Jump to content
SAU Community

Recommended Posts

I got my genuine Nissan idler bearing bolt and this is the first thing I see.

The runout of the last thread looks pretty nasty, lots of grooves (stress risers).

Has anyone else got a new idler bearing bolt to see if it is like mine?

Maybe post up a picture?

post-8140-0-86093900-1407136010_thumb.jpg

Link to comment
https://www.sau.com.au/forums/topic/446413-rb-idler-bearing-bolt/
Share on other sites

It's not a bolt that needs to be super tight so will not be a problem at all.

If it was a torque to yield bolt you might be concerned but not for an idler bolt that is only tight not stetched.

  • Like 1

Can't believe there was a thread made for this.......

You dont use the last thread

There is only about 20ish Nm of torque on the nut

I've seen worse, People re-use these without problems

Honestly. If it is worrying you that much, Just buy another one, They arent expensive

  • Like 1

Can't believe there was a thread made for this.......

You dont use the last thread

There is only about 20ish Nm of torque on the nut

I've seen worse, People re-use these without problems

Honestly. If it is worrying you that much, Just buy another one, They arent expensive

I know what is wrong with the bolt, I was curious if other people had noticed the same thing.

Just because you don't use that section of the thread doesn't mean its not doing anything. Its actually doing alot more than the threads that are engaged.

Torque for that bolt is 43 - 58Nm and it is in single shear.

I am buying another one.

Some suggested reading material.

http://www.engr.sjsu.edu/youssefi/me154/notes/Bolt%20failure.pdf

http://arp-bolts.mobi/p/tech.php?page=2

Remember that the stud/nut are clamping the stationary part of the bearing

My comment about the nut not using that part of the thread was more about - your not going to make the thread any worse, then say if you ran a nut over it and damaged either the thread on the nut or stud. I'm fully aware of how forces are applied on bolts/studs

I was only saying, I can't see a major fault with the thread from the photo, maybe its the way the flash has gone off but it doesnt look that bad at all to me. And there is always chances of minor defects in a manufacturing process. And for the sake of a $2 part.......

As for your reading material, don't assume people are clueless when you dont know what they do for a living.

  • Like 1

Quite a long time back there was a spate of engine failures due to breaking of the idler bolt.

I spoke with Gary Cook regarding better quality bolts as the stocker isn't anything out of the box.

Gary had bought a selection of Nissan studs and the quality control was appalling.

Plenty of Unbrako quality to choose from but they don't fit under the cover, head is a bit too long.

Then almost overnight, no more breakages of the stock stud.

So were owners over tightening the stud or perhaps the belt, or did Nissan improve their quality control??????

The cross section there looks to be a fair bit bigger than in the next valley where the thread is fully formed, and those scratch marks dont appear to deep. So it doesn't look too scary to me, but i've never looked that closely before. :unsure:

My method of installing bolts.

Does this bolt fit? > Yes > put it in and tighten it to FT spec

> No > don't use it

Do I have another one that fits? > Yes > Use that one then

> No > ......where did I put my tap and die kit....

Edited by iruvyouskyrine

I am buying another one.

It's your bolt. If you don't like it and don't want to use it get another one.

Think you may have skipped a post there.

I am just curious to see what other peoples thoughts are.

It turns out it's to hard to show fine detail in a picture and very few people actually understand how surface finish can affect the life of something is under stress, so hopefully this thread can educate some people.

Here is another excellent article, scroll down to Surface Roughness

http://www.efunda.com/formulae/solid_mechanics/fatigue/fatigue_factor.cfm

I believe you are over thinking the whole thing. I would use it unless the picture doesn't show some horrible defect.

It looks pretty standard like marks from the machines used to roll or cut the thread

Edited by 89CAL

The threads are rolled, very poorly I might add. The finish indicates worn forming tools. I can say this due to experience in manufacturing head studs.

So, back to my original question.

Has anyone else got a new idler bearing bolt to see if it is like mine?
Could you please post up a close up picture?

I'm not interested in anyone's opinion, that's not what I am asking for. I am asking for a picture of the threads.

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


  • Similar Content

  • Latest Posts

    • Given it is temporary, I bought a  cheapy gauge mount (which has become enflattened) which I will screw into the existing phone mount Also a first for me; given this is a temporary install I could not think of any reason not to use one of those "add a fuse" thingies to source the battery and IGN power. I had always figured they were pretty dodgy but having a good look at them I think they are a valid option for sourcing power from an existing source without cutting 
    • Finally for now, a bit more work on the transmission temp gauge. I was wondering how Raceworks do a gauge for $100 that autometer want $500 for. No idea about the accuracy of course, but they have cut a few corners that made things hard.  First one I mentioned above, the sender is physically difficult to fit and doesn't work with their own adapters (the extra fittings I used to get the sender into a hose cost more than the whole gauge, lucky I had stuff in the shed) Second, the temp sender wires are way too short. They are shown as 2.7m on the box and I know my routing was long from navigator headlight to driver's firewall back to centre console, but I had to lengthen them by about 2m total - 2 joins in each wire. Also, same with the supplied power loom, they needed about an extra 1m to get the fuse box where I sourced power. Another join in each wire since one end wasn't supplied terminated. I know they could argue that the wires might be long enough depending on situation, but when you consider parts and particularly labour, it would be a very expensive cheap gauge if you can't do the work yourself. And, only a small issue....but it would have been nice if they remembered to tap a tread onto *both* spacers they supplied for the bracket....I haven't had to use the M4 tap often!
    • If it does get a turbo it would blow the JCW Mini out of the water considering how "close" some of the tests were. Then again the Mini would probably get one of them Stage 69 tunes.
    • Next up, the extinguisher is mounted but really only temporary because I ran into clearance problems (the bracket fit fine....until I put an extinguisher on it). It picks up the seat bolt mounts but has long bolts running through 20mm spacers for now Doing it properly requires a bit of quick welding but I ran out of time, this will do for the practice day  
    • Family events weekend but a snuck a couple of things in. NSW state champs were down at Wakefield so I got Gordon Leven's to bring some A052s down in the right size for some spare rims I had that "fit" (actually ex-Leaf Nismo.Rays in 18x7.5). Tyres are 235/45/18 so they are narrower than stock (19x8.5s) but I need to keep road tyres on it for daily use for now. In a first, those weird size tyres had been in the yoko warehouse for so long (4.5 years apparently) that they offered 4 for the price of 2....so 4 practice tyres for about $1100. Bit of a bargain for sticker tyres, considering the real purpose of the practice day is mostly to see how the various temps go (and the weather is due to help, forecast 32o). In terms of race wheels, it looks like I should be able to fit 9.5 fronts and 10.5 rears but 18 vs 19 height will be based on what tyres I can get in the right size - good tyres are very limited in available widths in diameters above 17" so some planning is needed. Once I'm sure this car will work I'll order a set of custom BC wheels like I did for the R32, you can get exactly the right width and offset to make the most of the available space in the wheel well (the 32 has 295s all round on 18x10s and they are awesome) Incidentally A052 are asymmetrical but not directional which is good news for rally use if the front and rear wheel sizes are different because I can swap them side to side on the same axle. Directional tyres are a nightmare with staggered size wheels because each tyre is fixed on that corner unless you can get it rotated on the rim (not really practical mid rally in most cases)
×
×
  • Create New...