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IMS upgrade TOTAL FAILURE


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Ok so i have a 1999 c2 convertible that I decided to do the IMS upgrade from LN engineering (dual row bearing. Got the order in last week, and attempted to remove the bearing. The support stud broke. Called LN engineering and they said this happens occasionally and i needed an additional tool from kukko. so I ordered that. The Kukko tool has now broken!

There is so much force going into this puller i doubt the tool was defective. I doubt it is possible to pull the bearing. You can see from the pictures where the Kukko puller and the ims bearing were digging into each other so there is a lot of grip between the two. I have no clue what i am going to do at this point, and am quite frustrated.

any advise?

post-25388-126879328914_thumb.jpg

post-25388-126879329837_thumb.jpg

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The double row bearings are hold and saved by a circular steel spring, which is not accessible from outside, between the inner side of the tube and the outer cover of the bearing, and are very difficult to remove without damaging the tube, oil pump drive, etc. on the opposite side of the tube, one of the reasons Porsche refuses to sell the bearing separately. Single row bearings cause no problems by a replacement, the resistance is much less. Success.

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The double row bearings are hold and saved by a circular steel spring, which is not accessible from outside, between the inner side of the tube and the outer cover of the bearing, and are very difficult to remove without damaging the tube, oil pump drive, etc. on the opposite side of the tube, one of the reasons Porsche refuses to sell the bearing separately. Single row bearings cause no problems by a replacement, the resistance is much less. Success.

What would be the results if you loosen the case bolts in that section of the housing? Could that create enough slack to release the bearing?

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I doubt it, but it will create more oil leaks than you ever imagined could exist...............

Suggest you give Jake Raby a call, he once described pulling one of these that went flying around the shop when it released; seems to take a lot of force to dislodge it.

Edited by JFP in PA
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Based on the position that your bearing is in as pictured I'd say the bearing puller was not centered over the IMS correctly during the procedure. This created an issue where the bearing contacted the puller during extraction, creating a situation where the bearing could not move and something had to break.

This would also explain why the Kukko internal extractor also broke.

With that pic I can see that the bearing has already been extracted past the point where the internal snap ring is compromised, meaning that there should be nothing else locking the bearing in place, except maybe contact with the puller body due to being improperly centered. From this point the bearing should extract very easily.

Some bearings are more difficult to remove than others, I've done the procedure over 100 times since the pullers and procedures we have now were developed and I have had 3 bearings that gave me a difficult time, two of which were due to my own inability to properly center the bearing and the puller... Once I remedied that situation they extracted like all the others.

FYI- I've never broken a center stud during extraction, not even with the most securely locked dual row bearings. I have broken DOZENS of Kukko internal extractors when doing this, which is the reason why I developed the technique of pulling from the center stud, then that was shared with LN when we teamed up to make the current pulling tool.

You'll need another Kukko puller and this time make absolute sure that the body of the IMS bearing will be totally centered with the bore of the IMS bearing puller, any contact is bad as it loads the bearing sideways into the IMS tube, increasing difficulty. If the bearings has some way become loaded sideways into the IMS tube you could have some serious difficulty heading your way.

BTW_ Loosening case bolts will DO NOTHING to assist with this procedure. Look carefully and you'll se that the bearing is being extracted from the IMS tube, not the crankcase!! The bearing just so happens to pass through the bore in the case during extraction. Leave those case bolts intact, don't touch them.

Edited by Jake Raby
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well I got the new tools in, and when i attempted to pull it out the inner race broke up. i have cleaned up all of the ball bearings and the inner race. From my last conversation with LN Engineering i will need a different puller to extract the outer race from the ims.....

when i started the pulling proccess tonight the inner race had cracked already. i tried to center the puller as best as i could however it did not take much force for the race to pull out.

I tried to center the race as best as i could by placing a strip of card board arount the ims. this created a shell to help align the ims with the puller. the puller itself is .2" thick in wall thickness. I beveled about .025 around the edge to give me about .05 additional in clearance. i just don't think there was enough structure left to pull the race out

It will be another long wait for another tool. hopefully like Jake said it is an alignment issue and with the right tool and getting it aligned properly i will be able to pull it out

If not then I dono.....

Edited by iornman86
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well through frustration and despair got the outer race out....it was not pretty but everything looks to be in good condition now, the new bearing is installed.

time to start putting everything back together so i can reinstall the engine

oh and the circlip never did get popped out of place, i did verify that, not sure why the thing would not ever move, except that it was extremely tight. The new bearing going in was quite tight too, however i do believe the new bearing would pull out if i removed the retaining clip

Edited by iornman86
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well through frustration and despair got the outer race out....it was not pretty but everything looks to be in good condition now, the new bearing is installed.

time to start putting everything back together so i can reinstall the engine

on and the circlip never did get popped out of place, i did verify that, not sure why the thing would not ever move, except that it was extremely tight. The new bearing going in was quite tight too, however i do believe with the clip removed on the new bearing that it will pull out again

Not sure of your last statement? You didn't put the clip back in did you?

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More than likely if the fit was tight enough to have caused the extraction issues the new bearing would have been impossible to fit. One thousandth of an inch separates success from failure in this game.

Glad to hear you finally removed the old bearing, your difficulty has to be the worst to date... Heck thats not bad considering this time last year the general consensus was this bearing was impossible to replace.

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well the car is finally back together! I want to thank LN Engineering who overnighted extra tools to me at his expense to help me get this worked out and flat6 for their advice! and the people on this forum whom i could have never figured out how to do all the stuff i have done. for those who are curious here is a list of "maintenance items" i did

replace ims bearing

lower temp thermostat

replaced cam to cam wear pads

replaced cam to cam timing chains

replaced starter (found the main power lug stripped out)

replaced starter again (first napa one was defective made a horrible noise)

replaced bracket on engine that supported vacuum canister (it was zip tied before)

replaced hose from AOS to passenger side engine (it had broken before i replaced it with rubber hose and that leaked, had to have engine out for this)

cleaned engine well from various oil leaks over the past 10 years

Flushed cooling system, which probably didn't need it, the coolant looked new from draining it out did not find any debris

fixed vacuum line routing, the intake flap was not hooked up to the vacuum switch for some reason

changed oil

now the only lingering item is to fix the convertable top, the cylinder is leaking. Also need to trouble shoot a sticky clutch. I think the clutch pedal has worn bushings, bad spring or the master cylinder is defective. the slave had been replaced and did not fix the issue.

Edited by iornman86
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Let us know how the 160 deg. thermostat performs!

Funny -- or sad --- we are having the same problem with our most recent IMSR.

Snapped the bolt right at the inner race.

we destroyed a Kukko 21-4 as soon as we got it. $90 in 10 sec :-( Not happy.

a hand made butterfly/molybolt style extraction "tool" didn't work -- it failed several times.

We are going to resort to welding to the ims and trying again.

What tool did you use to pull the outer race? Just in case we need to order that one too.

BTW: you are pulling the IMS out of a tube that "floats" in a carrier so to speak.

There is no loosening of anything that will make pulling the IMS any easier.

The tool fits in a whole in the case and presses against the end of the IMS tube, and attempts

to pull the bearing assembly out of the tube. For the double row bearings there is an internal grove

in the tube that a metal o-ring sits in that locks the double row bearing sets in place

that sits between the rows. You have to crack this o-ring to be able to extract the IMS.

For the single row bearings there is a simple compression ring that locks the bearing in place

accessible as soon as your can see the bearings.

Hope that helps explain things.....

thanks,

Mike

Edited by txhokie4life
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Let us know how the 160 deg. thermostat performs!

Funny -- or sad --- we are having the same problem with our most recent IMSR.

Snapped the bolt right at the inner race.

we destroyed a Kukko 21-4 as soon as we got it. $90 in 10 sec :-( Not happy.

a hand made butterfly/molybolt style extraction "tool" didn't work -- it failed several times.

We are going to resort to welding to the ims and trying again.

What tool did you use to pull the outer race? Just in case we need to order that one too.

thanks,

Mike

THE kUKKO 21-4 can be reinforced with an allen bolt of the same thread type. grind down the allen bolt head to a wedge shape and it will never break, i stripped the 15/16 bold but that wedge was still strong.

ultimately if it dosent come out the inner race will break apart, make sure none of the balls fall into the case, collect all the stuff out of the ims with a magnet and then pull out the grinder

I used cardboard from a roll of paper towels and cut strips of it to go around the IMS. this will protect he sealing surface on the block. make sure you put enough cardboard around there to seal it tight to keep steel debris from getting into the block. Also put a rag down the ims to keep debris out of there.

I used an air powered die grinder. grind down one part of the outer race so it is paper thin all the way to the back. be careful not to grind into the ims, if you stop often as you get close you will see a small hole form when it breaks through. . you will break through the snap ring area first, as it is raised. make sure it is very thing from front to back. the hard part is getting through the back part of the bearing as the IMS steps up behind the bearing.

After you have ground down one section, grind down another section 90 degrees away paper thin again. then take a screw driver and snap that section out. as long as you have ground it paper thin all along it will snap out easy. then cloose a section in the middle of the remaining bearing and start grinding again. as it gets then you can bend it out with a screw driver

as i was grinding i stopped often to wipe up all the debris. after the race is out wipe everything down good, pull the rag out from the ims. Then use a magnet to clean out all of the area that you can. put a rag back in and use compressed air to blow the area clean. then pull out the card board. dont forget to plug the screw holes before you start grinding, the metal debris will get EVERYWHERE

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also the allen bolt i purchased to reinforce the puller was from fastenal, it was "just" barely long enough to reach but it did the job it was 12.8 grade harness or whatever the top one is, i forget, metric stuff and all :)

also when you attempt to pull it out you may put a piece of that cardboard around the ims to help center the puller Flat6 thought that may have been part of my issue. I also ground the puller a little. if i remember right the thickness of the puller wall is .2" i ground maybe .05" around just to give a little additional clearance. i wouldn't take too much off otherwise it may load the ims weird or something....but .05 give .1" larger hole just a little extra clearance in case it is not being aligned correctly

example of the cardboard is below

post-25388-12693827859_thumb.jpg

Edited by iornman86
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also the allen bolt i purchased to reinforce the puller was from fastenal, it was "just" barely long enough to reach but it did the job it was 12.8 grade harness or whatever the top one is, i forget, metric stuff and all :)

also when you attempt to pull it out you may put a piece of that cardboard around the ims to help center the puller Flat6 thought that may have been part of my issue. I also ground the puller a little. if i remember right the thickness of the puller wall is .2" i ground maybe .05" around just to give a little additional clearance. i wouldn't take too much off otherwise it may load the ims weird or something....but .05 give .1" larger hole just a little extra clearance in case it is not being aligned correctly

example of the cardboard is below

thanks for the suggestions. I think my mechanic did something similar to what you suggested and stripped the Nut just like

you mentioned -- we've almost got it out -- but need to get a new nut.

PITA,

Mike

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also the allen bolt i purchased to reinforce the puller was from fastenal, it was "just" barely long enough to reach but it did the job it was 12.8 grade harness or whatever the top one is, i forget, metric stuff and all :)

also when you attempt to pull it out you may put a piece of that cardboard around the ims to help center the puller Flat6 thought that may have been part of my issue. I also ground the puller a little. if i remember right the thickness of the puller wall is .2" i ground maybe .05" around just to give a little additional clearance. i wouldn't take too much off otherwise it may load the ims weird or something....but .05 give .1" larger hole just a little extra clearance in case it is not being aligned correctly

example of the cardboard is below

thanks for the suggestions. I think my mechanic did something similar to what you suggested and stripped the Nut just like

you mentioned -- we've almost got it out -- but need to get a new nut.

PITA,

Mike

so the bearing has begun to pull out?

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also the allen bolt i purchased to reinforce the puller was from fastenal, it was "just" barely long enough to reach but it did the job it was 12.8 grade harness or whatever the top one is, i forget, metric stuff and all :)

also when you attempt to pull it out you may put a piece of that cardboard around the ims to help center the puller Flat6 thought that may have been part of my issue. I also ground the puller a little. if i remember right the thickness of the puller wall is .2" i ground maybe .05" around just to give a little additional clearance. i wouldn't take too much off otherwise it may load the ims weird or something....but .05 give .1" larger hole just a little extra clearance in case it is not being aligned correctly

example of the cardboard is below

thanks for the suggestions. I think my mechanic did something similar to what you suggested and stripped the Nut just like

you mentioned -- we've almost got it out -- but need to get a new nut.

PITA,

Mike

so the bearing has begun to pull out?

Yes I think so -- I took a quick look last night -- but I didn't get a chance to measure

the distance to the lip -- so I might have been my wishful thinking :-)

but I asked if he could tell if the lock spring had broken (popped) -- but since he is

deaf -- he could not tell when the nut had sufficiently stripped.

I should know soon whether he was completely successful or not.

mike

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HI,

Fortunately I didn't have a problem pulling out the old bearing, but I'm having a terrible time trying to get the new LN bearing in.

Did you have any difficulty with yours?

The instructions say that the bearing should go in easily. However the LN bearing will go in about 1/4 of the way and won't go in any further, no matter how hard you hit it with the dead blow mallet.

I've checked to make sure the bearing is going straight into the IMS hole, the hole is clean and and I've used light oil to see if it would help. I've even put the bearing in the freezer which brought the diameter down about .001". But still it won't go in.

I'd appreciate any suggestions on what I can do next to get the bearing in.

Jake, you seem to have a lot of experience installing these bearings, I'd appreciate hearing from you on what can I do next.

Thanks,

Dan

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HI,

Fortunately I didn't have a problem pulling out the old bearing, but I'm having a terrible time trying to get the new LN bearing in.

Did you have any difficulty with yours?

The instructions say that the bearing should go in easily. However the LN bearing will go in about 1/4 of the way and won't go in any further, no matter how hard you hit it with the dead blow mallet.

I've checked to make sure the bearing is going straight into the IMS hole, the hole is clean and and I've used light oil to see if it would help. I've even put the bearing in the freezer which brought the diameter down about .001". But still it won't go in.

I'd appreciate any suggestions on what I can do next to get the bearing in.

Jake, you seem to have a lot of experience installing these bearings, I'd appreciate hearing from you on what can I do next.

Thanks,

Dan

Of the 6 or so we've done -- one had this problem -- and it was because of the engine stand -- we couldn't hit it cleanly -- and it angled on us.

We pulled it == straightened it out -- and it went in just fine.

mike

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HI,

Fortunately I didn't have a problem pulling out the old bearing, but I'm having a terrible time trying to get the new LN bearing in.

Did you have any difficulty with yours?

The instructions say that the bearing should go in easily. However the LN bearing will go in about 1/4 of the way and won't go in any further, no matter how hard you hit it with the dead blow mallet.

I've checked to make sure the bearing is going straight into the IMS hole, the hole is clean and and I've used light oil to see if it would help. I've even put the bearing in the freezer which brought the diameter down about .001". But still it won't go in.

I'd appreciate any suggestions on what I can do next to get the bearing in.

Jake, you seem to have a lot of experience installing these bearings, I'd appreciate hearing from you on what can I do next.

Thanks,

Dan

Hi Dan,

I had the exact same problem with my installation of the new IMS bearing (from LN Engineering). My extraction of the single row bearing went just fine and I was eager to install the new bearing. However, my first attempt went horribly wrong.

I started using a dead blow mallet to drive the new bearing in, and it did seem to go in a bit. Then, to my disappointment, it wouldn’t move any further, no matter how much I was hitting it. Thus, I had to extract the new bearing, at which point I thought I’ve damaged the new bearing (it made a strange noise when I spun it by hand). I called LN; they were VERY helpful and agreed with me that I had an alignment problem. I was working on this project using larger jack stands, laying underneath the car, which positions your body at an awkward angle for any perfect alignment. Anyway, LN was king enough to sell me another new bearing (with another new stud pressed in) and shipped it to me ASAP. When I received the new bearing, I was very nervous to make a second attempt, but I overcame my fears, thinking that, after all, it was just a simple bearing that has to be driven in - no big deal right? Well, no matter how careful I was the second time, the bearing still didn’t just slide in. I started using the dead blow mallet again, but changed to the smallest hammer I could find, for more control. Well, because my IMS shaft was off center by just a little bit (to the right and up slightly, although the tensioners were loose), I sub-consciously overcompensated and was beating in the right side of the bearing more than the left. The bearing seemed to be stuck (again) and panic was setting in. I could visually tell that the right side of the bearing was in just a fraction of an inch deeper than the left (looking at the angle of the driver tool, supplied by LN). However, with a little bit more force, continued to beat that bearing in, now concentrating on the left side of the bearing a little bit more. FINALLY, the bearing started to slide in.

I was not happy about how difficult my bearing went in, but I think I just underestimated how much force was needed to pound the new bearing into place. Also, working on the floor, under the car, at an awkward angle, didn’t make things easier.

Peter

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