6L80 to 10L90 swap? Seeking insight on a 10 speed transmission upgrade

[Bigburb3500]

Are there any other shops doing the 10L90 swap? I have sent several inquiries into PSS and have not heard back from them.

 

[gmartin1215]

Are there any other shops doing the 10L90 swap? I have sent several inquiries into PSS and have not heard back from them.

I chatted with them today and asked about that and if they are still doing conversions. They said...

"Yes we are still doing them! We've had overwhelming numbers of messages and are working to increase the capacity to reply to them all but some may have been missed, especially if they tried messaging personal accounts or other methods other than here(Facebook Messenger) or by email.

 

[Bigburb3500]

I chatted with them today and asked about that and if they are still doing conversions. They said...

"Yes we are still doing them! We've had overwhelming numbers of messages and are working to increase the capacity to reply to them all but some may have been missed, especially if they tried messaging personal accounts or other methods other than here(Facebook Messenger) or by email.

Ok! Thank you! I’ve been emailing their email listed so I’ll just be patient.

Thank you!

 

[CMoore711]

@Bigburb3500 PSS was delayed in responding to me also. If it’s been over a week and no response I would re-forward the same email with a “hey just following up as I hadn’t heard back”. I did that and they finally got back with me…

I do think they’re getting a lot of inquiries. I also think that most are probably through Facebook, and for those of us that don’t Facebook may contribute to delay in response…?

 

[Bigburb3500]

@Bigburb3500 PSS was delayed in responding to me also. If it’s been over a week and no response I would re-forward the same email with a “hey just following up as I hadn’t heard back”. I did that and they finally got back with me…

I do think they’re getting a lot of inquiries. I also think that most are probably through Facebook, and for those of us that don’t Facebook may contribute to delay in response…?

Facebook… hmm… I don’t have one but my wife does… if I use her account then she will know what I’m up to! Lol

 

[gmartin1215]

More from PSS chat...

"We sell the electronic control kits on the website if you're wanting to install yourself. If you want one done at our Nederland, TX shop then email [email protected] for a quote."

 

[swathdiver]

Here you go:

These RPMs do not include converter slip, usually about 7-20 rpms when locked up. The chart shows for fresh tires at full tread depth.

 

[gmartin1215]

Here you go:

View attachment 461450

View attachment 461451



These RPMs do not include converter slip, usually about 7-20 rpms when locked up. The chart shows for fresh tires at full tread depth.

Thanks for running the numbers!

If I am reading these right, it almost seems like if I did the upgrade to the 10-speed and keep the 3:42 diffs, then I may be ok not upgrading to the 3:73 diffs. The low gears in the 10 look like they can get the rig rolling, and the upper gears will help on the highway.

 

[swathdiver]

Thanks for running the numbers!

If I am reading these right, it almost seems like if I did the upgrade to the 10-speed and keep the 3:42 diffs, then I may be ok not upgrading to the 3:73 diffs. The low gears in the 10 look like they can get the rig rolling, and the upper gears will help on the highway.

You're welcome. The 10 speeds gives you lots of options.

Why are you considering this? Do you plan to keep the engine's power level the same or about the same as it is now?

 

[gmartin1215]

You're welcome. The 10 speeds gives you lots of options.

Why are you considering this? Do you plan to keep the engine's power level the same or about the same as it is now?

With my 5.3, 6L80, and 3:42, and the weight of the truck with the bumpers, winch, and the 33" tires, it takes a bit of inertia to get her rolling. With all the extras on it, I was considering just upgrading my diffs to 3:73 (or maybe 4.10) to help with getting the inertia closer to where it was stock, but I know if I did that, I know I will loose more on the high end for highway speeds and probably eat more highway gas. I noticed that newer rigs with the 10-speed often have a differential ratio of 3:23 with a 5.3. So I started thinking that if I put a 10-speed on with my 3:42s then I may not have to worry about upgrading to 3:73 to improve the inertia.

Additionally, I am considering the 10-speed because I have heard that it offers a better transmission than the 6L80. My 6l80 is the original and has not been touched except for an ATF change, but it's starting to give signs of its age with 155k on it, and also towing. With the weight of the truck, the 33s, and towing, there will be increased wear, which will likely necessitate rebuilding or replacement soon, as well as the installation of a better torque converter. With this 10-speed conversion offering, I thought that when the time comes, why not do this upgrade? It appears that it will help address the inertia problem and offer more cruising gears than the 6L80.
I suppose I could do the tranny conversion and see how it feels after that. Then, if it does seem like I need more umpf on the low end, put the 3:73s in. However, I wanted to see the differences between the combinations to gain a better understanding. That's why I asked you to run your calculator, to see the differences. Hope that makes sense.

 

[swathdiver]

With my 5.3, 6L80, and 3:42, and the weight of the truck with the bumpers, winch, and the 33" tires, it takes a bit of inertia to get her rolling. With all the extras on it, I was considering just upgrading my diffs to 3:73 (or maybe 4.10) to help with getting the inertia closer to where it was stock, but I know if I did that, I know I will loose more on the high end for highway speeds and probably eat more highway gas. I noticed that newer rigs with the 10-speed often have a differential ratio of 3:23 with a 5.3. So I started thinking that if I put a 10-speed on with my 3:42s then I may not have to worry about upgrading to 3:73 to improve the inertia.

Additionally, I am considering the 10-speed because I have heard that it offers a better transmission than the 6L80. My 6l80 is the original and has not been touched except for an ATF change, but it's starting to give signs of its age with 155k on it, and also towing. With the weight of the truck, the 33s, and towing, there will be increased wear, which will likely necessitate rebuilding or replacement soon, as well as the installation of a better torque converter. With this 10-speed conversion offering, I thought that when the time comes, why not do this upgrade? It appears that it will help address the inertia problem and offer more cruising gears than the 6L80.
I suppose I could do the tranny conversion and see how it feels after that. Then, if it does seem like I need more umpf on the low end, put the 3:73s in. However, I wanted to see the differences between the combinations to gain a better understanding. That's why I asked you to run your calculator, to see the differences. Hope that makes sense.

A 6.2 motor would solve a lot of those issues!

4.10s on 33s is like 3.73s on stock tires. 4.10s behind the 6-speed gives you a little more 1st gear than the 10-speed with 3.42s.

If you plan on keeping her and in lieu of overhauling the 6l80, the 10-speed would seem a pretty good way to go.

Even with the same or higher gears, the 10-speed trucks beat the 4 and 6 speeds in races with the same horsepower. It's all about the gearing and keeping the engine in the power band.

 

[buckwild27]

Feel free to send the 6l80 my way if you do the swap I'll get it rebuilt for my truck.

 

[Bigburb3500]

I know this thread has been dormant for a bit but has anyone contacted Powertrainswap recently? I’ve been emailing them for several months trying to figure out if the 10L90 would work in my truck with no response.

Based on my research and what they have posted they have successfully don’t a Pontiac G8 V8 which I believe is nearly identical to the L96 I have in my truck. I just need to know if they are aware of any shaft changed or driveline changes. They haven’t done any 3/4 or 1-ton swaps yet…

 

[buckwild27]

If you're truck is a 3/4 or 1 ton I think you really want the Allison transmission 10L1000

 

[Bigburb3500]

If you're truck is a 3/4 or 1 ton I think you really want the Allison transmission 10L1000

It’s a Suburban 1-ton so it’s built off the GMT800/900 3/4 Sub chassis. I don’t know if the 10l100 will physically fit and it was not designed for mating to a Vortec LS… might be a more difficult swap?

 

[buckwild27]

It’s a Suburban 1-ton so it’s built off the GMT800/900 3/4 Sub chassis. I don’t know if the 10l100 will physically fit and it was not designed for mating to a Vortec LS… might be a more difficult swap?

Copy that. I would think it will be about the same as the half ton pickup but gm is good with wiring them all different..

 

[Bigburb3500]

Copy that. I would think it will be about the same as the half ton pickup but gm is good with wiring them all different..

I could be wrong but I believe the 10L1000 is a Duramax only trans. I don’t think it was ever connected to a gas engine… Now, if someone comes out and says it was I’m even more intrigued. But I’m equally as content with a 10L90 as those were rated up to 14-15k lb towing.

 

[buckwild27]

I could be wrong but I believe the 10L1000 is a Duramax only trans. I don’t think it was ever connected to a gas engine… Now, if someone comes out and says it was I’m even more intrigued. But I’m equally as content with a 10L90 as those were rated up to 14-15k lb towing.

Sorry I meant the 10L90 should be able to work in the there. Conversion wise like the 1500 truck unless gm wired the 2500 and 3500 different then the 1500

 

[buckwild27]

I could be wrong but I believe the 10L1000 is a Duramax only trans. I don’t think it was ever connected to a gas engine… Now, if someone comes out and says it was I’m even more intrigued. But I’m equally as content with a 10L90 as those were rated up to 14-15k lb towing.

To answer your question. No that is incorrect the Allison 1000 5 and 6 speed bolts up to the 8.1l gas engine in the early 2000's 2500 truck and the Allison 10L1000 bolts up to the L8T in the current gas configuration 2500's same bolt pattern across the board. The parasitic loss is like 40%in a 4x4 setup. Equivalent to the 4l80. But you are correct in not having the room to stuff that ****** in the tunnel with out modifications. That's a huge B*#$%

 

[Bigburb3500]

Sorry I meant the 10L90 should be able to work in the there. Conversion wise like the 1500 truck unless gm wired the 2500 and 3500 different then the 1500

That’s what I’m hoping. Powertrainswap has a plug and play system and it’s confirmed the 10l90 will bolt up to the 5.3 and 6.2 and fits in the 1500 Sub/Tahoes/etc but I don’t know what the difference if any on the 3/4 ton frame.
Would hate to make the $5-7k investment just to have it not fit correctly. Would rather upgrade to a 10l90 than rebuild a 6l90 as the rebuilds cost about the same from what I’m seeing.