Piston Question

[RoyLuke]

G'day All
I am doing an overhaul of my Disco I, 4.0 engine. I have 10 complete pistons/rods but not all are serviceable (see pix below).
There appears no way to remove the rods fro the pistons (unlike the Ford pistons).
Are they forged together and cannot be separated? I need to take them to be professionally cleaned and I am concerned they will not clean them unless totally disassembled.
TNX, Roy

 

[p m]

Pistons are aluminum and rods are steel, meaning there's no way they could be forged together (among other things).
If you have 4.0-4.6 workshop manual, pages 28-29 talk about how to push the gudgeon pins out of the pistons and rods using a special tool.
The tool is a simple screw-based puller, so you can make one by yourself.

That said, you can clean the pistons and rods as well as the shop can do it, without disassembling them. The only reason to separate them is slack.

 

[lordhelemt]

You may want to try ultrasonic cleaning. While I haven’t tried it on pistons/rods I’ve had pretty good success with carbs, valve/front covers, intake plenum/trumpets, etc. just make sure the solvent is compatible with the metal you’re cleaning. Some stuff (like simply green) can damage aluminum.

 

[JohnnoK]

The gudgeon pins press out and probably need the small ends heated up to refit them properly.