Alright so on to motor mounts

Discussion in 'V8 - Maintenance & Troubleshooting' started by 99sho-time, Jun 29, 2017.

  1. 99sho-time

    99sho-time SHO Member

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    Okay first off since I have made a ton of posts I like to ask the moderators to remove some of my more fruitless posts. It's been a rough road trying to figure out this rubix cube of a car out but I have made progress.

    Anyway i'm suspecting my motor mount(s)? are bad my engine moves around to much in my opinion.
    I feel like this may be the culprit to my clunky hard shifts.

    I have a few questions.

    For the front mount can I change that one out by just jacking up the engine? or will I need to go further and unbolt the rear mount and or cradle mounts? Also do these cars have a tendency to have the rear mount go bad first or the front mount?
     
    Last edited: Jun 30, 2017
  2. gamefanatic

    gamefanatic SHO Member

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    Replacing motor mounts is probably recommended at this point, assuming they have never been changed.
    Though without just replacing things for the sake of replacing them to check the front and rear mounts do the following:
    - Start the car.
    - Put your foot heavy on the brake
    Now pay attention to noises vibrations that occur coming from the engine. They will most likely feel like they are coming from the floor board.
    - Put it in reverse and press the gas. You want to get the RPM's up quickly to about where the torque converter stall RPM is at. But don't give it so much gas that the brakes can't hold it. You may want to bump the gas it a couple of times just to make sure.
    - Now put it in "D" or "1" and perform the same procedure. Again ensure you don't hit the gas so hard you take off just get the RPM's up quickly.
    You may hear a clunking which means the mount is likely broken, or just that the engine pulls moves to nearly it's full range very quickly.
    All things working correctly it will move smoothly to the full extension of the mounts range.

    Generally speaking the front mount takes the brunt of all driving, as it handles the rotation of the engine towards the cabin of the car. The rear handles reverse maneuvers and provides limited resistance to forward motion. The rear likely isn't bad, but you may want to do a visible check on that to make sure it's not cracked or missing chunks of rubber.

    Drive-ability you will notice what feels like a miss or lugging at low load driving. Usually the vibrations will be felt in the floor / gas pedal. This can be confused with rear brake / tire problems so it's not definitive without experience. ;) You definitely could have issues with mounts like you mentioned with your clunks if more than one is bad. Also note that there is a 3rd mount on the transmission side and almost never goes bad. I think on these cars it's mostly solid.

    These aren't expensive to replace from Rock Auto, I actually just put an order in today for the front mount.
     
  3. 99sho-time

    99sho-time SHO Member

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    I power braked it didnt even go that high in rpm and it seemed to move. I'd say like over an inch just reving it maybe 2.5k with brakes on. it def lugs in low load.
    I notice putting it in drive the engine moved but it vibrated and shuttered for a sec or 2.
    the shifting it will shift smooth if im going really slow and I let it shift. but if i put the engine under any torque load the shift can be bad the car feels heavy.

    I think I saw a video of a gen3 with new mounts and seemed to move alot less than my engine did.

    Im just wondering can I leave everything attached while I do the front mount?

    UPDATE
    Got in there took some pics guess my question is answered. the top of the front looks like it expploded.
    [​IMG]
    The rear looks like it's just dead in the water collapsed on itself.
    [​IMG]
     
    Last edited: Jun 29, 2017
  4. gamefanatic

    gamefanatic SHO Member

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    Well that doesn't look safe... Better replace them ASAP.
     
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  5. stephen newberg

    stephen newberg Moderator Staff Member

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    Agree, that needs replacement.

    pax, smn
     
  6. 99sho-time

    99sho-time SHO Member

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    So my rear one should be replaced as well?

    Also any tips on which com pany to use for mounts dea, anchor, waster pioneer or skp? lol all seem pretty lacking.

    Solid or stick with hydraulic?
     
    Last edited: Jul 2, 2017
  7. gamefanatic

    gamefanatic SHO Member

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    Well hydraulic should be used in the front. A solid mount would be for "performance" only. Keep in mind that solid will transfer more vibrations to the frame and into the car. I can't comment on the brands, other than that I went with the SKM2934 for my front. The picture just looked the cleanest... :) I got it yesterday and will probably put it in tomorrow.

    Yes, I would recommend replacing the rear. Not doing so will put more strain on the front one and wear it out. Had this problem all the time on my Cadillac SLS dog-bones until I replaced the motor mount...
     
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  8. stephen newberg

    stephen newberg Moderator Staff Member

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    I would also replace them all.

    pax, smn
     
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  9. 99sho-time

    99sho-time SHO Member

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    I can't believe I overlooked this. I always thought the motor didn't move around that much. But as I have noticed it's not that it moves all in one shot to much, but when the motor is torqued it moves to much in increments. Question is will this solve my shifting.
     
  10. gamefanatic

    gamefanatic SHO Member

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    It's not going to solve an actual problem with shifting, but if the the shifting rocks the engine around then yes. You may not feel the shifts as much from 2-3 as there may be less movement.
     
  11. 99sho-time

    99sho-time SHO Member

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    I read somewhere that you need to watch the motor mounts when resolving 1-2 shift.

    it will only shift hard if the engine is under hard torque and the severity of the hard shift depends and varies evrytime depending on the torque load.
     
  12. gamefanatic

    gamefanatic SHO Member

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    Normally it should be a smooth transition, even under WOT. Though if you let off the gas during the transition or have a larger boost valve setup mechanically this is how it would work. The motor mount would only give a "feeling" of hard shifts, but not actually cause the shifting to be harsh. The feeling is just the motor moving and causing lag in response.

    Just got done doing my fronts, and it's night and day difference. Real PITA to get at the bolts as I had to come from the bottom between the sub-frame and the radiator shroud to get at them. Having the perfect length extension will take the nightmare out of this project. Remove the lower bolt, raise engine enough to lift the mount nearly out of the whole, remove the bolts to the engine. Install in the reverse, there is just enough play in the serpentine belt to squeeze it through the wheel well. Pay attention when lowering the engine back down to line up the alignment peg. The mount should require a little coercing to get in properly, I used a pry bar.

    Now there is almost no perceived lag off the line making an instant 50% improvement to the FTLs!
     
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  13. 99sho-time

    99sho-time SHO Member

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    Sounds like the mount you bought was at the very least "working" out of the box haha thankfully i bought the same one as you.

    It seems like most mount manufacturers are garbage. I found an actual front motorcraft mount at some dealer for 275 lol thats to much for me atm.
     
  14. gamefanatic

    gamefanatic SHO Member

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    At that price you could just make your own and screw it up a couple of times... :p
     
  15. 99sho-time

    99sho-time SHO Member

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    Got it in! I actually went in there put a ratchet on those bolts through the wheel well then came around and broke them loose in between the radiator and the engine with a small breaker bar (they were tight!)
    I actually didn't need to jack it the engine up much at all to get it out i did however remove the belt off the big pulley and easily slipped the mount out. wasn't hard to get in at all either.

    Regrettable it stills has intermittent hard shift but the mount change did seem to help. im still glad I changed the mount because it was an improvement overall, take off and ride seems smoother and solid.

    next is my front main seal thing is just showering everything. I scoop out clumps of chocolate cake like batter out of the subframe.

    [​IMG]
     

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