Motor Mounts: Hydraulic vs. Solid

Motor Mounts: Hydraulic vs. Solid

Has anyone replaced their rubber hydraulic motor mounts with the early ones that are rubber-only? Does this require any modifications?

Thank you
91GT, 83 EuroS

I just performed this repair on my '83 Euro S and the solid mounts bolted right in. In fact, they went in easier than the hydraulic mounts came out because they are not nearly as large. I have not put the car back on the road yet due to weather and other repairs, so I can't say how they will compare to the hydraulic mounts in terms of vibration isolation. All I can say is that I drove a '79 with new solid mounts and it was very smooth. If mine is that good, I'll be happy.

My hydraulic mounts were completely sacked. The engine was probably sitting 1/2 inch lower than it was supposed to and overall vibration was pretty bad. Good luck with the installation. Let me know if you need any tips on how to do it.

Dean Cockshutt
'83 Euro S (headers, Eibach springs, rebuilt 5 spd, new blue leather
interior, soon to have Koni's)

[1 month later]
The solid mounts and hydraulic mounts seem to have different dimensions. (I've only seen photos of the solid). I'm surprised they went in without modification? My 87S4 with 74K, has mounts have completely failed, and your experience has makes me wonder if I can replace them with solid mounts as well. How is the ride with the new mounts?

87 S4 Venetian Blue Auto

Just last week I replaced my hydraulic motor mounts with solid ones. They fit perfectly with absolutely no modifications. Solid or hydraulic mounts are the same to assemble, no difference. The only thing you have to do is to replace the stud which come out of the hydraulic mounts by a M12 (1.5mm pitch) x 40mm for the solid mounts.

91GT, 83 Euro S

Why doesn't everybody use the solid mounts? There must a difference in quality/vibration dampening ability for the (hydraulic?) liquid filled mounts to justify the price, difficulty vs. the solids. Isn't there?


The hard rubber motor mounts used on 1978-82 928 also used two small tubular shock absorbers which mount to the engine lower cross member part #928 375 179 02 these sell for about $95 each later model cars do not have the mounting point for these two shocks.When you consider that the engine/central drive tube/and transaxle some 900 lbs are only attached to the chassis by the two front rubber engine mounts and the two rubber trans axle mounts these are being asked to do a very important task. When you accelerate these are the only things that keep the drive assembly from spinning inside the chassis They must maintain a force equal to the energy being transfered to the wheels. Porsche was very conerned about vibration of this driveline assembly and for the 78 model the battery and battery box is attached not to the body but is bracketed to the transaxle housing they were using the weight as a counter balance.


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