spud72

Do not touch the IMS bearing in that car.

808Bill

My apologies for the drift/Hijack but hope it keeps the topic on point.

I am about to look at an early 99 that the owner claims never leaked (could be BS?) with just over 60K miles.
IMSB? To replace or not? It's a Tip...
My first thought was to have the oil tested and install the Guardian but it no longer exists.
Thoughts?

Volkert

My 2c after a lot of reading up (others chime in please):
- RMS early design was not good so if it "never" leaked it was probably replaced before he took ownership?
- IMS double bearing has a low failure rate (<1%?) and to me with the whole IMS ladida one can even question that 1% (really IMS or other timing related issues?). IMHO there are many ways you can kill a 300HP engine and as my engineering master tought me (German guy btw) in the end there will always be a weakest link that goes first. So in this case maybe that is/was the IMS or related.
I plan to drive this car for considerable years to come so if the engine is still good AND you have a good (excellent) mechanic that will do the IMS replacement I think it makes sense. If not you'd better leave it alone and not make that investment.

Volkert

PCAR996C2

My 996C2 6 speed manual was first registered in NZ 12th of January 1998. 141000 kms so far with original IMSB no leaks etc. the car has a full service history from new. See attached identification.

jaetee

I would not touch that IMSB. If you are prone to paranoia, you may want to install a magnetic drain plug or even IMS Guardian. I'd put on a magnetic drain plug and LN screw-on filter adapter and just pay attention at each oil change.

docmirror

Yup. Full flow filter. 3k mile oil changes. Inspect filter on change. Mag drain plug or Chip detector for dual row bearing car over 60k miles.

808Bill

Exactly my thoughts after reading all related post's. Unfortunately Jake will not be making anymore "IMS Guardians"...

MoeMonney

needs new motor mounts also.

808Bill

All the rubber bits are going to need updating at some point...

Mike Murphy

When did we go from "do the IMSB as needed with a clutch change" to "leave it alone?" It is only these early cars like our that folks are changing their tune? Granted, I have a 1999 with a 1998 manufacture date, and fairly certain my car is a double-row example. But I also have a garage queen (48,000 miles).

Don't get me wrong, I'm not looking to spend money/time foolishly, but it just seems that the general wisdom over time is to get the IMSB done when you can.

docmirror

I don't know about any 'we', change to the op-ed on IMSB. Also, you made a qualifier in there that I didn't. I'm not going to Proactively change the bearing, but - if the trans has to come out I would change it. Just that I'm not going in for exploratory surgery like I would with a low mile single row deal.

jaetee

I can't speak for others, but will explain my thinking... With '99s and '98 built 996s, there is pretty much a 99.99% chance it has a dual row IMSB. And the basic logic that if there were any significant run-out in the car's IMS shaft it would have surely beaten up that bearing befote 50k miles.

In my particular case, I had done a lot of research prior to buying my car and learned the switch to weaker single row bearings started to happen as early as mid-2000. My C2 Cab has a build date of 5/2000, which is right in that mid-2k ballpark, so there was some question as to which bearing was in the car. I got no service records other than a receipt for a new alternator, and from the look of the bolts between the engine & tranny (zero tool marks) the car likely still had the original clutch. The engine did make significant sounding chain rattle sounds at start up and there was plastic in my oil, but no metals.

So, since I was also not clear on which bearing was in the car and feeling a bit leery of the clutch, the decision was made during the PPI to buy the car, drop engine and do a massive preventative refresh to the good engine and reestablish some proper service history. Car had other issues with the cab top and electronics, so a good price was negotiated appropriately. I chose to make my car as good as it could be via a project mindset, rather than try to go find a "perfect" one. It was a fun project. My mechanic is a friend as well and I spent a lot of time at the shop during the critical work, and was also able to take a lot of photos of the whole process.

Had I bought a '99 or '98 built car with same miles and a known good clutch, I would have left the engine in and just had the chain tension guides replaced to take care of the start-up rattle and to stop additional plastic bits from showing up in my oil filter. Granted, that would have just been deferring eventual mainenance on the AOS, water pump and a handful of other things, but it also would have saved me around $4k in immediate spend. But, I also might have had to pay that same amount more for such a car vs. the one I bought. I chose to go the route of new parts and intimate first hand knowledge of the car.

In the end, I have zero regrets with the way that it all turned out for my particular car and my wallet. I can't tell you how much more peace of mind I have driving it now vs. when I first bought it. Now she purrs like a kitten at start up and idle, and roars like a lion when I get on it. No more rattle, no ISMB paranoia. Good times.

Volkert

Hey hey, my kind of thinking!

How many miles had the car when you bought it?

Volkert

jaetee

93k miles. And I put in the EPS "Eternal" cylindrical bearing with the optional direct oil feed ($450) rather than the LN IMS Solution ($1500). Car now has almost 98k miles.

Noz1974

Congrats on the car I have a 99 c2, will check the sticker for dates, I have eps roller also with 2k on it now but I would possibly have left mine alone as thinking had changed since I did mine, dual row came out perfect!