39 replies to this topic

[Gedi]

That's a bit excessive, unless you plan on tapping holes and cutting threads onto bars.

An 8mm plug tap for a few quid will suffice. Make sure it's a plug tap and not a taper tap.

[MartinS]

I fitted them to the defined torque settings (I even bought a torque wrench for the job as realised it was important to get this right). The reason I even did the job was I wanted make my daughters car as safe as possible.

One thing I did notice when doing them was the range of lengths didn't match the originals. Some did match but some didn't which I wasn't keen on and seemed a bit odd.

Because of this some did need to be wound further in than the originals. Where this was the case, I checked the threads and cleaned them up as much as possible, as I realised on the first non original length bolt, that they hit a stopping point on the dirty thread.

I checked the heads position against the hub carrier to make sure they were fully in when it did hit the limit on the torque wrench.

Ideally, any uprated bolts would be the same lengths as the originals supplied I would have thought.

I will be using lotus ones now as all of them are being replaced.

Martin S

ps This car has a normal ride height and runs on original wheels/tyres and spax suspension. All I can say about camber shims is that there were two of them.

 

 

 

 

Edited by MartinS, 20 October 2014 - 03:51 PM.

[Scuffers]

as said, it may be an issue that your tightening up against the thread ends rather than the joint itself?

 

it's not something I have noticed before on these, but that does not mean it can't happen, the test would be can you screw the bolt all the way in without the plinth (ie, will the bolt thread into the upright all the way).

 

I know people say not to do this, but I tend always to use 21.9 cap heads and torque them to 84nm.

 

I also work on the principal of changing them at the slightest hint of issue.

 

Bolts are cheap, the consequences of then snapping is not.

[slindborg]

Were there two longer bolts and the rest all the same? iirc the front takes a longer bolt each side.

[MartinS]

There was on odd mix of bolts. I started on the back and was able to match the lengths (it was a rear that went) then had an odd assortment left. Didn't like that, but as the lengths didn't seem critical at the time carried on.

 

 

Either way, it does seem that though we're all aware you need to upgrade these bolts, it wasn't clear (I wasn't told anything) how critical it is, that if the new ones are longer, you must make sure to clean up the thread they're going in, though I personally would just get ones the exact same lengths as the originals.

 

Martin S

 

 

 

[PaulCP]

How do you know that the ones you replaced were the originals? Previous owner may have put them in

[Zoobeef]

Mine were the same Martin, longer is fine as the extra thread just exits through the other side of the hub. Running a tap through the threads is the best way as 10+ years of corrosion on the last few exposed turns will effect them. Shame I wasn't there as she could of had the bolts out of my car and driven it home!

[Nev]

Shame I wasn't there as she could of had the bolts out of my car and driven it home!

I'm sure that poor girl doesn't want to see you "nuts and bolts" Mark

[sworks]

I had my mango bolts fitted by maidstone sports cars. They told me some of the bolts were the wrong lengths. I haven't been overly impressed with their service so assumed they had got the bolts the wrong way around, so was going to get them checked/replaced again by BoT. Maybe now not so sure and will definetley get them replaced by BoT.

[CHILL Gone DUTCH]

Are these the bolts which need removing to alter the camber ??

[smiley]

Are these the bolts which need removing to alter the camber ??

Yes. You can see them shine very well here.

 

[CHILL Gone DUTCH]

👍

[firehawk]

 

Are these the bolts which need removing to alter the camber ??

Yes. You can see them shine very well here.

 

 

 

These in the picture are BZP caps, although they are probably rated at 10.9 or 12.9 (it will say on the top of the head if they are made by a reputable manufacturer) the zinc plating can cause hydrogen embrittlement, personally I would only used black ones. your local engineering supplier should be able to supply the bolts, they normally will be a high quality brand ie unbrako or bossard (ours do anyway).

 

Sounds to me the bolt may of torqued up ok but was bottomed out on the threads hence allowing it to flex and then break. Or supplier supplied sub quality bolts, there are a lot of Chinese origin bolts around now so beware.
 

[Arno]

The silver looks too dull/satin to be zinc plating. Most likely it's a Dacromet (or similar) coating that provides the corrosion resistance but does not have the hydrogen embrittlement problem. Usually a common suface treament option on most 10.9 or 12.9 grade bolts that will be used in exposed conditions.

 

Basic blackened ones are OK as well, but make sure you spray the exposed parts (threads, head) liberally with a corrosion inhibitor or sealer like Waxoyl or the like as the blackening treatment provides little or no surface protection against rust. Otherwise you won't be happy when you need to remove them at a later point.

 

Bye, Arno.

[Scuffers]

FWIW, I have always used 12.9 BZP's

 

Yes, they are probably not as 'strong' as chemi-blacked, but corrosion is a real issue unless your on top of it really regularly.

 

other point I mentioned earlier is camber shims, the more you run (as in the less camber), the more the stresses on the bolts.

 

it does not help this that some shims are pretty soft and narrow, reducing the contact patch on the plinth and also the 'angle' against the bolt, (years back somebody started making ali shims, that was a really bad idea as they started to deform and then the bolts were loose).

 

these days I use hard stainless ones.

 

what I am getting at is that you may well initially torque up the bolts to the correct point, but 100 miles later they may well not still be that tight as the shims bed-in or deform.

[siztenboots]

on the basis of less surfaces for the bolt to clamp, one thick shim , is better than several thin ones

[vocky]

just run a tap through the threads, it's good practice and makes fitting the new bolts much easier.

 

ps: whip the shocks off at the rear and you get loads more room to change the bolts 

Edited by vocky, 21 October 2014 - 09:55 AM.

[Scuffers]

quicker to just loose the toe link and turn the hub.... (or at least, that's what I do!)

[vocky]

quicker to just loose the toe link and turn the hub.... (or at least, that's what I do!)

if they are in decent condition that is also a good option, but when they are really rusty it's probably best to avoid even trying    

 

strangely they always seem rusted up when I have to fit those damn hub bolts 

[FLD]

Lotus have changed the camber shims several times and the bolts several times so there may be different specs on different cars.  When I swapped mine I found the threads weren't cut right through the uprights so I had to properly tap them (I will only use dormer taps since an issue with a cheap one).  It was this issue that caused one of mine to fail I'm sure of it.

 

Have you used your torque wrench to undo any bolts?  If you have then the calibration could be way off resulting in an under or over torqueing.