spacer the trailing arm bracket or longer trailing arms

Toys-N-Joys

Forum Member
Joined
Nov 23, 2013
Messages
39
Location
NY
which one would be best?

i plan on going ironman springs, and lift spacers on the strut tops.

which would help me re center the wheels and have the strut sit better?


forester sf model
 
To keep the same geometry you need to lower the trailing arm mounting plate by the same amount as you've raised the suspension (or lowered the hubs relative to the body).

So if you have 1 1/2" suspension lift (springs) & 1" strut blocks you would add 2" lift blocks to the trailing arms. The extra 1/2" wont matter. If you're using 2" strut bolocks with your suspension lift then you could use 3" lift blocks on the trailing arms but this then starts putting more stress on those captive nuts. I used both 2" blocks & trailing arms lengthened by 20mm with my rear raised by a total of 4 1/2". The wheels are centred but this is a more difficult way of doing it
 
will the adjustable trailing arms work for what i need?

they can be adjusted about 1" longer.

i plan on the ironman springs, 1" spacers and maybe a 3/8 saggy butt spacer. with the sg rear struts. 215 70 16


or is the spacer the best?
 
No, trailing arm spacers do not make the trailing arms longer, they push them down to the ground away from the body. You don't want them to be longer, you want to push them down and away from the body. If you do a 2" lift, you would want to push the mounting of them down by 2". It's the way the geometry of the rear suspension works.

trailingarmspacer001_zps4d4a6b75.jpg
 
Last edited:
Blue Fox said:
You don't want them to be longer, you want to push them down and away from the body. If you do a 2" lift, you would want to push the mounting of them down by 2". It's the way the geometry of the rear suspension works.
Click to expand...

Exactly right.

trailingarmspacer001_zps4d4a6b75.jpg
Click to expand...
These spacers are the type you dont want. They have no crush tubes plus they aren't tied together so under load (braking, accelerating over potholes & ruts) they'll rock back & forward. This causes metal fatigue in the metal of the rails & the welds of the captive nuts. One member on here had severe cracks in his rails, another has had the nuts ripped clean out of the rails when he hit a rut at speed. By connecting them, the rocking motion is eliminated plus stresses shared by all 3 nuts/bolts more evenly.

Crush tubes are small tubes welded inside the spacer that the the bolt goes through, preventing the spacer box from being crushed from torquing up the bolts, also the stresses involved in driving esp offroad. Without these the spacer will be crushed, allowing more movement which further fatigues the rails/nuts/bolts. There is also the risk of the bolt coming undone.

Make sure the trailing arm spacers you get have crush tubes (mandatory in Oz) & demand that they are connected.
 
NachaLuva said:
Exactly right.

These spacers are the type you dont want. They have no crush tubes plus they aren't tied together so under load (braking, accelerating over potholes & ruts) they'll rock back & forward. This causes metal fatigue in the metal of the rails & the welds of the captive nuts. One member on here had severe cracks in his rails, another has had the nuts ripped clean out of the rails when he hit a rut at speed. By connecting them, the rocking motion is eliminated plus stresses shared by all 3 nuts/bolts more evenly.

Crush tubes are small tubes welded inside the spacer that the the bolt goes through, preventing the spacer box from being crushed from torquing up the bolts, also the stresses involved in driving esp offroad. Without these the spacer will be crushed, allowing more movement which further fatigues the rails/nuts/bolts. There is also the risk of the bolt coming undone.

Make sure the trailing arm spacers you get have crush tubes (mandatory in Oz) & demand that they are connected.
Click to expand...

Actually, this spacer used on my car is all once piece, it is connected. (you can see the diagonal piece in the middle). Regarding the stress against the captive bolts......I've put this kit through some pretty tough stuff, and haven't had any issues thus far. The RallyX was by far the most torture they could have been put through. That stainless steels is extremely thick and is a very stout spacer. Pictures do not do it justice. When I torqued the bolts down, the spacer box didn't crush, it's extremely thick steel. Much stronger than what it's bolted to, and what is being bolted to it.

If someone wanted to, they could use the same spacer without the need for any crush tubes though. You would just bolt the spacer straight to the frame with the stock bolts, then use another set of bolts to bolt the trailing arm to the spacer with a nut and bolt. Again though, the stainless steel used for the spacer is stronger than any of the components that's bolted on to it. Sumo Parts knows what they're doing with this kit.
 
Last edited:
That steel looks thick enough not to need crush tubes (if its stainless too that's a plus) crush tubes are nice though, alternatively you could also cap the RHS. But i'm not an engineer so many dedman could pipe in, otherwise I'll ask the inlaw when i can, the SF i also noticed between the newer models, the trailing arm mounting bolts look weaker longer threads on the newer ones and more beefy rails.
 
My bad Blue Fox, I didnt see that. Even though its very thick guage stainless, I would still prefer crush tubes but I take your point about the strength of the blocks compared to the rails. Thats why I would prefer to be extra cautious when it comes to the rear trailing arm blocks, also the front control arm blocks

Kevin, thats some lovely welding on your blocks :biggrin:
 
yarney said:
I used Outback trailing arm mounts they push the wheel back about 8 mm it don't sound much but it works.

They are getting harder to get as word gets around shh dont tell anyone:iconwink:

Jan
Click to expand...

Seems to be a good idea.
 
thats what i just ordered.

outback trailing arm brackets and some adjustable obx trailing arms
 
You must log in or register to reply here.
Back
Top