Swapping SS 14 bolt in place of 8.0

[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

 

[Ilikemy3s]

very very nice hows the performance?

 

[HARDTRAILZ]

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 next week's front diff install now.

 

[Bartonmd]

My BDS shocks are complete junk and have just stay compressed when off the truck.

Are they the high end gas shocks (now replaced by the Fox ones), or are they the emulsion ones? The emulsion ones will lose the little bit of gas they came with in pretty short order, and even though they still damp just fine, won't extend themselves off the vehicle.

Mike

 

[HARDTRAILZ]

5500. They slide around too easy to be really good anymore. They have had a rough couple years, but they leaked right away and have not leaked in a year, so I doubt there is much left in there.

 

[Bartonmd]

5500. They slide around too easy to be really good anymore. They have had a rough couple years, but they leaked right away and have not leaked in a year, so I doubt there is much left in there.

Oh, gotcha... Emulsion shocks are a 25,000-30,000 mile service interval, anyway... Likely time, as it is...

Mike

 

[HARDTRAILZ]

Yep. Figured they had served their purpose. Just got to figure out what I want to run next. May work on brake lines to maximizes articulation before ordering anything.

 

[DJones]

The axle certainly came with plenty of useless $crap.

 

[gmcman]

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.

Which sensors are you referring to? Just curious if I am to run into any problems swapping a SS rear to a 02 voy.

Nice job BTW and write up.

 

[HARDTRAILZ]

Which sensors are you referring to? Just curious if I am to run into any problems swapping a SS rear to a 02 voy.

Nice job BTW and write up.

Wheel speed sensors. You can just cut the wire and leave them plugged in the SS if swapping into an older one. They wont affect you if you do this.

 

[Scooter Scott]

That was a long night!! But honestly those pictures don't do these axles justice on the size and strength different. Once you see the size difference it's actually pretty amazing. Glad I got to be a part of another great GMTNation build!

 

[HARDTRAILZ]

Been working great so far. Much nicer than before. The locker is loud, but very drivable. If it was quiet I would hardly notice it.

 

[ScarabEpic22]

Nice Kyle, did you ever figure out your brake line issue? I ask because on TBSSOwners.com you can buy a set of stainless brake lines for ~$200 and they're 1.5" longer to accomodate lifting/lowering. Since you have an SS rear and an 06+ truck, they would work no problem. And give you better brake feel at the same time.

What did you do with the rear calipers?

- - - Updated - - -

Nice Kyle, did you ever figure out your brake line issue? I ask because on TBSSOwners.com you can buy a set of stainless brake lines for ~$200 and they're 1.5" longer to accomodate lifting/lowering. Since you have an SS rear and an 06+ truck, they would work no problem. And give you better brake feel at the same time.

What did you do with the rear calipers?

 

[HARDTRAILZ]

Rear calipers are the same so i kept mine.

The SS lines were not available when i tried to get them. I asked to be notified when they were and never heard back.

 

[ksimm92]

You can just cut the wire and leave them plugged in the SS if swapping into an older one. They wont affect you if you do this.

that's what I ended up doing when I swapped my axle, I got a 08 with the sensors and just cut the wires since my 04 doesn't have the sensors in the rear. Nice write up, and great pics too!

 

[ScarabEpic22]

Rear calipers are the same so i kept mine.

The SS lines were not available when i tried to get them. I asked to be notified when they were and never heard back.

They're available now, Steven has 6 sets in his hands. Didnt know if you'd seen them or not!

Stupid double post above, sorry everyone.

 

[HARDTRAILZ]

Got a lead on some lines for cheaper this weekend but not for sure yet. Also got to fix a few things first.