connecting rod and piston pin problems

[KJlibertyBR]

I’m rebuilding the engine of my Jeep Liberty 3.7 V6. The issue is that here in Brazil, parts for this engine are extremely scarce, and when they are available, they’re prohibitively expensive.





Right now, I’m facing a problem with the piston pin fitment in the connecting rod – it’s worn and has become oval-shaped. Has anyone here ever installed a bushing in the small end of the connecting rod on a 3.7 V6 Cherokee? Does it work reliably?





Also, has anyone successfully used piston pins from a different engine as an alternative?





If anyone has the technical specifications for this engine, could you please share the exact measurements? Specifically, I’m looking for the piston pin diameter, the connecting rod small end inner diameter, and the correct clearance between them.





Thanks in advance!

 

[Robochop]

I would like to say that any 3.7 parts can be interchangeable as long as it is the same year. I have purchased several rebuild kits from Ebay and Amazon for under $500. I still like to run my engine parts by a machine shop before putting back together. I imagine that could be difficult in Brazil!

 

[KJowner]

Have you downloaded the manuals for the car? All the specifications should be in there.

Index of /manuals/Jeep/KJ

I don't see any issues with a thin bush being fitted to the little end of the rod.

 

[KJlibertyBR]

I can’t find new connecting rods for sale. I’ve already managed to get two sets of used rods and pistons — one set has slightly less clearance than mine, and the other has much less, almost unnoticeable. But there is still some play… it’s still there. I don’t know what to do anymore. I’m unsure whether to assemble the engine with this last set or have bushings adapted to my original rods. My fear is that adapting bushings will make the rod too weak.

 

[KJowner]

How do the used rods compare to the specifications in the manual?

 

[DadOSix]

I'm not so sure the engine data is in the FSM for the kj's

Here is something I came across when looking for those dimensions.

https://nitro.gruppo-radicale.ch/docs/REPAIR/3.7l_engine.pdf

Download that and get to about page 24 - it starts with a few tables about 3.7L engine specs on an 07 Dodge Nitro. My apologies if you already found this!

I googled "Mopar 3.7 l machinists manual pdf" to find this. Dang shame there are so few real machinists in my area anymore.