IMS - Going with SKF hybrid

[Jamesp]

You're on the right path. I'd go (went) sealed to eliminate contamination from taking out the bearing. The bearing in most of the Boxsters out there costs about $6.00 retail.

[JFP in PA]

Originally Posted by Gelbster

Maybe these "SKF" branded tools?
Bearing puller kits by SKF - Fast and easy bearing dismounting

You do realize that is a $700+ tool..............

[Silber]

Originally Posted by Jamesp

You're on the right path. I'd go (went) sealed to eliminate contamination from taking out the bearing. The bearing in most of the Boxsters out there costs about $6.00 retail.

In doing more research I have selected sealed as well. The grease in the bearing I have selected is one of the best greases SKF makes and will last 6,000ish hours at the temperatures this bearing will see, worst case scenario with engine at max temp and 7000 RPM continuously. (GPF 4, n*dm 329,000, temp 120c see diagram 1 at below link.) So, there is really no advantage to opening the bearing to the engine oil that I can see given the grease is good for 200k miles minimum, I/e the engine is at max temperature/max RPM its entire life. If it is more normal usage with more average temps and engine speeds, 10,000+ hours is more likely. I want to keep the grease intact as long as I possibly can, oil may wash it out a bit over the life of the bearing, but the longer it hangs in there the better off I'll be. Huge side bonus is keeping the contaminants out. No random flake of metal can trash my entire engine via an open bearing sitting in sump oil.

Grease life for capped bearings

[cnavarro]

Originally Posted by JFP in PA

You do realize that is a $700+ tool..............

Use that puller on an ims bearing and see what happens. :-) Remember, the ims sprocket is just press fit onto a pipe with about .250" of interface.

[Bilmar72]

I am very much with 10/10ths on this one. I have just changed out the IMS on my gorgeous 2004 Boxster S which is my first Porsche. After doing the research I went for the IMS Solution. Yes expensive but in my opinion worth every penny. The IMS Solution is the only permanent solution to the problem. And I like the idea of an oil fed plain bearing, being simple, reliable and even if worn should not destroy the engine. Being cautious I also bought the tool kit and supplementary tool kit. Now I have seen comment on various forums about the high price of the tool kits, but I was blown away by all aspects of the tool kits and the IMS Solution bearing kit. The quality of every component was first class, the packaging was superb and the instructions which came with the new bearing detailed and complete. All in all completely professional and greatly appreciated. After pulling the tiptronic transaxle and then followed the IMS Solution detailed instructions step by step and to the letter. Also installed a new RMS. And all good, running like a dream and no leaks. For a bearing that when fails will most likely eat the engine I just don't see the point in taking shortcuts. But each to their own.

[thom4782]

I'm with Bilmar72 on this. I went with the IMS Solution on a 120K mile engine. It made no economic sense. But I know the engine's complete history and, most importantly, I wanted to avoid the time and money needed to source a replacement engine and pay for installation if it ever came to that.

[Gelbster]

See Post #24 above.
Just think about what this noob( :-) called Charles is saying.
If you use an improvised puller you risk doing concealed damage that will only reveal itself later, maybe sooner, maybe much later. If you compromise the the relationship or retention of the sprocket/tube, imagine what can happen when the chains move the sprocket at a different moment/speed to the IMS tube. Not good.
Disclosure like Charles, I have an LN tool and use it even though I have Kukko and similar.But Charles has more LN tools than I do.

[Silber]

none of this really applies to me, as I plan on using standard tools and method with an alternate bearing.

However, I believe you can use any puller you like if you brace it against the sprocket, not the case. Slide Hammer would be a very bad solution. If you had your bolt snap, you would probably have to create a hybrid between the LN puller and a Kukko puller such that you are pushing on the sprocket.

Silber

[Gelbster]

If the extractor design pushes against the gear, the sprocket assy could be pushed deeper along the tube.Or .... Not good.
I agree with you. Just use the same tool that has worked thousands of times for this specific and unique task. Guinea pig Threads are always interesting and cn be valuable when new parts/tools/techniques are shared.
Good luck with your bearing choice.
Long ago there was a disaster Thread on this subject where an infamous Poster used a self-selected bearing against the advice of the Bearing distributor. If you search "Boca Bearing" it may come up.
Here it is. A classic , best-of-intentions goes badly wrong Rennlist gem.
All I am doing is trying to help the P.O. make a fully informed choice about the many gotchas in this subject.They have all been covered in scattered Posts here but maybe it is futile to help.
https://rennlist.com/forums/996-forum/929113-i-bought-kk-s-car-long-story-5.html
Finding a good bearing substitute is easy catalog work.
Finding and installing one that works well is another story.

[particlewave]

I thought this was a thread about how the OP was going to install an SKF bearing.
I guess I missed the part where he wanted tired opinions and recommendations on LN products which are actually transparent attempts at turning this into yet another needless IMSB debate thread.

Silber - Looking forward to your install. It's always great to see owners take initiative and your install and results, good or bad, will be invaluable to the community.
Please post pictures and details as you go.

[Smallblock454]

Originally Posted by Silber

…worst case scenario with engine at max temp and 7000 RPM continuously.

The IMS isn't rotating at crankshaft 7.000 rpm. The camshafts are rotating at 3.500 rpm when the crankshaft is at 7.000 rpm (4 stroke engine). So because the IMS seems to have the same gearwheel diameter (didn't count the teeth, so i don't know exactly) as the cams i would say it rotates at around the same rpms as the cams and not as the same rpms as the crankshaft.

That means you have to look for an extreme high speed capable IMSB.

But it's important to take a look at the individual bearing specs.

I also would go with a sealed version.

And please remember that an engine in a car with acceleration, deceleration is not an engine on a engine stand. So if you have around max. 1g acceleration in changing directions, there is engine oil everywhere,

And if you want to reuse the center bolt, don't pull it with the cheapo "standard" tools some people like to sell for a lot of money. They are only OK if you replace the centre bolt anyway.

OK, enough IMSB talk for today. Think if you do a good research you'll find enough information to get everything right.

Regards, Markus

[78F350]

Originally Posted by Smallblock454

... And if you want to reuse the center bolt, don't pull it with the cheapo "standard" tools some people like to sell for a lot of money. They are only OK if you replace the centre bolt anyway.... Think if you do a good research you'll find enough information to get everything right.

Regards, Markus

I respect Markus's opinions, but Why not replace the center bolt? The original bolt design is flawed. During the replacement of the bearing it is simple to just put a new center bolt in (Silber sourced one easily with the Pelican kit).




As for the bearing selection, +1 to what Particlewave said. Thanks for posting, Silber, and looking forward to seeing the results.

[Silber]

Originally Posted by Smallblock454

The IMS isn't rotating at crankshaft 7.000 rpm. The camshafts are rotating at 3.500 rpm when the crankshaft is at 7.000 rpm (4 stroke engine). So because the IMS seems to have the same gearwheel diameter (didn't count the teeth, so i don't know exactly) as the cams i would say it rotates at around the same rpms as the cams and not as the same rpms as the crankshaft.

That means you have to look for an extreme high speed capable IMSB.

The one i have chosen is very high speed capable, reference speed of 17k RPM.

However, I think you may have it backwards. Since the camshaft turns at half the speed of the crank, the RPM I have to worry about is 3500 max not a high rpm Max. That will make the grease last even longer and the bearing in general last even longer.

I am thinking since I'm going with the sealed bearing, the oil splashing around in the crankcase won't make too much of a difference. That is the hope anyway. I selected sealed because that will keep the high performance grease intact the longest AND keep small particles away from the bearing. I just cannot see putting an open bearing in the sump of the engine where all of the junk ends up. If you could do it oil fed without it being exposed to sump oil, that would be good, but you can't it's sitting smack dab in the sump, imho it will get particles in it if there are any there to float in.

I'm also thinking as my engine has 115,000 miles on it, and this SKF hybrid IMS bearing I am selecting has a calculated life of 350,000 miles, even if I went with half that, 175,000 miles, that puts me out to 290,000 miles on this engine. Basically a lifetime solution. I may just let it ride and see if I can get a lifetime out of the one bearing. This is assuming I don't find any more information out about the bearing that limits its lifespan compared to what I've seen so far in the documentation.

Then again, with how much I love preventative maintenance, if I am in there for some other reason I may just replace it if it is close to the hundred thousand mile mark.

And finally, thank you to all for the encouragement. It's nice to know that I am contributing, regardless of Final result.

Regards,

Silber

[thom4782]

Sealed bearings are great until...

Over time acids and other contaminants in the oil cause IMS bearing seals to degrade. When this happens, leaking oil causes the grease to wash out. When the grease is gone, splash oil isn't sufficient to lubricate the bearing because not enough oil gets through the seal to adequately lubricate the bearing. With too little lubrication, the bearing fails eventually.

BTW: if you don't buy what I've said, why do you think aftermarket suppliers like LN and TuneRS use unsealed bearings as their fixes to a design flaw?

[Gelbster]

Almost all reputable kits use a single seal bearing to facilitate splash lubrication.There has been a huge amount of discussion on this and few dispute its positive results.
Some diy guys removed both seals .They did not read the oil-in-the-ims-tube discussions.
The potential flaw in the 1RS IMSB proposal is filtration.That can be addressed by a filter upgrade.
But this is just one part of the total subject
The TuneRS kit has the oil line but you can choose not to fit it. If you check experience mentioned by JFP ,you;ll note some serious problems with using the supplementary oil line fed by the port on top of the camshaft cover.

Originally Posted by thom4782

Sealed bearings are great until...

Over time acids and other contaminants in the oil cause IMS bearing seals to degrade. When this happens, leaking oil causes the grease to wash out. When the grease is gone, splash oil isn't sufficient to lubricate the bearing because not enough oil gets through the seal to adequately lubricate the bearing. With too little lubrication, the bearing fails eventually.

BTW: if you don't buy what I've said, why do you think aftermarket suppliers like LN and TuneRS use unsealed bearings as their fixes to a design flaw?

[Silber]

Apparently according to Jake Raby, the inner seals on his bearings are leak free:

which ims bearing upgrade

I would assume with a high quality bearing the seals will be better than the OE porsche ones, but i need to do more research, perhaps combined with a freeze plug in the ims shaft to block thermal expansion and contraction the grease would remain intact.

This post does a good job explaining how oil will get sucked into the tube, though I'm not sure I agree with his solution.

https://grassrootsmotorsports.com/forum/build-projects-and-project-cars/the-frugal-mechanic-meets-a-porsche-boxster/120457/page2/

Scroll about halfway down, look for a wall of text.

Silber

[thom4782]

If you're going to continue to research this, find out first who Porsche sourced its bearing from. If you find out and compare specs, your choice may be better or not. If it/s dramatically better than Porsche's on all measures, then hopefully your choice will last at least as long or longer as the Porsche bearing does.

Keep in mind, there are lot's of folks out there whose opinions are just guesses. Porsche's and LN failure rates are well known after use of thousands of units and thousands of miles in the real world. Others are speculative. When faced with a potential $5K to $20K consequence of a failure, I'd suggest you let real world results guide your decision.

[Gelbster]

"Apparently according to Jake Raby, the inner seals on his bearings are leak free"
Just to be clear, Jake does not sell anything.Not even bearings. He is referring to specific bearings sold by LN and a few others .
The leakage into the IMS tube occurs when ppl install substitute bearings with no seals or eventually/sometimes with 2RS sealed bearings. It is all in prior posts with theories about why.
The plug in the IMS tube has similarly been discussed/dismissed for substitute IMSB with 1RS .

[Silber]

Originally Posted by Gelbster

Just to be clear, Jake does not sell anything.Not even bearings. He is referring to specific bearings sold by LN and a few others.

My mistake, i thought he was as affiliated with LN. Apologies for muddying the water.

I am actually thinking that a plug with 2RS is the best of all worlds. If you block off the air space in the tube, it cannot suck oil to wash out the grease when expanding and contracting with engine heat cycles. If you can prevent the incursion of oil, then a lifetime greased bearing makes a lot more sense.

If you have any links to discussions of plugging the IMS tube and why it would not be a good idea, I wouldlove to see them.

Regards,

Silber

[Bilmar72]

Originally Posted by Gelbster

If the extractor design pushes against the gear, the sprocket assy could be pushed deeper along the tube.Or .... Not good.
I agree with you. Just use the same tool that has worked thousands of times for this specific and unique task. Guinea pig Threads are always interesting and cn be valuable when new parts/tools/techniques are shared.
Good luck with your bearing choice.
Long ago there was a disaster Thread on this subject where an infamous Poster used a self-selected bearing against the advice of the Bearing distributor. If you search "Boca Bearing" it may come up.
Here it is. A classic , best-of-intentions goes badly wrong Rennlist gem.
All I am doing is trying to help the P.O. make a fully informed choice about the many gotchas in this subject.They have all been covered in scattered Posts here but maybe it is futile to help.
https://rennlist.com/forums/996-forum/929113-i-bought-kk-s-car-long-story-5.html
Finding a good bearing substitute is easy catalog work.
Finding and installing one that works well is another story.

Me too, just providing another view such that a member may be fully informed before making a decision. Certainly not "trying to present tired opinions and recommendations on LN products". I thought a range of opinions was the point of a forum. Having said that, whilst I have no connection with LN I am mystified as to why they cop so much criticism on the forums. They make a great product but it is priced beyond many budgets. That's fine, don't buy from them. But why bag them.

And when I see suggestions of using a slide hammer to pull these bearings, whowa!

As to bearing choice, remember Porsche themselves read a bearing catalogue and look where that got them!

Overall though I take my hat off to anyone who works on these engines, they are beautiful pieces of engineering but they do need thought and care. Good luck to all.