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YOUR RESEARCHReplacing Crankshaft
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Replace on some and not
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Read evidence and context
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Performed · outcome unconfirmed
I do know that crankshaft cradles can be swapped on some and not on others due to block casting.
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Suggestion
.So I needed to source a corresponding intermediate shaft,which has the larger bearing,I suggest your purchase of crankshaft is contingent upon the crank magnafluxed.There are good “looking “ cranks out there that are cracked.As always this information is what I found…..always double check for veracity.
Leading evidence: 'Replace on some and not' (no explicit attributable resolution; this is a reported action or suggestion). Across 1 matching discussions, The most frequently discussed action is 'Check veracity' (1 discussions). For that action, 0 discussions report a resolution and 0 report an unsuccessful attempt. No action has an explicit, attributable resolution report under the current rules. These are forum reports and suggestions, not a confirmed diagnosis.
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Suggestion
.So I needed to source a corresponding intermediate shaft,which has the larger bearing,I suggest your purchase of crankshaft is contingent upon the crank magnafluxed.There are good “looking “ cranks out there that are cracked.As always this information is what I found…..always double check for veracity.
Explicit resolution reports before identified causes, performed actions and suggestions. Within each level, matching component labels precede direct query mentions and inherited thread context; successful versus unsuccessful discussion counts, owner confirmations and independent discussion support determine order. This is not a probability of success.
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Suggestion
If so just to clarify when attempting to use a 2001 - 2003 crankshaft in an earlier 2000 model you also have to change the intermediate shaft to account for the hyvo chain difference am I understanding this correctly
Explicit resolution reports before identified causes, performed actions and suggestions. Within each level, matching component labels precede direct query mentions and inherited thread context; successful versus unsuccessful discussion counts, owner confirmations and independent discussion support determine order. This is not a probability of success.
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Suggestion · Original poster
For reference, the part Number that came out of my engine was 9961015R, the one i sourced to change with was 981012R.
Explicit resolution reports before identified causes, performed actions and suggestions. Within each level, matching component labels precede direct query mentions and inherited thread context; successful versus unsuccessful discussion counts, owner confirmations and independent discussion support determine order. This is not a probability of success.
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Suggestion
Tex,you always contribute good info ,just piggybacking on your post.It looks like you have assembled enough parts do a dry run engine assembly.It would be nice to see you find a good roller and do a rebuild.I�m thinking the new �roller� number is 10 to 12k not 5k anymore.I will be back in the hunt for another car in the spring.
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Check veracity
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Suggestion
.So I needed to source a corresponding intermediate shaft,which has the larger bearing,I suggest your purchase of crankshaft is contingent upon the crank magnafluxed.There are good “looking “ cranks out there that are cracked.As always this information is what I found…..always double check for veracity.
0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.
0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.
Suggestion
If so just to clarify when attempting to use a 2001 - 2003 crankshaft in an earlier 2000 model you also have to change the intermediate shaft to account for the hyvo chain difference am I understanding this correctly
0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.
0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.
Suggestion
Tex,you always contribute good info ,just piggybacking on your post.It looks like you have assembled enough parts do a dry run engine assembly.It would be nice to see you find a good roller and do a rebuild.I�m thinking the new �roller� number is 10 to 12k not 5k anymore.I will be back in the hunt for another car in the spring.
Counts describe captured discussions, not unique people or a diagnosis. Author identities are not reliably stored. Exact duplicate evidence is counted once across matching discussions; one discussion counts at most once per action/state. Multiple repairs reported together remain a combination. Suggestions and failed attempts do not establish a fix. Matches cover whole discussions and can include related faults, model variants and incomplete threads.
22 eligible posts · 0 unverified posts · 1 discussions match the subject in their title or opening post.
Rennlist: 1 discussions
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Generation: 20261026T091943Z · outcome-qualification-6. Deterministic extraction; no AI model inference. How we use sources
Hi all,
I have a 1999 C4 that had a spun bearing on cylinder 4. The crankshaft unfortunately was not salvageable so i sourced what i think is a great donor from eBay. When I received the part and went to a machine shop, all the journals are the same size but there is a difference in counterbalances. I have picture of the two part numbers below and my question is are these interchangeable? For reference, the part Number that came out of my engine was 9961015R, the one i sourced to change with was 981012R.
Any help would be awesome thanks!
I'm sure there will be others that have way more knowledge about Porsche's stamping patterns than me but most of my (996) internals has part numbers including 996 in it. As I'm sure you know, 981 is a third generation of the Boxter. My guess is that you received the wrong part.
The factory rods also have non-standard part numbers on them.
This one has "
996 103 102
GR" embossed on one side but the part number is "
996.103.975.01
"
Unfortunately I don't know how you correlate the correct part number with the sometimes "embossed one."
Looks like LN shows a later revision for the 3.4 crankshaft:
New:
https://lnengineering.com/products/p...rankshaft.html
Reconditioned:
https://lnengineering.com/products/p...rankshaft.html
It might.
I believe what you see is not a part number, but a casting number.
I don't know how you would verify.
I do know that some crankshafts & rods for the Boxster (M96.2x) 2.7, 3.2 and M96.01/M96.02/M96.04 3.4 can be swapped.
But I don't know for certain that ALL of them can be swapped.
I do know that crankshaft cradles can be swapped on some and not on others due to block casting.
What do your chain drives look like??
The 99 3.4 will have a dual roller chain drive ....it was changed to a Hyvo chain drive somewhere in mid 2001 ....
If the crank has the dual roller chain drive and same stroke...it will work....
I found the solution. The 2.7 and 3.2 crank from the boxster 986 works with the 3.4 996 engine. Got a perfect polished crank ready to use for $600.
Post above is from 2017 ,I am in the process of reassembling a 99 3.4 engine that needed a crank.I sourced one from a 3.2 boxster engine later style (hyvo chain)
.So I needed to source a corresponding intermediate shaft,which has the larger bearing,I suggest your purchase of crankshaft is contingent upon the crank magnafluxed.There are good “looking “ cranks out there that are cracked.As always this information is what I found…..always double check for veracity.
Tex,you always contribute good info ,just piggybacking on your post.It looks like you have assembled enough parts do a dry run engine assembly.It would be nice to see you find a good roller and do a rebuild.I�m thinking the new �roller� number is 10 to 12k not 5k anymore.I will be back in the hunt for another car in the spring.
Thanks.
Yeah, I have almost everything I'd need to rebuild an M96 except for the Nickies/pistons/rods/head gaskets.
The 996 roller prices are certainly up now.
But so are rebuild costs.
I may pick up a 986 and rebuild it since you can easily get a running driving car for less than a 996 roller.
First I need to sell one of my vehicles in order to have room for another in the driveway.
Ok so any idea on if the one I posted above is from either of those? Where are the part numbers located on the Cranks? They are both at a machine shop so i will go tomorrow to check what the new i got is. Also is there any performance loss with using one of the cranks out of a boxster?
Sorry can’t help with actual part and or casting numbers on mine…. Cannot see counterweights engine partially assembled..have machine shop compare crankshafts to one another,particularly the stroke.
Can anyone tell me the difference between a 2000 crankshaft with a part no of 996 102 011 57 and a 2001 crankshaft with a part no of 996 102 011 56 they both seem to be for 2.7 and 3.2 Boxster engines or 3.4 996 engines but due to the part no I assume there is some difference is it the hyvo chain that is mentioned above. If so just to clarify when attempting to use a 2001 - 2003 crankshaft in an earlier 2000 model you also have to change the intermediate shaft to account for the hyvo chain difference am I understanding this correctly
Yes, 2.7 , 3.2, and 3.4 all have the same stroke and are interchangeable on one condition, the early 3.4 had dual row IMSB and a dual row roller chain....later models changed to single row IMSB and Hyvo chains ..
So when interchanging you have to use the matching IM Shaft.. ( the wrong one will not fit no matter what)
