1999 996 IMS Bearing Question: to DIY or not to DIY?

Hi everyone, I'm a 928 guy and a frequent poster on the 928 side of Rennlist... but I do also have a '99 996. It is in beautiful condition, 39K miles, and the interior is pristine. My father gave it to my wife and I as a wedding present (he was the original owner.) He hardly drove it... when I told him that our cars need to be driven frequently, he just gave it to us. I haven't done much on the 996 but bleed the brakes and change the oil. I have some experience on the 928, doing electrical things up through changing the timing belt, rebuilding the oil pump and tensioner, and doing a complete top-end refresh of the intake, throttle body, etc. I documented these procedures in the link at the bottom of my signature. My father's other car, a Boxster (1998) just had IMS failure. This made me begin to worry about the 996. The wrinkle in the story is that my dad passed away a year ago yesterday, so I feel extra careful about the 996. There is a lot of sentimental value in this car. Given my non-professional but somewhat experienced aptitude in wrenching, would you recommend that I change the IMS bearing myself, or should I bring it to an experienced person? I live in Missouri. Sorry for writing this short novella... I really could use some advice here. Thanks everyone.

Hi everyone, This is a question for those of you who wrench both 996 and 928s. I apologize for this being somewhat off-topic. Two years ago my father gave my wife and I a 996 as an engagement/wedding present (he was the original owner.) He hardly drove it... when I told him that our cars need to be driven frequently, he just gave it to us. I haven't done much on the 996 but bleed the brakes and change the oil. I have some experience on the 928, doing electrical things up through changing the timing belt, rebuilding the oil pump/tensioner/clutch slave, and doing a top-end refresh of the intake, throttle body, etc. I did these procedures successfully, with the help of the many kind Rennlisters whose knowledge far surpasses my own. So, my father's other car, a Boxster (1998) just had IMS failure. I feel the need to do the IMS on the 996 before something bad happens. The wrinkle in the story is that my dad passed away a year ago yesterday, so I feel extra careful about the 996. There is a lot of sentimental value in this car. Plus, he bought it new, whereas I paid a total of $14K for both of my 928s. Given my non-professional- but higher than beginner- aptitude in wrenching, would you recommend that I change the IMS bearing myself, or should I bring it to an experienced person? I live in Missouri. Thank you all in advance for your input.

you can do it yourself. you need a couple special tools and be able to get the engine or trans out. it will go quicker and easier if you have a shop do it.

Syoo8, There are several of us who own both. Couple questions regarding the 996. What year? 6 speed or tiptronic? How many miles? how many miles nd what yr is Boxster when the IMS failed? Where in MO? One of the issues with replacing the IMS is that you need some specialized tools to do the repair. Typically when folks do the IMS they do the RMS and possibly clutch (depending on miles) as they are all right there when things are apart. Not all 996s were created equally, for example my 99 has the original Porsche IMS but it's dual row so they were much less prone to failure. My RMS is starting to weep so will probably take care of those this fall and with 82K miles will probably do clutch as well. KCAttorney on here has had both (just sold his 996) but can probably provide names of good indie shops in KC area of your closer that that side of the state. Good luck!

-1999 - 6 speed - 42,000 miles The Boxster was 1998, with I think over 100K miles. I live in Columbia, halfway between KC and St. Louis. I know Jeff (KCAttorney- what a nice guy!) and will ask him.

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Columbia a great place! From what I can gather the 99s are much less suseptible to IMS failure and it typically happened within 1st 30k miles. (one of the reasons I looked for a 99) but there are others on here that have much more knowledge than I. I'm originally from north of KC so next time I'm back am going to swing by the museum and introduce myself to Jeff. Again, good luck, I will be following the thread.

There is no safe 996. Every one of them will eventually need IMS and possibly RMS. It's just question of needing IMS at 50k, 100k or 150k. Waiting one mile too long will basically kill the engine. Clutch, IMS and RMS at same time every 50-75k isn't that bad job.

Disclaimer: I don't own a 996 but have been investigating them for months. Now, I know your level of work product and I think there is no question you can do the IMS if you aren't time constrained(I presume). I've seen the trans out, and looked at the job from several angles and there's nothing in the job that is particularly complex, just a lot of wrenching on stuff. You will almost surely need access to a 4 post or 2 post lift, unless you want to do all the work on your back, not recommended. You'll need to rent or borrow the IMS bearing tools, which are becoming more widely available. You'll also want some special cam chain alignment/locking tools avail. While you are in there jobs: Air Oil separator; Rear main seal; Clutch plate; axle gaiters; Alt Y cable. The folks on the 996 board are much, much less DIY friendly than this board. If you post about this over there I assure you it will be pages of doom and gloom, and advice to take it to the most expensive indy Porsche shop in north Amer. They mostly do NOT work on their cars over there, which is a shame. For the few that do work on their cars, they do NOT post DIY steps. I believe there is a DIY guide on Pelican that I read which is fairly good. http://www.pelicanparts.com/techarti...MS_Bearing.htm

Guidance on IMS failures shows up regularly. My new local PCAregion (Oregon) website has a section devoted to it. It mostly outlines the potential for failures in the various iterations of the engines, and how repairable each one is. There are penty of online references to the problems, some with solutions of various flavor. If you are OK with the tools, can follow instructions, and have the time, DIY is reasonable. Your Boxster engine might be rebuildable, depending on how much debris circulated with the oil and whether there is cylinder and head damage from valve interference. On the 996, you can carefully monitor oil and filter condition, magnetic drain plug debris, etc, for signs of the bearing coming apart. That's not my style generally, as I'd rather pick a convenient time and location for a repair effort rather than have the location, timing and magnitude of expense chosen for me. If you decide to not do it immediately, remember to change the oil frequently and monitor what comes out and what's captured in the filter. You want to catch the first (and only) bearing fragment before the oil system needs a full flush with block cleaning. I'm never that lucky. --- Neighbor in our new neighborhood has a 2001 996, and is in denial for the most part about IMS failure potential. He says, correctly, that many cars don't seem to have these failures. "Yet" I remind him. I offered to help him over the winter with a watch-and-learn-together program, but it didn't happen. I saw his car out today for the first time this spring, just a wave as he drove away. Big red bulls-eye on the engine lid.

Pelican Parts used to have a very good tutorial for the IMS replacement. My '99 Boxster died of other causes two years ago, but I was preparing to do it myself at the time of it's death. I had picked up a used LN replacement tool set that I can loan you.

You can do it (given your experience on the 928), as other 928 & 996 owners have done it. Read long-time 928 owner Shark Attack's approach in "I'm going in alone" at the link and you will see that it is not that difficult: https://rennlist.com/forums/996-foru...t-bearing.html

Scott - Knowing what you have done to your 928, I know that you possess the ability to DIY. But, having said that, I would recommend that you take it to Doc at Rennsport KC to let him do it. AND, having said that, and given that it is a '99, I would wait til you think it needs a clutch (or is close to needing it) and do them both at the same time.

Oh, and I don't remember your mentioning the 996 before. My memory going bad? I was in CoMo over the weekend for a fraternity weekend - I should have called you to grab a beer.

The question really is: Do you have access to a lift, a transmission jack, and all the special tools required? After speaking with somebody who has done it himself yesterday, with all the right tools (he did it on his back), I would say it's easy for a DIY mechanic who knows what he is doing. If you have to buy all the tools, there really isn't much savings over having somebody do it for you. At this point, when it's time, I will do mine.

Also, spend some quality time on the 986 forum. Even though it is Boxster centrick, it is still the M96 engine. Lots of help and discussion there. By the way, the only time to do the IMS fix is before you have symptoms of bearing failure. Once you have metal and/or plastic in the oil, it is too late. So if the car is clean, do it or otherwise get it done.

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This is a very kind offer. If I decide to do it myself, I may take you up on it-- in either case thank you very much.

For what it's worth. To change a double race bearing of the 99 model I would say you are being paranoiac for no good reason.

More than likely you have a 99/996 with the double row bearing. These have a very small failure rate. Do not fall for the internet hysteria. Save yourself some money and sleep...change your coolant, brake fluid, put in some fresh oil, a LN Engineering spin on filter adapter, a LN magnetic oil plug and drive the car. Sounds like you are going to keep the car for a long time, so you'll have a chance to monitor things as you go along. At 39K mileage it is doubtful you even need a clutch at any point soon. Preemptive replacement of the dual row bearing has caused more problems due to the experience required to properly replace the bearing. There will be lots of other stuff to be concerned about upcoming and to tinker with: water pump, thermostat, coolant tank, AOS, brake pads, etc. Probably the biggest thing to do is to keep fresh oil in the car and drive it everyday, and enjoy the heck out of it before falling into "doomsday scenarios". Just my two cents....and edited maybe for your peace of mind: mine is a 99/996 with 133,000+ miles, driven everyday like a delivery truck for my work, OE bearing not replaced, OE clutch not replaced, OE rear main seal not replaced, but I have done the other things I listed. My car is still beautiful and runs like a champ.

I'd go for it as long as you have the tools to do it safely.

Scott, One caveat to the wise 'don't bother -it's a low failure rate double-row bearing' advice. If it has a leaking RMS (fairly common)it will eventually contaminated the clutch.If it is a Tip ,you could wait longer? Lots of other Modes of Failure would be higher on the list.

I did mine. I did not have a lift - I used 4 stout jackstands. You will definitely need a good low-profile tranny jack. You will need some specialized tools like the LN Engineering IMS toolkit to lock the timing and pull the old bearing and drive in the new one. Mine is a C2 - so I don't know what complications a C4 might bring. Mine is manual also. I changed the rear main seal and clutch friction plate and all the clutch bolts to new. I used the 4" PVC adapter to seat the RMS. You will need a 16mm flex socket to get the upper transmission-to-engine mount bolts off and back on, along with a star wrench (like a giant torx, dunno, maybe it IS a torx) to remove the one odd bolt on the transmission. I added the DOF flange to mine for continuous lube of the new bearing. You will also need some way to hold the crankshaft to remove and then reinstall/torque the clutch bolts -- I booty-fabbed a holding fixture for mine from some scrap steel, two holes aligned with clutch bolt heads and one of the big tranny mount bolts. It really is not that difficult.

As long as finances are not the main consideration, it comes down to whether you think you'll do the work as well or better than your mechanic would, and whether or not you have the expertise and tools to handle any complications that arise. Whenever I see a towtruck delivering a partially dismantled car to my mechanic, I always wonder how much extra that's gonna cost. I trust my mechanic as far as one should trust a mechanic, but you're not exactly in a terrific bargaining position when you show up with a car you disassembled...

I guess it all will depend on your level of comfort of doing DIY's on the vehicle. We have a great IMS Bearing Replacement DIY that should be of some assistance to you. Take a look at it and see what all it entails and then go from there. We also have a select few of IMS bearing update kits here . Check them out and read up on their differences. If you need any further assistance, please don't hesitate to ask. -Luccia

I just finished doing it myself and know a couple more 996 owners that are not mechanics that also did it themselves. Yes it's a critical piece, but there really isn't much to it. Couple of critical steps, but plenty of info on the net, just take your time and have proper tools for the job.

double post.

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I would just say you are doing everything you can to make the odds even more in your favor. I can see a good reason to do it, first would be peace of mind.

SORRY, DOUBLE POST

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Hi Joe, It is actually my brother's hysteria- he took ownership of my dad's 986 which just suffered IMS failure. I warned my dad about IMS and he replied that '98 cars have a low failure rate... I think our family would feel so horrible if both of my dad's cars suffered IMS. Noted. It looks like I would be wise to change (WYAIT) - clutch plate - AOS - RMS - am I missing anything? It sounds like, in addition to the replacement bearings, replacement seals, etc, I will need: - IMS bearing removal tool (I think I can borrow this from a friend) - RMS tool - cam timing tools - am I missing anything? (I had a standard assortment of tools, and will pick up a transmission jack at Harborfreight.)

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Hi! I've been away for a while, and will be out of town until August... Let's definitely get together when you are next in town (in the fall, for school starting?)

Age and lack of use can have a negative effect on a car. Your dad barely drove it...and now the car is 16 years old. And the other Porsche he had with the same engine issue just broke. Low mileage was also a factor in some IMS failures. The IMS bearing is at one end of the shaft...but things can also go wrong at the other end. I'd want to best wrench I could find to be doing this work on my car. You have years to play under the shade tree and have fun...but this is something that can really bite you if you do it wrong.

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Thank you Luccia for your reply. What would be helpful on Pelican is if you could list: a) WYAIT items for IMS bearing replacement. My friend docmirror listed the AOS, RMS, clutch plate, and a couple of items I am not familiar with. Are there others? Is it a good time to change the water pump as well (or is the water pump on the other side of the engine?) b) Special tools for IMS bearing replacement. So far what I've seen listed are: - LN IMS bearing puller - special tool to properly seat the RMS (couldn't find this on your website) - 16mm flex socket - giant torx socket - tool to lock the engine to TDC (I see this as part of your kit.)

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With this there is really nothing a shop can do that would be all that much different than someone at home who is comfortable with tools and around cars. The biggest difference is that (and although you pay a shop) it takes them less time. I had the pleasure of paying a little over $2k to have my IMS replaced, and that's really all they did. Clutch was fine and was put back in, they replaced the RMS, everything else checked out. Granted I would have missed replacing my cabin air filter, didn't even know I had one, but for the most part if I had a shop it wouldn't have been hard to do what they did. But, on the other hand, if I was doing it myself it would have been a whole weekend job rather than just around 8 hours for the shop. I'm not in anyway saying my shop is expensive, bad, or anything. Just that it's something I would have wanted to do myself if I could have.

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And what about the Mezger?

Look at it from the mindset that you're not paying extra for labor; you're paying for expertise. After all, there are laborers lurking around in front of Home Depot for $150 a day but how much expertise can they offer? On the flip side, you would probably follow the instructions religiously, whereas an expert might rely too much on his expertise and end up missing something. Which is more comforting to you is your call.

I would not recommend it to a novice. Period. I've seen enough novice work towed to a dealer. That would not be too good on this job.

I don't have any experience with the 996 or the IMS, but if you need and would like an extra hand to turn a wrench, I would be happy to help.

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Mezger only used on turbo and gt3.

There is a 996 tech forum here that you can post in - right?

The hardest part of the whole process is removing and putting back the transmission on jack-stands. Just don't do the AOS "while you are in there" unless you have an early model. I was ready to weep a couple of times during my replacement on 2004. Between Bentley Manual, Pelican, and the info on this board there should be no surpirses.

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Oil cooler o-rings while u r in there

Great thread. getting ready to do the same thing. Hope we get more updates!

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I think after 5 years there is likely to be no updates. Call me silly....