BMW X5 E53 DIY OEM Hitch Installation Notes and factory installation PDF

[AquilaBMW]

Originally Posted by brptrailrider

mine came with the module and wiring and all the mounting hardware..

Picked the kit up this afternoon - it does indeed come with a module! YAY!

[AquilaBMW]

Originally Posted by Giznaz

The trailer module only provides lights and certain programming functions.

What it does not provide is brake control, if you tow heavier trasilers.

You will need a brake controller for that function, I used a Tekonsha Prodigy P3.

Thanks for the info - good to know. For this time, I will be using a U-Haul Car trailer which is a braked trailers. I believe some type of hydraulic system. Will that suffice?

[JCL]

Yes, those are surge brakes. The trailer includes a master cylinder attached to the hitch coupler on the trailer, so when the truck brakes and slows it activates the trailer brakes mechanically. If properly maintained, they work fine. I throw that in only due to your rental trailer scenario.

What they don't allow is any form of weight distribution hitch, or independent control of trailer brakes. But they do handle straightforward braking.

[AquilaBMW]

Originally Posted by JCL

Yes, those are surge brakes. The trailer includes a master cylinder attached to the hitch coupler on the trailer, so when the truck brakes and slows it activates the trailer brakes mechanically. If properly maintained, they work fine. I throw that in only due to your rental trailer scenario.

What they don't allow is any form of weight distribution hitch, or independent control of trailer brakes. But they do handle straightforward braking.

Can this cause any problems for the X5?

[JCL]

Short answer: in your case, no.

It just means that you can't use a weight distribution hitch. Not much of a problem with an auto transporter or similar trailer, as you can usually adjust the carried load front and rear to get a reasonable tongue weight. It matters more with a trailer with more bulk and windage as those trailers will benefit from sway control and weight distributing hitches. If you have 600 lbs of tongue weight (maximum) it means that you are putting over 600 lbs on the rear axle of the X5, and lightening up the front axle (due to the leverage of the location of the hitch ball) A weight distributing hitch puts some of that tongue weight back on the front axle, maintaining steering control. But the linkage involved doesn't work with surge brakes, so it is one or the other.

BMW doesn't acknowledge weight distributing hitches, since they aren't legal in Europe where the design engineers live and work.

[AquilaBMW]

JCL - Thanks very much for the information. First I have to tackle installing the hitch and then I'll tackle the trailer / car trailer from U-Haul. I wonder how much the SLS will compensate on the rear?

[admranger]

Suspension will be fine. I've run a UHaul box trailer and loaded less than a car weight, but it wasn't light (my back let me know from the pain of loading/unloading it…). Surge brakes were fine, but you need to give yourself extra room (what do your brake pads look like?).

Also, grab an 18" pipe wrench and use it to torque down the knob that holds the ball on to the hitch ball. Hand tightening just doesn't keep it secure over the long haul -- it'll loosen up on you!

Remember to cross the safety chains in an "X" pattern. Double check that all the lights work. Check tire pressures on the trailer (and the X -- see door for high load pressures).

Have a safe tow!

[JCL]

Agree with admranger, if you go carefully and methodically, you will be fine.

Air suspension does nothing for balancing the load across other axles, and maintaining sufficient axle weight on the front axle to not impact the steering.

What it does is lift up the rear so the vehicle is level. Makes it look correct. Keeps the headlights pointing in generally the right direction. But the vehicle is still carrying a heavy load some distance behind the rear axle, and that doesn't help vehicle handling. The good news is that the X5 handles very well to start with, so it tends to tolerate this load bias better than some other vehicles.

You need around 10 or 12 % tongue weight for proper trailer stability. More than that will just pull down the rear of the X5 more. Less will contribute to trailer sway. With a trailer and tongue load kept within the X5 specs, it will be fine.

[AquilaBMW]

Thanks guys! The information is much appreciated. The brakes and rotors are brand new, just installed them about a week ago - Zimmerman coated rotors and Akebono pads.

The X tires are running about 40F - 42R at the moment. Any suggestions on what the trailer psi should be?

Again, thanks very much.

[JCL]

U Haul trailers have the tire pressure on a label on the fender, in my experience.

That's a lot of pressure in the vehicle tires. Never ran them anywhere near that, even when fully loaded or towing.