Dear PO: Replacing the Motor mounts 360.

Dear PO,

Original Owner, thank you for paying thousands above MSRP to import my euro. She is loved. PO(s) (prior owner), I decided to replace the motor mounts on the car today. I did it in my garage with the rear wheels on ramps. I saw when she was on a lift before that you had upgraded the motor mount to the more modern part. I commend you for that. I basically raised the rear end, took off the bottom panel and saw there were five bolts on each mount. Four that hold the mount to the body and one big bolt and nut in the center. I started by taking a 24 mm socket and 24 mm wrench that I bought at Northern tool for about 15 bucks. I put the wrench on the top of the big bolt to secure the nut. I then took the 24mm socket and put it on the bolt head on the bottom of the car. I used a cheater wrench to help me do the deed. It was tough, but I managed to get it moving. I turned and turned. The bolt fought me. It was a fine thread.. but it fought. It groaned, it creaked. But in the end I got it off. As it turns out your mechanic, Klaus, the one that used to repair tanks for the Romanian army? The one that you took the car to because he once fixed your wife's 500sl that time.. I know that a tank tread takes 300-400 ft/lb of torque to get seated... but you don't have to torque it down so much. You see with all that cranking the threads almost stripped off. Luckily I went to an ACE hardware and they had a tight thread 5/8 x 4" standard bolt and nut that worked perfect. The 24mm wrench and socket worked perfect to get it in. It only cost me 2 bucks each nut and bolt.
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.. I then went and undid the other four(4) 17mm bolts and nuts on each motor mount. They came off real easy and didn't strip.

I then took a wooden pad and placed it on my floor jack. I raised the engine juuussst enough to remove the old mounts. It went in on the side of the car to make room. I placed the pad right behind the oil drain plug on the bottom of the engine. I raised it real easy, millimeter by millimeter, always checking the water hoses. After 15 or 18mm or so, the old mount came out. I did have to stretch the bottom of the rubber to get it out. But get it out I did.

As you can see, they were very flat. But my new ones are not smushed.

I squeaked and pulled on the rubber and got the new mounts in. The key was getting the bottom rubber into the hole where it rests. Its tough to squeeze it in, but it won't hurt the mount.
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Now that's what I am talking about.

Fun!

 

When ever I wrap my knuckles around a cheater bar I can't say it's fun but it is exciting that's for sure!

Curt what were your symptoms that made you want to replace the mounts?

 

Ah ha, but what grade bolt did you decide on? So many choices at Ace.

 

Nice job. Though, I cannot imagine it not being a metric bolt and nut, originally... Why would you put a standard bolt on there instead of doing it right? They are only a few $ from Ricambi, #47 and #51 here: Ferrari 360 Modena Parts : Table 1 - CRANKCASE
Jes

 

But you see I noticed something. When you had Klaus "update the motor mounts" so you could sell it and buy a GTR or M5, he skimped. You see, the new motor mounts use a different washer on the bottom. See in the diagram below the new, how it has that little raised section in the middle? Well, Klaus used the old flat type. I get it, I really do. The stupid new washer is $60 some odd bucks! The mounts were $150 a piece! I have no problem when your mechanics use an "equivalent" solution when they jury rig.

The problem is that when Klaus re-used the washer, it "smooshed" down the motor mount. In essence it compressed it wearing the mount out prematurely. Indeed the rubber itself isn't even too cracked.

Its OK. When I replaced the bolt, I put 2 5/8" spring washers above the flat washer on each side.. in essence doing what the raised potion of the new washer does when compressed down. When I put it all together and bolted it all up, it worked perfect! (100 lb/ft big bolt, i think 70 ish smaller ones. I just did it nice and tight with some thread locker on the big bolts even given the heat there) Who knew $1.00 worth of washers could have a similar effect as $120 worth of Ferrari parts. I wish he'd done this. Overall about 3 hours for both mounts. There were no more vibrations in the cabin. Heck, it even felt as smooth as my Boxster! Quieter, smoother. So nice.

So PO, with this I'll say goodbye. I'm sure I'll write you again. If you see Klaus, give him my best and tell him I hope that old mercedes Diesel holds up. There isn't anything else to do now except enjoy the car. It really is running great.

All the best,

Curt
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I want to drive it. Now.

Seriously. Exact same diameter, exact same length. Exact same nut, head, weight, etc. The only thing that is different is the threads on the bolt and the matchign nut. Which for all practical purposes is immaterial. The exact same bolt with just differences in threads. For half the price of the Ricambi part. Functionally they are identical. Seriously, it's just threads. Metric fine vs. standard fine.

Works great.

 

Awesome job! I'm actually thinking about a 360. Do motor mounts really go bad that often? The reason I ask is you mention your car has had 2 sets already? I currently have some high end exotic cars but all of them have been reliable. The more I read this forum the more worried I get on reliability of Ferrari's. I do wrench on my own cars but have only had to change motor mounts on a 25 year old Porsche (to be expected at this age).

 

I grew up around those things; I can vouch for their build-quality

Nice write up...as poetic as a motor mount replacement can get.

 

These motor mounts were actually pretty easy to replace. The hardest part was the large center bolt that shouldn't have been that challenging to replace.

In contrast to other cars, I'll use my 928 as a reference to which you have to drop the steering rack and a cross member and IIRC to then lift the engine off the mounts, the FCar is a breeze. If I had a lift it would have been a 1-2 hour job max. I'm just being a redneck and using ramps. At least for the 928 the book has what 6-8 hours? With bolts that break and are frozen.. 12?

Motor mounts are reported as a "high wear" item. They are close to the headers and can heat up rather easily.. but my mechanic reports he's never done a replacement on a 360. I think in my case, an inexpensive 360 that I bought knowing it needed some things, this was due to erroneous installation by a prior mechanic. Bear in mind I also owned this car now 3 years before replacing this part. It's not mission critical so to speak. Its also a relatively easy enough job that if I ever have to do it again, I won't mind doing it versus lets say replacing the oil/water intercooler below the air intake which is a much bigger PITA with tight spacing. I think this car at 13 years of age at least as reliable as the Boxster I had. It's easier to fix, and once fixed holds up just as well.

 

Curt,

Great write up on this procedure!!! I appreciate the work around using the washers instead of buying new $$ parts. Very timely as I was informed that my mounts are kaput by a local F-car dealer (I would not have known they were bad). Ricambi is delivering new mounts today.

What a GREAT web site!!!!!
Thanks again!!!!

 

Do you notice a difference changing them? I immediately notice a difference. I had no idea that there would be so much slop in slightly worn vs new. Plus I had the old version where the metal plate did not exist on the top.

 

Great write up! Do you have the parts #'s for the mounts and any other parts? Did you also change the tranny mount? Any pics of the mounts installed? Sounds like an easy winter DIY project.

 

Good story but many inaccuracies.

Ferrari uses a self locking nut that destroys the threads so that was not Klauses fault. It is the norm. You have to fight them all the way out. I am pretty big and I use a long breaker bar to get them off. I have a good selection of 16mm taps and dies to repair them.

Your mechanic has never replaced a motor mount in a 360?? That is very scary.
They are a well known problem area and require regular inspection.

At that age the mount would look like that, no matter the correct lower washer. Dumb not to use it but the outcome did not change. On your spacing of the washer, did you leave a gap between the washer and the bottom of the mount?

Your use of non metric hardware is yet another example why I try to steer people away from owner serviced cars. When it gets sold and winds up in my or any other shop we will not be expecting hardware store parts. We will have no matching nut even if we notice. It is a train wreck waiting to happen and it will cost someone extra to sort the mess out in the future.

Sorry but that is just dumb.


Sorry but posts like this just continue to contribute to the already large body of internet disinformation that skews peoples perception of reality.

I also find it very hard to criticize whoever replaced them before (You assume it was a mechanic. Sounds to me like another misguided do it yourselfer) in the face of the repair just done.

 

The second that I put them in I noticed a dramatic reduction in vibrations.

Mr. Crall,
I understand where you're coming from and respect your feedback.

However, please allow me to issue a rebuttal.

1) Metric hardware versus non-metric hardware. The dimensions of the bolt and the nut in metric and non-metric are EXACTLY the same. Down to the 0.02 millimeter. I checked with my caliper. The pitch of the thread and the locking nut perform the EXACT same function, in the EXACT same manner in both cases. It application is documented in my repair log. If the next owner (I have no intention to sell) doesn't look/doesn't care. Their problem. I have no intention to flip this car. Ever.

If the original ferrari nut trashes the bolt the way mine did.. a mechanic will just use a new set of each right? Which means a non-metric application is a moot point for the next mechanic..

2) Fit. As a 99' the original mount did NOT have a lower spacer, so you could put the bolt through the mount and just tighten it up. The newer mounts require a spacer and this evident on the install. The PO assumed the old modality and tighted to the end. Thus, the mount was overcompressed and failed.

3) Spacers. A spacer is a simple piece of metal. Nothing more, nothing less. One thick $60 piece of aluminum does the exact same thing as steel washers below it. Furthermore the contact point on the metal within the center of the motor mount is maintained with the washers that I used, it did not extend into the rubber. The mechanics of the mount, vertical forces downward and lateral forces are EXACTLY the same in both configurations. Which is why..

At a year out.. its flawless performing as expected and designed. Inspections in 3, 6, and 9 month intervals show no degredation of the mount, no overcompression of the rubber, and no issues with bolt placement or function.

In essence, the repair does EXACTLY the same as the OEM configuration.

Now how was this dumb?

I admit I would PREFER to do the OEM repair with OEM equipment. And if it fails I will.

So far its been funtioning perfectly.

Edit: As clarification, this was the new mount.. NOT the original round 99' mounts. It had been replaced prior and in the past few years with the new style. But because of over compression the mount had failed.

 

Did not change the tranny mount. I'm having symptoms yet.. but when I do I might evaluate doing it myself versus having someone else do it. Its the press fit in. Not sure I feel like using some brake pads with holes drilled in them..

 

If you have a later car with the new mounts you'll probably NOT need to Macguyver the spacer like I did... It really is easy.

 

#1 If you understood how they are replaced by a pro it will matter and your intentions aside it will be done by someone else unless you total the car.

#2 I get that. But it would have failed by now anyway.

#3 Answered a question I did not ask. How did you know how far to space it? It does matter.
How do you know it is working flawlessly? What is your basis for comparison?

Sorry but well intentioned or not it still comes under the heading of a jury rigged fix and the fact that you did not answer one of the more important question shows your misunderstanding of the dynamics involved. An important point given the 99's reputation for breaking their frames at the motor mount brackets.

 

All answers given respectfully.. .

#1. If the threads are that degraded with removal.. would I want them cleaned and prepared with a tap and die or re-used. That is a question for the owner. It is very much appreciated cost wise to clean and re-use. Or.. just buy new bolts and nuts and re-apply. You know its going to work. Regarding the physical labor of removing 5 bolts per side, replacing, and then reassembling... what would a professional do differently?

#2. Ergo it didn't.

#3. So the old mount is a single cylinder of metal surrounded by rubber with a bolt going through it with a large washer on the bottom and a washer on the bottom. When you torque the bolt throught the center, it compresses the metal cylinder (lets say 2.5 inches long?) between two washers. The new design uses a shorter metal cylinder that abuts the engine mount on the top with no washer, and has a metal masher with a built in spacer on the bottom. the main bolt is torqued to compress the shorter metal cylinder. When you put the washer on the newer style mounts, there is a space between the large washer on the bottom and the metal cylinder in the center of the mount. As you know with the newer mount, this is filled with a thicker metal extension ontop of the large washer on the bottom, that in essence makes up the difference in distance in the mount that was lost from the prior design. The difference in height from the inside cylinder to the flatter aspect on which sites the lower washer. +/- some compressible rubber of 1-2mm lets say. Measured the difference with my calipers.

As I understand it, the frames crack on our early cars with track use even with professionally installed motor mounts, with proper spacers.

How do I know it works as intended? Comparable vibration reductions to 360's I ride in, and reduction in the vibration in my car. I didn't see in the WSM a specification for engine deviation and motion under operation at a given RPM. I also don't see any difference in operation with other 360's I've ridden in or seen running. Is there a spec that I haven't seen?

In addition, on inspection of my cars frame. There is no cracking.

So.. I reiterate with only the highest regard for your input here.. there is no cracking, reduction in vibration comparable to other cars I ride in and observe operating, no further compression in the rubber, no new vibrations, no shifting of the bolts, no bolts coming loose.. if I have the results that appear the repair functions equivalent to OEM, exactly how don't I understand the dynamics? I just don't understand what I'm missing?....

 

Not quite understanding how a lock washer is performing same as the pictured new style washer/spacer.

No mention of the bolt material. Was this an ACE grade 5, grade 8, or the cool shiny ones? Weight of the bolt will not distinguish the difference in strength (assuming they are all some type of steel).

edit: to achieve equivalent pre-load with different thread the torque would be different than called out for the OEM bolt/nut.

 

You can be happy with the repair and when it causes problems you will not be connecting the dots then either so you will continue to be happy with it.

When you find your car sale proof, remember this thread.

 

Intalling standard hardware in place of metric hardware is such a big no-no!! I see the irony in that your post was intended to discredit the prior mechanic's attention to detail, but in actuality you seem to have jury rigged it even further! But I do give credit for changing your own motor mounts and not being afraid to work on your Ferrari.

 

I am quite sure I have the old style mounts. I will put the car on my lift tomorrow and start digging in.

Last year I replaced the large round transmission mount. I bought the special tool and used a lot of grease on the threaded rod. Took some work, but I got the old out and the new one in. I heard someone say they apply some heat to the aluminum casting to expand the housing. I did not do that.

Good luck!!

 

Curt, it appears that your repair is possibly fine, and may work fine for many years. However, I have to agree with Brian, not that a "pro" should have done it, but that you should have used all OEM hardware. I'm anal like that. Unless it's an emergency, I always use OEM hardware.
And for those that think "pro's" do better work, it would be true if they followed the procedures to a T. I know for a fact that they take short cuts and rush just to get the car out. I've tried several dealers, private shops etc. and I always seem to feel disappointed and wondered why I didn't just do it myself. As a matter of fact, today I had the timing belt replaced on my 2000 Xterra at a Nissan dealer. Not only did they charge me at least 50% more than it should cost, but I got home and antifreeze was spewing out! I drove straight back to them to fix it again. Apparently they didn't clean the water hose nipples and the corrosion/debris prevented it from sealing properly. If I did the job, I would automatically clean them up with a little emery paper, just to avoid a possible problem. In addition they used the old hoses! I told them that was like taking a shower and putting on old underwear. If I did the job, I would have put all new hoses, and all new belts. Once they are off, why not put new ones? The mechanic told me that he used an airlift and it wasn't leaking prior to filling it with coolant. I had to explain to him that since it was a minor leak, the negative pressure can easily suck the hose tight and seal the leak. I kindly asked him to please check it with positive pressure, so I don't have to come back. Now I just have to hope that the old hoses hold up and don't fail any time soon. I really need to find these professional good mechanics that people talk about! I can't seem to find any that actually do things properly. In addition, even if they are mechanical experts and do a quality repair, they find another way to piss me off, ie. scratch the car etc.