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"996 had Double Row for engine numbers up to 661 14164
996 have Single Row from engine number 661 14165 onward
Quote:
Originally Posted by Stephen Tinker
My old Boxster S was assembled in January 2001 but still had a double row bearing when I replaced it back in 2010, so the engine was assembled quite some time before final installation into the chassis. Boxster: Double Row: up to 651 12851 (M96.22)
Boxster: Single Row: from 651 12852 onward (M96.22) Boxster: Double Row: up to 671 11237 (M96.21)
Boxster: Single Row: from 671 11238 onward (M96.21)"
Uh, no... It never has and never will be determined down to serial #'s... This issue has been discussed to death and no solid cutoff has been identified. The only foolproof way to determine which bearing you have b(if you've got a "transition year car" -between '00-'01) is to pull the transmission and look at the bearing flange. Dual row = Deep flange Single row = Shallow flange
Uh, no... It never has and never will be determined down to serial #'s... This issue has been discussed to death and no solid cutoff has been identified.
While, as I stated, I question that data myself, an important point I think you are overlooking is that the data is based upon engine number, not car serial number. A car serial number cutoff would make no sense at all for the reasons you stated. An engine number cutoff, however, would seem to make all the sense in the world (at least on a logical level) assuming they numbered the engines in chronological order and made a hard cut switch on the engine assembly line.
The reason I question the exact engine number cutoff specified is because my car does not seem to follow it. Unless they did something weird in the factory to switch back and forth between bearing types during chronological production, or to assign engine numbers in non-chronological order (both of which are possible, even though neither seems likely), it seems like there would be an engine number cutoff.
Allow me to muddy the water just a bit more. This is OPINION, has no basis in FACT, and is a supposition based entirely on logic, and puzzle pieces.
There was an industrial fire in the Stuttgart production plant which affected the M96 engine line. It happened in either mid or late 2000. Engine production was moved from Stuttgart to Ulm, or NecarsUlm facility. Notwithstanding the engine SN method, I believe that all engines built in Stuttgart were dual row, as that is what the engine machine robots were designed to produce. When M96 production was setup in Ulm factory, the change to single row machining was coded into the case boring mills, and those engines were fitted with single row bearing. At some time in the future, those engines from Ulm, and remaining engines from Stuttgart which could be salvaged were mated to chassis in a rather ad-hoc way, as there was no difference in mating a single row engine or dual row engine to either a manual or tip trans car. Thus, if there were 50 engines with single row sitting there, and there were 50 2000 chassis ready for assembly, then the deed was done. If there were 50 dual row engines, and 50 2001 chassis ready, then they got a dual row(would need to be very early 2001 prod series).
YMMV, don't try this at home, objects in mirror, contents have settled, and may cause **** leakage. Have a nice day.
^^^ Regardless of which theory you subscribe to (the above seems as plausible as others I've heard/read), the fact is that there is no reliable way to determine (i.e. chassis serial # or engine serial #) which bearing was used in the transition year engines short of looking at the flange or actually removing the bearing itself.
^^^ IF my theory is correct, engine SN would have to be allocated to both production lines, as there cannot be engine SN overlap. Finding the assignment of SN by engine mfg location would confirm my theory, and define the boundaries of the bearing by SN. I don't know that such an allocation scheme exists, but knowing the Germans attention to detail, I would guess that somewhere in the bowels of production records it has that type of identifying info.
I'm not sure if this has been discussed before, but what about the engine type code? In my 2000 C2 certificate of authenticity from the factory, it specifies the engine "type" as M96/04. I think the early 1999 cars had engine type M96/01. I have no idea what the difference is between "01" and "04", but it seems like dual versus single row IMS would have been significant enough to warrant assigning a different "type" number.
Originally Posted by docmirror
^^^ IF my theory is correct, engine SN would have to be allocated to both production lines, as there cannot be engine SN overlap. Finding the assignment of SN by engine mfg location would confirm my theory, and define the boundaries of the bearing by SN. I don't know that such an allocation scheme exists, but knowing the Germans attention to detail, I would guess that somewhere in the bowels of production records it has that type of identifying info.
I'm just guessing also, but I do agree it seems very likely there is an engine number cutoff or clearly defined ranges of engine numbers that delineates single versus dual. It's impossible that Porsche doesn't have that info, but maybe they don't share it because of the lawsuit mess.
M96-01 & -02 were the earliest 3.4l (5 chain) engines. M96-03 is the 3 chain 3.6l engine. M96-04 is also a 3.4 (5 chain)engine that was built from 2000 until the M96-03 (3.6l 3 chain) began being built. See what's going on here with Porsche's numbering system? I'm sure it makes sense to them for their internal controls. That doesn't mean it makes sense to us (not in the normal sense anyway)...
M96-01 & -02 were the earliest 3.4l (5 chain) engines. M96-03 is the 3 chain 3.6l engine. M96-04 is also a 3.4 (5 chain)engine that was built from 2000 until the M96-03 (3.6l 3 chain) began being built. See what's going on here with Porsche's numbering system? I'm sure it makes sense to them for their internal controls. That doesn't mean it makes sense to us (not in the normal sense anyway)...
Thanks for the explanation. Definitely weird. I guess one possibility for the numbering is that they started working on the "03" 3.6 design before they decided to do whatever updates were in "04" for the 3.4 (though early 2000 would seem somewhat early to start on the 3.6). I wonder what the differences are between 01, 02, and 04. Seems weird that they wouldn't have different type for the IMS change. I guess if the 01/02/04 changes were visible externally, and the IMS change was internal only, that might explain it.
I wonder what the rationale for switching to single row was to start with, at least on the 3.4. It's possible they needed a narrower space for the expansion to 3.6 (<- this is a guess, I have no idea if true), but it seems odd that they would go back and change the 3.4. The only thing I can think of is that maybe they made the change on the later 3.4's as assembly line prep for 3.6's.
I wonder what the rationale for switching to single row was to start with, at least on the 3.4.
Porsche updated the shaft to a more durable, tooth type chain which ushered in the single row bearing. The 3.4L engine were known for breaking their chains, but not as much on the 3.6L because of the improved strength. Unfortunately, the horrors of the single row failures overshadowed the much improved chain system.
Porsche updated the shaft to a more durable, tooth type chain which ushered in the single row bearing. The 3.4L engine were known for breaking their chains, but not as much on the 3.6L because of the improved strength. Unfortunately, the horrors of the single row failures overshadowed the much improved chain system.
I don't know if this has been discussed before, but it seems like the Porsche IMS settlement VIN qualification criteria (cut & pasted below) would have to definitively identify which cars had single row IMS. It specifies a start year of 2001 -- that would not seem to be accurate if 2000 MY cars were affected, but maybe the VIN ranges includes 2000 models if they were affected.
The class action settlement covers people that own or lease a 2001-05 Porsche 911 or Porsche Boxter manufactured between May 4, 2011 and February 2005 with the following VIN ranges.
The settlement covers both owners that have had an Intermediate Shaft (IMS) failure, and also provides protection for those that have not had this failure. Estimated Amount:The settlement provides for reimbursement for repairs according to the following schedule. The amount of reimbursement depends on whether the case was bought new, certified pre-owned (ACPO), or used and on the mileage on the car at the time of the issue.New PurchaserACPO PurchaserUsed Not ACPOUp to 50,000 miles100%100%25%50,001–60,000 miles90%100%25%60,001–70,000 miles80%100%25%70,001–80,000 miles70%100%25%80,001–90,000 miles60%100%25%90,001–100,000 miles50%100%25%100,001–130,000 miles40%40%25%The settlement also provides towing and car rental expenses up to $200. Proof of Purchase:NOT required Claim Form:Porsche IMS Settlement Claim Form Case Name:Eisen v. Porsche Cars North America, Inc,
Case No. CV11-9405 CAS (FFMx) (C.D. Cal.) Case Summary:Plaintiffs claim that the Intermediate Shaft (IMS) on Porsche 911 and Porsche Boxter vehicles is defective and can fail leading to very expensive engine repair bills. Porsche denies the claim, but settled the case prior to trial. Settlement Pool:uncappedSettlement Website:Porsche IMS Settlement Site Porsche IMS Settlement (Plaintiff’s Attorney’s Site) Claim Form Deadline:October 15, 2013 (for those suffering from IMS related engine damage prior to July 17, 2013)Claims Administrator:Eisen IMS Settlement
c/o GCG
P.O. Box 35049
Seattle, WA 98124(866) 254-4760
Thanks for the clarification. It's a bit mind numbing to wade through the list of numbers to see if a given car is a match, but seems like this would identify all single row IMS cars (for cars that still have their original engines at least).
10-04-2018, 11:40 AM
