Thread: Motor Mounts / Popout?

Hey guys,

I think the motor mounts in my '91 SE-R are a bit weak at this point, wanted to run this by you all and see if this is symptomatic of failing motor mounts:

Particularly in first gear if I race up to 5000~ RPM and then let off the gas (talking driving, under load of course), the shifter jerks forward abruptly. Like there is always some shifter movement expected, but this seems like a lot.

At the past RallyCross and on rough (and I mean REALLY rough) roads, if I am really getting on it over a series of successive bumps, the shifter will slide out of gear. I can literally feel the bumps on the road through my shifter.

Sorry if this explanation sounds ridiculous, I can try to explain it better somehow if that came out as being completely stupid. I know that the transmission is fine and it's literally only a high-impact bump under heavy load that will cause it to slide out of gear. I remember hearing somewhere that strong transmission mounts in particular are extremely important on these cars, would anyone recommend something in the aftermarket that would hold up better?

DOesn't sound ridiculous at all. In my B13 with 84k miles, the shifter does quite a dance during transitions of input. Quit disturbing. I would love to get a transmission poly mount and a rear cross member poly mount and use the stock front and pass. side mount.

Glad to hear that I am explaining it correctly enough! I should probably consider getting a set of poly mounts! Don't know if my current ones are indeed failing, but poly mounts would be the way to go for replacement regardless!

yeah,yuo cant be rally crossing and beating on stock mounts.
seriously surprised you are just now having issues.
I have had a car with a blown rear mount that would pop out over bumps.
After looking underneath with the car in 5th you could see it was hitting the swaybar .
Atleast get a prothane rear,and even a dogbone.You can keep the sides stock and get by.

Just ordered a set of Prothane mounts in black. Going to at least have the transmission ones replaced before the next RallyCross. Certainly a smart investment, just wanted to run it by and confirm it's a mount problem. Thanks guys! Even though my engine is stock, I can see why this is SO important for higher-power builds!

I cracked a transmission case from excessive wheel-hop in my otherwise stock B14 SE-R. When I replaced all the mounts in that car with Prothanes, I was happier than a pig in $*&^! I don't mind the vibrations at all.

I tried solid nylon mounts in my P10 and that was vibration city. No joke, under 4000 RPM, you could not have a conversation with anyone in the cabin unless you were screaming at the top of your breath! Slowly, I replaced each mount with an OEM brand new mount to discover which mounts do what as far as NVH is concerned.

The passenger mount (front of the engine) seems to transmit about half of the interior cabin NVH so I would retain that as stock in any future car upgrades and worry about the front and rear cross member and transmission mount/s.

100% agreed

Yup, had prothanes in my B14 and kept passenger side OEM. Same with my NX.

So I got my Prothane kit in today.

Could anyone help me reference which of these inserts go where? They don't look obvious enough that I can directly place them where they need to go, at least not for the larger ones and the two-piece insert.

I could be wrong, but 3 and 5 go with the front or dog-bone mount. Number 4 is passenger side motor mount. 1 and 2 have to be crossmember and transmission mount. Do they not have part #'s on them that you can search?