Flat tow bar question

[Jayhawk]

I am finally getting back to a tow bar project (per the DIY page here) I started a couple of years ago.  Tonight I drilled out the eye bolt holes - yay!

Then I found out I had bought 4" grade 8 bolts instead of 4 1/2" - sigh. 

Back to Lowes, which leads to the next question - how long should those 1/2" spacers be?


Many thanks!

Andrew Russell

[94touring]

I really wish I could remember, surprised I didn't write it down.   I want to say an inch in a half.   You'll have to set the x brace in place and take a measurement to be for certain.   

[MiniDave]

I expect mine are different since my car is a Clubman, but mine are 3" long......also, since I used fairly thick material for the spacers (1" diameter OD, 1/2" ID) I had to machine down the last 1/2" of the spacer to fit into the mount properly - I think I took it down to 7/8" to fit.

Also, since mine were made of stout stuff, I welded them to the cross bar for a little more rigidity - that makes the bar and spacers one unit, so all the forces of pulling and turning are carried by the entire bar and subframe together.

So Andrew, are you a former KU student?

[Jayhawk]

Getting back to the tow bar project after visiting relatives have departed (and a niece's wedding) ...

The current question is the cross bar.  I bought a piece of 1-1/2" by 1-1/2' angle iron, but after test mounting the bracket, there is a bit less than a 1/4" of material left from the bolt hole to the bottom edge of the bar. So I looked a bit harder at the pictures and I am guessing I need a 1-1/2" by 2" piece of angle iron. Is that right?

I am planning on trailering my Innocenti from San Diego to Mini Meet West this summer, but would like to have backup tow capabilities.

"So Andrew, are you a former KU student?"  Rock Chalk!  77.gif  (my family has been going to KU's engineering school since my grandfather showed up in Lawrence in 1901.  Four generations of KU engineers - so far)

[94touring]

Yeah it does look that way.  Two views of the cross brace.  One showing you'll need to shave the angle iron around the license plate brackets, and the other showing the length is longer on  the bracket side of the angle iron.

[MiniDave]

I used a 2 X 2 piece for mine, but mine doesn't run thru the lic plate brackets, it's slightly below them - the Clubman is different.



You definitely want 2" where the bracket bolts onto the angle iron.....

I lived in Sandy Eggo for almost 20 years, before moving back to KC....<sighs> I SO miss my house in Bay Ho!

[Jayhawk]

Dave, I get back to KC a couple of times a year - my bother lives in Overland Park.  I'll try and look you up so I can see your Clubman next time I'm back that way.  And I know what you mean about Bay Ho - I live in Pacific Beach (aka "Baja La Jolla") not far away.

[MiniDave]

I'm in OP too....

I really would like to go to MMW, I've done the Mini Meet East meets West twice, and those Canadian guys are a hoot! They drove from Vancouver to Milwaukee in their classics fer chri sakes!

Where they're having the meet is a beautiful valley with lots of fun roads and mountains all around it - are you towing with your 2004 MINI?

[Jayhawk]

Am I towing with my'04 MINI?  No, but it's doable as a flat tow.  There is an individual in SCMM who has (among a bunch of cool cars) a MINI and a Mini, and has towed the latter with the former - I have a picture of the rig at the annual San Diego British Car day a few years ago (see below...).  The MINI has a stated tow capacity of 1400 pounds, and his MINI has been hopped up to over 300 horsepower, so he has no problems.  But he also has a diesel Mercedes Sprinter with a custom MINI trailer he tows to track days, so the MINI towing a Mini trick is mostly just for fun.

I'm currently searching for a trailer to rent, buy, whatever to put my Inno on and tow behind my '04 Tacoma pickup for the trip north this summer.

[MiniDave]

Interesting Canadian Mini he has.

I'm planning to tow my Mini with my '09 Clubman S.

[Jayhawk]

Well, it's finally done! (except for actually towing it...)

See picture at end of post.

Tools used:
Bench top drill press
4" angle grinder
step drills
12V DeWalt drill (lovely little drill, light and strong)
12 V DeWalt shop light (very handy!)
3/4" deep socket and wrenches
1/2" drive torque wrench
Dremel tool with router bit
center punch
bastard file

Parts:
one Harbor Freight ("HF") towbar kit
one 1-1/2" x 2" angle iron, 32" long (should have cut it to 31")
two 5-1/2" Grade 8 1/2" hex bolts
two 3" long Protofab steel spacer 3/4" x 1/2"  (.120 wall) Part No. B750500
numerous 1/2" nuts, washers, etc.
...oh, yeah - one Mini Cooper

Lessons learned:

The nominal distance between the subframe mount holes is 26.0". Your milage may vary some - mine did.  Thus the above mentioned router bit in the Dremel after drilling holes in the crossbar 26.0" apart...

1" by 2" angle iron would have been nice to avoid grinding the notches for the license plate mounts. But that size apparently does not exist.  Note the Harbor Freight  brackets are 2.5" from center hole to edge, thus 26" plus 2.5" plus 2.5" gives a 31" long angle iron cross bar - but YOU check your measurements and math - don't trust ME.  ("There are three kinds of people in the world..those who can do math, and those who cannot...")  4.gif

The recommended 4-1/2" Grade 8 bolts were too short for my project. It didn't help that I first bought 4" by accident.  5" bolts were okay, but the crossbar barely cleared the valence of my Innocenti and there wasn't quite enough thread to completely double nut the bolt.  Finally used 5-1/2" bolts with the 3" Protofab spacers and the "square spacers" from the HF kit, which positioned things to my satisfaction.  Anybody need 4" or 4.5" or 5" long grade 8 hex bolts? I have some spares...

The thick wall Protofab spacers were just about perfect. Recommended.

The space behind the subframe for the bolt to pass through was too tight on one side for a standard 1/2" washer. I had to use a 3/8" washer drilled out to 1/2", then flattened on one side down to the diameter of the bolt head and lock washer to allow the bolt to slide up to the back of the subframe.

The two 'side bolts' on the mounting bracket are way too long.  Tightening down the nylock nuts took forever.  I'm going to pick up something shorter when this rig is next taken down.

Step drills are Very Nice when drilling out the bolt holes in the angle iron.

One of the mounting brackets from the towbar kit did not have the center bolt hole.  Harbor Freight says that they now all come without that.  Drilling out a 1/2" hole through 3/8" of steel with my tired old drill press was a big pain.  Next time, I'm buying a new drill press!

Marshall's Industrial Supply and Industrial Metal Supply Co. are great outfits to have in San Diego to supplement Harbor Freight.  Hope your city has similar! 

Andrew Russell

[94touring]

Nice writeup explaining your experience.   

[MiniDave]

I shortened the HF bolts and put the nuts on the back rather than the front. I also put the long bolts thru to the rear as well, I found that if the bolt is long enough to double nut it interfered with the thru pin for the HF tow bar attachment.

Andrew, what did you do for safety chains? I bought three packages of the HF chains, one set cut in the middle and used for the Mini end, the other two I cut off the end and used most of the length for the tow car end.