Will a truck or CTS V 6l90 work in an SS? - Camaro5 Chevy Camaro Forum / Camaro ZL1, SS and V6 Forums

SLOW1SS · 06-08-2020, 06:22 PM

Looking to do a 6l90 swap as I’m on my 3rd 6l80. But I can’t seem to find any zl1 6l90s. I’m aware of having to change the crossmember and drive shaft. But my question what will it take to make a truck or CTS V trans work in these cars.

Warship2k15 · 06-11-2020, 06:43 AM

I’m interested in this also.Someone has to know this.Back to the top

SLOW1SS · 06-11-2020, 09:27 AM

I found out the answers to the cts V. But I can’t find any of those for sale either. I’m more interested in these truck 6l90s because they are everywhere and cheap. So I know you may have to change the shaft and yoke. But are gear ratios, valve body, and everything else the same?

'10CamaroDude · 06-11-2020, 03:59 PM

The 6L90 is a heavy-duty version of the 6L80 six-speed automatic, with a
strengthened input gearset that has two additional pinion gears (six in total) and a
strengthened output gearset that uses wider gears than the 6L80. Its flexibility
extends to the clutches, where the 6L90 has one more clutch plate in each clutch
than the 6L80 for heavy-duty applications. There is also a 6L90 version without the
additional clutch plate to more closely match application requirements, where
appropriate.

The 6L90 shares about 75 percent of the parts as the 6L80, although the case of the
6L90 is 35 mm longer than the 6L80 case. The 6L90’s case also accommodates
additional fasteners between the transmission and the transfer case for improved
driveline noise/vibration performance.

Gear Ratios
First: 4.030
Second: 2.360
Third: 1.530
Fourth: 1.150
Fifth: 0.850
Sixth: 0.670
Reverse:3.060

Vehicles:
Cadillac CTS-V Sedan, Coupe, Wagon
Chevrolet Camaro ZL1
Chevrolet Express CNG
Chevrolet Express LPG (Cutaway)
Chevrolet Express (Cargo, Passenger, Cutaway)
Chevrolet Silverado HD
GMC Savana CNG (Cargo, Cutaway)
GMC Sierra HD

https://www.repuestoscambiosautomati...f142_6l80e.pdf
https://www.trucktransdiag.com/downl...nical_tips.pdf
http://d2q1ebiag300ih.cloudfront.net...0-ZIP-IN_D.pdf

SLOW1SS · 06-12-2020, 04:52 PM

Quote:

Originally Posted by '10CamaroDude

The 6L90 is a heavy-duty version of the 6L80 six-speed automatic, with a
strengthened input gearset that has two additional pinion gears (six in total) and a
strengthened output gearset that uses wider gears than the 6L80. Its flexibility
extends to the clutches, where the 6L90 has one more clutch plate in each clutch
than the 6L80 for heavy-duty applications. There is also a 6L90 version without the
additional clutch plate to more closely match application requirements, where
appropriate.

The 6L90 shares about 75 percent of the parts as the 6L80, although the case of the
6L90 is 35 mm longer than the 6L80 case. The 6L90’s case also accommodates
additional fasteners between the transmission and the transfer case for improved
driveline noise/vibration performance.

Gear Ratios
First: 4.030
Second: 2.360
Third: 1.530
Fourth: 1.150
Fifth: 0.850
Sixth: 0.670
Reverse:3.060

Vehicles:
Cadillac CTS-V Sedan, Coupe, Wagon
Chevrolet Camaro ZL1
Chevrolet Express CNG
Chevrolet Express LPG (Cutaway)
Chevrolet Express (Cargo, Passenger, Cutaway)
Chevrolet Silverado HD
GMC Savana CNG (Cargo, Cutaway)
GMC Sierra HD

https://www.repuestoscambiosautomati...f142_6l80e.pdf
https://www.trucktransdiag.com/downl...nical_tips.pdf
http://d2q1ebiag300ih.cloudfront.net...0-ZIP-IN_D.pdf

What are the differences from car to car though what needs to be changed to make the truck version fit in the camaro?

Warship2k15 · 06-13-2020, 05:20 AM

I Think you could get a one piece driveshaft made with the correct slip yoke so you wouldn’t have to change the rear output shaft.Now I still don’t know if the mounting position is compatible. And if you can just swap transmission computer from the 6l80e to the 6l90e like you can with the zl1 and cts-v version.

SLOW1SS · 06-14-2020, 09:05 PM

Quote:

Originally Posted by Warship2k15

I Think you could get a one piece driveshaft made with the correct slip yoke so you wouldn’t have to change the rear output shaft.Now I still don’t know if the mounting position is compatible. And if you can just swap transmission computer from the 6l80e to the 6l90e like you can with the zl1 and cts-v version.

That makes sense since I need to have a driveshaft made anyways. Is the valve body the same on all 6l90s? If so im assuming I can just swap the computer from the 80 like the other versions.

cal30_sniper · 06-15-2020, 10:56 AM

Came here to post basically the same question, so I’ll contribute here instead and hang on for answers.

The output shaft spline counts are different between the 2WD and 4WD truck 6L90s. The 2WD truck trans uses a 36 spline output. The 4WD uses a 29 spline output.

Now, interestingly enough, the ZL1 6L90 also uses a 29 spline output. Novak lists the total length from bellhousing to output shaft of a 4WD 6L90 as 28.559”. I can’t find the same length measurement for a ZL1.

IF the 4WD truck trans and ZL1 trans have the same length from bellhousing to tip of output flange, it would imply that a ZL1 tailhousing and yoke could be used on a truck 4WD trans. Knowing the penny pinchers at GM, it’s just possible that’s the only difference between the two.

The 2WD 6L90, in addition to having a 36 spline slip yoke output shaft, is also longer than the 4WD version.

cal30_sniper · 06-15-2020, 11:10 AM

Further research shows we probably aren't so lucky. Advance Adapters has a trans guide that shows the 4WD truck, 2WD truck, and 2WD fixed yoke (ZL1/CST-V) trans output shafts. While the length between 4WD truck and LSA trans appears to be very similar, the 4WD truck trans is missing the o-ring and threaded extension to hold on the yoke of the passenger car 6L90.

I don't see why one couldn't run a 2WD truck trans with a custom driveshaft and crossmember though. In fact, your driveshaft would work out being a bit shorter than with a ZL1 trans, which is a good thing.

Link with photos and measurements:

https://static.summitracing.com/glob...dd-50-9600.pdf

quinthawk · 06-15-2020, 03:35 PM

I purchased a truck 2wd 6l90 last year. Have not installed it yet. I also purchased
a ZL1 tailhousing to compare to the truck 6l90. It looks like the mounting pad is the
in the exact same spot. I think a ZL1 crossmember could be used with a custom drive
shaft from a place like DSS.

quinthawk · 06-15-2020, 03:48 PM

Here are some dimensions:

https://paceperformance.com/p-28983-...imensions.html

cal30_sniper · 06-15-2020, 04:19 PM

Quint,

I agree. Visually, the 2WD truck trans and ZL1 trans appear as if they could use the same crossmember.

The numbers I pulled in my first post were from Pace Performance, but they don't match up with the Advance Adapters specs on the 4WD trans. I don't know which to believe, but have had very good experiences with Advance Adapters technical information in past builds.

I wonder why GM developed special fixed yoke tailhousings and output shafts for the 2WD passenger car applications.

Hcd3ss · 07-20-2021, 09:13 PM

Bump any new info

78novacaine · 11-22-2022, 08:23 AM

Has anybody found a definitive answer on what 6l90's will work in our cars and what won't? Zl1 transmissions are getting harder to find and truck versions are everywhere. It seems like the only hurdles would be getting a custom driveshaft and trans mount made. I'd hate to jump into a project like that and find out after a bunch of work and money that it won't work for some oddball reason though.

06-08-2020, 06:22 PM	#1
SLOW1SS Drives: Camaro SS Join Date: Dec 2015 Location: Washington, DC Posts: 60	Will a truck or CTS V 6l90 work in an SS? Looking to do a 6l90 swap as I’m on my 3rd 6l80. But I can’t seem to find any zl1 6l90s. I’m aware of having to change the crossmember and drive shaft. But my question what will it take to make a truck or CTS V trans work in these cars.

06-11-2020, 06:43 AM	#2
Warship2k15 Drives: 2010 Camaro 2SS Join Date: May 2016 Location: Kissimmee Posts: 158	I’m interested in this also.Someone has to know this.Back to the top

06-11-2020, 09:27 AM	#3
SLOW1SS Drives: Camaro SS Join Date: Dec 2015 Location: Washington, DC Posts: 60	I found out the answers to the cts V. But I can’t find any of those for sale either. I’m more interested in these truck 6l90s because they are everywhere and cheap. So I know you may have to change the shaft and yoke. But are gear ratios, valve body, and everything else the same?

06-11-2020, 03:59 PM	#4
'10CamaroDude Account Suspended Drives: 2010 Camaro LS Join Date: Nov 2019 Location: Pgh Posts: 739 View My Garage	The 6L90 is a heavy-duty version of the 6L80 six-speed automatic, with a strengthened input gearset that has two additional pinion gears (six in total) and a strengthened output gearset that uses wider gears than the 6L80. Its flexibility extends to the clutches, where the 6L90 has one more clutch plate in each clutch than the 6L80 for heavy-duty applications. There is also a 6L90 version without the additional clutch plate to more closely match application requirements, where appropriate. The 6L90 shares about 75 percent of the parts as the 6L80, although the case of the 6L90 is 35 mm longer than the 6L80 case. The 6L90’s case also accommodates additional fasteners between the transmission and the transfer case for improved driveline noise/vibration performance. Gear Ratios First: 4.030 Second: 2.360 Third: 1.530 Fourth: 1.150 Fifth: 0.850 Sixth: 0.670 Reverse:3.060 Vehicles: Cadillac CTS-V Sedan, Coupe, Wagon Chevrolet Camaro ZL1 Chevrolet Express CNG Chevrolet Express LPG (Cutaway) Chevrolet Express (Cargo, Passenger, Cutaway) Chevrolet Silverado HD GMC Savana CNG (Cargo, Cutaway) GMC Sierra HD https://www.repuestoscambiosautomati...f142_6l80e.pdf https://www.trucktransdiag.com/downl...nical_tips.pdf http://d2q1ebiag300ih.cloudfront.net...0-ZIP-IN_D.pdf

06-13-2020, 05:20 AM	#6
Warship2k15 Drives: 2010 Camaro 2SS Join Date: May 2016 Location: Kissimmee Posts: 158	I Think you could get a one piece driveshaft made with the correct slip yoke so you wouldn’t have to change the rear output shaft.Now I still don’t know if the mounting position is compatible. And if you can just swap transmission computer from the 6l80e to the 6l90e like you can with the zl1 and cts-v version.

06-15-2020, 10:56 AM	#8
cal30_sniper Drives: '11 Caprice PPV Join Date: Apr 2017 Location: NC Posts: 9	Came here to post basically the same question, so I’ll contribute here instead and hang on for answers. The output shaft spline counts are different between the 2WD and 4WD truck 6L90s. The 2WD truck trans uses a 36 spline output. The 4WD uses a 29 spline output. Now, interestingly enough, the ZL1 6L90 also uses a 29 spline output. Novak lists the total length from bellhousing to output shaft of a 4WD 6L90 as 28.559”. I can’t find the same length measurement for a ZL1. IF the 4WD truck trans and ZL1 trans have the same length from bellhousing to tip of output flange, it would imply that a ZL1 tailhousing and yoke could be used on a truck 4WD trans. Knowing the penny pinchers at GM, it’s just possible that’s the only difference between the two. The 2WD 6L90, in addition to having a 36 spline slip yoke output shaft, is also longer than the 4WD version.

06-15-2020, 11:10 AM	#9
cal30_sniper Drives: '11 Caprice PPV Join Date: Apr 2017 Location: NC Posts: 9	Further research shows we probably aren't so lucky. Advance Adapters has a trans guide that shows the 4WD truck, 2WD truck, and 2WD fixed yoke (ZL1/CST-V) trans output shafts. While the length between 4WD truck and LSA trans appears to be very similar, the 4WD truck trans is missing the o-ring and threaded extension to hold on the yoke of the passenger car 6L90. I don't see why one couldn't run a 2WD truck trans with a custom driveshaft and crossmember though. In fact, your driveshaft would work out being a bit shorter than with a ZL1 trans, which is a good thing. Link with photos and measurements: https://static.summitracing.com/glob...dd-50-9600.pdf

06-15-2020, 03:35 PM	#10
quinthawk Drives: 2010 camaro ss, 2012 ZL1, 2021 LT1 Join Date: Oct 2009 Location: Iowa Posts: 125	I purchased a truck 2wd 6l90 last year. Have not installed it yet. I also purchased a ZL1 tailhousing to compare to the truck 6l90. It looks like the mounting pad is the in the exact same spot. I think a ZL1 crossmember could be used with a custom drive shaft from a place like DSS.

06-15-2020, 03:48 PM	#11
quinthawk Drives: 2010 camaro ss, 2012 ZL1, 2021 LT1 Join Date: Oct 2009 Location: Iowa Posts: 125	Here are some dimensions: https://paceperformance.com/p-28983-...imensions.html

06-15-2020, 04:19 PM	#12
cal30_sniper Drives: '11 Caprice PPV Join Date: Apr 2017 Location: NC Posts: 9	Quint, I agree. Visually, the 2WD truck trans and ZL1 trans appear as if they could use the same crossmember. The numbers I pulled in my first post were from Pace Performance, but they don't match up with the Advance Adapters specs on the 4WD trans. I don't know which to believe, but have had very good experiences with Advance Adapters technical information in past builds. I wonder why GM developed special fixed yoke tailhousings and output shafts for the 2WD passenger car applications.

07-20-2021, 09:13 PM	#13
Hcd3ss Drives: 2011 camaro 2ss/RS Join Date: Nov 2013 Location: Waycross, Ga Posts: 80	Bump any new info

11-22-2022, 08:23 AM	#14
78novacaine Drives: 2014 Camaro SS Join Date: Feb 2022 Location: Houston, Tx Posts: 53	Has anybody found a definitive answer on what 6l90's will work in our cars and what won't? Zl1 transmissions are getting harder to find and truck versions are everywhere. It seems like the only hurdles would be getting a custom driveshaft and trans mount made. I'd hate to jump into a project like that and find out after a bunch of work and money that it won't work for some oddball reason though.