Another IMS bearing thread

[flaps10]

The problem isn't that you didn't lock the crankshaft, it's that you didn't undo the chain tensioner.

There are plenty of good detailed write ups on doing this job correctly. If you look at one you'll see you caused yourself a ton of extra work. You are now facing a complete cam timing job.

[Boxe1]

Originally Posted by flaps10

The problem isn't that you didn't lock the crankshaft, it's that you didn't undo the chain tensioner.

There are plenty of good detailed write ups on doing this job correctly. If you look at one you'll see you caused yourself a ton of extra work. You are now facing a complete cam timing job.

So i face a big problem now ,
Any other advice ?

[Jamesp]

Originally Posted by Boxe1

So i face a big problem now ,
Any other advice ?

If it were me, first thing I would do is slowly and carefully turn the engine clockwise to zero timing and lock it. Now you've unloaded the valve spring tension from trying to rotate the cams. Chances are good you won't lose valve timing, and you need the engine at TDC in any case. I would not remove a tensioner before rotating the engine, you want chain tension to keep from losing timing. The pickle you are in now is losing timing by rotating the engine (my engine ran at low RPM for two blocks with a failed IMSB before it was turned off and did not lose timing) or loosening the chain tension to try and center the IMSB bolt, which might allow the valve springs to rotate the cams. I have first hand knowledge that the cams can rotate in spectacular fashion due to valve spring tension (one of many mistakes I've personally made during engine re-assembly). The other thing that is going on is the IMS shaft is supported by a journal bearing at the other end, and the geometry of that bearing is none too happy with the loads currently being imparted on it. That's my 2 cents, with luck others will chime in with their respective experiences.

[Boxe1]

Originally Posted by Jamesp

If it were me, first thing I would do is slowly and carefully turn the engine clockwise to zero timing and lock it. Now you've unloaded the valve spring tension from trying to rotate the cams. Chances are good you won't lose valve timing, and you need the engine at TDC in any case. I would not remove a tensioner before rotating the engine, you want chain tension to keep from losing timing. The pickle you are in now is losing timing by rotating the engine (my engine ran at low RPM for two blocks with a failed IMSB before it was turned off and did not lose timing) or loosening the chain tension to try and center the IMSB bolt, which might allow the valve springs to rotate the cams. I have first hand knowledge that the cams can rotate in spectacular fashion due to valve spring tension (one of many mistakes I've personally made during engine re-assembly). The other thing that is going on is the IMS shaft is supported by a journal bearing at the other end, and the geometry of that bearing is none too happy with the loads currently being imparted on it. That's my 2 cents, with luck others will chime in with their respective experiences.

Thanks for your detailed help,
i did remove both tensioners at the back first,something made a click noise inside the engine,i think it is the cam moved because of the valve springs,still i am afraid to turn the crank to lock the engine at TDC,i removed the rubber covers of the valves and it looks like the timing is lost now

[Jamesp]

I certainly understand not wanting to crash the valves into the piston by rotating to TDC with slipped timing. I saw some sage advice recommending finding a good mechanic when this happens. You might be at that point.

[Gelbster]

Did you mean this ?
https://lnengineering.com/pel-ims-1-pelican-parts-intermediate-shaft-bearing-update-kit.html

The budget IMS (LN) bearing is now the RND bearing..Suggest you forget the Pelican bearing .The cost increase for using a much better bearing is insignificant in the overall cost of thIMS replacement job + all the wise "while you are in there" work.
https://rndengines.com/roller-bearing-ims-retrofit-kit/
My Pelican bearing fitted by P.O. worked O.K. but he failed to remove all the circulated debris from the original IMS failure. Result was the need to rebuild the entire engine.
So whatever bearing you use, the results can be compromised by lack of due diligence .This is often dismissed as excessive. For example the "Solution" fitting Instructions are 33 pages long and the pre-qualification Instructions are 11 pages.
So skill.,specific specialized tools,diligence and strict observance of Instructions is probably more important than just bearing design ?

[78F350]

Originally Posted by Gelbster

Did you mean this ?
https://lnengineering.com/pel-ims-1-pelican-parts-intermediate-shaft-bearing-update-kit.html ...

Yes, that's the one that I had intended. The old link I had for it is re-directed here now where it shows the $399 price: https://www.pelicanparts.com/catalog/shopcart/986M/POR_986M_UPG996_pg2.htm

I wasn't recommending it, but trying to remember some history on this forum to add to a discussion on another forum.

Personally, I like two retrofit options for the single row bearing; Single Row Pro which I have installed and IMS Solution which I may install when I replace the clutch on my '04.

[Danimal]

When I was looking at IMS options the other day I noticed the same thing. On the LN website I still see the cheaper one, but on Pelican’s site they rebranded it Rennline and jacked up the price. They both use the exact same picture too.

I like some Rennline stuff, but others seem like a cash grab.