Wheel bolt length....too long?

[Yzfr1]

Hi,
I have 20" Hawke alloys on my T6.
I'd like to put spacers on the rear to bring the rear track out to match the front.
I've worked that out to be 15mm spacers. (30mm total)
I have 75mm long taper bolts on the wheels at the moment. That is 50mm of thread.
If the rule of thumb is 1.5 X thread diameter to get thread engagement length ...that's 21mm.
I've measured and I have 28mm engaged.
I should be able to use 85mm wheel bolts and thread engagement will be in limits.

My question is........is there a length of wheel bolt that is too long for these vans where strength is compromised or am I over thinking it?

 

[YellowHound]

The only problem with bolt length will be physical fitment - length won't compromise strength.

 

[Howzat]

Hi @Yzfr1. I think your rule of thumb should be taken as the minimum length. I guess the maximum would be the point the bolt can't tighten on the wheel OR if it starts to protrude from the back of the hub which I don't think is possible with these hubs.

 

[StueyStuey]

I had a heart stopping moment the other week when I got a puncture on the rear and needed to put the spare steelies on to get me to the tyre shop. I have a longer bolts on the rears as I’m running spacers on my Canteras but it bolted up fine.

I’d be more worried about bolts being too short than too long.

 

[Yzfr1]

I had a heart stopping moment the other week when I got a puncture on the rear and needed to put the spare steelies on to get me to the tyre shop. I have a longer bolts on the rears as I’m running spacers on my Canteras but it bolted up fine.

I’d be more worried about bolts being too short than too long.

I always carry 5 original bolts for my spare just incase.

 

[Yzfr1]

Hi @Yzfr1. I think your rule of thumb should be taken as the minimum length. I guess the maximum would be the point the bolt can't tighten on the wheel OR if it starts to protrude from the back of the hub which I don't think is possible with these hubs.

I think it's time to take a wheel off again and measure the full thread depth of the hub.

 

[StueyStuey]

I always carry 5 original bolts for my spare just incase.

It only occurred to me at the moment I needed them most

 

[Yzfr1]

Right....removed wheel and measured the depth the wheel bolt can go.
From the face of the disc to the thread bottoming out is 26mm.
However there is a recess in the disc before the thread starts of approximately 10mm...so at max I have 16mm of thread engagement.
I put bolt in the wheel and measured the projection from the back face of the wheel. It's 25mm.
So that's as good as you get.
If I put on a 15mm spacer I'd need a 90mm wheel bolt to achieve the same engagement. However I can only find 85mm bolts. 5mm less will be 20mm of bolt projection and 11mm of thread engagement.
Looks like I'm outta luck and I've just ordered the spacers.

Just looked up M14 thread bolt info and they say 9.5 turns minimum which is 14.25mm.
So VW are giving you just 1 turn more than minimum requirement.
Or have I got my calculations wrong?

 

[DXX]

Right....removed wheel and measured the depth the wheel bolt can go.
From the face of the disc to the thread bottoming out is 26mm.
However there is a recess in the disc before the thread starts of approximately 10mm...so at max I have 16mm of thread engagement.
I put bolt in the wheel and measured the projection from the back face of the wheel. It's 25mm.
So that's as good as you get.
If I put on a 15mm spacer I'd need a 90mm wheel bolt to achieve the same engagement. However I can only find 85mm bolts. 5mm less will be 20mm of bolt projection and 11mm of thread engagement.
Looks like I'm outta luck and I've just ordered the spacers.

Just looked up M14 thread bolt info and they say 9.5 turns minimum which is 14.25mm.
So VW are giving you just 1 turn more than minimum requirement.
Or have I got my calculations wrong?
View attachment 118279

With carbon steel you should have a minimum of one diameter of thread engaged, M14 so 14mm engaged in thread.
Get longer bolts and cut them down as required, my advice is use a hacksaw not a grinder so they are not heated excessively.

 

[Pewt]

I've had these fitted for ages with no issues......you could check check the bolts specs

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[Yzfr1]

I've had these fitted for ages with no issues......you could check check the bolts specs

VW T5 T6 Hubcentric 15mm Black Wheel Spacers & Tapered Bolts PCD 5x120 65.1CB | eBay

Find many great new & used options and get the best deals for VW T5 T6 Hubcentric 15mm Black Wheel Spacers & Tapered Bolts PCD 5x120 65.1CB at the best online prices at eBay! Free delivery for many products.

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They look fine for original wheels...but I already have long bolts due to aftermarket Hawke alloys. They are range rover like in that they have a special collar to suit the 60deg bolt and have to be alot longer than the standard bolt.

 

[Yzfr1]

Any one know where to get 17mm hex taper seat wheel bolts with 65mm or longer thread length?
I've had no luck.

 

[Howzat]

I struggling to comprehend how thick your RR wheels must be to need such long bolts!

You may have to rethink the spacers and go 10mm instead?

 

[Yzfr1]

I struggling to comprehend how thick your RR wheels must be to need such long bolts!

You may have to rethink the spacers and go 10mm instead?

Thought bolts would be an easy find.....I was obviously wrong ..lol
I bought h&r 15mm spacers earlier today and now struggling with the bolt.
The wheels are Hawke Chayton.

 

[Ads_Essex]

it starts to protrude from the back of the hub which I don't think is possible with these hubs.

I’m testament to say you can

@Yzfr1 an old thread I know, but Watfields appear to offer custom length items, so wheel bolts may well be included