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2003 ML55 AMG - 2005 E55 AMG
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316 Posts
Discussion Starter #1
Hi,

I just received an OEM trailer hitch for my 2003 ML55, and am now looking for the correct bolts, washers, nuts etc. necessary for the installation.

After much research I understand that I do NOT need support brackets as the ML55 is already equipped with those, so I guess I only need the hardware that holds the actual hitch to the frame.

Does anyone have the original hitch instructions from MB or could tell me exactly which bolts etc. is necessary (size, material etc.)

On a side note: Will I find the harness plug behind left taillight? I took out spare tire and tried to locate the plug through the inside of the trunk like on other MLs, but without luck, and my guess is that since there is barely any room to find it, they might have stuck it at the taillight?

Keep in mind that this is for the ML55

Thanks in advance, everybody has been great at helping me to start with.
 

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1990 190E 2.6,.... 1998 ML320, 2005 ML500SE
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3,104 Posts
From the Factory instruction parts list:

Microencapsulated hexagon
screw M14X1.5X55-10.9 (4 items)

The Microencapsulated is basically thread lock sealer similar to Permanent Loctite.

Everything you need to know about trailer wiring.

http://www.benzworld.org/forums/w163-m-class/1338598-trailer-lighting-wiring.html

Your plug, depending on year is either at the Post #2 or Post #10 location. My 09ML was located under panel in Post #2 and my 05ML was located in the Post #10 location.

According to instructions, Vehicles with external tire carrier and type AMG ML55 Existing braces must not be removed. Parts list for ML55 does not include the brackets so you are correct in that you must already have them.

OK now I need to get back to working on my trailer in this oppressive heat.

Mike
 

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2003 ML55 AMG - 2005 E55 AMG
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316 Posts
Discussion Starter #3 (Edited)
Great Info, thanks. Getting closer. I might try and figure out the harness plug from the link you gave me as well.

2 questions though: what kind of washers do the instructions give? Trying to do this as correctly as possible. Does anyone know where it would be the easiest to get these parts from? Would a hardware store have these? Webpage?

I found this page, which does not have 55mm by only has 60mm long bolts, would that be a problem?
http://www.boltdepot.com/Metric_hex_bolts_Zinc_plated_class_10.9_steel_14mm_x_1.5mm.aspx

Besides, should all 4 be equally long? The hitch looks like it need longer bolts for bottom 2 holes???

Would this shopping list do it (4 of each item)?
15190 - Metric hex bolts, Zinc plated class 10.9 steel, 14mm x 1.5mm x 60mm.
4830 - Metric lock washers, Zinc plated steel, 14mm.
7745 - Metric flat washers, Zinc plated class 10.9 steel, 14mm.

And some loctite threadlocker or similar.

OK, one more thing. Torque number for the trailer hitch bolts?

Thanks
 

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Registered
1990 190E 2.6,.... 1998 ML320, 2005 ML500SE
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3,104 Posts
Great Info, thanks. Getting closer. I might try and figure out the harness plug from the link you gave me as well.

2 questions though: what kind of washers do the instructions give? Trying to do this as correctly as possible. Does anyone know where it would be the easiest to get these parts from? Would a hardware store have these? Webpage?

I found this page, which does not have 55mm by only has 60mm long bolts, would that be a problem?
Metric hex bolts, Zinc plated class 10.9 steel, 14mm x 1.5mm - Bolt Depot

Besides, should all 4 be equally long? The hitch looks like it need longer bolts for bottom 2 holes???

Would this shopping list do it (4 of each item)?
15190 - Metric hex bolts, Zinc plated class 10.9 steel, 14mm x 1.5mm x 60mm.
4830 - Metric lock washers, Zinc plated steel, 14mm.
7745 - Metric flat washers, Zinc plated class 10.9 steel, 14mm.

And some loctite threadlocker or similar.

OK, one more thing. Torque number for the trailer hitch bolts?

Thanks
The factory hitch was bolted on to the bumper with just 4 equal length special bolts and no other hardware.
No flat washers and no lock washers.
The factory bolts were the kind that had hex heads that formed into washers or incorporated washers all as one unit.
All 4 bolts were the same length.
There is plenty of room behind bumper nuts to accommodate a longer length bolt.
Lock washers were not used.
If your bolts do not have a washer under the hex as part of the bolt then I would use an appropriate flat washer but not a lock washer.
Hitch bolts are torqued to 118ft/lb(160 Nm). Sounds high but that is what the instruction manual says and that is what I used.
Mike
 

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1990 190E 2.6,.... 1998 ML320, 2005 ML500SE
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3,104 Posts
See Picture #2 and #17 for a view of the Hitch Bolts.

http://www.imageevent.com/benza/mboemtrailerhitchinstall

The pictures in my previous link on wiring show an aftermarket DrawTite hitch. Notice the aftermarket unit uses standard hex head bolts with washers.

Picture #2 on page 13 of DrX's link shows a good view of the Factory bolt on right side of the picture.

Mike
 

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2003 ML55 AMG - 2005 E55 AMG
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316 Posts
Discussion Starter #8
Thanks for all the info. I guess " be careful what you ask for" applies to this, as I have so much info I need to sort it. Think I have it figured out with exception of where to find the factory harness plug. I hope to find it once the bumper comes off, since there is no way I can get it from inside the trunk (ml55 spare tire in the way).....

I might do a write up of the process. Intending on using the metra harness modified to plug in the oem plug.

Last thing, do I have to disconnect the battery?
 

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Outstanding Contributor
2002 ML320, 2003 A160, 2002 ML500, 2018 GLS350d
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4,406 Posts
There is a way to remove the ML55 spare tire. See page 7 of this WIS collection.
Last thing, do I have to disconnect the battery?
If you read page 1 of my previous link, step 1 is "disconnect ground cable at battery". You don't have to, but that's the instruction. (A 12 V shock could be a useful learning experience.)
 

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2000 ML430 (Sold)
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1,209 Posts
Last thing, do I have to disconnect the battery?
If your not using the OEM harness thats simply plug and play, it would be a very good idea since your splicing into wires. Wouldnt wanna fry anything by accident, including yourself. DC volts are the hurty kind.
 

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2003 ML55 AMG - 2005 E55 AMG
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316 Posts
Discussion Starter #11
Although good information for removing spare tire (still debating if I want the extra room or not), I hope that will not be necessary to locate the harness plug. I have a feeling I can find it when I have the bumper off....

I'm creating a plug and play harness plug myself, and not splicing in wires, but might just disconnect the battery to be on the safe side.
 

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2003 ML55 AMG - 2005 E55 AMG
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316 Posts
Discussion Starter #12
Does anyone have a template for cutting the pull-out piece on the bumper to fit the hitch snugly?

Thanks
 

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2000 ML430 (Sold)
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1,209 Posts
I looked for one when I did mine. No luck. As far as I could tell, its a measure 17 times, cut once kinda deal

Sent from my GT-I9000M using AutoGuide.Com Free App
 
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