2000 V70R - Rear suspension Torque settings

Post by **scot850** » 29 Sep 2015, 16:52

I am trying to get this car back together and seem to hit snag after snag. Current one is I cannot find the torque setting and instructions for how to fit the upper rear control arm. I know how it fits, but need to know how to pre-load the inner bushes so not to stress the upper bushes when loaded. The original control arms appear to have been set at around horizontal. As you can't access the front bolt nut once the fuel tank is in you must have to pre-load prior. Any ideas out there, and the torque settings for the front bolt + nut, and the rear upper bolt?

Appreciate the help as always.

Neil.

P.S. Even the dealer couldn't find the answer!

Blockpartie · Post by **Blockpartie** » 30 Sep 2015, 05:24

Well... the dealer should know the torque settings. He just has to look for them in the right VIDA directory.

Pre-loading is required in a similar fashion as the two bolt front control arms. Set the car, or alternative the suspension, at ride height and tighten everything.

Post by **scot850** » 30 Sep 2015, 08:33

Dealer and I can't find the info in Vida directory for anything related to rear suspension. Outer rear upper mount yes, but not inner. The inner is front upper is not accessible as far as I can see once the fuel tank is re-fitted. Either way, still can't find any torque settings. Consider using the settings for the front one as per the older style 2 bolt front control arm, and use a generic size related torque for the rear inner upper bolt.

Neil.

Post by **scot850** » 30 Sep 2015, 17:02

Still no luck on the torque setting and install instructions for the upper rear control arm. I've e-mailed Volvo Sweden in the hope that they have the necessary info, as the dealer hasn't. We have looked at 3 versions of Vida back as far as 2012 version, and no info. They have even pulled out the old hard copy books to see. There is nothing obvious so they have invited me to go and have a rake through the info to see if I can find it!

Man is this car ever a pain in the butt. Nothing is easy or simple. Whether it is obsolete parts, hard to find information, wrong information, identifying parts it has it all!!

I will post the data if I can ever find it.

Neil.

Post by **scot850** » 01 Oct 2015, 13:19

Still no info from Volvo Sweden. Went to the dealer and foreman and I went through the old hard copy folders, right back to 850 AWD. No mention at all of the inner mountings of the upper rear control arm.

I have been given info that they are 80Nm, but as the max. recommended torque for a M10 8.8 grade bolt is 50Nm. and this is the torque for the same bolt for the top cover, and same spec. of bolt for the VC case to rear diff., and the rear brake caliper bolts, that 80Nm value worries me. That is the max. torque value for a M12 8.8 grade bolt.

I have spoken to a bolt supplier and asked for their info and they are double checking for me.

You would think that as you can buy the parts (rear sub-frame/upper rear control arm) there would be an install process for them??!!

Neil.

Post by **scot850** » 05 Oct 2015, 23:01

Well again, it seems I have had to find my own answers, but no criticism here, as it took a lot of hunting and bit of luck, and a discovery of an error I had made.

Got an e-mail from Volvo Sweden this morning saying they could not help! They built the frisking car and they don't know how!! They'll happily sell you the parts but not tell you how to install them, or even a dealer.

I sent them a lot of flack, and then went to PnP to pick up some stuff I had planned, and then went to Volvo to talk to the Service Manager.

He is a good former mechanic, and always tries to help if he can. After being shown what parts were involved he said he would see if he could track the info down for me.

By the time I got home, there was an e-mail from the workshop foreman waiting for me. He had found a old pocket details book they were given when the cars were first launched, and blow me, the info was there in black and white.

Front bolt and nut : 80Nm

Rear bolt : 50Nm.

But there was a twist to this, as it said the front bolt was a M12 and the rear a M10. Both torque values are what is recommended for a grade 8.8 bolt of those 2 sizes. What didn't make sense was I had measured the 2 bolts with digital calipers at 10mm dia.

I went to the garage and found one of the 2 bolts from my spare sub-frame, and measured it. It was M12 after all. When I took a closer look at the 'new' bolt here is what I found:

: Front upper control arm bolt

The upper bolt is the original, and the lower the 'new' bolt I had bought. When you look closely, you can see a slight 'collar' about 10mm long under the head of the bolt. Also the threaded portion is actually M12 too.

This is nuts as the bush is 12mm diameter, which means the only part of the bolt touching the bush in the sub-frame is about 15mm of threaded portion at the furthest end of the bush from the control arm. That is the stupidest thing of all the stupid things I have seen from Volvo yet. That means the control arm and sub-frame can move relative to each others by 2mm. Also, as the central part of the shaft is M10, you should not torque it above 50Nm.

In the end, I put the old bolts back in and torqued to 80Nm front, and 50Nm to the rear bolt.

I set up a height of the control arm using a wooden shim to give a height of 130mm

: Height of rear control arm

One side measured to the 'valley' in the control arm where the part number is stamped to the top edge of the sub-frame was 125mm on one side and 135mm on the other. I took 130mm as the average.

So like I said, the issue is Solved, but not entirely satisfactory. If I were to use the 'new' style bolt I cannot tell you what to torque to, but would suggest 50Nm max. If you re-use the original bolt, then use 80Nm.

Still cannot find the correct install procedure, and hence my own design/estimate.

IF any further info comes to light, I will update.

Neil.

Post by **mecheng** » 06 Oct 2015, 07:41

As you may know. Typically bolts are torqued to 75% yield, you can determine torque from that. Don't forgot lubed versus dry values

Post by **scot850** » 06 Oct 2015, 15:16

Thank for the input Carl. I am aware of the 75% rule, but it is worth mentioning.

If you go on line, you can find lots of info on bolts and bolt grades. I even spoke to a local bolt manufacturer in this process and they confirmed the M10 and M12 max. recommended values of 50Nm and 80Nm respectively.

Another very good point you made, is that 'lube'd' bolt threads need a lower torque setting. Again many of the on line resources include both recommended values as comparison.

Got more nonsense from Volvo Sweden today after my rant to them. Even after telling them that Volvo Canada has NEVER answered a technical query with anything useful, they usually refer me back to the dealer, they STILL sent my request to Volvo Canada!! Idiots.

You never know, I may one day get an answer, but not holding my breath on that one!

Appreciate the useful input,

Neil.