4wd to rwd

[DODelaney]

hey guys
when i bought my RX
the previous owner decided to remove the CVs and leave it in 4wd. so now im running rwd, will this be damaging my diff ??



link to my pics and post about her
showthread.php?p=75569#post75569

[Gannon]

Shouldnt do.

Its an R160 i believe, its supposed to be a pretty tough diff for its size

[INEEDABEER]

The previous owner did what????????????

[madmat]

I would be putting the CVs back in if i were you. the car was designed to have 4wd and so putting all the drive through the rear only will shorten the diff life.
I belive the OBW (outback wagon) has a power split arangement so that only 50% power is ever given to either diff so imagine how the diff feels when it get twice that. Not happy Jan:(

nothing wrong as far as i know running like this in the short term though. I blew the rear diff in a Toyota Bunderra and run for a couple of weeks on the front diff only.

[DODelaney]

so i should put the CVs back in ??
ok it will be done when motor is back in
INEEDABEER--old mate thought he would try drift it

[subalex]

I don't know for sure about that being a problem really. As said in an earlier post, they are a pretty tough diff. The same kind used in Datto 1600s that are used in rallys and they're always in rwd. There have also been some pretty well modified Subies, one Brumby comes to mind featured in a Hot4s mag years ago, where an WRX motor has been mated up to the gearbox run only in rwd too as a work ute carrying motors and gearboxes around.

My opinion, if it works already and you check the diff oil regularly for metal wear (grey metal flecks through it) and nothing shows up then you're obviously fine. As for AWD boxes such as an Outback or Liberty, they're set up to drive up to 90% power to one end or the other as needed so they are designed and tested to do so, they're not really made weaker because they expect to be running 50/50.

[AlpineRaven]

The previous owner did what????????????

A lot of people who dont like the idea of FWD or rather drive in RWD mode they get an Cup to lock the front diff shafts to enable RWD but if these cars have P/T 4WD will require to pull the 4WD selector up.

Subaru's rear diff isn't really designed to have all these stress in rear and I believe he has Clutch LSD.
Cheers
AP

[Craigus]

There might also be legal / insurance issues with doing this. What happens if you have an accident and the modification is discovered ?

[Outback bloke]

There might also be legal / insurance issues with doing this. What happens if you have an accident and the modification is discovered ?

Valid point.

I don't believe it will be doing the diff any damage. I know a bloke that had a turbo ute that he drove for years just in RWD.

The L's and MY's are better to drive when rear wheel drive. No torque steer or cv shudder/vibration.

It is a useless way to have your car for when the roads are wet or if you want/need 4wd.

[brumbyrunner]

A lot of people who dont like the idea of FWD or rather drive in RWD mode they get an Cup to lock the front diff shafts to enable RWD but if these cars have P/T 4WD will require to pull the 4WD selector up.

Can you clarify this?
I don't understand what you're saying.

[vincentvega]

either does he

[BrennyV]

if only it was as easy as my mates gtr
pull abs fuse and ur ripping up a set of rears in a blink of an eye :O

[AndrewT]

Can you clarify this?
I don't understand what you're saying.

Alpine was just giving quick explaination of how people "RWD convert" their MY or L series cars.

They just remove the front shafts and put blank outer CV cups in instead (to hold the hub together).
This means that you have to have the 4x4 lever in the engaged position at all times so the rear wheels are driven.
The car still works fine because of the locked centre diff in standard part time MY and L series gearboxes.

My 2 cents is that these cars do work okay like this but damage invariably IS done over time. The rear diffs themselves can usually take the punishment but the rear driveshafts and diff hanger bar will eventually show signs of weakness. They aren't designed to have 100% of the car's power put through them.
Although this is probably more common with people who do this and run a welded rear diff - this is required for maximum rwd fun!!

[SUBYDAZZ]

I would be putting the CVs back in if i were you. the car was designed to have 4wd and so putting all the drive through the rear only will shorten the diff life.
I belive the OBW (outback wagon) has a power split arangement so that only 50% power is ever given to either diff so imagine how the diff feels when it get twice that.

With the Subarus that have a centre diff (i.e. not most* L or MY) - viscous, clutch type or open - then at any time there is potential for *effectively* 100% of the drive to be apportioned to front or rear diff, surely it has been engineered to accept this? For the L-Series 100% of drive is usually sent to the front diff and I don't think that ever really bothers them

Not a lot has changed with the rear diffs in most models, and since the same diffs can be found in Subarus with 54kw to over 154kW then surely the rear diffs can certainly accommodate all the power of the lower powered models without issue (as it's be less than half of what the higher powered ones would be getting at any point anyway). Yes, some of the higher powered Imprezas have had the R180 diffs instead of the R160, but look a the vehicles which had the same diffs from other makes - RWD.

As Brett says, certainly the L Series will handle differently with this set-up, but they handled a lot better in 4WD than FWD anyway.

One caveat is that there are at least several cases I know where people have blown rear diffs / CVs, though I think there is a usually a good reason for that in how they were being treated at the time (anyone care to give examples?). In any case, I'd imagine you're more likely to break an axle-shaft / CV than the diff itself.

On the upside, you'll probably find your front tyres will wear a little less

[mattw]

I'm sure one of my very rare posts was on this.
I was curious myself, and so I did it to my L before the ea82t went in.
Results:
1. benefits of improved handling/corner balance when flexing in the hills, hanging the tail out on power
2. no more annoying front spinner action when cornering or taking off, just hook up and go!
3. first ever burnout in a subaru, and not a single spinner, both hooked up while the diff was still marginally lsd.(am I 34 or 14, I forget!!!!)
4. busted transfer gears while doodling away from lights, under minimal load. can anyone say "low cycle fatigue"?
the diff is not the problem, the transfer gears at the back of the box are. Steve_rising_sun shared my view that they are not designed to take full load all the time, at best 50% load, sometimes.
it lasted well over a year, on a tired box, so all the best if you wanta give it a go........ just have a spare box handy!

[theclick]

On this topic, I've never done it, but does it harm to drive in 4wd (l series) in the wet? I figured it would bind up and do all sorts of horrid things

[Gannon]

does it harm to drive in 4wd in the wet?

It all depends on how slippery the road is. If its smooth tar (like highway tar) and its raining heavily, there is probably enough slip to make it safe.

I drove 20km in 4WD in the pouring rain with nearly 1/2 ton of dirt in a trailer. I had to use 4wd otherwise the front wheels would spin the moment i put my foot down for a hill ect. It also gave me more confident when using the brakes, i felt much safer.

[Subafury]

sometimes i use 4wd in the rain - makes it heaps safer for cornering and freeway speeds.
rwd is fun if you have a powerful enough motor and smaller tyres. and youd be suprised like i was how far you can go on a beach with rwd and a lokka

[DODelaney]

thanks guys
SUBAFURY- the motor is bog stock minus podand zorst, 13'' rims.. and yes it is fun in the dry in RWD
but i want to get a good enough setup and try to keep it in 4WD full time

[AndrewT]

thanks guys
SUBAFURY- the motor is bog stock minus podand zorst, 13'' rims..

I can understand driving the car minus the pod and exhaust (would be a tad noisy)....but how does she handle with no rims??