seats out, false floor in, bolts too short

[Peter Comber]

Hi folks, I took out the rear 'dicky' seats and their mounts, and slid in my false floor and even manged to get some holes lined up pretty well. The four existing Nissan bolts are too short to go through the thickness of my false floor but I'm keen to secure it down. I took one to a bolt place and the guy confidently said "Oh yeah mate that's a _______________" - I have forgotten what he said of course but he sold me the four I needed that were a bit longer.

They don't fit - the thread is off.

Can anybody tell me what I need to know to find/order/ask for the right thread?

2003, GU wagon.

Thank you, Peter

[MudRunnerTD]

Nissan is a Metric bolt. the Seat bolts have a slight taper in then with a thread cut and are installed inte h factory to cut the thread at the same time. Pain in the arse to be honest. Note the originals have a slightly smaller end on them. You should be able to lay the new and old bolts on top of each other end for end, if the threads sit into each other then they are the same. and should be ok. can be a bit of a bugger though. even feel a little cross threaded to be honest. Check that they lay into each other before giving it any force.

[MudRunnerTD]

They will be an M10 or M12 though, i cant remember.

[Peter Comber]

Thanks MudRunner - are you saying if the thread is the same, put them in and because of the Nissan taper they may feel like they’re cross threading but just keep on going?

[PeeBee]

They are a fine pitch metric bolt in that size. I know because i have the taps now for the nissan threads. eg M10 x 1.5 is metric coarse, but the patrol bolts are either 1.25 or 1.0. If they don't match using MR's method, zip down to the local bolt supplier and they will sort it out pretty quickly. this goes for the m12 and m14 bolts as well, fine pitch. Below this nissan adopt metric coarse, such as m6 x 1p and m8 x 1.25P. I wasn't aware of the tapered profile as such, thought this was a design aspect to aid misaligned bolts and improve centering rather than a taper like a pipe thread - maybe i am wrong - seems odd though.

[Cuppa]

Just for interest there are some fine threads on my Patrol which appear not to be metric. They are in the chassis toward the back. I posted once before & no-one was able to ID what they were, & more surprisingly when I took the car to a bolt supplier with comprehensive stocks they too were surprised when they went through a heap of different bolts, checked with thread gauges etc & were unable to match the thread. They remain a mystery

[mudski]

Thanks MudRunner - are you saying if the thread is the same, put them in and because of the Nissan taper they may feel like they’re cross threading but just keep on going?
In a nutshell....:tongue:

81407

[Brissieboy]

On my 2015 GU wagon they are definitely M10 x 1.25. I use several of the existing seat anchor holes to secure my gear with non-Nissan bolts.

[threedogs]

The front seat bolts on my 04 patrol are 10mm x 1.25 pitch which is the fine thread

[pollenface]

Get a bolt/thread guage off ebay. They're worth everything.

[Peter Comber]

Thank you everybody.
Much appreciated.

PC.

[Dr Gary]

Large Metric studs have a number on the head, denoting bolt strength, small have geometric code. US studs have slashes radiating from the centre, more means stronger.

[NataleeEstrada]

When disassembling old things, it is sometimes difficult to unscrew bolts because some of them are rusty, which can break the threads when stripping, making it much harder to get the bolt out. I have worked as a builder for a long time, so our customers do not have to deal with this problem; we use high-quality stainless steel bolts that we buy here at scrooz.com.au (https://www.scrooz.com.au/fasteners/rivets/). This online store has a large selection of bolts, and I am especially glad they are sold at an affordable price.

[growler2058]

When disassembling old things, it is sometimes difficult to unscrew bolts because some of them are rusty, which can break the threads when stripping, making it much harder to get the bolt out.
Really, tell me more!

[mihit]

Just for interest there are some fine threads on my Patrol which appear not to be metric. They are in the chassis toward the back. I posted once before & no-one was able to ID what they were, & more surprisingly when I took the car to a bolt supplier with comprehensive stocks they too were surprised when they went through a heap of different bolts, checked with thread gauges etc & were unable to match the thread. They remain a mystery

Cross-threaded by a ham-fisted PO?

If you can't match it with a thread gauge....it's borked.

[mihit]

Get a bolt/thread guage off ebay. They're worth everything.

Or your friendly local engineering house...

[mihit]

Metric and fine pitch, as others have said. Vernier calipers and a pitch gauge and an "engineers black book" will tell you in short order. (These are 3 things that travel with me)

[Cuppa]

Cross-threaded by a ham-fisted PO?

If you can't match it with a thread gauge....it's borked.

Nope threads are in perfect condition, never been used. A fine thread, but not a standard metric fine thread. Same on both sides of the car.

86009

[MB]

There might be more to this agreed Cuppa Mate, GQ front end chassis’s might well have some variance too experienced. Could be 1.75mm pitch differences left to right and your Faithful Leafy GU could have a Commonwealth specified add-on?


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[MB]

That made no sense Apologies Cuppa, please do look up the chassis, if possible from the rear, if the nuts behind the chassis hole in question have a ‘tail’ welded/stuck for afterthought?


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[mihit]

Again, a pitch gauge in there will tell you. Only thing I can think would be if it was a maverick chassis destined for the usa and some standard imperial bolt-on thing was due there...

The option always exists to drill out the existing thread and either tap the holes a size/pitch up that you want, or tap them for a heli-coil/timesert.