Update Cont.
The parts showed up at the shop and the rebuilder found a few more things we needed that didn't come in the kit like the freeze plugs (since he hot tanked/cleaned the block) and the rod bearings (piston side) so I made a run to a local diesel parts supplier. In the end I think it would be the same just getting the parts local than getting them online but now I know. I did buy an ebay kit since they all seemed to come from the same place. So I got the lower and upper gasket set, piston kits which included wrist pins and rings, added valve guides and a cam bearing. The funny thing is that the piston kit included 6 pistons even though my gasket sets were for the 4bt. Plus I was sent a package of 6 cam bearings when all I needed was one. I talked to the seller before ordering and he was willing to eat some of the shipping which was still kind of rediculous.
This is the parts list for the lower gasket set. Cummins is all about the CPL number and serial number to make sure you order the correct parts since these engines where in all kinds of things. My CPL is 986.
Inside the box
Upper gasket kit
In that box
The work at the rebuilder included:
- a head job with new guides, seals, and porting. I had NO cracks at the injector holes which was great.
- block cleaning and honing
- crankshaft polishing
- balancing of rods and pistons (new piston were pretty good, but the rods were off pretty good)
- install cam bearing
- install and hone rod bearings (piston side)
He got the head and crank done first so I picked those up along with the rebuild kit on Monday, the block was done on Tuesday and he dropped it off since I live on his way home, and once he got the bearings for the rods those were finished yesterday so I picked those up and swipped some plastic. He let me borrow one of his ring compressors. The last time I did an engine assembly was with my dad over 15 years ago on a much, much smaller engine where as a teenager I could lift the block by myself and move it around. No chance doing that with this cummins block!
While I was waiting for everything I got some simple stuff done. I installed the rear main seal in it's housing. Cummins seals are installed dry and they come with an installation ring shown on top. You just put the ring on top of the seal and tap it in until the lip bottoms on the housing and that's it.
Thanks to lifting kids all day long my

and I dead lifted the block onto the engine stand using proper posture of course. Then I could start on the block. I installed the new piston squirters and the upper bearings. You can see the thrust bearing on No 4 main.
I did some quick research on what lube to use on reassembly. There are lots of different opinions on what to use but before I left the rebuilder he handed me some ARP assembly lube.
I put a thin coating on the bearings to get ready for the crank. After cleaning off the crank and drying it with compressed air I gently put that burly chunk of metal in it's home.
Mmmmm... polished crank.
Here's the wear that happened on the block from the missing thrust shoulder. I'm a little worried about the small gap between the bearing and the block and wonder if I'll go through thrust bearings quicker. Perhaps I'll drop the pan the first couple of oil changes and see what it looks like.
Lubed the lower bearings and the bolts and put the main caps back on. I followed the torque pattern and sequence outlined in my engine manual.
I'll obviously be painting the engine again. The freeze plug hole is where the block heater goes and the other hole it where the oil cooler goes. I got that installed while I was waiting for the rods.
There are three rings per piston; a top, intermediate, and oil control and I got those installed on the pistons. Then I put the wrist pins in and attached the rods. Not sure if you can read it but the rods were made in Brazil, which is fitting since I lived there for two years.
Lubed the rings, cylinder walls, and ring compressor with motor oil and carefully lowered the piston down. It took a little tinkering but I got it all lined up and tapped the pistons into the cylinders. I used the softer rubber end of a hammer handle to tap. If it felt like it was binding I'd stop and see what was up. Sometimes the ring compressor would slip out a ring before it made it into the cylinder and then I'd need to realign it. Ring position on the piston is important and I followed the manual for ring alignment/spacing.
It was about 9:30pm but I wanted to get all the pistons in and torqued. Three down, one to go.
Got them all in and followed the manual for the torque specs on the rod caps. I lubed those bearings as well. I used a strap wrench on the gear end of the crank to make sure the assembly still rotated. If I got the rods in wrong they would hit the side of the block and stop the crank from rotating but I followed the manual and it all worked fine.
It was about 10:30pm once done so then I bagged the block and taped it shut to keep out the elements. I cleaned up the tools and put stuff away and finally went in the house. I had to wake up @ 5:30am the next morning for work so it felt like a long day for me. I'm actually enjoying this so far and if I'm lucky I might have it on the road next week. If I can get the engine finished and painted on Monday and installed on Tuesday I might have a chance even though I'm not counting on it. I'm betting some of my vibs will go away after this rebuild and balancing work but it probably won't be a good mosquito repellant anymore since it'll clean up my smoke.