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More work on the m42 swap for Luna

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More work on the M42 swap for Luna

Battery (smaller AGM) has been tucked under the rear seat delete.

e30 M42 radiator modified for use in a late model 2002. As some of you know, the extra bracing on the late models means your radiator cap fouls on the underside of the hood, on the driver's side. So off we go! First, chop the expansion tank drain off, flush.

The bottom area around this hole is then melted with a torch. Using a large metal coin from the other side for support, we then melt the filler ABS into the hole in the end tank shell (where that drain was). I repeated the melting and drying process a few times to make sure the old and new plastic have bonded really well, and there's no holes. Here it is after a few cycles and it's all nice and smooth. I tested that this holds water overnight.

Cut mesh for reinforcing the interior plastic welding. Test fit and trim multiple times. I lightly (so that we don't undo our work on the other side) melted the inside of the end tank shell so that the mesh could be pressed into place. Make sure all the ports are unobstructed, and melt a lot of ABS filler in. We want to completely cover the stainless steel mesh and create a new "floor" that's thick and well bonded.

On the passenger side, nothing really needs to be done. However I did shave the peg and rubber pad for just a bit more clearance.

I took this opportunity to replace the input seal, output seal, and selector rod seal on the Getrag 240 transmission. Seems like lots of people struggle with this, but it's a pretty easy job if you've got some basic tools around.

For the input seal, you unbolt the shaft sleeve first. On my particular Getrag 240, the input shaft sleeve was stuck in place very well and wouldn't move freely once unbolted. Take a MAP gas torch on low, and warm up the base of the sleeve. I used a wood hammer handle and dead blow to knock around the base, and then used just the dead blow itself inside the bell housing. With small strikes to slowly rotate the base, the seal finally broke after a minute of small movements. There's a nice groove you can use as a pry point to get the old seal out. I carefully used a long flat blade screw driver, but you need to be cautious here as to not gouge the seat where the seal goes.

Before putting the new seal in, wrap the input shaft splines with some thick plastic. A ziploc freezer bag works great. I installed the sleeve loose, then hand tightened the small bolts in star pattern, and then went back around and torqued in star pattern as well. Sealed back up with the addition of some Elring Curil. I also drilled out the pivot point to accept one of the nice brass pivots.

From the back

The output seal was definitely the easiest, but that's only because the trans is outside of the car. Pry out the locking ring. If you are gentle, you can reuse this. Then a deep thin walled 30 will remove the nut, the IE flange holding tool makes this a piece of cake.

Pry out the seal (this one can be removed a few different ways) then clean the surfaces and start to set the new one in place. I had an aftermarket aluminum e36 rear spring perch that worked PERFECTLY for driving in the rear output shaft seal in.

I just tapped around the circumference slowly with a dead blow hammer.

I again used a tiny bit of Curil on the outside edge of the seal. Then some Curil to seal the output shaft splines and a bit of ATF on the sealing surface flange, used the deep 30mm to bump the flange in far enough for the nut to capture, then torqued into its final resting place. Don't forget the locking plate to finish this off!

The selector rod joint is easily the most scary to do. There's just so little space between the sealing surface and the selector rod, and the seal is pretty stout. I found the absolute best way to go was this: At the top edge, use a tiny little flat head with the square edges sanded down and softened, to minimize the amount of damage it can do. Lightly tap it straight in, then once it starts deforming the seal's metal edge, start angling down. The seal should be crushing in and down.

At the opposite side of it (180 degrees) Stab in a pick/pointed punch. You want to do this straight into the middle of the seal (not the edge like the other side). Once you've punctured through, you can swivel your pick to start prying outwards from the trans.

Alternate the first and second steps here and it should come out with only two reps. Not much room to clean, but do your best, and then use a deep 15mm socket to drive in your new seal.

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