21 replies to this topic

[mini1071s]

Interesting, though that crack is no where near the hole in the web, if the hole caused the weakness due to a stress riser from that hole, it would have cracked across that area.

More likely that somone in the past before you had the box overtightened the bolt in that hole? I see the thread is stripped, which is what you would expect if this was the case.

[Guess-Works.com]

No the hole in the web (being the whole cross section from side to side) is the bolt hole which is no longer there on the later A+ boxes for that exact reason... and no the thread is not stripped, and yes the bolts were secured with locktite...

[Dan]

Have to agree with Guessworks, cracking of the web there through the hole is a known problem of the four bolt webs and is why the fourth hole was dropped on later boxes.

[mini1071s]

OK, convinced me now!

[pistin broke]

dont you just love this forum good advice from both sides
thanks people think i will stay clear
and stick with my a+ box until some thing else comes a long :smartass:

[mini1071s]

Just stripped down a pre A+ box to find that hole is not there. I asked another box rebuilder when ordering some parts for it about this and it seems that the hole was drilled only in boxes between 79 and mid 81.

So if anyone does have to use an early box, like if they have a set of pre A+ drops, (I am using a 4 synchro magic wand box to keep the stock looks on a mk1 850 hence the pre A+), then avoid those years and you avoid the hole and the cracking problem.

[Guess-Works.com]

I beg to differ, but the workshop manual for 1959 - 1976 clearly shows 4 bolts... and so far EVERY pre A+ I have stipped has shown that trait... Magic wand, Remote and rod change.

So I would love to see a photo of that box and the casting number, so that I can watch out for them as they must be rare... and a bonus as you say for those wanting to keep the period look of the vehicle.