67 FJ45LPB build

[Cirbo]

October 2020

A couple of us decided to attend the Fall Crawl in Gore VA. The plan was for a 400-mile dash, camp and wheel, then 400 home. The truck was still running 4:10's, but I figured it should easily keep up with traffic when the OD was engaged.

We had a blast and the truck never missed a beat (or so I thought).

 

[Cirbo]

November 2020

Roughly 10 years of ownership and 8 years of engine life on the Turnkey LM4 Aluminum 5.3 (maybe 8-12k miles?)

After the 400-mile run back home, I left the muddy truck in the garage for a few weeks before returning to clean and sort things out. I noticed a few drops of oil around the back of the pan on the driver's side. It seemed that a small block-off plate on the side of the engine was weeping a bit. I sourced a new metal gasket and rolled back under to complete the replacement process. The block off plate was installed on this engine in leu of an oil cooler. All manner of covers and gaskets can be found online, including some fancy billet units with O-ring gaskets.

The bolts seemed a bit loose, so I felt reasonably confident that I was in the right location. When I tried to remove the plate, I had a good amount of trapped residual oil start to leak out. I (incorrectly) thought that dropping the oil level in the pan might stem that flow, so I loosened the drain plug to capture a pint or two. Unfortunately, the first thing that came out was a half cup of antifreeze, followed by a clean stream of engine oil (no mixing).

 

[Cirbo]

Internet searching showed that the casting numbers on the heads had a history of cracking, so I pulled of the valve covers for a visual inspection. The rear (cylinders 5-7) drivers side valve cover looked a bit cleaner than the other, so I started inspections there.

Other facts: I was not losing any noticeable volume antifreeze. No antifreeze appears to be mixing with the oil.

Nothing showed anywhere. I waited a few days and opened the pan again to check. Nothing. Then something kicked in the back of my mind. I remembered seeing what appeared to be a little condensation on the underside of the oil filler cap. Now the question was how long had this been the case? This whole time, I was brainstorming with a friend in the Cleveland area who is a master tech with loads of Chevy experience. He felt that the next step would be to pressurize the system and check again. I pulled the intake, keeping the throttle body and steam lines in place to maintain a closed system.

 

[Cirbo]

A complete inspection of the top end showed nothing. Next step was to remove the pan. I noticed that the pan bolts were not very tight when pulling that as well. The guys at Turnkey had asked my application and promised to match a pan for my clearance needs. It's difficult to see, but there is a small drop of antifreeze on #7's counterweight.

I guess I'm going to get the chance to address those misaligned pullies.

 

[Cirbo]

Pulled that suspect driver's side head first.

The head gaskets looked ok, but I did find this.

Yeah, but even if it did make it to a water jacket......?

 

[GLTHFJ60]

Woof.

 

[Cirbo]

Yanked the engine and put it on a stand for disassembly. When I pulled the thing down, the bolts on the rear main seal cover seemed to be no more than finger tight.

Inspection showed this between #5 and #7 (as viewed from the bottom of the engine).

 

[Cirbo]

Woof.

Yo Brother!

Yeah, I'm surprised to report that I'm still married at this point in the story, but I haven't told her yet.

 

[GLTHFJ60]

@NC LX was your block cracked like this? pretty rare right

 

[Cirbo]

I spent some time thinking about it while I sent the block to the recycler and sold everything else on Craig's List.

I didn't want it to come from a junkyard.
I didn't want it to be made out of aluminum.
I wasn't going to reuse those heads after all the problems I read about.
I wanted to maintain my cable-controlled throttle body.
It had to be Gen III.
I needed to re-use all front-end parts so I could to save money.
I had to fix the pulleys.
I had to dump the POS MEFI-4 computer.
Max HP needed to be under 420 to stay within spec for the Ranger Torque-Splitter.

I need to come clean and admit that there was another problem that my OCD would eventually cause me to revisit. The H42 in my truck would emit the slightest growl shifting up through 1 and 2 when the truck (and weather) was cold. This would only happen on cold days and disappear by the time I exited the neighborhood.

Bigger fish to fry! ForgetAboutIt!!

 

[Cirbo]

March 2021

A decision was made and an order placed with Summit Racing. The shipper dropped the first delivery, but I finally got a decent looking lump on their second attempt.

I won't bore everyone with my final choice but can provide a link for those who want to do their own research.

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[Cirbo]

Set about moving everything from old to new. Had the flywheel resurfaced and ordered up a new clutch and throw-out bearing. The old stuff looked fine, but I didn't want to go back there anytime soon.

I kept the 75mm throttle body but had to purchase a new truck intake that matched the rectangular ports on the new heads. I paired that with a new set of 37 lb./hr. injectors to complete what I hoped would be a "low end torque" solution. I hoped this would bring the final configuration down below the 420 HP spec for the OD.

Shortly after this build was complete, a club member reached out asking for any support he could get. Apparently, he had purchased a 40 equipped with a V8 and was having issues with a worn clutch. As he was a younger guy who had just shelled out a bundle for his dream wheeler, funds were a little low. I was able to donate the old parts from my swap to a good cause.

 

[Cirbo]

I added a new water pump, fuel rail, thermostat and throttle body adapter plate to complete the mix. I had to pull the power steering pulley and press it back on during the assembly, so I had a good opportunity to align everything on the front of the motor.

EFI more better......

Howell harness, computer, and MAF.

 

[Cirbo]

Tried to brush up on my questionable AC TIG skills and fab up a computer mount. Chose the same place as the old system with the relays mounted below and just out of view.

The larger computer was a bit of a tight squeeze. The mount fixed that pretty well.

MAF can be seen just after the air filter element.

 

[whitey45]

Wow, expensive cracked block issue my 6.0 ho came from bd turnkey( is this the company you used? Been trouble free for about 10 years now…

 

[Cirbo]

Wow, expensive cracked block issue my 6.0 ho came from bd turnkey( is this the company you used? Been trouble free for about 10 years now…

Different company. This was the group out of Oceanside, CA.

 

[NC LX]

@NC LX was your block cracked like this? pretty rare right

Mine was cracked top to bottom, from under the cam down to the crank and the crack continued into the #1 cap

 

[Cirbo]

Mine was cracked top to bottom, from under the cam down to the crank and the crack continued into the #1 cap

What block did you have? I believe my was the LM4.

 

[Cirbo]

July 2023

Spent the past two years driving and wheeling the old girl without any big issues. Unfortunately, the transmission was getting worse. The symptoms were the same but lasting longer and including all gears. As before, when things warmed up, all worked well. The cheapest replacement I could find was $450 for a '76 vintage unit that looked like it had lived a long life. While searching, I did find a pair of complete diffs out of an '84 FJ60. I had also been sitting on a complete set of mini-truck outer knuckles that had been cleaned and prepped.

Out with the 4.10's and in with the 3.70's and bigger knuckles. I rebuilt the ARB's while I was there with new seals and O-rings.

While I was under there, I added a moly additive to the transmission and things seemed to get better.

 

[Cirbo]

I found some additional photos and had to backtrack.

January 2018

Made the cover of Toyota Trails too.

Shots were from the 2017 Relic Run at Uwharrie National Forest.