Battery Terminal lash-up.

B

Bahnstormer

Member
The other day, as I started up, the lights flickered on and the dash clock reset to 00:00 !

Checked the battery leads and found this lash-up - An inverted wingnut , screwed down by a bold that wasn't squeezing the terminal enough to hold it on the battery terminal.

img_3919.jpg

I'm sure this is not a BMW thing, but must be some sort of post build 'mod' - :x What's wrong with a good old battery clamp with a bolt horizontally across it ? New battery terminal ordered.
 
As mentioned already, looks like it has had extras added and removed in the past, maybe a larger stereo system ??
Well done for finding it though.
 
that is infact a standard BMW terminal, and I can sure hazard a guess as to why there's an inverted wingnut in there!

See.. bmw make this STUPID design whereby you have an inverted T-shaped bolt come out from the bottom of the clamp through to the top, onto which a small nut is placed and tightened.
The T-shaped bolt is specially designed so that it "pulls" together the two sides of the clamp as it's head is pulled closer to the terminal (achieved by tightening the nut from the top), which in turn secures the clamp to the battery pole.

Sounds all good and stuff, until you find that the type of metal BMW used to manufacture the T-shaped bolt is softer than butter and after a few good uses, just snaps.
"It's fine, I'll just get another from the dealer for a few pence" you may think, but oh no.. you have to buy the whole earth strap as they dont sell the T-bolt separately, and yup, you've guessed it, said earth strap is NOT cheap.

So you resort to trying to find them on eBay - sometimes you do, sometimes you dont.
When you dont, you "bodge" the terminal with a filed down bolt, or perhaps use an upturned wingnut.
This is the story of German efficiency.


Oh.. and if you think you're gonna just pop to halfords and get a new terminal, you might be in luck for the earth strap, but when your positive terminal T-bolt goes too, you're s**t outta luck :thumbsdown:
 
sk93 said:
that is infact a standard BMW terminal, and I can sure hazard a guess as to why there's an inverted wingnut in there!

See.. bmw make this STUPID design whereby you have an inverted T-shaped bolt come out from the bottom of the clamp through to the top, onto which a small nut is placed and tightened.
The T-shaped bolt is specially designed so that it "pulls" together the two sides of the clamp as it's head is pulled closer to the terminal (achieved by tightening the nut from the top), which in turn secures the clamp to the battery pole.

Sounds all good and stuff, until you find that the type of metal BMW used to manufacture the T-shaped bolt is softer than butter and after a few good uses, just snaps.
"It's fine, I'll just get another from the dealer for a few pence" you may think, but oh no.. you have to buy the whole earth strap as they dont sell the T-bolt separately, and yup, you've guessed it, said earth strap is NOT cheap.

So you resort to trying to find them on eBay - sometimes you do, sometimes you dont.
When you dont, you "bodge" the terminal with a filed down bolt, or perhaps use an upturned wingnut.
This is the story of German efficiency.


Oh.. and if you think you're gonna just pop to halfords and get a new terminal, you might be in luck for the earth strap, but when your positive terminal T-bolt goes too, you're s**t outta luck :thumbsdown:
Click to expand...

SK's spot on.
Just checked mine and its a saddle arrangement (similar to a wing nut I suppose) that sits at the bottom and squeezes the battery terminal to the post as the top nut is tightened. Not a clever design! I thing some one has either lost the bottom saddle or has been trying to increase the squeeze by exchanging it with a wing nut......?
 
Machine monkey said:
I can probably make a few of these t nuts for you guys I will have a look at mine next time i am with the car.
Click to expand...

That would be great - Odd decision not to use an off the shelf clamping nut as on everything else !!!! :wink:
 
Bahnstormer said:
Machine monkey said:
I can probably make a few of these t nuts for you guys I will have a look at mine next time i am with the car.
Click to expand...

That would be great - Odd decision not to use an off the shelf clamping nut as on everything else !!!! :wink:
Click to expand...

But then they couldn't charge a small fortune to replace :wink:
 
http://www.ebay.co.uk/itm/Battery-Terminal-Bolt-Cable-T-Bolt-URO-Parts-fits-03-08-BMW-Z4-/161723897662?hash=item25a77ed73e
USA
http://www.ebay.co.uk/itm/BMW-E46-BATTERY-TERMINAL-EARTH-LEAD-/181836022934?hash=item2a56458496
Part number
61128373946
Battery cable, negative
From:01.03.1997To:-Weight:0.190 kgPrice:$22.75
Part 61128373946 was found on the following vehicles:
3' E46   (04/1997 — 08/2006)
Z4 E85   (01/2002 — 08/2008)
Z4 E86   (10/2005 — 08/2008)
So it looks like it fits an E46 so there will a plentiful supply in the breakers
Have you tried Sopers at Lincoln For the part??
 
I am off over to do some fettling to my car tonight. If i remember i will take the little bit in question out and have a look.
 
as the previous owner, I can assure you this remained unadulterated during my ownership. That is as it was when I first got it. I will admit that when fully tightened, the terminal wasn't immovable, but I never had powering issues like you have had. (except once where I forgot to tighten it altogether)
 
Hi Samax,

Car is an absolute peach and I'm still loving it , you took good care of her ! - the silky smooth six is lovely ,and this is an easy fix - the black battery terminal just bolts in so no issues ? - just an odd design for an otherwise perfect German machine !!

Cheers,

B.
 
Why not just take that terminal off, drill a hole horizontally through the flats like normal manufacturers do and stick a decent nut and bolt through to secure.
Keeping with that retarded T bolt seems pointless to be honest, you need something to do the job properly and that isn't it.
 
:thumbsup: Agreed,

Have ordered a new cable, as they are only a few quid, and it just bolts onto a terminal on the bodywork, and to the battery via a conventional clamp !
 
Ford use a similar method.
It makes it easier to remove the terminal as you are not faffing around at the side half a turn at a time with a spanner.

Stuart
 
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