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Transmission input shaft seal leak after JDM swap

Discussion in 'Gen 3 Prius Technical Discussion' started by Salopeck James, Jan 22, 2023.

  1. Salopeck James

    Salopeck James Junior Member

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    Hello, I swapped in a JDM engine into my wife’s Prius V. After doing so everything went great except a massive trans fluid leak . Pulled engine again and input shaft seal for transmission was destroyed. JDM had clutch dampener already installed . I looked up part number for it and U.S.A. domestic and JDM are same part. I don’t want to replace seal and put engine back in to have it happen again. Any thoughts on why this happened?

    thank you
     
  2. Tombukt2

    Tombukt2 Senior Member

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    Have no idea maybe in Japan or Asia when the engine was pulled out for some reason there might have been some damage or something they saw they didn't like on the old torque plate so they took one they had laying on the ground where they pull all these engines out and they do all this stuff and they just shoved it on there and bolted it up and didn't realize they screwed up the seal when they did that or the seal was just about to go anyway quite rare actually but it does happen so now you're going to remove the dork plate and what have you check the surface of what goes into the seal maybe put a little lube on that surface put the new seal in and said it with a seal setter and a light hammer Make sure it's in straight now offer up to part that goes into that lip seal Make sure it hits the lip properly slides right on and rotates well the part the torque plate. Now see what you got If you wanted to I guess you could possibly have the engine hanging level and slightly overfill the transmission on purpose and leave it sit there and see if anything happens between the torque plate and the back of the engine if your engine hoist and chain setup is proper You have a little crank device that you can crank and make the engine angle backwards or angle towards the right side of the car if you're standing in front of it which will put the transmission lower than the engine if you will making the fluid run all the way back and hit the seal and what's in the seal and see if any drips or anything runs out If not after a while level the engine fix the level of the transmission fluid while it's out and then set the mass back in the car.
     
  3. Salopeck James

    Salopeck James Junior Member

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    My transmission still in car and motor is out , torque plate is on engine still. No way to just slide it on and see .
     

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  4. Tombukt2

    Tombukt2 Senior Member

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    No way to slide just what on and see? If the old seal is leaking between the engine and the plate then you'd think you'd want to replace that lip seal in the back of the engine where the plate mounts I would think. And then to see if it leaks you might could fill the transmission up angle the engine so that the fluid runs toward that lip seal with the plate off you should be able to see the seal and it not leaking spin the crankshaft with your wrench a few times see if anything happens you need to grease that seal around the lip that seals against whatever inserts into it to make the seal and you need to make sure that the flange that's going into the seal is also pretty clean If there's remnants of a groove where the lip seal used to hit you need to polish that really well
     
  5. PriusCamper

    PriusCamper Senior Member

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    I don't have enough direct experience with this one, but the dampener already being installed is concerning... Have you checked with JDM about this yet?

    Probably the answer you don't want to hear is that you need to pull the transmission and match up the engine up with it to figure out what's broke or not compatible while also redoing the damaged seals as well as likely other seals too.

    But first finding someone who's done lots of these to give advice would be wise...
     
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  6. Salopeck James

    Salopeck James Junior Member

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    I found issue .. plastic piece was smashed , probably during shipping and I didn’t notice it.. it was smashed and little tab was out more.. it most likely caught edge of seal . I lightly filed it so it matched the others
     

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  7. Salopeck James

    Salopeck James Junior Member

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    With dampener slid on transmission it was scraping remaining seal .. I filed back in shape and now it doesn’t scrape

    Now I need to make a post about beat way to properly install seal without destroying it! Lol
     
    #7 Salopeck James, Jan 23, 2023
    Last edited by a moderator: Jan 24, 2023
  8. Tombukt2

    Tombukt2 Senior Member

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    I'd have to go look but I would think it would be the same as a flywheel for manual trans It has a little round hollow stub that should fit in to something maybe it doesn't maybe it just has a rear seal on the back of the crankshaft the big one good replace it maybe the torque plate just bolts up to the back of the trans back of the crankshaft just like the flywheel does so all there is back there is the rear main seal that's usually about three and a half inches diameter it's pretty good size it's a lip seal pounds into a aluminum bracket like all other Toyotas no matter automatic or manual or CVT You pull that torque plate off of the back of the crank and you're looking at the rear seal and it's holder. That should be the only thing back there that can leak I don't think there's any other holes or penetrations in that area The oil would have to be running down from the head or valve cover or from spillage which doesn't seem likely in this case.
     
  9. Salopeck James

    Salopeck James Junior Member

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    M leak was definitely from transmission input shaft .. it was red trans fluid and when I removed engine there was a trail from input shaft and the seal front side was destroyed with a small retaining tension spring on the shaft !
     
  10. Tombukt2

    Tombukt2 Senior Member

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    From what I can see on the back of the one NZ it looks like the torque plate should bolt up to the what is it 5 bolts or whatever on the crankshaft so when you undo those bolts and take off the torque plate you should be looking at the back of the crankshaft and the rear main seal which is like a $7 part You knock the old seal or pull it out with a lady slipper or a seal puller tap in the new one preferably with the aluminum bracket off the car and then you want to clean up the black line running around the crankshaft I usually use a roll lock pad on an air grinder the brown one and I gently go around that diameter and clean that black line off The new lip seal some of them actually the rubber lip that grabs the crankshaft will be moved in oh I can eighth of an inch to try and miss the original spot where the original seal ran round and round but I still clean it up
     
  11. Salopeck James

    Salopeck James Junior Member

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    transmission input shaft seal … not rear main .. the seal seats in the center of shaft . I don’t know if oute edge seats fully .. I don’t want to tap in place and bust out the center from the shaft .. a 1” deepwell socket fits outside edge but no contact support in center .. I was thinking a 1” washer with a big enough hole in center to clear input shaft . See photos


     

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  12. Salopeck James

    Salopeck James Junior Member

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    Backside of seal
     

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  13. black_jmyntrn

    black_jmyntrn Senior Member

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    if anyone wants a lightened flywheel let me know! got them on deck!