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H3 Opinion-Is the 100k mile mark, when most things start to fail on the H3?

Jeepwalker

Well-Known Member
Messages
857
Location
WI
That's a great question. I would say, No, Yes, Maybe. Depends on a lot of factors like how it's driven, maintained, location (salty north or arid south). Florida is pretty gentle on H3's as long as ya keep it out of the sea. Some items can fail at any time, really, just plain dumb luck (or not!). Like anything, the more proactive approach an owner can take, the more he/she may be able to extend the life of some items. Per the suspension joints I firmly believe one could just about add 50% more life to them (if not double) with periodic re-lubing. It's a lot easier and cheaper to coax them to last longer than go to the effort to replace them. Items like water pumps as you mentioned, are usually run-to-fail components and it's anybody's guess when they could fail. Mine has almost 170k on what I believe is the original water pump. Starters/alternators can be serviced proactively (especially alternators) to extend their life (e.g. new brushes/starter solenoid-bendix), but few people would do that. A lot of aftermarket replacement products generally suck and even Delco replacements aren't always up to factory installed products, so, yeah, it's a great idea to put whatever level of maintenance you can if you want to reduce the risk of failures. Depends how much work a person wants to devote.

These rigs have the potential to go well over 200k mi as evidenced in many online ads. But they're kind of high-cost to maintain when ya have to go back to GM for most parts. The more you can do to reduce costs, the easier things will be on your wallet. If you are thinking of getting rid of it in 2 years, you shouldn't need to do a whole lot. If you're in it for the long haul, consider some of the items listed below:

General: You should definitely clean out the throttle body and do a good look-over for problems. Sucking out the brake fluid and putting in new (if only the master cylinder is a good start), a complete brake fluid replacement is best. Probably needed with your humid summers. A lot of brake problems can be avoided by ensuring the fluid hasn't saturated with moisture (dark color), and ensuring all pins and sliders move freely. I generally push pistons in/out a few times during pad replacement to lubricate the seals and keep them free moving. If the other fluids haven't been replaced, now would be a great time to do so.

Suspension:
A major issue with a lot of greaseless suspension joints is, in a short time the grease gets worked out of the actual joint where it's needed the most. But during extended range of motion, some gets worked back in (which doesn't really happen much on street driven vehicles). The upper ball joints in the H3, for example, the ball stud is highly polished and is pressed into a nylon cup unlike the old days where the stud was sheathed with a hardened (polished) cage and all pressed into a heavy steel assembly. So here you have a polished steel stud against lubricated nylon. Well it works pretty well ....until the grease gets worked out and becomes dry and brittle (due to a ripped boot). And if the stud gets wet and starts to pit, that'll tear up the nylon cup pretty quick too. So, knowing how it's made helps put things into perspective. [Note: I'm not sure if the lower ball joints use a plastic bushing, I suspect not, but I can't say for sure]

With that in mind, if it were my vehicle at 100k mi, I would take an afternoon and disconnect the upper ball joints, the tie rods ends, and one end of each anti-roll bar link. Then move and rotate each joint through it's entire range of motion, rotate the stud in it's cup ...while gently pressing on the boots so as to re-work grease back into the joint. Don't press too hard. The joints I mentioned are fairly easy to remove with just hand tools and a hammer. As I did this to mine, I could literally feel them becoming re-lubricated. Rotate the spindles as much as you can to, again, re-work the grease inside the boot back into the lower ball joint. Upper control arm ball-joints are somewhat of a weak point on these vehicles anyway, if the ball joint studs feels 'loose', you can make a plan on replacing them sometime soon. If you wanted to get really crazy, you can carefully remove the retaining ring and slide off the ball joint boot and spread new grease up inside with your finger ..and replace the boot. Of course nobody that that, but there's no reason one couldn't.

Steering: While under there, inspect the steering rack bushings and the steering rack bracket (inspect for damage to the rubber beneath the 'clamp') near the front diff pumpkin, these are known weak areas. Also, inspect the rubber bellows for cracks which cover the inner tie rods. I would also put a large vice grip pliers on the input shaft of the steering rack, rope the vise grips tight to the frame (may need a piece of wood between) ...then wiggle your steering wheel back/fourth gently feeling for excess free-play. The intermediate steering shaft consists of two parts (upper and lower), two small U-joints, a slip joint and a flexible coupler. All at a pretty steep angle. Suffice it to say, each pivot point can gain a little wear over the years causing many rigs to have annoying excessive free-play at the steering wheel. Easy to replace.

Seals/bearings: I recently replaced transfer case seals and rear driveshaft bushing on mine too, and the front diff outer bearings which reduced the 'free play' noticeably. On other high-mile vehicles I've owned, I've removed the idler pulleys, popped off the seal and re-greased the pulleys. Reason is, the aftermarket pulleys are generally trash compared to those originally installed. Then ya never have to mess with them. The less vibration and harmonics introduced to rotating assemblies, the longer they'll last.

Misc: Make sure your batter teminals are good and clean. That's another source of issues. I replaced the two electrolytic capacitors in my driver's door 'window control module' as the ESR values were measured out of spec. Haven't had any window freeze-up/no-start issues since. Make sure the sunroof drains are cleaned (see youtube), replace your old sunroof gasket while they are still available to keep water from saturating your carpet (and causing mold/rust). Some people think the drains are are the primary problem for water intrusion, they're not. They're a fail-safe should water seep past the sunroof gasket. If the driver's door hinge is becoming sloppy resolve it. If ya have a tow wiring harness, make sure it hasn't rubbed bare back by the body/bumper. Thermostats seem to flake out a lot, but that's a run-to-fail item. There's a million things a guy *could* do. The common H3 issues are 'out there' and steps can be taken to avoid or minimize most of them. Depends on how committed a person is to their vehicle, their mechanical abilities, time, cost, etc.

Sorry, I got carried away with items. I'll stop there. I'm sure guys will chime in with other helpful items to check (and mock the things I've done as excessive and ridiculous :giggle:).

Good luck!
 
Last edited:

3Hummers

Super Moderator
Staff member
Messages
10,398
Location
Central Texas
We sold our H3 at about 125K miles if I remember correctly. We had replaced 1 cross member, one ball joint and one engine( wife issue ) Very little replacement or repair at 125K miles.
 
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