VR/S Rear Sub Frame Stengthening

[VRSenator065Participant Adelaide SAVR Senator LSx454 1960 Kombi (project) 1921 Nash Hot Rod (future project) View build HERE Member since: February 17, 2015 Posts: 5 777]

General
The rear sub frame on a VR and VS is a well known weak spot. They are very prone to cracking even with a standard 5L. So with mine I modified and strengthened it. There are a lot of different ways to do it, but very happy with how mine turned out, so thought I would post what I did.
I made up cardboard templates, then took it to a welder that used the templates to cut the strengthening pates. He fully welded it all, then I had it powder coated back.

I used 6mm plate for the top of the frame where the diff mounts, and also cut in a 10mm vertical member to tie the top and bottom together. I also added doubler plates to where the suspension arms mount as they tend to flog out when pushed hard. I also triangulated it all with gussets where ever possible.

This is how it turned out back from the powder coaters

And this is it all assembled.

[KenthorParticipant CanberraVS Acclaim - LS1 and HSV enhanced VS SS View build HERE Member since: March 2, 2015 Posts: 3]

I took a different approach, when I strengthened mine we added a 40mm flat bar around the edge as a border. Figured the the issue with them cracking is when the frame flexes so made sure it couldn’t flex.

Hoping these pics work!

Attachments:

You must be logged in to view attached files.

[VRSenator065Participant Adelaide SAVR Senator LSx454 1960 Kombi (project) 1921 Nash Hot Rod (future project) View build HERE Member since: February 17, 2015 Posts: 5 777]

Cool, nice to see a different approach.

[Brockfan05Participant AlburyVR Berlina 5.0L VS Clubsport View build HERE Member since: March 7, 2015 Posts: 39]

This is actually one of the areas I was curious about strengthening on both my vr and vs. Fortunately both of my irs cradles are in good shape still. Thanks for posting this up guys, very helpful. Just out of interest Gary, did you have a slot cut into the frame top and bottom for the ten mm plate that was welded in? I’m just trying to work out exactly what you’ve done there is all.

 

• This reply was modified 9 years, 9 months ago by  Brockfan05.

[VRSenator065Participant Adelaide SAVR Senator LSx454 1960 Kombi (project) 1921 Nash Hot Rod (future project) View build HERE Member since: February 17, 2015 Posts: 5 777]

Yea mate, I cut a lot top and bottom, dummied it up with a piece of 10mm thick timber, then replicated it in steel. The idea is is takes the torque as it loads up, works great.

• This reply was modified 9 years, 9 months ago by  VRSenator065.

[VRSenator065Participant Adelaide SAVR Senator LSx454 1960 Kombi (project) 1921 Nash Hot Rod (future project) View build HERE Member since: February 17, 2015 Posts: 5 777]

• This reply was modified 9 years, 9 months ago by  VRSenator065.

[KroozerParticipant Forbes, NSW91 VN SS View build HERE Member since: February 19, 2015 Posts: 336]

Why didn’t they make them like that out of the factory ;) hahaha

[VRSenator065Participant Adelaide SAVR Senator LSx454 1960 Kombi (project) 1921 Nash Hot Rod (future project) View build HERE Member since: February 17, 2015 Posts: 5 777]

They probably didn’t expect us to be putting 1000rwNm through them

[Brockfan05Participant AlburyVR Berlina 5.0L VS Clubsport View build HERE Member since: March 7, 2015 Posts: 39]

Cool, thanks Gary. Did you use a plasma cutter to get the slot that accurate? It’s so neat lol.

[VRSenator065Participant Adelaide SAVR Senator LSx454 1960 Kombi (project) 1921 Nash Hot Rod (future project) View build HERE Member since: February 17, 2015 Posts: 5 777]

Nah mate, just very careful with a 4″ angle grinder and a 1mm cut off disc.

[KroozerParticipant Forbes, NSW91 VN SS View build HERE Member since: February 19, 2015 Posts: 336]

VRSenator065 wrote:

They probably didn’t expect us to be putting 1000rwNm through them

Hahaha probably not hey :P

[[TUFFVQ]Participant Melbourne1991 VQ 304 View build HERE Member since: March 2, 2015 Posts: 171]

I put a 10mm plate across the top of the sub frame (like what you have done) and doublers on the trailing arm mounting bolts. Will be interested to see it’s condition after a few years on SSSL’s and a spool.

[VRSenator065Participant Adelaide SAVR Senator LSx454 1960 Kombi (project) 1921 Nash Hot Rod (future project) View build HERE Member since: February 17, 2015 Posts: 5 777]

I can’t remember who on SC suggested the doubler plates on the trailing arm bolts, I wasn’t going to do it, but apparently they flog out. I probably went a little overboard (surprise surprise) but at least its done. What sort of power are you putting through yours?

• This reply was modified 9 years, 8 months ago by  VRSenator065.

[[TUFFVQ]Participant Melbourne1991 VQ 304 View build HERE Member since: March 2, 2015 Posts: 171]

Nowhere near as much as you are, it’s the spool that was elongating them over time.

[VRSenator065Participant Adelaide SAVR Senator LSx454 1960 Kombi (project) 1921 Nash Hot Rod (future project) View build HERE Member since: February 17, 2015 Posts: 5 777]

Yea right, I have a locker, not as savage as a spool but I imagine still putting it under a bit more load than a regular lsd.

[Author]

Posts