with the timing cover.
2) I think I chewed the numbers. Don't see them.
3) with the way it is right now with no rubber inside the inner diameter is 2 and 1/2 in. The outer diameter is 3 and 1/4 in. 1/2 in. Height
4) Rock auto and partsgeek 9845 national , CR 17286

I have seen that thread before that you linked. Sadly those are no longer available after 2 clicks. I will be doing a deep dive into the site more tomorrow! Great stuff

Hagen

[James]

The attachments is a picture of the front crankshaft seal from a spare engine timing cover and a page from Mahle current catalog.

I also found the following web site that has some infomation on the seals (need to measure you seal dimensions to verify):

https://www.fleetpride.com/parts/nat...Z000001mKuzYAE

The seal above is sold on Amazon: https://www.amazon.com/National-4132.../dp/B002EP64I6

https://www.oil-seal-stocks.com/oil-...specifications

I hope this is helpful for you.

[Hagen]

Yes that's it on the timing cover. I'm unsure what to do with the catalog info.
This is amazing! I've ordered the seal from Amazon. My local didn't have it in stock.
The only markings I can see in my seal is National and PAT. I don't even see numbers in the chewed up section.

[OlsonsGaskets]

The National part number is almost certainly 450574. This seal is for a 2-3/8" shaft size and a 3-1/4" housing. It is 1/2" thick. I don't believe this seal is available anymore however I have National #480574 seals on hand. Same size as the one you pulled out just slightly different construction. I make the timing cover gaskets too. I'm not sure what you were able to get through Amazon, but I regularly stock all engine gaskets for this motor.
Richard

[AZKen]

CLICK

I shy away from NOS or "not available anymore" parts with rubber/nitrile/whatever....they will be brittleized, or softened or outgased or too old/too risky to seal.

[Hagen]

I've ordered the one off Amazon James suggested and Off Ebay from AZKen. Will update to see which one (or both) of these whatyallthinkitis fits or doesn't!

[Hagen]

Update: The seal from Amazon ( National 413246 ) looks to be the same size all but for the width. Part of me thinks its unusable but I'll leave that to you pros. The original is roughly just under a half inch (.468 inch). The new National is .375 inch. Is this completely fine?

[James]

Originally Posted by Hagen

Update: The seal from Amazon ( National 413246 ) looks to be the same size all but for the width. Part of me thinks its unusable but I'll leave that to you pros. The original is roughly just under a half inch (.468 inch). The new National is .375 inch. Is this completely fine?

I don't believe the thickness of the seal will have any effects on sealing. As long as the OD and ID is correct it should work, that is where the sealing need to be. Install the seal flush with the front of the timing cover and install the cover. Be sure to Scotch-Brite the hub sealing surface and coat it with oil before installation.