Bill Ball

We don't have enough experience to say if anything outlasts the factory mount. There were some incidents reported several years ago were some of the hydraulic (later model) type replacement factory mounts didn't last long or were defective, and the factory mounts are expensive, so alternative cheap mounts were searched out and started to be installed in some cars. Recently there have been some manufacturing issues with those mounts too. I replaced my factory mounts with factory at about 16 years. The originals were not shot but they were getting there and it was a "while you are in there" task when I was doing the leaky oil pan gasket. The new factory mounts look fine 7 years out.

Pcplod

What is this other MM that several people have mentioned?? For a Ford or something?? Is this to replace the newer hydraulic ones or the older ones??

dr bob

The common replacement cars seem to be the ones that came with the hydraulically-dampened mounts as original. That narrows the field to post-ob cars for the most part at least in the US. Early cars have a non-dampened mount supplemented by a small shock-absorber dampener. Some have swapped later crossmembers into their early cars to use the late mounts, BTW.

I'm thinking that it's been around five years since I installed the P mounts in my car. Still good as new, no sagging so far.

shmark

For me it wasn't about the reliability of the factory mounts, since they are proven to last quite a while, but that the factory mounts are bloody expensive. There's a good alternative out there that isn't necessarily better or worse, and is much cheaper. Easy decision for me, and after 28 years my factory mounts were completely collapsed solid. With the new solid rubber mounts installed, the difference is astounding, and would probably be just as astounding with the factory mounts - but I'd be poorer. Now if I was running a shop working on other people's cars and guaranteeing my work, I'd use nothing but factory parts. But personally on my own car, substitutions are just fine.

Tim Murphy

I just installed the Anchor 2698SR mounts.

Fingers crossed.

ROG100

78 to 82 cars are fitted with solid rubber MM's from the factory and they rarely fail and do not collapse. Last picture is one of the original solids.
The factory also uses two shocks one either side of the engine to help with vibration. These are often in a failed condition and can be replaced.
In circa 83 the factory moved to hydraulic MM's and these are the ones that cause all the problems.
Most are failed and owners do not know they are collapsed and live with the vibration not knowing any better. Replacement is expensive.
About 10 to 15 years ago some Rennlisters found that a certain Ford MM fitted the 928 and the rest has been well documented here on Rennlist.
Currently the factory MM's for the 83 to 95 cars are circa $250 each. The price has come down significantly from the high of about $400 each. Even at $500 for a set this is beyond the means of some owners.
Once a new set of MM's is fitted the difference is very noticable.

Hydraulic MM's are hollow as can be seen in the pictures and are filled with water and a little antifreeze. Once the liquid leaks the MM collpases.

The aftermarket MM's are either Corteco or Anchor and it would appear made by the same manufacturer DEA with factories in India and China.
Recently we have experianced issues with collapsing aftermarket MM's and stopped selling them as well as warning the 928 community of the issues. Even the distribution network and the manufacturer is aware of the problem but do not care at all.

Other sponsors continue to sell the aftermarket MM's as well which is beyond me.

I added some pictures of some MM **** for those unfamiliar with the subject.

IrishLegend

Thanks Roger! I appreciate it.