Mike Frye

Ron,

I did lots and lots of searches on this before I dove into mine. Here's what I got from it:

The original Porsche mounts probably last for upwards of 150k miles or 15-20 years. Jim B. is a firm believer that there is no substitute for the OEM part, especially for something this critical to ride and safety. Many (most?) of the people on here have issues with a part that cost 10 times more than one that 'works'. There is also no way to tell if you can feel the difference because:

a) New MMs always feel better than old beat up ones, no matter whether they're liquid filled, solid, OEM or Anchor and
2) NOBODY is going to do this twice to try to compare the difference in ride/feel in the same car

I agree with JB on the point that 15 years is acceptable for a 'wear' item like this, but I went with the solid Anchor mounts because I personally think the solid ones are just as safe and I had other places I needed to put that money.

Courtshark

C'mon down... except the shop is in Gaithersburg (saves you all of 45 miles on your 3000 mile journey).

3000teeth

So if you can do it in 4 hours, and it would take me 20, I'd just have to make it in under 16. This means I'd have to travel at roughly a consistent 187 mph to make it worthwhile --then of course, there's the drive back... and the $2000 in gas.

Throw a sixer in the fridge --I'll see you tomorrow. Oh wait... I'm supposed to bring the beer.

3000teeth

Ron, I'd definitely like to do this job with some help, and would be happy to give the same back. Let's sync-up on this soon. It'll have to be a little later in the summer, cuz I just dropped $550 on all new upper & lower ball joints and bearings for the front-end and still need to get my PS leak shored-up.

Dood!!! You're gonna give me nightmares!

dr bob

Some things make the job under the car go a lot faster.

-- Do as much cleaninig as you can in advance of D-day. Ramps or stands at the car wash with the pans off, throw-away coveralls and a case of engine cleaner. And this is just for the front undercarriage. Everything that ever leaked or spilled from the motor area , excepting those few little drops that made it to the floor, has accumulated on the parts you'll be working on. Laying under the car handling slimy parts is no fun at all. Having junk fall in your face is no fun.

-- Get the car as high as possible, on tall stands. I'm talking about the 6-ton stands with the big footprint, not the little 3-ton mini-stands that many of us used to depend on.

-- Clean workspace is kinda nice. Put some heavy painter's paper down on the floor, and replace it when you get it too dirty. I add a few dishtrays-type pans to catch fluids and hold parts as they come off.

-- Organize your parts as they come off. Place bolts with the pieces they are used on if you can. Order the parts on the laydown table or floorspace so they can be put back on opposite the order they came out. That way you won't "discover" the heat shields on the floor after everything else is buttoned up.

-- Echoing Ron H's experience, I had a welded-tube stand fail on me, under the rear of the Explorer. Brake job and I wasn't under it, but that little event made me a believer. If you still have the tube stands with the pin, toss them now while you are still alive.

-- Get all the parts together in advance. If you are using aftermarket mounts as many are, you'll need the right nuts and washers; the metric stuff you are taking off won't fit the new parts.

-- You'll need power steering fluid, engine oil and filter at absolute minimum. I used a new set of banjo washers at the rack end, replaced the filter/reservoir for the PS system since the system emptied itself through the rack hoses. If you have any steering system leaks, now's the time to replace hoses or even the rack if it's the leak. The rack will be hanging by the tie-rod ends, and can be out of the way pretty easily for tie rods, ends, or bushing leaks. I used some tie-wraps on the wiring harnesses both to hold them pout of the way and to secure them when reinstalling the crossmember.

-- Power tools are a huge timesaver. Air preferred, electric OK. There are some pretty good electric impact wrenches available now, and a cordless drill with a socket-drive adapter or two will pay for itself in the middle two hours.

-- A 10mm gear wrench for the pan bolts. There is no substitute.

-- GTS baffle kit in your future? Bring that forward to present while you have the oil sump off.

-- Make Sure you have a set of tapered punches, suitable for 10mm holes (same as 3/8" for this purpose...) to help align the cross-bolts above the ends of the crossmember.

-- Arrange for help from a local volunteer if you can. There are a couple parts of the job that benefit greatly from an extra set of hands, more benefit from an extra set of eyes.

-- The T-head bolts that hold the bottom steering rack cover can be secured with a screwdriver wedged in the top while the small impact spins the nuts off. After the crossmember is off and cleaned, use a little RTV to glue those bolts back into the rack.



My under-the-car protocol is similar to Sharkskin Dave's. Organize your thoughts and have a plan in mind. Regularly evaluate and update your plan as you progress, so you see and understand what you are doing and why. There are generally no mechanical maintenance tasks on the car that use a torch, sawzall, or 10-lb sledge, so anytime one of those thoughts enters your head, it's time for a break. Re-evaluate, get another opinion from the group before you do more damage.

My experience with the Porsche mounts is same as Bill Ball's. Old ones were sagging but not flat after 17 yrs. New factory mounts went in. I wes exposed to some interesting info from Ford regarding some NVH problems on early Explorers. Porsche supplied some hydraulic mounts (from a 928??) to help cure some of them, and that's why there are Ford htdraulic mounts that fit the 928. I know there was a big push to using the Anchor mounts from Rock Auto starting a few years ago, but the quality of them has tanked so badly that folks are going to the non-hydraulic mounts. I guess if I was looking today, I'd be looking for hydraulic mounts rather than "solids" to maintain the low NVH that only hydraulics give you. If I was really frugal I'd buy the Ford mounts, but from a place that has better ones than Anchor/Rock. Maybe the local NAPA store would get a visit. For my car, the factory mounts would go in. I'll be almost 70 by the time that need rolls around again.

Ron_H

I need to do my homework and research the various options. I was planning to use original Porsche mounts, but if they don't last, I don't want to crawl under there again anytime soon.

Dr.Bob, your suggestions are appreciated. One tool that Dave used to his advantage was a Dremel to cut the studs for the oil pan that were too long. He used it somewhere else too, but I think the heat had gotten to me at that point and I was deep into a siesta. I'll remember when I get into mine. I agree about cleanliness. I plan to get the underside steam cleaned before I begin. There is a place here in San Jose that does the entire underside of the car for $60. Dave also has a mini torque wrench which he used on the oil pan gaskets ( I told you he was meticulous for details).

3000teeth: I too and broke and penniless and with the Parade approaching I wanted to do this job first. Unfortunately, Uncle George wants some money also, and he has bigger guns so he wins. Later in the Summer is fine with me. Just tell me when it is best for you and I can add my two hands if needed.

ROG100

I have never seen a good Porsche Hydraulic MM on a 928 - every one was in an advanced stage of failure. The owners did not even know they were failing, just a slow degredation of smoothness of the engine. Porsche used solid mounts until 1983 and most of those are still OK, you do not hear of them being replaced.
The hydraulic MM has no substance to it and only the water/anti freeze inside holds your engine in place. Once that has gone you have no support. They were a good idea but no body realised they would fail so quickly - most are on the way to failure in as little as 4 years.
See the attached pictures to see the vast difference in design between the very flimsy hydraulic and the very robust but smooth solid. Proof is in the pudding - no failures of solids but thousands of hydraulics.

FlyingDog

Are those pics Porsche or Anchor?

I was advised against solids when I did mine for too harsh a feeling, so I used hydraulic US made Anchors.

ROG100

The first one is a aftermarket hydraulic and the second a solid. The hydraulic is identical to the Porsche one. Just did not want to chop up $300 of Porsche MM.
Anchor were OK but there was no way of telling if you were going to get a solid or hydraulic as the part number was the same. I changed to Corteco as they have seperate part numbers and wre the original after market MM adopted by 928 owners about 8 years ago.
How do you know you used hydraulic?

Ron_H

Roger, thank you for posting those photos and for explaining all of this to us. Now I understand the difference. I suspect that my mounts have been slowly failing since I had the car, because on the drive home from SoCal after I bought the car, I noticed the heat streaming into the car with the sunroof open.
(it was night on Hwy 99 through Central California and the AC was not working)
Jim Bailey advised that collapsed MMs would cause that condition. Someone else immediately examined the car and advised that the MMs were OK, but I was getting some vibration through the dead pedal. I took the advice ot "someone else" unfortunately and carried on. I now suspect that those mounts have totally collapsed because the vibration has increased slightly and I have put 60,000 miles on the car since buying it. I'll bet I don't even realize how nice the ride is with good MMs.

Do the solid mounts have some flex in them? I suspect that they must. I also now see the reason for using them. The cost of original mounts was also a tough pill to swallow. It is hard to believe that Porsche would offer such a design that is so prone to failure. However, in another current thread, Bill Ball expressed his disgust with Koni shocks (two separate pairs), while I have had good luck with my Konis. Are you certain it isn't just some MMs that go bad?

No matter. I think I'll opt for solid mounts. And spend the money I save on something else I need (like new wheels and fat tires )

ROG100

Here is a collapsed Porsche MM.
There is no difference in the feel between a solid and hydrauil when new.
The solid remains solid while the hydraulic deteriates.
My GTS was as rough as old boots when I got it 5 years ago. Major vibration through the mid range. New solid MM and it was like a new car. Same as it is today.
We pulled a pair of collapsed MM's from Sterlings car today. Only 6k miles over 8 years and they were toast.

ROG100

Ron,
They are flexible as you would expect and give a smooth smooth ride just like a new car.
They just do not collapse.
The original idea was a good one in that attenuation of vibration was better using the hydraulic. They did not count on them collapsing. The difference was marginal and probably undetected by the average human foot/butt.
I counted up sales over over 1000 MM sets in the last year. Not one unsatisfied customer.

FlyingDog

When I ordered them from Rock Auto I had a choice between hydraulic and solid. Maybe I received Corteco, but I thought it was Anchor.

ROG100

Hi Matt,
The only way to tell from Rockauto was to shake them. If they sloshed they were hydraulic and water filled.
Roger

FlyingDog

I guess we'll find out in a few years.