2006 Trailblazer Build

[Hardtrailz]

My truck came with a G80 3.73 equipped 8.0 rearend. While it has done alright with my big tires and multitude of modifications, I have always wanted more strength and reliability than the G80 8.0 offered. I have the sensors out on the end of the axle tubes requiring an 06 or newer rear and never found a 8.6 for a decent price. I got it in my head to swap to a lower gear set as well with the 35s going on as a permanent fixture soon. The front diff was the real sticky part in the gear change, but I found a decent price on a unit from an SS offering 4.10 gearing and the guy happened to have a 4.10 SS rearend as well. Bought them both as a good package price. The SS rear has 4.10s and a G86 limited slip rear differential. While the gears were to my liking, the LS was not going to meet my needs. I found a new in box LockRight lunchbox locker and snapped it up, but to facilitate its use I needed an open carrier. I sourced a used open carrier from WFO Concepts and got them to press on some new Timken bearing before shipping it and a super shim kit to me.

So now I had all the parts to step up from the 8.0 3.73 G80 rear to a locked 9.5 4.10 rear. The SS rear is a semi-float 14 bolt often found in 3/4 ton truck and in all SS TB's. It boasts a 9.5 inch ring gear, 33 spline shafts of good diameter. The general consensus is that this is about the equivalent of a Dana 60. Much stronger than my setup was.

I thought of attempting the carrier swap myself, but decided that enlisting some help from experienced friends would be much better. Even though I really was only concerned with backlash and pattern, I am glad I did not go it alone, but would not hesitate to do it again. Had the rear came with an open locker, this would have been a couple hour drop in job, but since I had to swap carriers...no quite so easy.

How about pics....

The Donor...08 SS


Junk stripped off


Ready to get to swapping


The help and axle on the sawhorses- Started about 8 Friday night


The locker


The motivation


Sticker in locker box


Cover off- Actually really clean with no metal clunks


Dirty inside


Cleaned up inside


The LS carrier had no gussets for strength


The open carier did...


Work






Help

[Hardtrailz]

After several attempts with following the crappy directions, we sat down and thought it throough and figured it out. Wasted a bunch of time trying different things thinking that was the "way" it was to be done and had too many chiefs, but once we topped and talked we thought it through and Bazinga..






The SF 14 has shims on only one side and this snazzy adjuntment collar on the other.


With stock shim and used carrier and gears, plus new bearings, the backlash came to .0008 and the gear pattern looked good. In fact my buddy, the actual certified mechanic that worked for Cummins and several other auto places, said it was one of the best patterns he had seen and he fully expected it to be off and have to redo it.






Buttoned it all back up about 330 am Sat and loaded it to head home for 3 hrs sleep then to get it in.

[Hardtrailz]

Too tired for pics, but my dad helped me by fetching tools and I got the rearend under truck in about 6 hours with much time wasted trying to find a replacement c clip for the u joint.

But here is a before shot of some 8.0 rears.




Here is an after shot of the 14 bolt




Some Detail's and Thoughts...
The u joints are different and requires a Precision #447 from Napa.

The driveshaft may be too long now even with the lift and longer rear control arms.

The locker is not silent when turning, but is awesome when on the gas on loose stuff.

The SOB is heavy to move around

My BDS shocks are complete junk and have stayed compressed when off the truck. Not too hard to just pull the shaft in and out.

The performance is good. Truck feels more solid. It is not a race truck and the gear ratio is not a big step, so who know if it is quicker. Not the goal of this.

With the big tires,, it does not drop lockup as easy as before.

My Scanguage indicates better cruising fuel economy.

The traction when punching the throttle of loose stuff is far and above the g80.

Sensors all worked first try.

SS rear brakes and standard rear brakes are the same. I am using my rotors and calipers even thought the rear came with the SS ones.

Need to check clearance to pangard bar. Seems close.

Anything longer than 26 inch extended shocks will necessitate me extending brake lines, but if I do...my spacer and spring combo wont be loose until about 28 inches.

Has drain plug on bottom and easy access fill plug. A huge improvement from the 8.0.

My speedo is off by 5 mph at 40 and 8 mph at 65. Should be better once 35s are on, but may send it to pcmforless for update.

Would I do it again...Hell yeah. Should have done sooner. I cant wait to have it all broke in a bit more and be able to beat on it some.

Really cant wait for sunday's front diff install now.

[Hardtrailz]

Finally got some good 35's to run and some new rims to replace my ones with some issues.

The new set-up is a set of 315-70-17 TreadWright Guard Dogs. Basically the old MTR tread on a BFG AT Carcass. These carcasses have the 3 ply sidewall. The unmounted height is right at 35 inches. The weight was about 76 lbs a piece. Actual tread measures about 11 inches wide. Which is interesting since the previous 305's were wider, but 315 and 11 inches seems to be standard.

The wheel are the Pro Comp 6032 in the new HD Chrome. There are a bit over 20 lbs and the size is 17x9. I like that the plastic center caps are bolt on. These wheels are light and the finish really is incredible. I think black rims look like cheap ghetto crap, so I knew with the discontinuation of the Knight Chrome I had to go with full chrome. My chrome wheels always get me home and dont look like spares doing it.

The combo gained me about 1.5 inches of ground clearance. The tires being a bit skinnier makes the truck seem taller and narrower, not a bad thing. The wheelwells are filled out better, but may have additional rubbing, although I doubt it is anything of consequence. My rear extended control arms do not appear to center the tires in the wells. Looks like an extention of more than 1/2 inch would be more appropriate, but Fishsticks said his 1 inch was too much.

I only drove around the neighborhood, under 30 mph, and these tires make more noise than the worn pro comp xtreme mt did. They do feel solid and smooth. Truck feels taller, but is very planted and not unstable feeling. Time will tell.

But what people want to see....pictures....

The rims and tires..










Old in front of new


Old


New


Some Measurements

Old Height


New Height


Old rear


New rear


Clearance to cut front old


Clearance to cut front new


Tire to fender clearance old


Tire to fender clearance new


And just some pics of the stance and such

[Hardtrailz]

Front diff has been swapped to 4.10 ratio'ed unit from a low mileage SS. Also rebuilt the splined disco w good synthetic grease. The swap forced a power steering fuild change as well. I am sure that's not a bad thing.

Hoping to get driveshaft shortened this weekend.


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Driveshaft shortened 1.25 inches . Works great.

For reference though, the shortened steel shaft on my truck is 1.75 inches shorter than spare aluminum one in the garage.

[Hardtrailz]

Real class 4 receiver that I wouldn't have a problem towing a car trailer or camper with, and/or using a load-distributing hitch with:





Progress on making the radii









Add 1" to the center portion, and this would look good as just a standard step-bumper, without the tire carrier:



And with the 35" tire... Glass still opens with the tire in the "closed" position:

[Hardtrailz]

Got 'er all finished up and in the truck to go to powdercoat in the morning... Been working on it since 4 this afternoon.

Here's a video I uploaded to show the swing-outs in action:

[youtube]kwdEor2TTeA[/youtube]

[Hardtrailz]

Plasti dipped hood


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Replaced the failed Japan springs and spacers with Skyjacker 25 springs. Rear is 1 inch higher than front now.

Old collasped springs


New Springs


Stance now...

[Hardtrailz]

Re-installed the interior divider/cage thing that came with it when I bought it. Was done by American body co or something like that. Previous owner had a wheel chair and this was to keep it from hitting the pasengers or him in a wreck. It mounts where rear coat hooks are and in some threaded holes above the driver and passengers head. The gate slides from behind front seats to behind rear seats. I put it in for 2 reasons...protect lil one from flying objects I keep back there and for mounting a few things.

Reason for it


Behind rear seat


Fits nicely between cargo cover and back of seat.

[Hardtrailz]

Some Tecore 7 shots