7 replies to this topic

[thebluepotato]

Anyone have any experience with replacing the 4 long rear trunnion bolts with new ones?  Need to know which is correct.

 

 

 

MiniSport (for example) shows fully threaded versions - which is what I just removed from my Mk3:

 

 

Other vendors show partially threaded bolts:

 

[Spider]

OK, just so we can get on the same page for terminology, the fastener in the top photo is actually a Set Screw and in the lower photo, is in fact a Bolt. Sorry if I sound like I'm splitting hairs here, but in the future you go asking for such fasteners at least it'll sound like you know what you're on about

 

All the car's I've ever done had Bolts in them and that makes sense when you think about it. Because the trunnion has long load bearing and locating holes in it for the Bolts to pass through, you really want as full contact as possible between the hole (or tunnel) and the Bolt, and not have a Set Screw in there that's going to saw away at the drilling or flatten it's threads and loose location.

[thebluepotato]

OK, just so we can get on the same page for terminology, the fastener in the top photo is actually a Set Screw and in the lower photo, is in fact a Bolt. Sorry if I sound like I'm splitting hairs here, but in the future you go asking for such fasteners at least it'll sound like you know what you're on about

 

All the car's I've ever done had Bolts in them and that makes sense when you think about it. Because the trunnion has long load bearing and locating holes in it for the Bolts to pass through, you really want as full contact as possible between the hole (or tunnel) and the Bolt, and not have a Set Screw in there that's going to saw away at the drilling or flatten it's threads and loose location.

 

Well, lets take a step back here...I am speaking about trunnion bolts - not set a screw.  Both pics above are trunnion bolts...both pics are representing product SKU's for trunnion bolts (5/16-24 UNF 2.5" hex bolt).  One bolt if fully threaded (the full 2.5") and one is not (about .5").  That is why I was asking if anyone has used a non-fully threaded bolt.  Sorry if that was not clear.

 

This is not a set screw:  http://usa.minisport...t-5-16-unf.html

Edited by thebluepotato, 04 March 2016 - 07:12 PM.

[Minilegs]

Re read what Moke has written

That's a set screw on your link !

[ukcooper]

The pictures are some times not off the product.

The original bolts are sort of a self tapping kinda thing. no longer made I think

minispares - http://www.minispare...rames.aspx|Back to shop

As M/S said better to fill the bolt hole with solid steel than thread.

As you only use the first 20mm or so of thread.

Think it more depends on the bolt spec material more than anything.

Edited by ukcooper, 04 March 2016 - 07:28 PM.

[thebluepotato]

The pictures are some times not off the product.

The original bolts are sort of a self tapping kinda thing. no longer made I think

minispares - http://www.minispare...rames.aspx|Back to shop

As M/S said better to fill the bolt hole with solid steel than thread.

As you only use the first 20mm or so of thread.

Think it more depends on the bolt spec material more than anything.

Thanks...and yes, pics may not be correct....but they do make bolts in the bigger size that are fully threaded link the pic shows.  Its all good.

[MRA]

The original bolts (ha ha) were set screws that had a long spiral groove for cleaning purposes, they where changed but not sure of when to standard bolts as my 1987 new to me had set screws, however I would go for the bolts as they are a higher tensile strength in this case.

 

Never fit zinc plated high tensile fixings..... there is no such thing, although this sounds like a contradiction, high tensile bolts are high tensile because they are made from higher grade steels, if you zinc plate a higher grade steel you will get hydrogen inclusion other wise known as hydrogen embrittlement !  google it, it is very scary stuff, as fixings can fail literally like a carrot and with very little force required to do so.

Edited by MRA, 05 March 2016 - 11:44 AM.

[MRA]

 

The pictures are some times not off the product.

The original bolts are sort of a self tapping kinda thing. no longer made I think

minispares - http://www.minispare...rames.aspx|Back to shop

As M/S said better to fill the bolt hole with solid steel than thread.

As you only use the first 20mm or so of thread.

Think it more depends on the bolt spec material more than anything.

Thanks...and yes, pics may not be correct....but they do make bolts in the bigger size that are fully threaded link the pic shows.  Its all good.

 

 

No they don't, a full threaded "bolt" is actually a set screw, that is Moke Spiders point and 100% correct he is !

 

A bolt is a threaded male fastener with a section of plane shank

 

Just because I have two animals that go miow doesn't give me the right to call them dogs just because well hey who cares !!!

Edited by MRA, 04 March 2016 - 09:33 PM.