10 bolt to 14 Bolt, 9.5 sf swap

[swathdiver]

Even better! So in the end your original u-joints worked right? Is ours a 1350?

 

[randeez]

well... mine is
might be a 6.2 thing

 

[swathdiver]

It's a AWD/4WD thing! Yeah, they are the same. the U-joints anyway, haven't verified all the other parts yet.

They are 1350s, 5-178X or 5-1350X (solid non-greaseable) and the GM number is 89059111 (solid non-greaseable).

 

[67RS427]

So now I'm curious as I will be needing a Eaton Posi to replace the G80 in my 10 bolt with 160k miles. How much power are you making? I also want to keep AWD and was planning on rebuilding my BW4485 transfer case... I'm currently rebuilding my front diff and was going to leave the 10 bolt until it blows up. I like the idea of the 14 bolt swap. Have you determined if the spoon adjustable panhard bar will fit yet? Looking good man, I will definitely be going the same route on my 2007...

 

[randeez]

On awd dyno...north of 400 hp/tq...6l80 doesn't have a 1:1 gear tho, and didn't lock converter
Using 1/4mile trap speed and weight calc about 460ish hp

Spoon bar works with stock 14b cover, the other should be here early next week.

 

[67RS427]

On awd dyno...north of 400 hp/tq...6l80 doesn't have a 1:1 gear tho, and didn't lock converter
Using 1/4mile trap speed and weight calc about 460ish hp

Spoon bar works with stock 14b cover, the other should be here early next week.

Nice! I'm gonna be in the 850hp range @ the crank so I think a 14bolt is a no brainer lol... How different is the driveshaft length? I'm about to order custom driveshafts and don't wanna have to do it twice. I'm kind of surprised the spoon bar fits with the tight fit on the 10 bolt already. Good luck fitting the aftermarket cover, let us know how that works...

What are you running for a center section? Posi or TruTrac?

 

[randeez]

Nice! I'm gonna be in the 850hp range @ the crank so I think a 14bolt is a no brainer lol... How different is the driveshaft length? I'm about to order custom driveshafts and don't wanna have to do it twice. I'm kind of surprised the spoon bar fits with the tight fit on the 10 bolt already. Good luck fitting the aftermarket cover, let us know how that works...

What are you running for a center section? Posi or TruTrac?

Yea, you're prob a good candidate for it .
Did it with plans for more power in the future, need to take care of a few things first.
stock g80 in there for now

Stock driveshaft works , going to drive it around let suspension settle and see how in the transfer case it is now, measured it's about half inch closer.

 

[randeez]

wasn't paying attention when we threw drive shaft back in....

driveshaft does go back into the transfer case 1/2-3/4"further, on mine that part of the shaft was covered in surface rust so after a few days it started leaking fluid while driving, not terribly, but it was all over the under side. short term pulled DS back out and cleaned it up, replaced the seal, and took a few measurements to order one.
also as it sits the drive shaft still has a little less than an inch before it bottoms out on the output shaft.

I did receive the PML cover, still trying to find panhard bar alternative (see pic of clearance), came with hardware but socket cap bolts are just zinc plated steel, and stainless washers. I ordered the same socket cap bolts in stainless:
-QA-1 bar, shows years 00-06? dont know if same length and kicks out at the cover, but not adjustable.
- go lower, the rear end pulls forward with the 4 link and may be enough to clear, but it would probably bug me not to have wheel centered adjustable 4link bars would put me right back where i am.
- stock bar - no adjustment but would probably clear.
- leave stock cover, keep adjustable spoon bar

 

[randeez]

Soooo since the 14 bolt swap went so well.... I ordered an 9.25 ifs
Why- a little bit of why not, but also am having to replace an outer bearing on my 8.25ifs, no lsd/locker available for 8.25, want to regear anyway....

The older 9.25ifs mounting points were off from their 8.25 counterparts and cast into the aluminum housing. Top ear had to be cut and relocated, etc etc.

Gmt900 1500 8.25 ifs has the two mounting bolts on the long stub shaft ( passenger side same as before) but it uses a bracket that bolts to two holes above the driverside stub shaft. Looking at the 2500/3500 9.25 ifs from 2011+ it mounts in the same fashion. I'm hoping/betting it mounts the same or possibly the brackets can be interchanged to work.
The newer 9.25 ifs is no longer a cast aluminum center chunk, without all the ribbing needed for strength I'm hoping it's size isn't much larger than the 8.25. I will confirm when I have the axle in hand and measure up mounting mounts.

IF (when) all that goes as smooth as I know it will

Axles will be the major hold up, I have a few ideas tho.

 

[randeez]

 

[randeez]

Found this:
http://www.demandaam.com/product-catalog/axle/output-shafts

Kinda sunk a few of my ideas....
thinking I would be able to swap in the stub shafts from the older 9.25, new one uses 8bolt pattern and 36 splines at the hub, and are 23.xx inches long. The older cv axles had a 6bolt bolt pattern (different than 1500s I believe) and are beefier than the 1500s but they would fit in the 1500 hubs, same size/spline. Would have made for a slick install using oem parts, modified cvs.

The length of the new cv axles is what has me wondering, cause according to rockauto my cvs are only 18" or so long, older 9.25 axles even shorter ~17". Don't know if the wms is actually wider on 2500/3500s or if this axle is that much shorter in width where the cvs mount. Will hopefully get mine up in the air to measure mounting points and widths over the weekend

May do a quick and dirty adapter, similar to what's included in lift kits and machine in whatever bolt pattern I go with for the inside cv mounts

Edit- that 23.xx measurement for the 2500 axles looks like inside mount to end of spline shaft. My other measurements are Inside mount to hub. Measured end to end looks like my 1500 cvs are 22-7/8. So might be real close. So make adapters and run 1500 axles or see if I can swap the outer cup on new 2500 axles with the older style 2500 cup that has the correct spline I need. Might do both, adapters to get it rolling as it'll be cheap and really no guess work. I'd need to buy 4 axles total to make the other work and its be a gamble

 

[67RS427]

I know I should be the last one to say this, but why? I love the idea and might attempt something similar in the future should I actually need it but I'm currently sitting at 850-900hp and don't see why you'd possibly need to do this swap. Don't get me wrong, it's a cool idea and we all appreciate you being the Guinea pig, but totally unnecessary... That transfer case will take a crap before your 8.25 IFS case cracks or something else breaks. With our trucks being AWD, only 40% of your power goes up front and it's through the BW4485 transfer case first. Your just cammed and stalled? Again, why the need? I get wanting a LSD/Posi up front but that's no big deal, mine puts the power down just find. Put that money into custom driveshafts and a good 6L80 build. Even at 1000whp, that front IFS only sees 400whp of that. Doesn't seem like it's worth it to me, the 8.25" should hold up fine... Time will tell for me but unless your planning a 1000+ hp build, your probably wasting your time and money except for the fact you are doing something that may not have been done too many times before.

Just my 2 cents...

 

[randeez]

that is exactly what im planning lol
all the same it probably isnt necessary, outer bearing on mine needed to be replaced, i wanted to regear...i was going to just grab another denali front diff swap gears and have it ready to throw in minimum down time, but theyre all $1100+. if it looked as involved as swapping in the earlier years i would have just did that, now it may still be a pita but initially it looks like a pretty easy swap for a much better front diff, and it was cheap.

 

[randeez]

I know I should be the last one to say this, but why? I love the idea and might attempt something similar in the future should I actually need it but I'm currently sitting at 850-900hp and don't see why you'd possibly need to do this swap. Don't get me wrong, it's a cool idea and we all appreciate you being the Guinea pig, but totally unnecessary... That transfer case will take a crap before your 8.25 IFS case cracks or something else breaks. With our trucks being AWD, only 40% of your power goes up front and it's through the BW4485 transfer case first. Your just cammed and stalled? Again, why the need? I get wanting a LSD/Posi up front but that's no big deal, mine puts the power down just find. Put that money into custom driveshafts and a good 6L80 build. Even at 1000whp, that front IFS only sees 400whp of that. Doesn't seem like it's worth it to me, the 8.25" should hold up fine... Time will tell for me but unless your planning a 1000+ hp build, your probably wasting your time and money except for the fact you are doing something that may not have been done too many times before.

Just my 2 cents...

its on the back burner, you win .....part of the main reason i was interested in the swap dissolved after a long search-apparently there are no traction aids for 2011+ 9.25ifs axles with the exception of maybe a lunchbox style locker which i am not interested in. And I would have still had to deal with either deleting the CAD with a long passenger side single axle (found a few shops that it looked like this may be possible) or wire the actuator on all the time (not preferred).
I had measured out all the mounting points, they were only about 1/2-3/4" off on width, i think that could have been made up easily the axle mounted to some brackets that mount to the frame on rubber bushings, by just by assembling the axle on the brackets and brackets on the frame loosely i think there would be enough play everywhere as it was tightened up to fit nicely. the other brackets over each stub axle were the same measurements.
for axles see previous post, i was looking into changing out the stub shafts on the transmission to delete the CAD but also change to the older 6 bolt cv pattern. if that didnt pan out either a simple 1/2 thick adapter 8 bolt to 6 bolt should work fine to get back to 33 spline at the hubs with 1500 axles or older 2500 axles depending on length.
The last step before i started cleaning up the 9.25" was going to be a quick test fit because the only thing I could not measure accurately is from the center line up to the top of the diff and there are all kinds of weird humps and shapes to try and lay out, it looks very close to the 8.25 but without physically removing the 8.25 and fitting the 9.25 in its place i didnt want to sink abunch of money into the 9.25 first to find out it would not fit. part number for the ujoints match, centerline of axle to the ujoint looks to be very close, to shorten and balance front driveshaft would be cheap if needed. with a diff drop lift kit it should be very easy to do the swap.
the other reason this is on the back burner, need to find a new daily as my other car was totaled a few weeks back so scheduling all this around swapping the front and towing it somewhere to have the rear done or having to buy whatever tools i would need for probably one time use vs spending the money to have someone do it. havent had the greatest luck with shops lately and didnt want to have to add this to the list of mods i would end up having to redo myself because i wasnt happy with the way it was after i paid for "professionals" to work on it. found a shop that looked competent/confident, price was right, and just going to swap the 8.25 at the same time. if the 8.25 gets tore up then ill worry about the upgrade

 

[randeez]

8.25 after swapping to 4.11s something messed up, pinion is seized up. Not sure what else it could be other than not correctly installed. Also to note mis-matches gears 4.10 rear 4.11 front could be messed something up, dunno.

In either case...dont care. Had some free time so I pulled the front diff out. I had the 9.25 (with 4.10) sitting here, looked damn close so I threw it in. It's a heavy sob compared to the 8.25. Looks like an ear on the 9.25 will need to get cut off- mounts to the 2500/3500 bracket not used/needed on the 1500 bracket. And may have to notch the crossmember or clearance a little on the case.

Soo going to pull it back out, cut the ear off. The passenger side tube is a little rusty new ones are only 100 bux but then I may need to shim the half shaft different.

 

[randeez]

 

[randeez]

Front ds will need to get shortened an inch or so. My ds guy local does a little bit with cv axles...I've got a few ideas but going to see if it's easy enough to whip some up before I go nuts

 

[randeez]

Bye bye ear, also I was messing with the CAD on the bench with 12v battery and I managed to get it to extend to engage the front axle...could figure out how to retract it so for the time being it's always engaged

 

[randeez]

and if anyone was wondering the awd tcase does act like an open differential. I left the front diff/ds/cv axles out to see if i could atleast move it around while i wait on parts but as soon as i dropped it i was reminded of the slope in my driveway nearly rolled into my daily driver.

9.25ifs is staying out for the time being because i will be replacing the motor mounts (with atomic polys), but waiting on new tq converter to show up and install first- would usually remove the tranny crossmember and angle down but not sure the atomic mounts will allow much articulation.

Spohn adjustable rear bars and panhard bar to match showed up saturday so I have an extra spohn adjustable panhard bar if someone's looking.... preferably local. was just to whooped to try and get all of that on also.

annoyed with my welder for slacking on my exhaust and then, what looks to be rushed and tacking it together all messed up so i spent most of yesterday grinding tack welds off.

dropped the front driveshaft off to get shortened and rebuilt, dude usually take a day or two.

And I ordered two cv axles...
1) for a 2010+ 3500 truck (that the 9.25 came from- cv axles to stub shaft are 8 bolt)
2) for a pre-2010 3500 truck, they are shorter than my stock axles but has the correct 33 spline at the wheel hub.

 

[swathdiver]

Are you using Total Truck Parts or Palm Beach Spring for the driveshaft work?