I don’t have any experience with the WJ specifically, but for bushings in general a high quality polyurethane aftermarket bushing is an easy to do upgrade that shouldn’t impact the reliability of your rig. If you want to keep stock control arms I’m sure you can find a set that will fit.
Bushings are wear parts in my book, and should be replaced at regular intervals. I tend to be very conservative with my intervals — 5000 KM oil change interval for instance — because I’d rather spend a little more on regular maintenance to enhance the long-term performance of my vehicles, and this gives me a buffer should I forget or be unable to turn a wrench for a period of time; even in a worst-case I’m still WELL below the recommended intervals. I would suggest a similar approach to bushings, and some will argue that Poly bushings are a waste if they are changed frequently but I disagree.
Very few vehicle wear components go from “bad” to “good” all of a sudden, and this is especially true of wear parts like shocks and bushings. They go from good, to pretty good, to adequate, to a bit rough, to really rough, to shot. In other words, its a progression.
So let’s say you decide to change bushings every 40,000 KMs. Depending on the bushing and the vehicle that could be a really short or a really long interval, but let’s just go with it. The Poly bushing is likely to still be functioning at 100% when this interval is reached, whereas the rubber bushings may only be at 80% over this same length of time. That 20% may be negligible but it may also mean more wear and tear on affiliated components; a half a mm of slop in a bushing means a bit more play on a ball joint, and that bit more play means instead of lasting 70,000 kms the joint gives up at 60,000 kms. Theoretically as long as bushings are performing as spec’d it should be fine, but I go on the theory that every OEM part on my vehicle was graced by an accountant, and that means it’s probably not the best product out there.
I’m a big proponent of keep it simple, keep it stock, and used to go OEM for every part. But for the wear parts (specifically bearings, shocks, bushings, fasteners, and sensors) I’ve had WAY better luck with quality aftermarket than I have with OEM. However, this can bite you which is why I’d say if you can, keep the stock control arms; for example — we did the clutch on our JK and replaced it with a Centerforce clutch, however that aftermarket clutch came with it’s own flywheel that is not compatible with OEM parts. That means that we could ONLY replace our clutch with another Centerforce one, which we didn’t know until after we ordered the LUK kit, which didn’t fit. So, if going aftermarket, go for quality, tested aftermarket with OEM compatibility, or go with OEM.
I don’t have any science or numbers to back this up, and I’m sure to some I’m wasting my money, but this is the theory I work under and I enjoy maintaining my vehicles; I’d rather spend $150 on bushings than on a night on the town, so it’s money well spent in my books. Your mileage may vary — figuratively and literally!
