Spinning Stud on motor mount

[LeCrux]

Hi All,

In attempting to refine my engine alignment, I ran into an issue with the rear starboard engine mount stud spinning.

I am trying to avoid hauling the engine again to replace this mount (as I just hauled it last year to replace a cracked oil pan).

My dream would be to cut the stud underneath the pan, that way I can just slip out the mount. This leaves me with the problem of getting a new one in. Is anyone aware of motor mounts that have removable studs so that I could slip in the new mount and install the stud from above.

Any advice or ideas would be greatly appreciated! Thank you

[tkeithlu]

The problem is that the moulded rubber that keeps the stud from spinning keeps it from being removable. That said, are you engine flanges cast as part of the block or do the bolt on like mine on a Detroit Diesel? You might be able to disconnect the flange, install the mounts, and bolt the flange back in place. If not, I think that you are stuck with loosening everything up enough to raise the flange and slip the mount into place.

[tkeithlu]

Second thought: If the mount is worth salvaging (I've got my doubts, given that it spun) you could grip the top of the stud with a locking pliers, adjust the mount, and let go.

Alternatively, you could compress the rubber part of the mount from the sides with a C-clamp to prevent its spinning.

[LeCrux]

It's an atomic 4. So the flanges are part of the oil pan, so they are not removable.

[Cheechako]

You cant remove the mount with the engine in place but jacked up or etc?
Can you compress what holds the stud by peening it tighter?

Hard to figger without pics....

[LeCrux]

I have one picture that sort of shows the mounts (though it does so poorly).

But no way to compress the rubber.

No way to lift the 2 inches necessary to slip the mount out whole without disconnecting shaft, exhaust, removing the cabinetry above it etc. Hence my search for a motor mount with a removable stud.

I'm hesitant to put vice grips on the stud to hold it while I turn the nut, as then I will likely be unable to put the nut back on top.

[Scubaseas]

If the stud is spinning you need to replace the mount as it won't hold the engine down. As in whatever gear has an upward force. As in if the stud spins it's a broken motor mount.

Check with R & D Marine which is part of PYI inc. They used to have mounts with removable studs.

Another option would be to buy a new mount , cut the stud and tap it for a bolt. You might have to go a size smaller like a 10 mm bolt instead of a 12mm stud but the A4 isn't that heavy and the lateral forces are not great. Use a grade 8 bolt.

[ShawnMack]

Grabbing it with vice-grips will almost certainly bugger up the threads. As an alternative you might be able to saw a flathead screwdriver slot to the top of the stud. A Dremel type rotary tool will be easier but be careful of the stray sparks, fire is not your friend. A hacksaw would also probably work and might be safer.

[Squanderbucks]

From the photo it doesn't look like you need a full 2" to raise the engine just the thickness of the nut and a little more.

How about blocking the engine and cutting out the engine bed where the mount sits - slide it out and replace with another one and then epoxy back in a new spacer under the new mount.

Or leave it cut out and put in just another thick aluminum strip that the mount is bolted to. Then if ever needed to be removed it could be unbolted along with the bolts/lags holding in the plate, dropped and slid out.

Many large engines do not directly bolt to the stringers but to aluminum brackets or plates that do bolt to the stringers.

[Boatyarddog]

Originally Posted by LeCrux

I have one picture that sort of shows the mounts (though it does so poorly).

But no way to compress the rubber.

No way to lift the 2 inches necessary to slip the mount out whole without disconnecting shaft, exhaust, removing the cabinetry above it etc. Hence my search for a motor mount with a removable stud.

I'm hesitant to put vice grips on the stud to hold it while I turn the nut, as then I will likely be unable to put the nut back on top.

Had a solution, but the confounding permanent mount arms, blew that.
So... Second idea...

How about removing the mount by supporting the engine, just taking the weight off, remove the bolts attaching to the stringer. The nut if you can, cut it off too ,or loosen it.
Using a cutoff tool or saws all.

Slice a SLOT, in the mounting arm, to the hole the stud goes into, both sides, slide the mount out.
Slide the new one in, with a decent washer under it, and one on top, lock washer and new nut.
You could then reweld or just tack would be best the piece you sliced out.
I think it would be fine.
SV Cloud Duster

[Bill Seal]

You could get another nut, cut through one of the flats, screw it on, squeeze the hell out of it with vise grips. That way you can keep the stud from turning without buggering up the threads.

[mike d.]

Remove your starter, From pic it looks like there is a nut below the pan mount also, if so then use a wiz wheel to cut the nut close to the stud, the heat from cutting the nut should make it so the whats left of the nut will turn, especially if you graze the stud threads ! Use the lower nut to stop the stud from turning ?

[Boatyarddog]

Hey found these online,
https://www.avproductsinc.com/mobile...dm-mounts.html
And these for adjustments, or shim it. https://www.avproductsinc.com/mobile...adjusters.html
Scubasea has the right idea.
SV Cloud Duster

[01kiwijohn]

I can't tell, looking at the picture, but if you can cut a nut in half, making two locknuts out of it, you may be able to lock them together at the top of the thread and hold it that way.
You're going to have to check the engine alignment afterwards, so disconnecting the shaft will be necessary anyway.

[Searles]

Tighten the nuts on the pedestal onto the engine foot best way you can,slacken off mount hold down bolts to bed ,shim up to suit alignment ,tighten mount hold down bolts ,fix,when time allows