Biggest thing is to make sure all the "joints" can handle that lift and what not. You have drive shafts and what not that have been running 120k miles at one angle and you are increasing the angle they will run at. You may see some wear out cause of this change.
There are so many subaru boards out there I figure you checked to make sure of anything that needs done when increasing the ground clearance in this manner.
I like the old subaru stuff but don't own any. I think they do best when kept light and nimble. I like the ground clearance idea but would not want a ton of weight on the roof.
Good point about running the driveshafts at a new angle - how will the CV joints respond, once the CV joint rollers are forced to run in different spots on the CV races?
Second, in the 2002 model - is the suspension McPherson strut at all four corners? If so, what are you going to use to reclaim your camber settings, once you lift the vehicle up in the air? Factory McPherson strut suspensions have a narrow camber setting range adjustment, from the factory - elevating the ride height, usually alters the camber settings to a point that they cannot be brought into factory alignment settings - there are compensatory devices that can be employed, at additional expense, to restore the factory camber settings in elevated McPherson strut suspensions.
Thirdly, bear in mind that the Forester already has a factory elevated suspension, with roughly 7-8" of underneath ground clearance, along with a corresponding higher "roll-center" - adding an additional 4+ inches of ride height will only move the roll-center HIGHER, possibly causing the vehicle's handing to become more "darty," due to a combination of higher roll-center and short wheelbase - ask the Jeep CJ owners about this well known issue. Throw in any significant amount of cargo/weight onto a roof rack, and the roll-center raises up an even greater amount while becoming more negatively pronounced/noticeable in how the car handles.
Also, bear in mind that the AWD system of the Forester does not have a low range, which is useful in extreme off-road terrain - nor does it have any axle-locking capabilities - the center-section will auto-lock via the computer, should the vehicle experience equal loss of traction at both the front and rear - but that can mean that you are left with one front tire spinning, and one rear tire spinning - no axle locking - unless you add such, at additional expense, to the rear differential, which will allow two rear wheels to attempt to grab traction, and only one front wheel, in an all-out traction limited situation - mud, snow, etc.
What transmission? Automatic, or manual? If it is the Subaru 4EAT (
4-speed,
Electronically/servo shifted
Automatic
Transmission) automatic 4-speed transmission, make sure to
FLUSH the fluid according to factory interval recommendations - FLUSH, not simply drain the pan and replace the filter - FLUSH - more expensive to have done than simply draining the pan, but aides greatly with transmission longevity, over the long haul. The 4EAT is a good transmission, when cared for and NOT abused via heavy-duty off-roading - too lightweight to survive much of that sort of operation - also, not really built strong enough to pull a trailer on a regular basis, unless trailer and cargo are kept at around 1000 LBS - believe that the 2.5L Forester equipped with a 4EAT is rated to pull 2500 LBS - IMHO, that is a bit of fantasy, if regularly pulling that amount of weight. The 4EAT will last 300K+ miles, if treated correctly - nearly all on-pavement use and/or solid-ground off-road use - fire/lumber access/field roads, long graveled drives.
Keep an eye on ALL FOUR of the CV joint rubber boots - especially the front CV joint rubber boots - you WILL have them deteriorate and crack open at some point (factory seems to last 80-100K - shorter boot life possible, since you are talking about raising the Forster's ride height more, which will cause the rubber CV boots to flex more as they rotate, due to the increased axle angle (as mentioned above by biere) caused by the increased ride height. Make sure to replace the cracked/ripped rubber CV joint boot as SOON as it is noticed, to prevent environmental contamination sand/grit from entering into the protected CV joint moving metal part areas.
FYI to all reading here - the cracking CV rubber boot issue is not unique to Subaru, and exists on any vehicle which uses an independent suspension at the drive-wheels - including most front wheel drive vehicles.
Aftermarket replacement CV axle half-shafts (many folks replace the whole CV half-shaft, rather than replacing the defective CV rubber boot) rubber boots seem to only last 40-60K before breaking open.
When a rubber CV boot fails, and assuming that the CV-joint is not clicking or making mechanical wear noises, especially when turning, we usually pull the CV half-shaft apart, both the inner and outer joints, and clean all of the CV rollers and races, reassemble using CV-joint rated grease and new Beck-Arnley rubber CV boot kit replacements - again, both inner and outer - messy job, but not that difficult nor expensive, and the Beck-Arnley boots are equal in quality to the factory Subaru boots, lasting much longer than other aftermarket brands.
intothegoodnight