350 rubber front crank seals

Discussion in 'Small Block Tech' started by UNDERDOG350, Sep 3, 2019.

  1. UNDERDOG350

    UNDERDOG350 350 Buick purestock racer

    To see which current offering is best I purchased 4 brands listed for a 73 350 on Rockauto. These are supposed to be rubber replacements for the OE rope seal.

    First off is National. The OD is too large to fit into the timing cover. Not sure what application it would actually fit. Made in Vietnam


    Next is Timken. Same dimensions as the National seal. Also does not fit. Made in Taiwan.


    Next is Fel Pro. PN 15200. Will fit the timing cover. Is rubber on the OD. Package says made in USA. Mexico is molded into the seal???


    Last is Mahle. 65025SF. This is a metal OD seal that may need a little sealant. It came with a very detailed instruction sheet. Made in Taiwan.


    All of these are meant to be installed from the inside of the cover. The first 2 may be for newer style covers that install from the front but I didn't have one handy to check. I have not installed the Mahle yet but have used the Fel Pro in the past with good results. Pricing is similar for all 4 at around $5.
    patwhac, Skylark-72, MrSony and 2 others like this.
  2. Dr. Roger

    Dr. Roger Stock enthusiast

    So I went through 4 or 5 of these... parts places would say they fit, but they weren't close. Finally got one that actually fit, then it lasted only a few months before it started to leak. Of all the parts I got for rebuilding the engine, the front seal was the biggest pain in the butt to get correct.
  3. patwhac

    patwhac Well-Known Member

    It seems like the TA neoprene piece would be worth it then?
    Dano likes this.
  4. Max Damage

    Max Damage I'm Working on it!

    Maybe so. I have definitely found that some of the stuff out there is pure garbage.

    The seal I used in my 350 came form my local autoparts store, and was a metal surround with neoprene insert and a spring surrounding the crank.

    It was very tight, but I was able to drive into the inside of the timing case using a block of wood and a hammer.

    No leaks. Guess I was lucky.
    patwhac likes this.
  5. Mart

    Mart Gold level member

    No, no luck.... it was the right o.d. dim's and it fit properly.
    Max Damage likes this.
  6. telriv

    telriv Founders Club Member

    Many times no sealant is put on the OD of the seal if it's metal. Also if the harmonic balancer hub is slightly worn it will leak. Time for a Redi-Sleeve.
    Max Damage likes this.
  7. Skylark-72

    Skylark-72 1972 Skylark Custom Convertible

    I installed the Fel-Pro 15200 for my 350, it seems to fit but there is a small gap in the front area on the timing cover where it doesn't touch. Should it be flush to the front? i havent fully put motor back together yet, i also have the mahle gasket as well.

    Attached Files:

  8. Max Damage

    Max Damage I'm Working on it!

    It should fit so that the flat flanged bit is flush with the inside of the case?

    Mine had a metal surround that was flanged on the rear edge(facing the carb)? Is your the same?

    it looks like yours might be all plastic?

    Did you remove the old staked in rope seal retainer?
  9. Skylark-72

    Skylark-72 1972 Skylark Custom Convertible

    mine was metal covered in rubber, it is flush on the inside of the case. there is a small gap in the front area facing the fan. i assume this might be for movement with the crankshaft and harmonic balancer. here is photo of inside crank case seal and one outside looking in.

    Attached Files:

  10. Max Damage

    Max Damage I'm Working on it!

    As long as it's all the way in (flush on the inside all the way around), I think you are good.

    FYI I just realized you had a lot of pretty pictures of all those seals at the top! Thanks for doing that. I think the one I used is most like the Mahle.
    Skylark-72 likes this.
  11. Skylark-72

    Skylark-72 1972 Skylark Custom Convertible

    ahh those at the top arent mine but i have the two lower ones. the mahle and fel pro nearly identical so similar and the fel pro seems to the type of gasket that i get from TA so i just used that one. the fel-pro had the gasket with the spring inside like the mahle.
  12. Mark Demko

    Mark Demko Well-Known Member

    Bob H.[/QUOTE]
    Your install is fine, as long as it was driven in all the way from the rear and seated flush on the inside flange of the timing cover.
    Skylark-72 likes this.

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