Bread:
Excellent write up. I like your approach to improving the Curt hitch, it is what I would have done if I had to use that hitch as you had to.
I don't quite agree with the following:
Quote:
|
The Curt receiver bolts directly to the reinforced rails and brackets on the unibody, and is only second to the factory hitch because it does not also incorporate the center brace like the factory receiver does. This is likely the reason the tow rating is reduced from the vehicle max of 6000lbs to 5000lbs.
|
The difference isn't the center brace, as the factory hitch doesn't use one. The difference is the reinforcement of the pentagon-shaped mounting surfaces located behind the collapsible bumper support struts. You have identified the attachment weakness, and rectified that. However, you are still relying on the stability of the rear mounting surface not to flex. The OE hitch removes the collapsible struts and replaces them with solid struts that are very beefy at the pentagon-shaped mounting surface, and which are cross bolted to the reinforced rails in the unibody some distance forward, in multiple planes. No comparison in terms of strength. Is it required? Well, it is keeping with the design approach of the vehicle, so in that sense it is very appropriate. I like it because it is classic German engineering.
I share your opinion of the Drawtite. Ghost, I am not questioning your manhood. Just your hitch receiver. 
Jeff
__________________
2007 X3 3.0si, 6 MT, Premium, White
Retired:
2008 535i, 6 MT, M Sport, Premium, Space Grey
2003 X5 3.0 Steptronic, Premium, Titanium Silver
2002 325xi 5 MT, Steel Grey
2004 Z4 3.0 Premium, Sport, SMG, Maldives Blue
|