2025 deleted member
Well-known member
Maybe I missed it, what was your goal for installing the new axles?
GMT800 2500 axle swap in 1500?
- Thread starter Lykos
- Start date
With quite a few (it's GM after all...)exceptions, the main axles in latebody GM trucks are:
8.5/8.6 10 bolt- 5 lug SF (Blazer etc.) SF
8.5 10 bolt- 6 lug SF (1500 axle)
9.5 14 bolt -6 lug SF (2500/ heavy 1500 applications- silverado ss, yukon xl, escalade, etc., usually with coils)
10.5 14 bolt- 8 lug FF (2500)- always? leaf springs
11.5 14 bolt- 8 lug FF (2500/3500)- always leaf springs
The great thing is if you have a 1500 with coil suspension, you can get the 9.5 14 bolt from a coil application (usually with a locker) and it is bolt-in (except as mentioned the U joint adapter and possibly the parking brake line may need to be modified depending on years)! The 9.5 is WAY stronger than the 10 bolt, but you don't lose as much ground clearance under the pumpkin as the 10.5.
NOTE- In my research I ave noticed the H2 axles (with elocker
) have wider spring perches.) Whether this is cheaper/ eaiser to move a spring perch than to install a selectable is up to you. I cannot confirm the H2's are plug and playThis is how to find a 14 bolt 9.5 that will bolt into a 1500 GMT800 with matching 6 lugs:
Burbone's How to find a 14 bolt for a 2000- 2006 GMT-800 1500 6 lug with coil springs
http://car-part.com/
2007
GMC Yukon XL 1500
Axle Assy Rear
(Your zipcode)
Press search
Pick one:
9-1/2" ring gear (14 bolt), 3.42 axle ratio (opt GU6)
9-1/2" ring gear (14 bolt), 4.10 ratio (opt GT5)
Optional: G80 will have the locker
\yelling\ MAKE SURE TO BEFORE BUYING OR SHOWING UP TO HAVE THEM TAKE PICTURES OF BOTH THE COIL SPRING PERCH, THE BACK OF THE HOUSING CLEARLY SHOWING 14 BOLTS, AND THE 6 LUGS. DON'T BOTHER GOING TO PICK IT UP OR PAY FOR IT UNLESS YOU ARE SURE IT'S THE RIGHT ONE /yelling/. Sorry the first one I drove 40 mins to had the wrong axle listed and was a 10 bolt.
Last edited:
Lykos
Super Trucker
My ten bolt is acting up so why not upgrade.
This thread is a winner because I didn't know the direct swap 14 sf existed.
Lykos
Super Trucker
With quite a few (it's GM after all...)exceptions, the main axles in latebody GM trucks are:
8.5/8.6 10 bolt- 5 lug SF (Blazer etc.) SF
8.5 10 bolt- 6 lug SF (1500 axle)
9.5 14 bolt -6 lug SF (2500/ heavy 1500 applications- silverado ss, yukon xl, escalade, etc., usually with coils)
10.5 14 bolt- 8 lug FF (2500)- always? leaf springs
11.5 14 bolt- 8 lug FF (2500/3500)- always leaf springs
The great thing is if you have a 1500 with coil suspension, you can get the 9.5 14 bolt from a coil application (usually with a locker) and it is bolt-in (except as mentioned the U joint adapter and possibly the parking brake line may need to be modified depending on years)! The 9.5 is WAY stronger than the 10 bolt, but you don't lose as much ground clearance under the pumpkin as the 10.5.
NOTE- In my research I ave noticed the H2 axles (with elocker
This is how to find a 14 bolt 9.5 that will bolt into a 1500 GMT800 with matching 6 lugs:
Burbone's How to find a 14 bolt for a 2000- 2006 GMT-800 1500 6 lug with coil springs
http://car-part.com/
2007
GMC Yukon XL 1500
Axle Assy Rear
(Your zipcode)
Press search
Pick one:
9-1/2" ring gear (14 bolt), 3.42 axle ratio (opt GU6)
9-1/2" ring gear (14 bolt), 4.10 ratio (opt GT5)
Optional: G80 will have the locker
\yelling\ MAKE SURE TO BEFORE BUYING OR SHOWING UP TO HAVE THEM TAKE PICTURES OF BOTH THE COIL SPRING PERCH, THE BACK OF THE HOUSING CLEARLY SHOWING 14 BOLTS, AND THE 6 LUGS. DON'T BOTHER GOING TO PICK IT UP OR PAY FOR IT UNLESS YOU ARE SURE IT'S THE RIGHT ONE /yelling/. Sorry the first one I drove 40 mins to had the wrong axle listed and was a 10 bolt.
I'M YELLING BACK!
THANK YOU!
😂
LOL
But seriously, that's good information. Hopefully the gt4 3.73 with g80 is an option as well.
Haha.
No worries. Yes, you will find the Gt4 3.73's around with G80 easy enough!
If you plan on going 33's or 35's maybe worthwhile to upgrade to 4.10's, depending on how fast you want to get rid of your $
It's a lot more cost effective to buy the diff with them, and regear the front, than it is to do both ends later.3.73's on 33 are fine too, Truck feels stock with 4.10
02TahoeMD
Explorer
One thing I should add - there is a difference in the brake lines from 2000 - 2002 and then 2003 - 2007 GMT 800s. I did have to transfer my original brake lines over to my replacement 14 bolt axle, but it was not a super difficult issue to address. Everything switched over just by bolting up, thankfully I already had put on stainless lines a couple years prior so I had no breakage when I took the lines off the 10 bolt. I would recommend using some brake line "stoppers" that clip onto the end of the lines to minimize leakage.
I did my switch in my carport with just a few minutes of help from my brother in reseating the rear coils. Probably took me 2 afternoons of work by myself. I also took the driveshaft to a machine shop to switch out the new U joint since I did not feel like fighting with removing a 13 year old part. Money well spent in my book.
I did my switch in my carport with just a few minutes of help from my brother in reseating the rear coils. Probably took me 2 afternoons of work by myself. I also took the driveshaft to a machine shop to switch out the new U joint since I did not feel like fighting with removing a 13 year old part. Money well spent in my book.
2025 deleted member
Well-known member
Ah makes sense. Thanks and good luck. Sorry I have nothing constructive to add!
02TahoeMD
Explorer
This is exactly why I did my swap. I was quoted $900 to $1K to rebuild my 10 bolt by a local shop since the pinon bearings needed replacing. I figured I would rather spend the money towards an axle that is considerably stronger.
Lykos
Super Trucker
Thanks to all of you who helped me sort this out.
I started the thread thinking there was only one way to get a stronger axle under the back of my Burb and that was to swap in a 2500 ff. Of course at that point you have to do the work and replace the front diff too and that's a PITA.
Now I know about this wonderful hybrid axle!
This is why I love EXPO. If you can dream it up someone smarter than you had done it and done it better and are happy to tell you about it.
Thanks folks. The search for a cheap AXN has started and probably won't end until my 10 bolt grenades and I pay whatever it takes for what I can find. LOL
I started the thread thinking there was only one way to get a stronger axle under the back of my Burb and that was to swap in a 2500 ff. Of course at that point you have to do the work and replace the front diff too and that's a PITA.
Now I know about this wonderful hybrid axle!
This is why I love EXPO. If you can dream it up someone smarter than you had done it and done it better and are happy to tell you about it.
Thanks folks. The search for a cheap AXN has started and probably won't end until my 10 bolt grenades and I pay whatever it takes for what I can find. LOL
Stryder106
Explorer
Are you rock crawling? The 14 bolt is a great idea, but the 10 bolt gets a very bad rap - and very undeservedly. I've seen MANY MANY very high horsepower high torqued race cars with essentially stock 10 bolts do just fine. Being conscious of weight, I swapped in G2 axles (60% stronger than stock) and matched bearings, G2 gears, ARB locker, ARB cover, and trussed the diff. If I had thought about it before I started all of that, I likely would have hunted down a 14 bolt just because - so if you are just starting out with it then it's a solid direction.
//
Becareful with the G80 though - mine had one in it and it was completely fine. I was at 160,000 miles and kept reading all of the catastrophic G80 failures over 100,000 miles. But mine was fine (I change fluids very regularly). I called Eaton to inquire about the life expectancy of the G80 - the guy asked me how many miles on my Av so I told him. His reply, "Wow - and it STILL works? That's surprising. You should replace it though."
//
The front diff can also be helped out - again G2 gears 60% stronger than stock, matched bearings, and what is going in next week: RCV axles - which are stronger than an SAS.
//
If I was rock crawling I'd have a very different opinion, but I'm exploring and overlanding, so if I'm into anything that's going to break either diff then something went very wrong with my mapping skills.
//
Becareful with the G80 though - mine had one in it and it was completely fine. I was at 160,000 miles and kept reading all of the catastrophic G80 failures over 100,000 miles. But mine was fine (I change fluids very regularly). I called Eaton to inquire about the life expectancy of the G80 - the guy asked me how many miles on my Av so I told him. His reply, "Wow - and it STILL works? That's surprising. You should replace it though."
//
The front diff can also be helped out - again G2 gears 60% stronger than stock, matched bearings, and what is going in next week: RCV axles - which are stronger than an SAS.
//
If I was rock crawling I'd have a very different opinion, but I'm exploring and overlanding, so if I'm into anything that's going to break either diff then something went very wrong with my mapping skills.
02TahoeMD
Explorer
I do not personally trust wheel spacers nor want my tires stuffed out beyond the wheel wells. It is actually a motor vehicle violation here where I live to have one's tread stick out too far. Do I love a real, heavy duty 8 lug wheel? Sure thing, but was not going to get either spacers / adapters / new wheels with different offset. There have been a few people out there who have done 8 lug wheel conversions on 1500 SUV rigs but for me, the "Hybrid" axle was a nice compromise.