Just doing mine today - oil pan is still off. I tried the method used by the OP to pull the straight tube down through the grommet. Gave up.

Realized later that the grommet is positioned all the way past the o-ring and onto the smooth inner part of the lower tube. Having researched several postings on this job - I didn't see the grommet position mentioned.

The grommet on my car was as hard as a rock and came out in pieces. I had no idea of the original position of the grommet to the tube. Read another posting that the grommet slides on until it is "locked" onto the tube - this is not correct.

Probably spent 2 hours fighting the darn thing, only to finally figure out that the grommet should go completely onto the smooth portion of the tube, then insert the tube into the pan. I used a clamp to pull the tube all the way down into position.

Finally, push the grommet down starting with the most difficult to access point (closest to the block) and work your way around to the most accessible. This will leave good access for hands/screwdriver to wedge & start the grommet into the hole. (Another 20 minutes fighting to figure this out.) I did use the claw of a hammer to pull down on the top of the grommet to finish the job.

Hope this might help someone in the future - perhaps as an alternative to the OP technique.

By the way - this certainly rivals the oil coolant hose replacement I did some time ago. However, I'm confident I could tackle this task in a much more efficient manner - not so sure with the oil hose!

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83 300d - 390k