Transverse arm connecting bolt 987186 torque spec mystery

johnnyfd · Post by **johnnyfd** » 18 Nov 2023, 08:12

I just replaced a broken, passenger side, transverse arm mount / bushing on my 96 850 Turbo wagon. It was and still is quite a bit more involved than I was expecting. I have looked through countless sources and seen a few other people ask on forums, but have never found an answer to the question of: what is the torque spec for the horizontally positioned bolt which attaches the end of the transverse arm to the mount / bushing. This has turned into more of a PITA then the job itself. Other than seeing the question go unanswered on forums, I have noticed this singular piece of information conspicuously missing from most of the typically reliable sources. Volvo's own documentation which is available on "Volvo tips" website and other sources definitely does not list the spec. I have also noticed some confusions in their statements of the specs for the other rear control arm bolts, namely pertaining to one of their diagrams. I should state that I do know the correct terminology of the difference between the "transverse arm" and the "trailing arm" sections of the rear control arms as described by Volvo. I hope anyone trying to help me with this knows this difference, because I have already read many responses to inquiries about the rear control arms which were confused by the misidentification of the different sections of the control arm. Since Volvo, and therefore several sources who have relied on Volvo's documentation, seem to have made one or two mistakes with what they did write, I'm beginning to suspect that the torque spec I'm seeking was an accidental omission on their part and now nobody actually knows it. I hope someone out there has access to this bolt's torque spec because it seems like a too important single bolt to just make a guess on. Thanks in advance for assistance.

Post by **scot850** » 18 Nov 2023, 10:30

Volvo does have a spec for bolts by diameter for where there may not be a listing. I am sorry, but I am not understanding which bolt you are talking about. Do you have a picture of the bolt location or a reference from a parts listing?

I can't guarantee that I have the answer, but I have Vida running in my garage and can look up the Volvo work info to see if it is there.

This is a document I got years ago from a Volvo dealer foreman I knew. Sorry it is not rotated, but the document won't let me rotate and save.

P80 torque specs.pdf: Torque specs; (415.09 KiB) Downloaded 57 times

Hopefully what you are looking for is there and you can recognize it.

Neil.

johnnyfd · Post by **johnnyfd** » 18 Nov 2023, 11:02

Thanks for your response. As you probably already know, the long thin part of the rear control arm that spans the width of the car attaches at its endpoint to the other control arm. It attaches to the other control arm by the bracket/ mount / bushing. Where the long narrow transverse arm attaches to this bracket is a single point where the bushing housed in the bracket is. The single point of contact between the transverse arm and the bushing is held together by the one bolt I am referring to and asking for the torque spec of. It is the bolt that screws into the pointy end of the transverse arm after going through the bushing of the bracket. I think I was unable to include a picture because I used the quick response. It is included with the other bolts in the transverse arm mount "kits" and is the only bolt that is black. The other two are silver.

duke1 · Post by **duke1** » 18 Nov 2023, 11:17

johnnyfd wrote: ↑18 Nov 2023, 11:02 Thanks for your response. As you probably already know, the long thin part of the rear control arm that spans the width of the car attaches at its endpoint to the other control arm. It attaches to the other control arm by the bracket/ mount / bushing. Where the long narrow transverse arm attaches to this bracket is a single point where the bushing housed in the bracket is. The single point of contact between the transverse arm and the bushing is held together by the one bolt I am referring to and asking for the torque spec of. It is the bolt that screws into the pointy end of the transverse arm after going through the bushing of the bracket. I think I was unable to include a picture because I used the quick response. It is included with the other bolts in the transverse arm mount "kits" and is the only bolt that is black. The other two are silver.

i found the same and just used sensible tighten to contact and then a reasonable length ratchet pull also used a threadlock compound as the tightwads at pro parts do not supply a new bolt and local store said it has nothing even similar,i hate reusing bolts but sometimes have no choice i think once its done up reasonable tight it is not going to work itself loose easily,fun job not.

mine had one of the main bolts rusted in place and took 2 days of heat and grinding to remove!

johnnyfd · Post by **johnnyfd** » 18 Nov 2023, 11:43

Thanks for the reference book. There is one listing that says "Bushing-Transverse arm" (I'm pretty sure the dash means connected to) and gives an M12 Bolt at 80 newton meters (59 ft lb). I'm not completely confident but I don't know what else this could be other than the point at which the transverse arm connects to the bushing as I mentioned in my previous post. If you now know which bolt I'm talking about; what is your personal experience with this bolt? I'm concerned about just cranking that bolt up to 59 foot pounds in case I'm wrong. What do you think? The bolt seems like it is about an M12 but I don't have it with me at the moment to measure it. Now that I think about it, it seems like there is the possibility that the reference I gave is for the connection between the large delta link bushing and the female receiving part of the control arm that it inserts into and everyone has a hard time extracting out of with burning and tons of force if they don't have the special tool. Now I'm even less confident. I hope someone out there knows with certainty. The listing does say transverse arm though. That should be only the part of the control arm that is long and narrow and goes across the width of the car but I have seen documentation that mixes the terms.

johnnyfd · Post by **johnnyfd** » 18 Nov 2023, 11:49

Duke1 I got away easy with those aspects of it but still found it difficult messing around with my heavy duty sway bar in the rear which interfered with lining everything up the way I wanted to for temporary alignment . It was also no joy accessing the hidden bolt which I have been trying to find the torque spec for.

duke1 · Post by **duke1** » 18 Nov 2023, 13:30

mine does not have the rear sway bar which i would imagine made it easier,still not a job i care to repeat! worst thing was i only lifted the back to bleed the brakes and when i lent on the hub to get up it moved,loads! a proper o shite moment.
still nicer than my previous car to work on peugeot 406 bloody horrid and designed by a sadist,cheers

Post by **scot850** » 18 Nov 2023, 19:16

Here is a parts drawing of the rear suspension. Which part is is by the number on the drawing:

https://www.volvocarstorontoparts.ca/a/ ... 68893.html

Neil.

johnnyfd · Post by **johnnyfd** » 18 Nov 2023, 20:46

Post by **scot850** » 19 Nov 2023, 00:27

I have looked everywhere for the torque for that bolt. The problem is Volvo and others call it many different things and then don't mention it in the torque values or they have changed the name during the changing of the part. Same on YouTube, Vida and Haynes manuals.

I can then only suggest using the generic torque value Volvo uses for the diameter of bolt.

Neil.