Roof rails - Are MK3 and MK4 SWB the same fitment?

[SkyRocket1976]

As above, will rails from a 2017 MK4 fit a 2011 MK3?

I know they're very similar but there are minor differences. I'm hoping those differences don't extend to the roof.

Thanks in advance for any replies.

[SkyRocket1976]

Just to follow up on this for anyone looking for an answer in the future.

I picked up a set of factory fitted roof rails yesterday which had been removed from a 2017 Caddy.

Doing a quick test fit and it seems the roof shape of the mk3 and mk4 roof is identical.

There does however seem to be a minor difference in the fitting.

The rails are fitted to the mk4 with a M8 x 25mm spline bolt front and rear and a M8 x 17mm bolt in the centre. The shorter bolt in the picture is the blanking plug that was fitted to my roof. As with every bolt on my van, the previous owner managed to round out the heads on some of these too. Honestly, every bolt that touched on my van has been butchered!

On my mk3, the centre bolt fits fine but the front and rear bolts are too long. The 17mm long thread of the centre bolt fits the depth of the front and rear holes though so I'll source some shorter bolts and use those.

I'm not sure why the bolt hole is shallower on the mk3 than it is on the mk4 but looking inside the van, my bolt holes don't seem to be open all the way through to the inside of the van but I've heard the bolt hole is open to the inside on the mk4.

Unfortunately the rail end covers seem to have been removed without any understanding of how they're fitted so some of the retaining clips have snapped off.

Looking at prices, a new set of plastic covers is over £120 which is more than I paid for the rails so I think I'll just use a dab of Tiger seal on the front and back of each cover to hold them in place. It'll create a challenge if I ever need to remove them but realistically I don't see why I'd ever need to.

Once I've found some bolts that fit the final challenge is making sure the threads are sealed. The middle bolts have some blue threadlock on them and looking at replacement parts this comes pre applied to new replacements. But then looking in the bolt holes, the threaded part in the hole is only around 7 to 8mm deep so there's really not much thread for me to use PTFE tape and blue lockthread. I'm thinking though that lockthread should seal the threads to I'll probably just go with a generous application of blue threadlock and see how that goes.

[PJD]

Really appreciate the update. I will for roof rails at some point and this is very helpful

[SkyRocket1976]

Further little update.

This:

https://vwvanpartsdirect.co.uk/product/ ... oof-rails/

Would suggest that the bolts should actually fit so I'm going to investigate a little bit more. I don't want to fit roof bars with shorter bolts and find out that one day my roof load finds itself on the road!

[OliverTwistUK]

Keep us posted on the bolt situation, I’m hunting some rails currently for my SWB mk4