Transverse arm connecting bolt 987186 torque spec mystery

[johnnyfd]

Thanks so much for looking Neil. What do you think about the listing in the book you showed? After I matched up all the listings in the "2WD" sections with the bolts which connect to the control arms by carefully scrutinizing the terminology, it does appear to me that the listing "Bushing - Transverse arm" is a good fit for the bolt in question especially since all the other bolts have terminology matches in the listings. After matching them all there is only that one listing left for the bolt in question and the terminology does fit although like I have said before there always seems to be some degree of ambiguity in these listings. Does the detail of this reasoning make sense to you? I'm certain you're more familiar with the use of all this terminology than I am. Does the 80 newton meters in this listing sound right to you? It does not have an additional angle tightening as the other bolts do.
Do you think that book is one of the original factory manuals since it's listings are only in newton meters?
Thanks again. I really appreciate you sharing your knowledge on this forum.









wd

[scot850]

What diameter is the bolt? That may help tie it to the Volvo general specs that I need to now find the info on!

General torque specs (002).pdf

Volvo general bolt torque specs

(54.35 KiB) Downloaded 60 times

Now we may not be able to leave this on the website for long as it is a Volvo document. So read and we can then remove.


AS to your reasoning, I would suggest it is what I was thinking as well that that may be the torque value. If the diameter gels with that of the general specs, or is in the area, then that is what I would use. If the bolt has thread locker then make sure to use it.

Neil.

[Chuck W]

I'm kind of confused on what the whole issue is.

You know the diameter of the bolt. Check the standardized torque spec for it and install with a bit of thread-locker and be done with it.

[scot850]

OP was concerned that he had not installed correctly. The larger issue is Volvo seem to randomly name a part in parts listings or even in the repair text in Vida, and then promptly go off and called the torque spec ID something un-related which made identifying the correct spec impossible (well nearly). He thinks he has now identified it correctly, and I have supplied the general specs so that he can confirm to himself he has done so correctly or it is in the ballpark. Volvo mostly used 8.8 steel bolts.

Neil.

[johnnyfd]

The bolt is an M12 as I suspected by eyeing it. I verified this with my bolt size checker and also found the thread pitch to be 1.75. It is an 8.8 class of bolt that is not galvanized and comes with thread locker already applied and dried. Your Volvo general reference ( as well as Industrialmetalsupply.com ) for this particular specification of bolt gives 80 newton meters . I have found different torque specs for this specification of bolt at other sources, but at the sources I stated this is the exact number shown in the old reference book you supplied under the listing I guessed to be the correct application . The listing "Bushing - Transverse arm" . Does this all seem correct to you Neil? If so what would you factor in to the torque spec for using a pinless universal impact socket in order to apply this torque to the bolt's awkward position? As far as Chuck's comment goes I understand why you would think that for someone that is an engineer or has plenty of experience deciphering matters like this . Unfortunately I am neither of those, so this has been a very valuable learning experience for me which will definitely be very useful to me in the future and I really appreciate Neil's efforts to investigate and explain . My laborious questioning and the generosity of responses given really has given me some new and extremely useful specific methods for understanding how to work with fasteners correctly.

[Chuck W]

Apologies. My comment was more meant to point out that some things don't need to be that complicated. A lot of fasteners just need to be "gutentite". There is some knowledge to not over-do it on the smaller ones, but unless it's a critical area, like a head bolt, or some sort of TTY fastener, you can usually judge when things are good enough.

You are correct that I have probably spent 40-45 years turning wrenches in some manner. The bulk of which was before the internet made information available at an instant. There was a lot of trial and error (A LOT of error) in working on bicycles, cars, etc in my younger days.

I tend to just dive into things and I forget not everyone has my knowledge and comfort with wrenching.

[johnnyfd]

No apology necessary for me Chuck . I was not offended by your comment and accepted it as another perspective to be applied. I have worked on mechanical things off and on for most of my life , but I do not feel that I have yet learned enough specific methodology to make my tasks go as efficiently as they could. This circumstance has been a significant boon to that cause.

[scot850]

Likewise! No offence intended or taken!

As I don't do these jobs every day, and being a retired mech eng, I prefer to work to spec than guess work where my experience is not sufficient. I still torque my vehicle lug nuts even though I replace the wheels for summer and winter on 3 cars every year. 80 Nm sounds about right to me for an M12 bolt. Run with that and the description you found. Both work!

Neil.

[Chuck W]

Not quite at retirement age myself, but also a mech engineer. I just really enjoy wrenching and building stuff.

[abscate]

Like magic, the part number slumbers in the title, awaiting the search functions’ gentle prodding.

Described as self locking by skandix, so I would use 93 Nm as a torque. Derate that 30% with Ni antiseize, I’m 50-50 in using that there.

93 Nm about 60 imperial meter Newton’s, commonly called foot pounds