I had the same problem with my first 240D, the thread is buried on the forum somewhere. My current ones air cleaner had completely sheared off all three mountings. The front rubber mount had sheared in half. The other two had actually stripped the threads out of the mounting points on the intake manifold. So. To work...


First task was to clean the area sufficiently that I wasn't completely covered in crude oil. The intake manifold was up to a quarter of an inch thick with caked on oil in places. I started scrubbing with Purple power and a very stiff bristle brush. It was a miserable job. In this pic you can see the front half of the manifold still covered in the stuff.


But eventually I got it clean enough that I was happy to work in the are without getting filthy.


First I enlarged this hole with an 8mm tap.


The result looked good so...


In goes the 6mm thread insert.


New thread insert in place.


This one was a problem. The mounting screw had enlarged the hole in a oval shape and eventually bounced around on the outside of the manifold so much it had started to make a new indentation as you can see in this pic. It was difficult tapping the hole even with the 8mm tap because of the oval nature of the hole, but eventually it got enough purchase that it seemed to go ok. The thread insert seems to have fit in there decently.


The three mounts in place. The front one didn't need to have any work done to the threads fortunately. As the mount itself had sheared in half I simply removed the remmnants of the old mount and installed a new one. Because of the oval nature of the outside hole and the damage to the aluminum in that area I used a heat shield for a Turbo 300D application to act as a sort of washer and spread the load across that area.


Gasket in place. Unfortunately this was a URO part and I had a devil of a time getting it to fit correctly. Took several tries to get the air cleaner housing to fit on there without pushing the gasket off on one side of the other.


The re-circulation pipe back in place.


Air cleaner housing mounted. It took me a couple of days with Purple Power and a brush and towels to get all the oil off of this and clean it up. Both inside and outside.


Almost done.


Filter in place.


Done. I'll keep an eye on the job for a while, especially the outboard mounting point, but based on the success I had with my last 240D's repair I'm confident this should hold for a long time.

- Peter.

__________________
2021 Chevrolet Spark
Formerly...
2000 GMC Sonoma
1981 240D 4spd stick. 347000 miles. Deceased Feb 14 2021
2002 Kia Rio. Worst crap on four wheels
1981 240D 4spd stick. 389000 miles.
1984 123 200
1979 116 280S
1972 Cadillac Sedan DeVille
1971 108 280S