09-14-2020, 12:38 AM | #1 |
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6L90 refresh/rebuild?
Installing a 6L90 soon. Trans has just over 50k on it and came out of a running ZL1 Camaro. Wish I could just run it as is but have to do a tear down to change the output shaft for the t-case adapter. So the question is if clutches etc look good should I leave it be. Considering a couple of "upgrades" such as a 4/5/6 boost valve and apply piston. Will be my first 6 speed tear down, have done a th350, 4L60e and a 4L80e. Can not be that different, right?
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Richard 1972 K10 Custom Deluxe SWB Fleetside My build https://67-72chevytrucks.com/vboard/...d.php?t=800746 |
09-14-2020, 07:30 AM | #2 |
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Re: 6L90 refresh/rebuild?
You have some really big snap ring pliers?
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09-14-2020, 06:26 PM | #3 |
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Re: 6L90 refresh/rebuild?
Suggest you do a lot of research on this one before you commit...
Below you will find the ratio differences between a 6L80 and 4L80 Along with some other thoughts.... 6L80/90 boxes are a totally different animal build wise from a 4L80 style... 6L80/90 Note...Notice no 1:1 in this trans 4.03 2.36 -- 58.56% (high) RPM Retention 41.44% RPM DROP 1.53 -- 64.83% (high) RPM Retention 35.17% RPM DROP 1.15 -- 75.16% (high) RPM Retention 24.84% RPM DROP 0.852 -- 74.09% (high) RPM Retention 25.91% RPM DROP 0.67/.70 4l80/85 2.48 1.48 -- 59.68% (high) RPM Retention 40.32% RPM DROP 1.00 -- 67.57% (high) RPM Retention 32.43% RPM DROP 0.75 Hope that you know that 6L's will not work with LS1 based engine. If your going to put LS2 in front of it check with Mast Motorsports or others and make sure their ECM will work with it. Mast Motorsports are the only one I know of that claims to have LS 2 ECM that will work with it. Only GM's LS3/7 or 9 ECM work with it.
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09-14-2020, 07:57 PM | #4 |
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Re: 6L90 refresh/rebuild?
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Richard 1972 K10 Custom Deluxe SWB Fleetside My build https://67-72chevytrucks.com/vboard/...d.php?t=800746 |
09-14-2020, 08:30 PM | #5 | |
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Re: 6L90 refresh/rebuild?
Quote:
So..... I have heard these transmissions are pretty reliable. Do not really want to go full aftermarket on the innards. Should I do a full rebuild?
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09-14-2020, 10:20 PM | #6 |
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Re: 6L90 refresh/rebuild?
The huge center support snap ring is the biggest hurdle......Though the snap ring CAN be walked out & back in with a modified flat blade screwdriver, It's best to use the correct pliers.....Those will probably work.
Oversize Clutch Boost Valves require Tooling & a Fixture to install. I wouldn't be surprised if you found some distressed frictions & wouldn't be a bad idea to refresh the unit. |
09-15-2020, 01:58 AM | #7 | |
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Re: 6L90 refresh/rebuild?
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09-15-2020, 09:17 AM | #8 | |
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Re: 6L90 refresh/rebuild?
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09-15-2020, 09:51 PM | #9 | |
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Re: 6L90 refresh/rebuild?
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09-16-2020, 02:29 AM | #10 | |
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Re: 6L90 refresh/rebuild?
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I generally hang on to to everything I have until it is up and running. Have not forgotten about you.
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09-16-2020, 02:29 AM | #11 |
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Re: 6L90 refresh/rebuild?
Thanks for your recommendations!
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Richard 1972 K10 Custom Deluxe SWB Fleetside My build https://67-72chevytrucks.com/vboard/...d.php?t=800746 |
09-17-2020, 02:33 PM | #12 | |
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Re: 6L90 refresh/rebuild?
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Tyler '57 3100 http://67-72chevytrucks.com/vboard/s...d.php?t=813888 '72 K20 Cheyenne http://67-72chevytrucks.com/vboard/s...d.php?t=662879 ‘69 K10 SWB http://67-72chevytrucks.com/vboard/s...d.php?t=805206 '98 Silverado LT K2500HD ECLB Vortec 454/4l80E: 6" lift 315/75/16's ‘87 IROC-Z all original 50K mile survivor TPI 305 IROC Blue ‘10 Camaro 2SS/RS Aqua Blue Metallic #93 -version 2.0 |
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