- Apr 2, 2012
- 4
Ok, so what I've gathered from reading on here and other sites is that there are 3 different rear ends that were put into the TV trucks.
The major breakdown between them all comes by model year due to differences in the ABS. The 2002-05s do not have any ABS sensors on the axle, but the 2006-09s do (02-05 uses the speed sensor in the trans/transfer case to control the ABS for a 3 channel setup, whereas the 06-09 has a 4 channel setup).
The standard 113" wheelbase trucks have an 8.0" 10-bolt rear end in them with 3.42 (GU6), 3.73 (GT4), and 4.10 (GT5) ratio's available. Was this rear end still used even if the truck got the 5.3 V8?
The EXT (129" wheelbase) trucks have an 8.6" 10-bolt rear end in them with the same ratios available. (I'm thinking these were also put in the 5.3 V8 standard wheelbase trucks, but not sure). This rear end shares many internal components with other GM 8.5" 10-bolt rears but the outer housing is different
The SS trucks have a semi floater 9.5" 14 bolt rear that is the same as found in 2500/HD fullsize trucks as well as other GM vehicles (granted the suspension mounting points, width, bolt pattern, and brakes are all specific to the TB and also the SSR's that got the 6.0). They were only made available in the TBSS's with the 4.10 ratio (GT5)
As far as transfer cases go, the SS's got the AWD NR9 transfer case. Were there any other models besides the SS that this tcase got put in? The non-SS trucks then either got the NP4 or NP8 tcase. Can anybody tell me what the difference is between the two?
Lastly, when it comes to the front differentials, is there any difference in size of those between standard wheelbase/EXT/5.3/SS? Or did every TV get the same size one, just the ratios are different to match the rears?
What I'm wanting to make sure is if my '05 TB LS 4.2 4x4 standard wheelbase has the 8.0" rear. By everything I've read it should, but I'm hoping there's some chance I'm wrong and it has the 8.6". I come from the S10 world where the 8.5" rear is the holy grail of stock S10 rear ends, and if my TB has the 8.6" (which is essentially the same as an 8.5") it would work out well for me.
What I am wanting to do is upgrade my rear in my TB to a 9.5" like the SS's have. Instead of buying an expensive SS rear (which is '06up and would mean I'd have ABS sensors built in that would be useless to me), I was thinking of trying to just find a rear out of a 2500 pickup. They can be had for much cheaper and then I could actually find a rear that has either a 3.42 or 3.73 ratio (to match what my TB already has, because I'm pretty positive it's on of those and not 4.10s). Then I'd also not have to purchase gears to change a TBSS rear to match my front gears (or regear the front diff to 4.10... I'd rather stick with one of the lower ratios anyway). If I swap rears in the truck I plan to narrow the new rear 1" per side from stock, since I'll be bagging eventually and that will be necessary to tuck, so having a fullsize pickup rear that's wider than a TV rear won't be an issue since either rear will get narrowed anyway. Narrowing means I'd need new axle shafts too, so redrilling from fullsize pickup bolt pattern to TV bolt pattern would be a non-issue, as I'll just have the new shafts made up with a TV bolt pattern. I would just need to verify that the brake mounting flange/pattern is the same so that my TV brakes would mount up, and also that the Ujoint size is the same so that will fit as well. I realize I'll probably need to either have my driveshaft shortened or get a driveshaft out of a TBSS when I do the swap. Then I'd simply cut the 4link/panhard/shock/spring mounts and bumpstop pads off my current rear and re-install them on the new rear and be good to go.
Now, that brings my to why I'm hoping my rear is an 8.6". I have a project S10 that I need a new rear for, and have always just planned to find an 8.5" S10 rear (plenty strong to handle the power I want to put through it). Well I also plan to narrow that rear, so that opened up more possibilities of rears I could use (I could branch out into 4x4 S10 rears and especially ZR2s). It also led me to think that if I have my current rear out of my TB sitting around, and it's essentially the same as an S10 8.5" (if it's the 8.6"), that I would just narrow that and use that in the project S10. Of course narrowing would mean an easy change on the bolt pattern, just like putting the 9.5" into the TB. Secondly, my daily driver S10 has an 8.5" that I swapped into it, but it is a 3.42 ratio and I'd like to switch it to 3.73, and it's also an open rear end and I'd like to add a locker/limited slip to it since it's 2wd and isn't good in winter with an open rear. Since all the internals in the 8.6" are the same as the 8.5" it would allow me swap the carriers and gearsets from my 'old' TB axle into my 8.5" rear that's in my S10 and gain my ratio change and locker/limited slip all in one. And then the 3.42 open rear would be in the project truck which won't be getting a motor for a while so it really wouldn't matter that it's that ratio or an open rear.
I guess if my TB really is an 8.0" rear it's not that big of a deal, as I could get an 8.6" 3.73 G80 rear from an EXT in the junkyard, swap the carriers/gearsets with my S10 8.5", and then put it in place of the 8.0" that's in the TB until I get around to doing the 9.5" swap (Provided my TB is a 3.42 ratio so it matches the front diff. I'd then sell the 8.0" rear). Although that would mean that the TB would have an open rear for that duration of time. But with it being 4wd and having much more weight on the rear tires than my S10 has I'm not sure an open rear would be a problem. I think I did read something about needing conversion bearings or something when putting the 8.5" rear internals into the 8.6" rear housing, so that may be an issue that would prevent the whole thing. And I guess I could also just get an S10 8.5" rear that's 3.73 with a limited slip to swap those internals into my daily and use the housing with the 3.42 open rear for my project truck and then not even have to mess with the TB, although going that route would leave me no rear end to sell at this point to make back some of the cost involved
Then as far as the transfer cases go, if I wanted to switch to the NR9 AWD case and make my TB AWD would there be anything involved in that swap other than switching the tcases?
Sorry for the novel, just trying to wrap my head around some things here. Thanks for any and all help
-Brent
The major breakdown between them all comes by model year due to differences in the ABS. The 2002-05s do not have any ABS sensors on the axle, but the 2006-09s do (02-05 uses the speed sensor in the trans/transfer case to control the ABS for a 3 channel setup, whereas the 06-09 has a 4 channel setup).
The standard 113" wheelbase trucks have an 8.0" 10-bolt rear end in them with 3.42 (GU6), 3.73 (GT4), and 4.10 (GT5) ratio's available. Was this rear end still used even if the truck got the 5.3 V8?
The EXT (129" wheelbase) trucks have an 8.6" 10-bolt rear end in them with the same ratios available. (I'm thinking these were also put in the 5.3 V8 standard wheelbase trucks, but not sure). This rear end shares many internal components with other GM 8.5" 10-bolt rears but the outer housing is different
The SS trucks have a semi floater 9.5" 14 bolt rear that is the same as found in 2500/HD fullsize trucks as well as other GM vehicles (granted the suspension mounting points, width, bolt pattern, and brakes are all specific to the TB and also the SSR's that got the 6.0). They were only made available in the TBSS's with the 4.10 ratio (GT5)
As far as transfer cases go, the SS's got the AWD NR9 transfer case. Were there any other models besides the SS that this tcase got put in? The non-SS trucks then either got the NP4 or NP8 tcase. Can anybody tell me what the difference is between the two?
Lastly, when it comes to the front differentials, is there any difference in size of those between standard wheelbase/EXT/5.3/SS? Or did every TV get the same size one, just the ratios are different to match the rears?
What I'm wanting to make sure is if my '05 TB LS 4.2 4x4 standard wheelbase has the 8.0" rear. By everything I've read it should, but I'm hoping there's some chance I'm wrong and it has the 8.6". I come from the S10 world where the 8.5" rear is the holy grail of stock S10 rear ends, and if my TB has the 8.6" (which is essentially the same as an 8.5") it would work out well for me.
What I am wanting to do is upgrade my rear in my TB to a 9.5" like the SS's have. Instead of buying an expensive SS rear (which is '06up and would mean I'd have ABS sensors built in that would be useless to me), I was thinking of trying to just find a rear out of a 2500 pickup. They can be had for much cheaper and then I could actually find a rear that has either a 3.42 or 3.73 ratio (to match what my TB already has, because I'm pretty positive it's on of those and not 4.10s). Then I'd also not have to purchase gears to change a TBSS rear to match my front gears (or regear the front diff to 4.10... I'd rather stick with one of the lower ratios anyway). If I swap rears in the truck I plan to narrow the new rear 1" per side from stock, since I'll be bagging eventually and that will be necessary to tuck, so having a fullsize pickup rear that's wider than a TV rear won't be an issue since either rear will get narrowed anyway. Narrowing means I'd need new axle shafts too, so redrilling from fullsize pickup bolt pattern to TV bolt pattern would be a non-issue, as I'll just have the new shafts made up with a TV bolt pattern. I would just need to verify that the brake mounting flange/pattern is the same so that my TV brakes would mount up, and also that the Ujoint size is the same so that will fit as well. I realize I'll probably need to either have my driveshaft shortened or get a driveshaft out of a TBSS when I do the swap. Then I'd simply cut the 4link/panhard/shock/spring mounts and bumpstop pads off my current rear and re-install them on the new rear and be good to go.
Now, that brings my to why I'm hoping my rear is an 8.6". I have a project S10 that I need a new rear for, and have always just planned to find an 8.5" S10 rear (plenty strong to handle the power I want to put through it). Well I also plan to narrow that rear, so that opened up more possibilities of rears I could use (I could branch out into 4x4 S10 rears and especially ZR2s). It also led me to think that if I have my current rear out of my TB sitting around, and it's essentially the same as an S10 8.5" (if it's the 8.6"), that I would just narrow that and use that in the project S10. Of course narrowing would mean an easy change on the bolt pattern, just like putting the 9.5" into the TB. Secondly, my daily driver S10 has an 8.5" that I swapped into it, but it is a 3.42 ratio and I'd like to switch it to 3.73, and it's also an open rear end and I'd like to add a locker/limited slip to it since it's 2wd and isn't good in winter with an open rear. Since all the internals in the 8.6" are the same as the 8.5" it would allow me swap the carriers and gearsets from my 'old' TB axle into my 8.5" rear that's in my S10 and gain my ratio change and locker/limited slip all in one. And then the 3.42 open rear would be in the project truck which won't be getting a motor for a while so it really wouldn't matter that it's that ratio or an open rear.
I guess if my TB really is an 8.0" rear it's not that big of a deal, as I could get an 8.6" 3.73 G80 rear from an EXT in the junkyard, swap the carriers/gearsets with my S10 8.5", and then put it in place of the 8.0" that's in the TB until I get around to doing the 9.5" swap (Provided my TB is a 3.42 ratio so it matches the front diff. I'd then sell the 8.0" rear). Although that would mean that the TB would have an open rear for that duration of time. But with it being 4wd and having much more weight on the rear tires than my S10 has I'm not sure an open rear would be a problem. I think I did read something about needing conversion bearings or something when putting the 8.5" rear internals into the 8.6" rear housing, so that may be an issue that would prevent the whole thing. And I guess I could also just get an S10 8.5" rear that's 3.73 with a limited slip to swap those internals into my daily and use the housing with the 3.42 open rear for my project truck and then not even have to mess with the TB, although going that route would leave me no rear end to sell at this point to make back some of the cost involved
Then as far as the transfer cases go, if I wanted to switch to the NR9 AWD case and make my TB AWD would there be anything involved in that swap other than switching the tcases?
Sorry for the novel, just trying to wrap my head around some things here. Thanks for any and all help
-Brent
