Post: #1

Back to redoing things that IMO are sub standard on my "kit"
Having put my cross member back from stock to fit my Ford tranny.
What I'm wondering is will a 1.5" hole weaken the frame rails this far back to where I should not do this?
The reason I want to drill holes is to add a nut (or bolt) and washer to replace the
lag bolt that the "kit" suggests using.

   

Thoughts?

Post: #2

What about using something such as a riv-nut?

Post: #3

Yes it will significantly weaken the frame rail unless you go in thru the top IE the floor pan.

^ Easier to mock up.

Or chop out a section on the bottom and weld in a new slightly thicker plate with the nut already fastened.

^ Requires more fitting and measuring.

Post: #4

drill a small hole big enough for the nut
weld the nut to the back of a fender washer
insert the nut in the small hole
weld the fender washer to the frame rail.

or do like the VW guys do when the captive nut holding the control arm bolt comes loose...
cut a window in the side, insert your nut&washer, tack in place, then close the window and weld it shut.
http://forums.tdiclub.com/showthread.php?p=985929

Post: #5

What one of the Volvo shops used to do when they'd convert an autotragic early 240 to a Aw70/71 transmission, was to create some brackets about 1/2" thick with three holes. One hole would have a nut tacked to it, the other would be pass-through. Bolt the brackets in place with the front bolts, then use a longer bolt on the middle holes, and the regular bolts on the rear holes. Firmly mounted, and no mods to the frame rails.

-J

Post: #6

What year did they add the extra holes?

Post: #7

1981 was when the frame rails were modified to have the extra pair of holes... Very easy to put an Aw70 or 71, etc, into a 1981 240. The earlier cars, however, need the brackets...