07-14 4WD to 2WD conversion GMT900
08-09-2021, 02:55 PM
#1
07-14 4WD to 2WD conversion GMT900
Ok, like ***holes we all have one. This is not my first internet day so I know nothing can be done to the warriors and their opinions. 4WD, 2WD, mask, no mask who cares? It was supposed to be a free country, and this is my write up on the 4WD to 2WD conversion I did to my truck.
Background: Truck is 2009 GMC Sierra Denali 6.2 AWD. So not technically 4WD to start but same thing, only I could not take the truck out of 4WD, like...ever. So I have been toiling with the idea for sometime, but never figured go through the hassle with no real reason to do so. After all the only gain would be fuel mileage and a decreased resale value of the truck. I had plans to put an LSA on this truck but life happens and that has yet to happen. Now enter in at 253k on the clock the 6L80 eats itself. Welp, we have the reason and perfect time to do this conversion so here we go!
On the surface this is as easy as it comes, sure you can take the front drive shaft out and net essentially the same results but how clean is that? We like to remove tumors, not just cut off blood flow to them. And with my set up, I'm sure that would have been fine, but who knows if the borg warner AWD T-case can handle the power I'm wanting to throw at it? Then, keep it simple stupid right? Less parts available to break = less parts possible to break IMO. It should also be said that in the 253k miles on this truck....it has never once needed AWD traction, like...never. It is a street truck, daily driver that I tow things with occasionally. It has the locker rear end in it too. That's worth a mention because if the truck was a one wheeler peeler I likely would have kept the AWD. Hoping to get 1 MPG out of this weight reduction and .2 tenths off quarter mile time. Losing 242 LBS with taking out the trash, truck did 14.1 with is so I'm just going to go ahead and say I'm in the 13's now.
Now the trans eating itself is 99% likely my fault since my dumb*** was at 90k between services. Stupid stupid stupid. Oh well, we pay for the dumb mistakes we make, and this was a doosey. Please y'all service that trans at 50k, flush at 100k. So, like the rabbit hole of modding cars....the truck is no different! Off to CDT transmission in Houston for a stage 2 build! If I ever do put on some FI she shall be ready. So far its LT headers full exhaust and CAI but that's all. At any rate removing the trans is easy even on an inclined driveway as the racecar is holding down jack stands in the garage. Can you say holy shavings! Trans pan was straight glitter! It should also be mentioned that the first signs of the trans slipping it felt like the plugs were misfiring. Changed plug and problem still existed. About 20 more miles and it was VERY apparent the trans was slipping, not just torque converter issues. Fluid was clear and dirty, so I rushed and flushed the trans in hopes of saving it in time, after all we are talking 30 miles tops since it was first noted slipping. Yeah, pipe dream. Wasted $120 on fluid and filter only to tell myself I'm an idiot. This was a full flush too not just 6 qt service, oh well. Best lessons learned are the hard ones. Maybe that's why I'm more of a manual and clutch type guy. #manpedal
So stripping the truck down is easy and straight forward, hell for me there aren't even any wires attached as the AWD T=case doesn't care about your feelings. Short of the wheel hubs and transmission plug there are no electronics to deal with. So for me this indicates the truck won't care tuning wise the front diff is gone. And I found a front CV boot cut sooo...yay a plus to doing this. All the small things. Will report back on fuel mileage as soon as I drive it enough to determine if it changed. Did I mention I will be able to do burn outs now!? Anyway, taking it all apart and changing the front hubs is as easy as it gets.
Now my truck had the HD trans cooling auxiliary cooler up front but it's tiny, and I was never happy with Texas heat and boat towing how hot it would get. That and CDT recommended putting on a larger stacked plate cooler. So the tru cool is fantastic, just need to figure how you want to bolt it on (very easy mods) and then bend the lines only slightly and boom. Will fit right in the stock cooler location and get you 45K GVW cooling! Oh, I had to get the GM cooler line adapters too. Now, problem is you need to hot flush the trans lines and radiator tank cooler for a truly good flush of the transmission cooling system. Well F**k. How am I supposed to do that now? With trans being new I can't risk putting it back in and sending old metal shavings through a new trans. Flush was going to cost $150-250 any way so...for $345 I can get all new cooler lines and a radiator. So....5k trans damage or $345 more sting? Bend over and spread-em! Now is a good time to change your rear main seal btw! You know, while your truck is on jack stands in the drive way for 3 weeks, I'm sure the HOA won't mind.
So knowing the rear driveshaft would need to be changed as well I started drive shaft shopping. I knew this was going to get pricey quick so I nailed down the shaft and ordered it first before I truly committed to this ordeal. You can get a stock shaft for in and around $500 but its wildly long, has critical speed issues, and breaks at the first signs of track prep. Luckily I find performance driveline shop and their 2 piece shaft conversion kit. Which is meant for lowered trucks but who cares! It's a nice piece, and for under 1k for their HD shaft its worth the piece of mind. No fancy tools, just a drill gun and some bolts. Nothing to really fear with doing this mod. I mean, if the lowered guys can handle it, am I right?
Cool! ready to go back together, bolt it all up reinstall all necessary items, bolt in cross member and quickly realize the trans mount is different. No big deal, quick ride to O'reilys and $15 gets you the mount. Crawl back under truck and wonder why trans mount isn't tall enough, doesn't reach, needs like 3" more height to get trans to level ride height. WTF?! Go take a dump to calm down and do parts research, I don't know about you, but my best parts researching is done on the can. Quickly figured out I need a 2WD cross member as it has a hump in it for the trans mount. Pinch and wipe then proceed to call all local parts to find one, nada. Discontinued at dealer, awesome. No time to find junk yard parts...to eBay we go! Order it from vintage parts in Wisconsin. Vintage!? It's a 2009? Damn it man, you're going to hurt my trucks feelings. Oh well, I'm wayyyyyyy to frugal to be new truck shopping. Hell with the decreased value of the truck and all the money to repair this M-fer I'm better than 50% over its market value at this point. Frugal and stupid, see we do exist.
So the driveshaft is easy, measure up and mark location of the cross member from the kit, drill frame holes, bolt it up and put in drive shaft. Now my driveshaft can go over 100 MPH and handle the 600 HP future plans. Moving on, button her all up, use Amsoil ATF (yes I belong to that cult) And realize just how much is now new on this damn truck. All new fluids, hell even the brake fluid was changed while I waited with the truck in my driveway tranny less. Off to the tuner! for engine and trans re-tune yay I get to go on the dyno now to see what it actually makes for power! hahaha Sike! tuner only street tunes trucks. Sad face SOAB. Oh well, having the second vehicle back and not riding with the wife to work anymore....PRICELESS!
Wanted to write this up because when I did the search some guys had kicked the idea around, but were always met with opinions and then never reported back if they did it or not. I mean, I can't be the only one who went through with it am I?! Unicorn!
I can post pictures if ya like? Not sure what would want to be seen?
Trans rebuild stg 2 (with my damaged parts) converted to 2WD output $4,565 includes $180 freight to H-town. Picked up for return trip $0 Worth every penny picking it up to see CDT, nice place. Clean and organized like no other shop I had seen, this alone would get me to recommend them to anyone.
Parts Needed:
Cross member 2WD $60 (with shipping) PN:: GM 10398965
Trans mount $15
2 piece HD shaft $940 ($840 for reg shaft)
2 WD output shaft $150
2wd tail housing $85
Ultra power front wheel hubs $66.5 EA $133 total (rock auto) OEM are dumb expensive in my book.
Transmission retune $600 (required for warranty)
Additional sh*t I put on for ease of mind:
Radiator $239
Trans cooler Tru cooler 47391 $150
Double cooler line $94
single HD cooler line $13
Cooler line GM adapters $20
I have all my stock parts for sale too, hopefully that sells and I can re-coop some costs! Please someone buy them!
Background: Truck is 2009 GMC Sierra Denali 6.2 AWD. So not technically 4WD to start but same thing, only I could not take the truck out of 4WD, like...ever. So I have been toiling with the idea for sometime, but never figured go through the hassle with no real reason to do so. After all the only gain would be fuel mileage and a decreased resale value of the truck. I had plans to put an LSA on this truck but life happens and that has yet to happen. Now enter in at 253k on the clock the 6L80 eats itself. Welp, we have the reason and perfect time to do this conversion so here we go!
On the surface this is as easy as it comes, sure you can take the front drive shaft out and net essentially the same results but how clean is that? We like to remove tumors, not just cut off blood flow to them. And with my set up, I'm sure that would have been fine, but who knows if the borg warner AWD T-case can handle the power I'm wanting to throw at it? Then, keep it simple stupid right? Less parts available to break = less parts possible to break IMO. It should also be said that in the 253k miles on this truck....it has never once needed AWD traction, like...never. It is a street truck, daily driver that I tow things with occasionally. It has the locker rear end in it too. That's worth a mention because if the truck was a one wheeler peeler I likely would have kept the AWD. Hoping to get 1 MPG out of this weight reduction and .2 tenths off quarter mile time. Losing 242 LBS with taking out the trash, truck did 14.1 with is so I'm just going to go ahead and say I'm in the 13's now.
Now the trans eating itself is 99% likely my fault since my dumb*** was at 90k between services. Stupid stupid stupid. Oh well, we pay for the dumb mistakes we make, and this was a doosey. Please y'all service that trans at 50k, flush at 100k. So, like the rabbit hole of modding cars....the truck is no different! Off to CDT transmission in Houston for a stage 2 build! If I ever do put on some FI she shall be ready. So far its LT headers full exhaust and CAI but that's all. At any rate removing the trans is easy even on an inclined driveway as the racecar is holding down jack stands in the garage. Can you say holy shavings! Trans pan was straight glitter! It should also be mentioned that the first signs of the trans slipping it felt like the plugs were misfiring. Changed plug and problem still existed. About 20 more miles and it was VERY apparent the trans was slipping, not just torque converter issues. Fluid was clear and dirty, so I rushed and flushed the trans in hopes of saving it in time, after all we are talking 30 miles tops since it was first noted slipping. Yeah, pipe dream. Wasted $120 on fluid and filter only to tell myself I'm an idiot. This was a full flush too not just 6 qt service, oh well. Best lessons learned are the hard ones. Maybe that's why I'm more of a manual and clutch type guy. #manpedal
So stripping the truck down is easy and straight forward, hell for me there aren't even any wires attached as the AWD T=case doesn't care about your feelings. Short of the wheel hubs and transmission plug there are no electronics to deal with. So for me this indicates the truck won't care tuning wise the front diff is gone. And I found a front CV boot cut sooo...yay a plus to doing this. All the small things. Will report back on fuel mileage as soon as I drive it enough to determine if it changed. Did I mention I will be able to do burn outs now!? Anyway, taking it all apart and changing the front hubs is as easy as it gets.
Now my truck had the HD trans cooling auxiliary cooler up front but it's tiny, and I was never happy with Texas heat and boat towing how hot it would get. That and CDT recommended putting on a larger stacked plate cooler. So the tru cool is fantastic, just need to figure how you want to bolt it on (very easy mods) and then bend the lines only slightly and boom. Will fit right in the stock cooler location and get you 45K GVW cooling! Oh, I had to get the GM cooler line adapters too. Now, problem is you need to hot flush the trans lines and radiator tank cooler for a truly good flush of the transmission cooling system. Well F**k. How am I supposed to do that now? With trans being new I can't risk putting it back in and sending old metal shavings through a new trans. Flush was going to cost $150-250 any way so...for $345 I can get all new cooler lines and a radiator. So....5k trans damage or $345 more sting? Bend over and spread-em! Now is a good time to change your rear main seal btw! You know, while your truck is on jack stands in the drive way for 3 weeks, I'm sure the HOA won't mind.
So knowing the rear driveshaft would need to be changed as well I started drive shaft shopping. I knew this was going to get pricey quick so I nailed down the shaft and ordered it first before I truly committed to this ordeal. You can get a stock shaft for in and around $500 but its wildly long, has critical speed issues, and breaks at the first signs of track prep. Luckily I find performance driveline shop and their 2 piece shaft conversion kit. Which is meant for lowered trucks but who cares! It's a nice piece, and for under 1k for their HD shaft its worth the piece of mind. No fancy tools, just a drill gun and some bolts. Nothing to really fear with doing this mod. I mean, if the lowered guys can handle it, am I right?
Cool! ready to go back together, bolt it all up reinstall all necessary items, bolt in cross member and quickly realize the trans mount is different. No big deal, quick ride to O'reilys and $15 gets you the mount. Crawl back under truck and wonder why trans mount isn't tall enough, doesn't reach, needs like 3" more height to get trans to level ride height. WTF?! Go take a dump to calm down and do parts research, I don't know about you, but my best parts researching is done on the can. Quickly figured out I need a 2WD cross member as it has a hump in it for the trans mount. Pinch and wipe then proceed to call all local parts to find one, nada. Discontinued at dealer, awesome. No time to find junk yard parts...to eBay we go! Order it from vintage parts in Wisconsin. Vintage!? It's a 2009? Damn it man, you're going to hurt my trucks feelings. Oh well, I'm wayyyyyyy to frugal to be new truck shopping. Hell with the decreased value of the truck and all the money to repair this M-fer I'm better than 50% over its market value at this point. Frugal and stupid, see we do exist.
So the driveshaft is easy, measure up and mark location of the cross member from the kit, drill frame holes, bolt it up and put in drive shaft. Now my driveshaft can go over 100 MPH and handle the 600 HP future plans. Moving on, button her all up, use Amsoil ATF (yes I belong to that cult) And realize just how much is now new on this damn truck. All new fluids, hell even the brake fluid was changed while I waited with the truck in my driveway tranny less. Off to the tuner! for engine and trans re-tune yay I get to go on the dyno now to see what it actually makes for power! hahaha Sike! tuner only street tunes trucks. Sad face SOAB. Oh well, having the second vehicle back and not riding with the wife to work anymore....PRICELESS!
Wanted to write this up because when I did the search some guys had kicked the idea around, but were always met with opinions and then never reported back if they did it or not. I mean, I can't be the only one who went through with it am I?! Unicorn!
I can post pictures if ya like? Not sure what would want to be seen?
Trans rebuild stg 2 (with my damaged parts) converted to 2WD output $4,565 includes $180 freight to H-town. Picked up for return trip $0 Worth every penny picking it up to see CDT, nice place. Clean and organized like no other shop I had seen, this alone would get me to recommend them to anyone.
Parts Needed:
Cross member 2WD $60 (with shipping) PN:: GM 10398965
Trans mount $15
2 piece HD shaft $940 ($840 for reg shaft)
2 WD output shaft $150
2wd tail housing $85
Ultra power front wheel hubs $66.5 EA $133 total (rock auto) OEM are dumb expensive in my book.
Transmission retune $600 (required for warranty)
Additional sh*t I put on for ease of mind:
Radiator $239
Trans cooler Tru cooler 47391 $150
Double cooler line $94
single HD cooler line $13
Cooler line GM adapters $20
I have all my stock parts for sale too, hopefully that sells and I can re-coop some costs! Please someone buy them!
The following users liked this post:
swathdiver (09-14-2021)
09-16-2021, 02:00 PM
#4
Regarding trans servicing: Know too many people first-hand that developed transmission issues right after a flush. Flushing can force small debris into orifices it shoudn't go. For all the family vehicles, I always instruct the shop during service intervals to drain and refill only, and do NOT flush. I'm sorry you had to go through all that.
09-16-2021, 11:47 PM
#5
TECH Apprentice
Nearly all dealerships use the fluid exchange method. The only thing they flush, if they follow the shop manual, are the oil cooler and oil cooler lines. We did many hundreds of fluid exchanges when I managed a Jiffy Lube with no failures. It's never good to "flush" dirty fluid forcefully through the system, that's asking for trouble and makes transmission shops lots of money.
The following users liked this post:
68Formula (09-17-2021)
09-28-2021, 09:53 AM
#6
Regarding trans servicing: Know too many people first-hand that developed transmission issues right after a flush. Flushing can force small debris into orifices it shoudn't go. For all the family vehicles, I always instruct the shop during service intervals to drain and refill only, and do NOT flush. I'm sorry you had to go through all that.
Nearly all dealerships use the fluid exchange method. The only thing they flush, if they follow the shop manual, are the oil cooler and oil cooler lines. We did many hundreds of fluid exchanges when I managed a Jiffy Lube with no failures. It's never good to "flush" dirty fluid forcefully through the system, that's asking for trouble and makes transmission shops lots of money.
But, a flush isn't pushing any dirty fluid through any system. When you do the pan filter only the first thing the trans will pump is new fluid, and the new fluid will just circulate and mix with old fluid already in the trans.
Doing a flush is no different. You change fluid in pan and filter and you allow that to pump into the trans (via the engine running) and remove line from cooler return. Let it pump out 5-6 qts and just refill. So instead of the 6 qts only, you're replacing a full 12 (or whatever amount you'd like). This is just in an effort to replace as much old fluid as possible. But you would not be forcing any used/dirty fluid any where. Just trying to replace as much fluid as possible.
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