More angle for CV shafts? Subie content.

So I bought a new crosstrek. Mine runs fine. However, a lot of the guys on the crosstrek forums have lifted there's using subframe spacers from reputable companies. I REGULARLY see these people posting about blown out cv joints. I have also tried telling these guys that the cv shafts were never designed for that much angle and that the OEM CV shafts were already more angled because Subaru used the same cv's from the non-lifted Impreza! I feel like the only "car guy" over there, because nearly all of these guys refuse to believe that the lift could be causing these blown out CV joints, even though some of them have 2-3" lifts! So, the discussion goes... is there a way to have someone design a cv shaft to allow more angled operations?

I know high-angle CVs are common in the offroad world:

https://teraflex.com/shop_items/55c3f57205a25c5bb1173c17

Here's some info on how they work:

http://www.ntnglobal.com/en/products/review/pdf/NTN_TR75_en_P016.pdf

On the Crosstrek the rear is done with a subframe(body) lift. The front is done with strut spacers. The rear subframe lift has no effect on the CV joints because it lowers the whole differential. The front strut spacers do increase the CV angle.

A couple Subaru mechanics I have talked to say I can go to 2" on my Outback but the Crosstrek should only go 1 1/2". The company I am going to get my kit from only makes a 1 1/2" kit for the Crosstrek.

If they are having CV problems, I would want to know what tires they are running. On my Outback the BFG KO2's (very popular tire) in the stock 225/65/17 size weigh 10# per tire more than the original tires. In addition to the heavier A/T tires, a lot of people are running larger sizes which increases the weight.

As with any modification, do a lot of research. Get on a forum and ask questions, etc. I have been researching for a couple months now and am ready to order the lift kit for my Outback now.

Could it be a plunge instead of an angle problem?

No it's an angle problem. It's always the front cv, and usually the passenger side I think. And they are running the same size bfg KO's mentioned. These guys try rock crawling with these crosstreks.... and then Whine about "Subaru didn't make it strong enough".

You'd probably be looking at modifying the stub axles and making drive flanges to use the VW/Porsche type desert racing CV joints and shafts.

In reply to BrokenYugo:

Now that's good info!

Trackmouse wrote: No it's an angle problem. It's always the front cv, and usually the passenger side I think. And they are running the same size bfg KO's mentioned. These guys try rock crawling with these crosstreks.... and then Whine about "Subaru didn't make it strong enough".

I think you have the reason/answer there. Subaru's are very capable but do have limits. They are not very good for rock crawling for several reasons. If you want to see what a slightly modified one will do search Youtube for "Bruceyyyyy".

Trackmouse wrote: No it's an angle problem. It's always the front cv, and usually the passenger side I think. And they are running the same size bfg KO's mentioned. These guys try rock crawling with these crosstreks.... and then Whine about "Subaru didn't make it strong enough".

Interesting. I had a basic idea of how CV's work but hadn't really read much on them. This Article says plunge is taken care of by the inner joint and outer joints are typically capable of 47-50 degrees of angle.

That's a good article, I should share it with those guys. It is the outboard joint that destroys itself BTW.

I've never messed with a crosstrek but from what I remember of the Impreza platform I don't see what would be difficult in spacing the front subframe as well. If the axle issue is due to angles seems to me that could possibly be a fix. If there's a bumpsteer issue created with the strut spacer a subframe spacer would help with that.

A subframe spacer was all that was added to the older foresters to get more ride height out of the Impreza chassis.

You have to wonder about people who don't use a vehicle for intended purposes then whine it didn't work. There are reasons why you don't take a chevy cavalier to Baja.

In reply to appliance_racer:

I've tried telling those people. There are three people besides me on that forum with the knowledge of automotive vehicles. The rest start threads like "how do I turn the e brake off?"

In reply to Trackmouse:

That sums up why GRM is the only forum I participate.

The funny thing is, I USED to like forums, but lately it seems to put me off. (Exception- this forum!) I can't tell if people have gotten dumber, or if My knowledge has gotten to the point that I've out grown those types of forums...

appliance_racer wrote: I've never messed with a crosstrek but from what I remember of the Impreza platform I don't see what would be difficult in spacing the front subframe as well. If the axle issue is due to angles seems to me that could possibly be a fix. If there's a bumpsteer issue created with the strut spacer a subframe spacer would help with that. A subframe spacer was all that was added to the older foresters to get more ride height out of the Impreza chassis. You have to wonder about people who don't use a vehicle for intended purposes then whine it didn't work. There are reasons why you don't take a chevy cavalier to Baja.

A front subframe spacer won't work. You need the transmission to drop, which means far too much other stuff needs to drop at the same time.

sachilles wrote:

appliance_racer wrote: I've never messed with a crosstrek but from what I remember of the Impreza platform I don't see what would be difficult in spacing the front subframe as well. If the axle issue is due to angles seems to me that could possibly be a fix. If there's a bumpsteer issue created with the strut spacer a subframe spacer would help with that. A subframe spacer was all that was added to the older foresters to get more ride height out of the Impreza chassis. You have to wonder about people who don't use a vehicle for intended purposes then whine it didn't work. There are reasons why you don't take a chevy cavalier to Baja.

A front subframe spacer won't work. You need the transmission to drop, which means far too much other stuff needs to drop at the same time.

would spacing the subframe and the trans crossmember basically be a body lift and put everything where it needs to be?

edizzle89 wrote:

sachilles wrote:

appliance_racer wrote: I've never messed with a crosstrek but from what I remember of the Impreza platform I don't see what would be difficult in spacing the front subframe as well. If the axle issue is due to angles seems to me that could possibly be a fix. If there's a bumpsteer issue created with the strut spacer a subframe spacer would help with that. A subframe spacer was all that was added to the older foresters to get more ride height out of the Impreza chassis. You have to wonder about people who don't use a vehicle for intended purposes then whine it didn't work. There are reasons why you don't take a chevy cavalier to Baja.

A front subframe spacer won't work. You need the transmission to drop, which means far too much other stuff needs to drop at the same time.

would spacing the subframe and the trans crossmember basically be a body lift and put everything where it needs to be?

Yes and no. You'd lower the engine, you'd lower the oil pan, you'd lower everything. You'd only gain bumper break over height. You'd be better off with a shorter bumper on stock height. With your engine down, you run into interference in a few systems. Getting spark plugs changed may very well be a case of having to raise the engine temporarily, as the spark plug hole will have dropped between the frame rails. Lots of other stuff still mounts to the unibody above, some might have enough slack, some might not. The engine stay on the firewall would likely need to be modified. Those already have a tsb on them, that might be a good excuse to modify it. Not impossible, but not the easiest path to an extra inch, for very little benefit. Better off just doing different axles, and arms. In the long run, cheaper, easier and likely a better choice to reach the goals desired.

Since everything subie is interchangeable, and everything subie gets lifted/lowered, it seems like there would be an aftermarket for cv axles like this. Why hasn't someone done this? Lol.

Trackmouse wrote: Since everything subie is interchangeable, and everything subie gets lifted/lowered, it seems like there would be an aftermarket for cv axles like this. Why hasn't someone done this? Lol.

The answer is $$$$. If you are going to do it properly you need longer struts, control arms, and axles. There are a few people who have done the longer control arm/longer axle thing. They are individuals doing their own fabrication. We have some people on here who could do it but, the vast majority of the Subaru world is populated with "bolt-on the latest craze" people.

So, I'm not convinced that raising the vehicle puts the added angle on the CV joint that breaks it.

Go look at your stock vehicle, and turn the wheel all the way to lock on one side. Then look at the CV joint on the (inside) wheel. Turning will induce far more CV angle than suspension movement.

Now, maybe it's the combo of lift plus turning, but I bet if you didn't ever romp on it at full lock you'd be fine.

I'd be curious to see what things look like at full droop with the lift.

In reply to Robbie:

I suspect, what is happening is larger more grippy tires, high degree of steering lock and extreme suspension angles, putting to much stress on the joint. The open front diff, if using traction aids is going to make some pretty interesting shock loads when the bigger tire finds traction, then suddenly doesn't have it....then has it again. It is all addressable, but the subframe in the front is not the correct, nor the cheap way to do it right. restricting steering lock to lock would help, but the right axles will also help.

Unfortunately, the budget boost is pretty limited, and maybe not the right choice for the desired duty.