2005 GMC Sierra 2500HD - Duramax Tuner 6 Speed Conversion

[@josephheasley615]

01-05 is a 5 speed 06 -19 is a six speed 20and newer is a ten speed Allison branded transmission 01-19 is a genuine Allison

[@bonecrrusherSS]

Hopefully the newer branded ones have been resolved - seen a few failures on them.

[@360plussynthetics]

Awesome job! I did the 6spd conversion on my 04.5 lly a couple years ago now (video on my channel also), and agree with everything you pointed out in the video. Much nicer to drive on the highway now. 👍🏻

[@bonecrrusherSS]

The one or two videos I saw mention the drop in engine noise on the freeway - but I really had no idea how different it would be.

[@ryllyduc1198]

Did you experience rough shifts even after the relearning process? Have you felt like this was a worthwhile upgrade in drivability and feel?

[@bonecrrusherSS]

It only shifted rough once - and that was when it went into 6th gear for the first time. It shifted fine after that. Drivability - had no issues. Feel - it made the truck quieter on the highway since it is dropping it 300 RPM.

[@ryllyduc1198]

@@bonecrrusherSS thanks for making the video and the response. I'm in the process of deciding to have them build the transmission and if I want to add the 6 speed valve body.

[@daviderickson6933]

I think the tire size only changes shift points slightly I don’t think it changes the mph that’s a different sensor

[@bonecrrusherSS]

Tire size absolutely changes the MPH - you have to adjust it in the PCM for it to read correctly if you go with a non oem size wheel and tire combo.

[@jordanpearcy2814]

Can you send a link of those other instructions or show what part you're talking about that you adjusted

[@bonecrrusherSS]

When you pop the valve body out - the gear selector arm is hanging there inside the transmission. If you don't get the aligned properly - you will have to drain the transmission again. Otherwise it won't move out of park.

[@ryanneedham8820]

Where on their website are the instructions?

[@bonecrrusherSS]

Might be on Google.

[@SSANCHEZZ_505]

Crazy thing is i just got my GMC and decided to see if I'd like to do this swap and your channel came up but im already subbed to you cuz i also have an SS haha apparently I'm just copying you at this point

[@bonecrrusherSS]

Lmao - now you need a C6 and a Silverado ZR2! Yeah checkout the Duramax playist. I did the HD hood swap, the Quadrasteer bed swap, 6 speed swap - and some basic engine bolt ons. After 13 years of ownership - I only had 2 issues with truck - a plugged transcooler that I replaced with a bigger aftermarket one. The other was a water pump that was seeping at 250,000 miles!

[@SSANCHEZZ_505]

@bonecrrusherSS one day I'll definitely get a corvette! But that's good to hear that you had it so long with minimal issues. I'll definitely be going through that Playlist to see what mods to do. My SS is already done besides a better hood some day🤙🏽

[@casanovazombies356]

Did u have any problems with your transmission after this?

[@bonecrrusherSS]

No none - it drove perfectly fine. I did have that shift lever issue as I mentioned in the video - so I did have to pull the valvebody back off. Adjust for that - and got lined properly the second time.

[@casanovazombies356]

@@bonecrrusherSS yea I seen that how was your shift points? Were they like factory? Just with 6 gear at 58-60mph?

[@lost0187]

Excellent video I offer a similar 6 speed conversion option for the 2001-2005 truck, where I can supply all the parts or the buyer can farm out the parts themselves and I supply a remapped TCM with vehicle specific maps for upgraded internals or modified engine applications. Not a one tune fits all also my software update uses all 6 forward gears in both Normal & Tow haul drive modes. you will retain you OD Lockout (4th locked) for 2003-2005 Vehicles. If you want to do a do it yourself application you can contact me and I can supply the TCM & Valve Body harness to your specific application 2006-2010 or 2011-2019 Allison 1000 transmissions. I support both 6.6 duramax and 8.1 votrec trucks and suvs.

[@bonecrrusherSS]

Cool to see other products out there - I had zero issues with the kit from DuramaxTuner.

[@kentkurt9065]

Efi live they ask tire size to program the ECM and that did correct the speedo

[@bonecrrusherSS]

Wonder if thats something you could fix in HP Tuners.

[@kentkurt9065]

@@bonecrrusherSS im thinking so

[@EverybodyWorksChris]

Would you do it again?

[@bonecrrusherSS]

I should have done it sooner. I only had the truck for another year or so with the 6 speed. It drops the RPM down a few hundred RPM - makes it quieter on the interstate. I never had any issues with the kit after I installed it. If you drive a ton - it will eventually pay for itself. I work from home - so I never put a lot of miles on my vehicles.

[@dougpage1309]

That’s a mod I’m like to do to my truck. Thanks for the video. I’m curious if I’ll hold the taller gear longer when under load with the new tcm? I’ll have to ask duramax tuner that.

[@bonecrrusherSS]

Yeah it does seem to hold a few of the gears longer. Fair warning that it took awhile for the tcm to learn all the new shift points - and 6th gear made a huge clunk the first time I shifted to 6th. I just went on an 4+ hour road trip for a future video - and I had zero issues with the new 6th gear setup.

[@2015_Rubicnn]

You need to get a tire size calibrator or if you get the truck tuned they can address the speedometer being off with the ECU tune. One thing I suggest, is actually measuring the tire and not using the advertised tire measurement. All tires for the most part, are undersized from what they advertise.

[@bonecrrusherSS]

Truck for sure could use a tune.

[@dcdave]

What did you have to do to make the detent pin slide in ? Did you have to remove the valve body again ?

[@bonecrrusherSS]

Drained the fluid, caught all of that. Lowered the valve body down - put the pin and the selector shaft together. Put the pan back on - poured the fluid that I captured back in - and haven't had a problem since.

[@dcdave]

@@bonecrrusherSS thanks for the insight I finally figured it out by having someone slide the gears shifter through gears and was mad that the instructions didn’t include a diagram (drawing) of the half moon groove at the bottom of the gear selector and have an arrow pointing to it being where the pin should be placed. Thank you again, I knew I wasn’t the only 1 having problems deciphering those instructions

[@gabrielmalcolmstudent3363]

The 06 LBZ came factory with a 6 speed.

[@bonecrrusherSS]

Yup - I didn't have a 6 speed.

[@2015_Rubicnn]

They are all a 6 speed, but GM opted to not utilize that feature when the Duramax was first released. For some reason they decided to in 2006.

[@joeymetz6495]

How much?

[@bonecrrusherSS]

$1400 or so?

[@justinstroupe5079]

Will this work with a stock trans?

[@bonecrrusherSS]

My Allison is stock - just has the deeper pan, filter, and filter brace.

[@shawnwinters4327]

@@bonecrrusherSS do u think the deeper transmission pan is better than the stock ? Is it a must when u make the conversion?

[@gabrielmalcolmstudent3363]

@@shawnwinters4327 More fluid is generally better, especially for tow pigs. I imagine he’s putting in those parts because they have to come out for the job anyways.

[@2015_Rubicnn]

@@shawnwinters4327 While more transmission is typically better, a bigger cooler is the way to roll. The cast pan does provide more rigidity for the transmission case though.

[@2015_Rubicnn]

I did this a couple years ago too.😎

[@bonecrrusherSS]

It's for sure more quiet on the interstate.

[@2015_Rubicnn]

@@bonecrrusherSS Yeah, I have 33s on mine with the stock 3.73 gearing and it's just relaxed cruising at 70 mph.