671TI Main Bearing Cap Cracked after rebuild

[John Dickson]

I recently had my 671 TIs rebuilt
Then the pistons were all recalled and had to be replaced due to bad slip bearings in the piston
One engine only had 6 hours on it since the rebuild but the 12 month rebuild warranty had expired
Upon dropping the pan to replace the pistons the tech noticed that I had a cracked bearing cap
Now the block needs to be line bored and the quote is higher than the original rebuild
This engine ran for 35 years, then a rebuild, then a cracked cap

Could the rebuild or the recalled pistons cause the cap to crack?
Has anyone had an issue with cracked bearing caps?
Is this a common Detroit 671 TI thing?
Does anyone know if I have any recourse against the rebuilder?
Any advise on how to proceed?

Thank you!
John

[Captain Ralph]

My friend
The inline 671 has a beast of a crankshaft, block supports and main shaft caps.
I'm sure it has happened somewhere, but yours is the first I have really heard of a cap failure.
I am really bummed and bummed for you.

Sadly, I feel there is no real recourse for you but to Bend Over And Take-it (BOAT).
I have in-frame built engines for customers before and this is what our rebuild warranties usually state; Your original block is not warrantied. Our parts and labor only.

Plus, you are past their calendar warranties when discovered.
Really sux but testament that that crank is a brute.

Now, last thought, the piston recall,, Why were they recalled. Obviously not OEM. It may take some digging into the reasons, maybe an investigator in this field, but if you smell something fishy here, I'd find an attorney.

I can see unbalanced pistons causing issues with the crankshaft. That brute crankshaft may have passed on any unbalance, vibration, harmonic, un-designed stress to the block and or caps.

The more I think about it, yes, I'd go there,, at least a try..

[cww]

My friend
The inline 671 has a beast of a crankshaft, block supports and main shaft caps.
I'm sure it has happened somewhere, but yours is the first I have really heard of a cap failure.
I am really bummed and bummed for you.

Sadly, I feel there is no real recourse for you but to Bend Over And Take-it (BOAT).
I have in-frame built engines for customers before and this is what our rebuild warranties usually state; Your original block is not warrantied. Our parts and labor only.

Plus, you are past their calendar warranties when discovered.
Really sux but testament that that crank is a brute.

Now, last thought, the piston recall,, Why were they recalled. Obviously not OEM. It may take some digging into the reasons, maybe an investigator in this field, but if you smell something fishy here, I'd find an attorney.

I can see unbalanced pistons causing issues with the crankshaft. That brute crankshaft may have passed on any unbalance, vibration, harmonic, un-designed stress to the block and or caps.

The more I think about it, yes, I'd go there,, at least a try..

This is a widespread problem right now, everybody with Detroits knows about it. Detroit built a factory in China and shifted production over there. After their first batch came in the cylinder kits started failing regularly with very low hours on them. So they recalled those and replaced them with new ones that also failed. Then they decided they were not selling anymore until they figured out what the problem is. So for over a year now you can't get cylinder kits, they're backordered with no expected arrival date. As best anybody can tell the problem is defective castings. They're restarting production but they've got 2 years of backlogged orders to fill, so you're still not getting them anytime soon.

I just rebuilt my engines and the guys who did it recommended Interstate-McBee parts, so that's what we used. USA made and I didn't have to wait a year for a part that may or not blow up after 20 hours.

[Captain Ralph]

This is a widespread problem right now, everybody with Detroits knows about it. Detroit built a factory in China and shifted production over there. After their first batch came in the cylinder kits started failing regularly with very low hours on them. So they recalled those and replaced them with new ones that also failed. Then they decided they were not selling anymore until they figured out what the problem is. So for over a year now you can't get cylinder kits, they're backordered with no expected arrival date. As best anybody can tell the problem is defective castings. They're restarting production but they've got 2 years of backlogged orders to fill, so you're still not getting them anytime soon.

I just rebuilt my engines and the guys who did it recommended Interstate-McBee parts, so that's what we used. USA made and I didn't have to wait a year for a part that may or not blow up after 20 hours.

Detroit liners have long (longer) been an issue, but not because of DDC quality issues. When we rebuilt our 12V71, Detroit liners came in from all over. Took weeks to get 12 kits together. 13 came in. That was 16 years ago.
16 years ago, the Detroit kits were hard to get because a few non DDC companies were making problem liner kits. This suddenly put the DDC kits under stock / high demand.

So, your saying these newer kits, had bad pistons and are getting recalled?
And what goes in under the recall? More ChinaJunk?

When did MTU/Detroit move a factory to China? I had poorly assumed that MTU was selling only quality spares for these many years.

[cww]

Detroit liners have long (longer) been an issue, but not because of DDC quality issues. When we rebuilt our 12V71, Detroit liners came in from all over. Took weeks to get 12 kits together. 13 came in. That was 16 years ago.
16 years ago, the Detroit kits were hard to get because a few non DDC companies were making problem liner kits. This suddenly put the DDC kits under stock / high demand.

So, your saying these newer kits, had bad pistons and are getting recalled?
And what goes in under the recall? More ChinaJunk?

When did MTU/Detroit move a factory to China? I had poorly assumed that MTU was selling only quality spares for these many years.

The problem has been just the last couple years nothing before that, since 2019 or so. You won't have a problem with anything before that. I heard the explanation from mechanics who have heard it from people inside DDC. It became a problem during my recent rebuilds because the cylinder kits were still backordered.

I read last year that even Rolls-Royce is building a factory in China, at the rate all of this is going we won't have a choice where everything comes from before long. I hope their manufacturing sector figures out how to get the quality control kinks worked out.

[DCMY #92]

I started to rebuild one of my 6V53 naturals (1963 vintage) two years ago. I ordered DDC cylinder kits for both engines and waited 5 months to get them. After arrival I measured everything as always. Out of 12 cylinder kits 2 were serviceable. The DDC parts manager was happy that I suggested returning the whole lot for a refund instead of insisting on another batch of DDC parts. He actually gave me the contact information for the Mac-Bee dealer and suggested I call him. All 12 Mac-Bee kits measured perfectly. It's a tragedy that a company like DDC/MTU could screw things up so bad with a bullet proof product.

[Canuck Dennis]

I had my 2 12v 71's redone with Mc Bee parts, all 100% no problem that was 3 yrs ago.

[John Dickson]

Hello Gents

My post was directed at the bearing cap crack not the kits. The pistons had a bad slip bearing and are being replaced by the manufacture at no charge.
My concern was whether anyone has heard of or had any issues with cracked bearing caps and what the cause may be.

Thanks!

John

[rustybucket]

Hello Gents

My post was directed at the bearing cap crack not the kits. The pistons had a bad slip bearing and are being replaced by the manufacture at no charge.
My concern was whether anyone has heard of or had any issues with cracked bearing caps and what the cause may be.

Thanks!

John

Any chance a bearing cap installed facing the wrong direction would cause something like this? I know rod ends are directional and will cause issues if installed the incorrect direction, not sure about main bearing caps.

[Captain Ralph]

Hello Gents

My post was directed at the bearing cap crack not the kits. The pistons had a bad slip bearing and are being replaced by the manufacture at no charge.
My concern was whether anyone has heard of or had any issues with cracked bearing caps and what the cause may be.

Thanks!

John

As my first post here, No; real bearing cap failure, never heard of it. That may not mean much, but I have been around Detroits all my life.
But your screwed blaming the rebuild shop and getting any help. Even if they did cause it.