Hub Bolt Pinch Bolt

Greeners · 27th April 2020, 13:50

Does anyone know what the pitch of the hub bolt is ? RYG000500 is M12 x 65mm, just wonder if anyone knows the thread pitch is

Thanks

T-Cut · 27th April 2020, 15:27

Looking at Rimmer's image of RYG00050, I'd say it has the standard coarse pitch for M12 at 1.75mm. That's 6.9 thread crests to match the OD. Visually, you'll see it's right.

TC

Greeners · 27th April 2020, 15:56

Thanks TC, I was hoping it would be 1.5......never mind. My mini needs two new pinch bolts, and BMW want many arms and legs, MGR ones are about £2 each

Greeners · 27th April 2020, 18:06

This is the original bolt

Is there any reason why I shouldn't change it for one like this ?

I'm assuming the hub isn't threaded all the way through

bl52krz · 28th April 2020, 21:36

The bolt you show in your second photo has not got the lead in tapered thread that the correct bolt has. Not sure quite why the lead on the correct bolt is there but I imagine it is because when tightened the bolt actually bends as it tightens up. A straight thread would more likely seize if it had to be taken out again. Also is the bolt the same grade as the original?

AndyN01 · 29th April 2020, 07:52

As an aside; having just discovered a broken front spring I love the RAVE instruction/description for its removal:

"12. Remove bolt securing damper to hub"

From what I've read it might, just might, not be quite that straightforward

Good luck with the mini.

Andy.

KWIL · 29th April 2020, 08:02

Since the thread pitch on the tapered portion is the same as the full thread, might it not be provided so as to ease the start of the engagement/tightening if the bolt end is not quite on centre?

marinabrian · 29th April 2020, 08:29

The Mini "bolt" is a machine screw, the Ford Item a bolt, the tapered lead in is not a problem, and as Ken says it is merely to aid starting the bolt.

I would suggest the Ford item to be slightly better in reality, as there is a shoulder mirroring the major diameter of the rolled thread adjacent to the flange, which will provide a much better location in the clearance hole in the hub assembly than the BMW item.

Given the choice, I'd prefer to fit the Ford item over the OEM one

Brian

Mike Noc · 29th April 2020, 08:39

Quote:

Originally Posted by marinabrian

Given the choice, I'd prefer to fit the Ford item over the OEM one

Brian

Me too, and I'd put a bit of Copaslip on the shoulder, just to make it easier to get out next time round.

Greeners · 29th April 2020, 10:54

Thank you for confirming my hunch gents...The Ford bolt is £3 delivered the BMW one is £9 plus postage

and the old one that came out is so grotty on the upper threaded section, I can see why they seize over time, they'll be well greased when the go in

27th April 2020, 13:50	#1
Greeners Moderator MG-ZTT Join Date: Mar 2007 Location: Ware, Herts Posts: 19,798 Thanks: 161 Thanked 1,249 Times in 1,036 Posts	Hub Bolt Pinch Bolt Does anyone know what the pitch of the hub bolt is ? RYG000500 is M12 x 65mm, just wonder if anyone knows the thread pitch is Thanks __________________ *David* Impecunity is the mother of ingenuity Useful how to's for common problems Car Of The Month Jan 2014 [SatNav Power Down] [Coolant Level] [SatNav Repair] [Diesel Non Starting] [Paint Codes] [Rear Light Seals] [Reversing Light Switch] [Bleeding Brakes][Sunroof Drain] [Early ZT's][Instrument Pack Diagnostics][ATC Diagnostics]

27th April 2020, 15:27	#2
T-Cut This is my second home Rover75 and Mreg Corsa. Join Date: Nov 2006 Location: Sumweer onat mote o'dust (Sagin) Posts: 21,753 Thanks: 341 Thanked 3,660 Times in 2,924 Posts	Looking at Rimmer's image of RYG00050, I'd say it has the standard coarse pitch for M12 at 1.75mm. That's 6.9 thread crests to match the OD. Visually, you'll see it's right. TC Last edited by T-Cut; 27th April 2020 at 15:33..

27th April 2020, 15:56	#3
Greeners Moderator MG-ZTT Join Date: Mar 2007 Location: Ware, Herts Posts: 19,798 Thanks: 161 Thanked 1,249 Times in 1,036 Posts	Thanks TC, I was hoping it would be 1.5......never mind. My mini needs two new pinch bolts, and BMW want many arms and legs, MGR ones are about £2 each __________________ *David* Impecunity is the mother of ingenuity Useful how to's for common problems Car Of The Month Jan 2014 [SatNav Power Down] [Coolant Level] [SatNav Repair] [Diesel Non Starting] [Paint Codes] [Rear Light Seals] [Reversing Light Switch] [Bleeding Brakes][Sunroof Drain] [Early ZT's][Instrument Pack Diagnostics][ATC Diagnostics]

27th April 2020, 18:06	#4
Greeners Moderator MG-ZTT Join Date: Mar 2007 Location: Ware, Herts Posts: 19,798 Thanks: 161 Thanked 1,249 Times in 1,036 Posts	This is the original bolt Is there any reason why I shouldn't change it for one like this ? I'm assuming the hub isn't threaded all the way through __________________ *David* Impecunity is the mother of ingenuity Useful how to's for common problems Car Of The Month Jan 2014 [SatNav Power Down] [Coolant Level] [SatNav Repair] [Diesel Non Starting] [Paint Codes] [Rear Light Seals] [Reversing Light Switch] [Bleeding Brakes][Sunroof Drain] [Early ZT's][Instrument Pack Diagnostics][ATC Diagnostics]

28th April 2020, 21:36	#5
bl52krz This is my second home Rover 75 cdt club + Rover 2.5 KV6 Conni SE Join Date: May 2008 Location: Birmingham Posts: 11,394 Thanks: 6,587 Thanked 2,262 Times in 1,729 Posts	The bolt you show in your second photo has not got the lead in tapered thread that the correct bolt has. Not sure quite why the lead on the correct bolt is there but I imagine it is because when tightened the bolt actually bends as it tightens up. A straight thread would more likely seize if it had to be taken out again. Also is the bolt the same grade as the original? __________________ Great Barr, Birmingham.

29th April 2020, 07:52	#6
AndyN01 This is my second home Toyota RAV4 Join Date: Jun 2017 Location: Tamworth Posts: 3,076 Thanks: 2,478 Thanked 1,579 Times in 968 Posts	As an aside; having just discovered a broken front spring I love the RAVE instruction/description for its removal: "12. Remove bolt securing damper to hub" From what I've read it might, just might, not be quite that straightforward Good luck with the mini. Andy.

29th April 2020, 08:02	#7
KWIL Precise Rover 75 Tourer 2.5KV6 Connoisseur SE Join Date: Mar 2013 Location: Fleet Posts: 2,954 Thanks: 630 Thanked 617 Times in 480 Posts	Since the thread pitch on the tapered portion is the same as the full thread, might it not be provided so as to ease the start of the engagement/tightening if the bolt end is not quite on centre?

29th April 2020, 08:29	#8
marinabrian MG ZT Join Date: Jan 2011 Location: Newcastle Upon Tyne Posts: 20,151 Thanks: 3,565 Thanked 10,837 Times in 5,718 Posts	The Mini "bolt" is a machine screw, the Ford Item a bolt, the tapered lead in is not a problem, and as Ken says it is merely to aid starting the bolt. I would suggest the Ford item to be slightly better in reality, as there is a shoulder mirroring the major diameter of the rolled thread adjacent to the flange, which will provide a much better location in the clearance hole in the hub assembly than the BMW item. Given the choice, I'd prefer to fit the Ford item over the OEM one Brian

29th April 2020, 10:54	#10
Greeners Moderator MG-ZTT Join Date: Mar 2007 Location: Ware, Herts Posts: 19,798 Thanks: 161 Thanked 1,249 Times in 1,036 Posts	Thank you for confirming my hunch gents...The Ford bolt is £3 delivered the BMW one is £9 plus postage and the old one that came out is so grotty on the upper threaded section, I can see why they seize over time, they'll be well greased when the go in __________________ *David* Impecunity is the mother of ingenuity Useful how to's for common problems Car Of The Month Jan 2014 [SatNav Power Down] [Coolant Level] [SatNav Repair] [Diesel Non Starting] [Paint Codes] [Rear Light Seals] [Reversing Light Switch] [Bleeding Brakes][Sunroof Drain] [Early ZT's][Instrument Pack Diagnostics][ATC Diagnostics]