Front end rebuild checklist

[CaseyS]

Once I finally get moved into my new house and get a garage back, my front end is due for a complete overhaul. 270,000+ miles with nothing but 2 alignments. Everything is noticeably worn, tires are badly worn, steering is bad and wobbly, and I'm now carrying an extra 400 lbs on the front end with the engine swap. I plan to tackle everything in one job if at all possible so I want to make sure I haven't missed anything while I have access to stuff.

1. Upper control arms. Includes new ball joints and inner bushings
2. Lower ball joints
3. Lower control arms inner bushings
4. Front brake job
5. New tie rod ends
6. Steering bracket fix kit
7. New front shocks
8. Alpha torsion bars

My diff seals are good and I've already replaced the lower main bushing in the crossmember. Anything else that I should possibly look at while the whole thing is apart?

Unrelated to this, I have to change the Cummins power steering pump and some other stuff on the top end. My or may not happen at the same time.

 

[cgalpha08]

It might not be a bad idea to upgrade the torsion bars to alpha torsion bars to help with the extra weight you have up front.

 

[06 H3]

X2 on the alpha torsion bars. They are stiffer for the V8 compared to the I5. They may not be enough even with the alphas but they will certainly improve over what you have now. If you could find the rare sway a way torsion bars I would go with those. Supposedly 15% stiffer then the alphas IIRC

 

[alrock]

It may make sense to just replace the steering rack too. I suspect the inner tie rod ends are worn too.


Check the sway bar end links and bushings for wear as well

Sent from my SM-N900V using Tapatalk

 

[CaseyS]

Yes, torsion bars were on the list. Edited the original post to include those.

 

[4speedfunk]

Diff mount bushing kit (all three).

 

[SolidusJ]

Would you say at this point the aluminum from diff can hold up the 4BT without a problem?

 

[CaseyS]

I have 6000 miles on the swap so far. So far its pretty reliable, and I drive it almost every day. I have not put it offroad yet and I have not driven it hard. About 6 weeks after the first drive on the road, I sold my house so I am garageless right now waiting closing on a new place. That has limited how much I am doing with it, and since its very driveable right now, I am content to just leave it be for now.

I have turned the power screw one turn and I am not going any further until I get gauges on to see where I am at. Low end is pretty good on driveability. Right now the torque converter is not locking up and I suspect a solenoid issue. This puts me at 2500 RPM at 70 so acceleration feels good until about 50 or so and then it feels like I need another gear. Plans are to solve the lockup issue and eventually regear to 3.73s.

As far as driveline goes, I have not had any self inflicted injuries. I had an initial low pressure problem on the trans after the rebuild that I found and corrected and the current lockup issue that is either a solenoid or a cut o-ring in the transmission. I plan to keep power levels reasonable and not abuse it on the street. The longevity of the other components is going to vary by use I suppose. The engine definitely has plenty of low end grunt. It will probably take some trial and error offroad to learn its manners. For the cases where it takes torque to get up and over, a light foot will likely suffice, especially in low range. Stuff that may take a little more speed and or some wheelspin may chance putting some pretty good torque on components. Just like anything else, getting things in a bind, hopping and shock to the driveline are all situations where things could go wrong.

I'd say with the power levels now, it is not an issue. I do plan on turning it up some more, but I'm not going to go crazy with it. I think with this swap and the 4L60e transmission, you will have to tune to keep all the components happy.

That said, my front end is in rough shape and I need new tires. Can't wait to get a garage to tackle the necessary stuff.

 

[4speedfunk]

Instead of re-gearing...try up-sizing the tires. The H3 loves 35"s and they fit it very well. This will save you the expense & hassle of a re-gear and also make your truck look & perform better. You can even go to 37"s with a Daystar body lift...simple & easy install. This might put your gearing about perfect, and the look & performance is well...awesome. The only reason most H3 guys don't run 37"s is the lack of low-end torque (and you seem to have fixed that!).

The front axle issue cannot easily be fixed. Alum or cast iron...they are both horribly inadequate for even the stock 5-cyl. About the best you can hope for is to beef up the outboard mounting bushings and the crossmember bushing under the diff snout. The factory rubber bushings are too soft and they let the entire assembly flop around way too much. These bushings are guaranteed toast at 100K miles (and I know you've got far more than that)...so without question, replace them with something more substantial. IMO...to be effective, you need to replace all three together. But, since you've already done the crossmember, maybe you can just buy the outboard bushing kit...

http://www.outfitterdesign.com/hummer-h3-kits.html

Tie rods? Forget it...stock ones work great, if you don't get stupid. If you are planning to replace your rack (and install a rack bushing kit)...the new rack will come with new tie-rods.
Half-shafts? Same thing...stock ones are plenty durable.
Other items? Check the front driveshaft CV & U-joint. Check the tiny U-joint on the steering shaft. Check your front wheel bearings...270K miles might be a world record.

 

[CaseyS]

I already have 35s and the gearing is still too high :giggle:. If I would go to 37's I'd run 4.10s. 3.73 will be right for 35's. So 37's will fit with just a body lift and t-bar crank?

I'll check the bearings when I have everything apart. Right now my tire wear and front end shake are horrible. Really looking to freshen everything up and since I am spending the money, upgrade where it makes sense.

 

[06 H3]

Regearing it with a lower numerical gear set will help strengthen the diff. Would it still be an inadequate weak diff? Yes, it always will be but lower numerical gears have larger pinions and contact patches.

Perfect example is the H1, a loaded up wagon can weigh close to 9k lbs. they are geared with 2.73 gears. A diff with a ring gear smaller then a 9in shouldn't last but the portals keep that diff alive. Same thing applies to the h3. If we could gear it to 2.73 we would NEVER hear of diff problems but the h3 can barely move with 4.56s lol

 

[MaxPF]

Regearing it with a lower numerical gear set will help strengthen the diff. Would it still be an inadequate weak diff? Yes, it always will be but lower numerical gears have larger pinions and contact patches.

Perfect example is the H1, a loaded up wagon can weigh close to 9k lbs. they are geared with 2.73 gears. A diff with a ring gear smaller then a 9in shouldn't last but the portals keep that diff alive. Same thing applies to the h3. If we could gear it to 2.73 we would NEVER hear of diff problems but the h3 can barely move with 4.56s lol

You already mentioned why the AMC diffs in the H1 live - portal hubs. Taller gears in the little AAM front would simply move the failure point to the pinion shaft or pinion bearings.

 

[4speedfunk]

I agree. Gearing doesn't make a huge decrease or increase in an axle's strength. A turd is a turd...no matter what gearing is inside. The AAM-7 is just too small and too light-duty for a 5000lb truck.

 

[CaseyS]

Who is it on this board that has the OEM parts connection. Zach? I need to get some pricing. About ready to get parts coming.

 

[06 H3]

Zach is the man to talk to

 

[USMC_TOP]

Don't forget sway bar links and bushings............. if you do everything you say you are brother you'll feel like your driving a brand new Hummer! Love your diesel setup bud! Wish I had that hookup!