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Oil Filter Housing Over Torquing Nightmare

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by geeter, Jun 24, 2011.

  1. Mendel Leisk

    Mendel Leisk Senior Member

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    Ok.

    We went to an "Open House" for new owners, and they did a demo oil change. I noticed the mechanic used a torque wrench when installing the filter, I would assume using the proper torque specification (though I wouldn't count on it). It was some sort of Toyota minivan (their courtesy vehicle) on the lift, but had similar bare filter and reusable housing.

    In your case it could have been some green mechanic's mistake. If the dealership had been doing the next oil change, they would have encountered the same issue. Doesn't dismiss it, shouldn't have happened, though.
     
  2. tumbleweed

    tumbleweed Senior Member

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    I agree, the Prius Technician is unlikely to be the person who changes your oil. The kid in the lube bay probably works for minimum wage and has no training. He may have been flipping burgers at Mickey D's the week before.
     
  3. rudiger

    rudiger Active Member

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    I'm having the same problem getting my oil filter housing off. Turns out the 'free' maintenance oil changes aren't so great after all.

    I wonder if the morons who put the housing back on are torqing it down so tight that they actually put another revolution on the housing to get it past the tang. That would easily explain why they've managed to get them on so tightly that it can't be budged under normal circumstances.
     
  4. Mendel Leisk

    Mendel Leisk Senior Member

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    The instructions, both on the oil filter box and repair manual, have a half-baked instruction showing a 90 degree symbol between something on the cap and something else. I think this is supposed to be the starting position, when you place the cap back on. And the intent is to end up with the tang in the tab. It's not clear though.

    I think part of the problem is this is a complicated design who's intent(s) are not that well understood or communicated, either to mechanics or owners doing their own changes.
     
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  5. rudiger

    rudiger Active Member

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    I think you're on to something. After getting a 'special' 64mm end-cap wrench, I was finally able to get the housing off. However, before removing it, I specifically noted the orientation of the plastic housing tabs in relation to the metal tang. The tabs were definitely past the tang (but just barely).

    However, when I reinstalled and torqued the housing to the proper 18 ft-lbs (221 in-lbs) spec, both tabs did not make it past the tang. One made it but the others were about an inch short.

    So it's entirely possible (and likely probable) that in the minds of the mental-giant, minimum-wage, grease monkeys that dealerships employ for menial tasks, they figure that all the housing tabs have to be tightened past the metal tang for a proper fit, and muscle that bad boy for all they're worth with no regard for torque (or how difficult it will be for the next guy to get the housing off).

    After all, it's not their problem and they're just putting the housing back on in the manner it appears it should be.

    The oil filter housing is a poor design which, unless research is done, lends itself to improper installation on visuals alone.
     
  6. Mendel Leisk

    Mendel Leisk Senior Member

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    Maybe they had some reports of housings working loose, so came up with this tang, for insurance. I wouldn't doubt that if some worked loose it was due to the "just hand tighten" school of thought.

    I'm inclined to make a half-hearted attempt at setting the tab and 90 degrees apart at outset of re-install, then spin it on and torque to 18 ft/lb, no matter where it ends up.

    I've done one change like that, and I vaguely recall the tang and tab were a little away from each other. Not sure which direction, but I think I overshot slightly. Again, seems a somewhat goofy, trouble prone concept.
     
  7. rudiger

    rudiger Active Member

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    That's the way I did it. I just torqued to spec (221 in/lb) with no regard as to where the tabs/tang ended up. But I think the tang did finally come to rest close to being between the set of two tabs that are close to each other on one side (which I'm guessing is as it should be). In fact, there seems to be another, smaller tab between the two close tabs. I'm guessing that's the ultimate target point for the metal tang.

    I still say the metal tang is solely there for alignment and not insurance to prevent the housing from coming loose. When I was finally able to loosen the gorilla-tightened housing, the tang offered no resistance, whatsoever.
     
  8. Mendel Leisk

    Mendel Leisk Senior Member

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    There's a flattened area in the cap's threads that's at play in this tangled web of instruction, too. The 90 degree instruction is relating to this flat spot, I think...

    I gleaned this from reading in the Repair Manual. And it's purpose seems to be so you can rock the cap when it's about half way unscrewed, to drain the oil before the cap's fully removed.

    This thing's way too engineered, LOL.
     
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  9. rudiger

    rudiger Active Member

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    I saw the cut-outs, too, but didn't give them much thought. But now that you mention it, I did notice there was no big gush of oil when the housing was pulled out of the engine as is normally the case with a traditional oil filter. I just put it down to a lower level of oil in a smaller case but it must have drained thru the cut-out as I was unscrewing it.

    Could one of the tabs on the housing relate to the flattened area? That would mean that as the housing is unscrewed, the single tab would have to be in the down-most position at some point in the process to allow the oil to drain from the housing prior to it being completely removed.
     
  10. Mendel Leisk

    Mendel Leisk Senior Member

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    (Moderators, if this is copyright infringement, please delete, and my appologies. IMHO, this should be in the Owners Manual.)

    Have a read through the attachment, it's a clip from the Repair Manual, just the oil change instruction. It's still not that clear, but might help. Some of this is on the oil filter box, though a little different I think
     
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  11. spiderman

    spiderman wretched

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    ^ helps a lot. "Align the cutout in the oil filter cap threads 90° to the grooves in the oil filter bracket and temporarily tighten the cap." Doing that might line the clips up correctly. Next change I will have to give that a go.
     
  12. rudiger

    rudiger Active Member

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    Thanks for the posting. It's still not perfectly clear but does shed more light on the purpose of the housing tabs. It's also helpful to know that the oil should drain with four turns of the housing with the tabs in a vertical orientation.

    I can see the dolts tightening the housing to 25 ft-lbs because that's the first number they'd see (even though it's clearly N-m).

    This info should be in the owner's manual. OTOH, I guess Toyota-USA didn't figure that many owners would be changing their own oil.

    It's also interesting that no mention is made of the oil change 'door' in the engine 'under cover'. Rather, it looks like the manual says to completely remove the entire cover. That's like 17 plastic pins! I've read where there are four pins for the oil change flap but I could only find three.
     
  13. Mendel Leisk

    Mendel Leisk Senior Member

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    Honda put's the rudiments of an oil change in their owner's manual, fwiw. That's about it though: a few comments on checking tran fluid level, and d.o. I think for coolant overflow reservoir level. brake fluid level.

    It's odd about the lack of mention of oil change door in the Toyota Repair Manual. In fact, they seem to be saying to pull off another couple of pieces, as well. FWIW, I've had the whole panel off and it's not that difficult, takes maybe an extra 10 minutes. It's good to be on your toes: there are at least 2 styles of fasteners, and of course a few hex head bolts at the leading edge.

    You might want to push them into a piece of cardboard, in the same pattern as you take them out. You might also put a daub of whiteout or whatever on the different ones. You are right btw: there are only 3 fasteners needing to be removed for the small access door.

    I think it's worthwhile taking the whole thing off if:

    1. You're also changing the transmission fluid. It's off to the other side, might end up messy with the panel in place.

    2. You really want to keep the the panel pristine.
     
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  14. Mendel Leisk

    Mendel Leisk Senior Member

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    That's actually a puzzler for me. What do they mean by "temporarily". My take was it meant to start screwing the cap on with it positioned thus. And "grooves in the oil filter bracket" doesn't ring a bell either. Maybe next time I'm looking at it.

    Good to hear someone is making sense of it: would appreciate if you could take a stab at translating it.
     
  15. rudiger

    rudiger Active Member

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    Since the 'temporarily' instruction (e) is followed with (f) "Using SST (Special Service Tool), tighten the oil filter cap assembly", I took 'temporarily' to mean 'hand-tighten'. It's 'temporary' until the next step when the SST (and, presumably, a torque wrench) is used, then it becomes 'permanent'. The word 'temporarily' then makes some sense - they don't want you putting the SST/torque wrench on the assembly immediately and trying to force it down when the threads might not have been started properly.

    In fact, substituting "without using the SST" for the word "temporarily" might be even more accurate.

    Although it sounds kind of silly, it's a possiblity since the SST can easily get attached to the oil filter housing when removing it (especially when the previous installer overtorqued it and a lot of force was needed to get it off). That's what happened to me. Since I knew I was going to be using the SST to tighten it back up, I just left it on when reinstalling. But I sure didn't put a ratchet on it until I had tightened the housing by hand first. After it'd been torqued down (to the proper spec), I then actually had to use a screwdriver to pry the SST from the housing.

    Likewise, "aligning the cutout...to the grooves in the oil filter bracket", sounds like "do not cross-thread the oil filter cap assembly when reinstalling". It's a pretty hokey instruction in that there's not really any way to not align the cutout to the grooves in the oil filter bracket. It's only going to go in one way, regardless of where the cutouts are when started.

    But it is good to know that the housing tabs correspond with the drainage cutouts, regardless.
     
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  16. tumbleweed

    tumbleweed Senior Member

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    I have done 7 oil/filter changes and never once worried about the tabs being lined up. I just tighten the cap to 18 ft/lbs and let the tabs and groves line up as they will. If you tighten it by hand as tight as you can you will feel quite a bit of resistance anyway, I don't think there is a chance of it coming loose by itself. I don't worry about the tabs when I remove it either, I guess they must move themselves out of the way.

    I do like the drain hole feature though, it's nice to be able to empty most of the oil out of the filter before it comes completely off.
     
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  17. rudiger

    rudiger Active Member

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    The fact that the tabs don't seem to hit the metal tang at all is the reason I suspect the tang is for alignment rather than security.

    Although the drain cut-out feature in the housing is nice, the best thing for Toyota to have done was simply locate the housing vertically at the top of the engine, a la BMW. There wouldn't have been the need for any tabs, tangs, or drain cut-outs. BMWs may have their flaws as much as any other car, but the way the oil filter is designed to be changed isn't one of them.

    About the only glitch I remember with the BMW oil change 'system' was that you actually had to change the filter before draining the oil from the pan because there was a release at the bottom of the filter element that would hold the oil in the canister until the old filter was pulled. Once the element was lifted to be removed, the oil in the canister would drain down into the pan. If you'd already drained the oil and replaced the plug, that oil stayed in the pan and would mix with the new oil (unless you went down and drained the pan a second time).

    But there wasn't any need for a lame 14-flat, 64mm, canister-style end-cap wrench. There was a 36mm hex-head solidly molded into the top of the cap of the canister. It was just about as easy and mess-free as it got.
     
  18. tumbleweed

    tumbleweed Senior Member

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    Yes I agree with that 100%. I had an e46 330i and changed my own oil. Great to have the filter on top where it belongs. As you said just pull the old filter up and it broke the seal and drained the filter housing into the pan. Also the under covers were made of sheet metal instead of cheap plastic. Unfortunately the run flat tires and a very sparse dealer network will keep me from owning another BMW.
     
  19. mchbc

    mchbc Junior Member

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    About the swing-down panel "door" with the three plastic push-rivets: After three oil changes my panel is just about broken off. The plastic that forms the hinge is work-hardened and broken, almost all the way across. I plan to screw some hinges on it. That may be a weak link in the system and thus the reason the dealers do not open that door for oil changes, but have the techs completely remove the three plastic body panels.

    (My reference is to the details in the pdf posted by Mendel at comment #30.)
     
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  20. Fostel

    Fostel Member

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    #40 Fostel, Feb 27, 2019
    Last edited: Feb 27, 2019
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