Any changes needed on a 4L80 build?

[1977ShortWide]

I just picked up a LS6.0 with a new/rebuilt 4L80 that will be going in my 1977 Short Fleet 2WD project. The trans appears to be new and maybe a GM replacement. I plan on adding a cam to the motor and running a 2800 stall with 4.11 gears. Other than running a good oil cooler does a 4L80 need additional mods to survive being used hard occasionally? I will be having it dyno tuned for shift points.

thanks,
Jeff

 

[yevgenievich]

For a basic 6.0 with a cam it should be fine. I would do a partial hd2 kit and run it as is. Using a sonnax valve body with modification for overrun clutch as well as partial hd2 kit on my 97 with 454.
Planning to upgrade a lot of hard parts when a built big block gets installed.

Using a basic rebuild with hd2 kit on my 99 with a slightly modified 6.0

My old 91 had same basic reman 4l80e with hd2 kit, but motor was just a stock 350tbi

 

[1977ShortWide]

For a basic 6.0 with a cam it should be fine. I would do a partial hd2 kit and run it as is. Using a sonnax valve body with modification for overrun clutch as well as partial hd2 kit on my 97 with 454.
Planning to upgrade a lot of hard parts when a built big block gets installed.

Using a basic rebuild with hd2 kit on my 99 with a slightly modified 6.0

My old 91 had same basic reman 4l80e with hd2 kit, but motor was just a stock 350tbi

Thanks! Adding it to the list.

 

[yevgenievich]

The only reason was mentioning a partial on hd2 kit, is the pressure relief part that can be achieved with a better boost valve instead. I also prefer to do an internal dual feed modification instead of what hd2 kit offers, but have used it as is before.

 

[Matt69olds]

If your comfortable with transmission disassembly/reassembly, put a CK or Jakes performance shift kit in it. If your not comfortable with that, but can do valve body work, use the TransGo kit.

If your not comfy with any of the above, I wouldn’t think a trans shop would charge too much

 

[1977ShortWide]

If your comfortable with transmission disassembly/reassembly, put a CK or Jakes performance shift kit in it. If your not comfortable with that, but can do valve body work, use the TransGo kit.

If your not comfy with any of the above, I wouldn’t think a trans shop would charge too much

I’m comfortable with disassembly of anything . Its the reassembly that sometimes is problematic . So both CK and Jake’s have the dual feed mod as part of the kit? Net result is increased trans longevity? I really don’t want a super hard shift under part throttle.

 

[Matt69olds]

The Jakes and CK kits include the parts to internally dual feed, the TransGo kit does it thru the spacer plate. How hard they shift depends on how big you drill the holes in the plate.

If you just want a decent firm shift, go with the TransGo. It includes a boost valve that replaces the stock part that has a tendency to wear and stick. This cause line pressure to go thru the roof, sometimes high enough to break the reverse band or shatter the piston in the direct drum.

The TransGo shift kit is pretty easy to install. Besides basic hand tools, all you need is a pair of snap ring pliers to remove the pressure regulator valve. Use Vasoline to hold the check balls in position. Don’t use wheel bearing grease, it won’t dissolve in the fluid. Next time you have the pan off, you will find a blob of wheel bearing grease stuck in the filter. Get a bunch of brake clean, have a large clean work area, work slowly and clean everything.

 

[1977ShortWide]

Thanks Matt. Sounds like the TransGo is a good choice for me. I did a shift kit on my first car some 40 years ago…. Damn time flies. Just a FYI I searched the PN on the case and it’s a ATK rebuilt unit with new TC.

 

[Matt69olds]

They really aren’t too difficult to install. Get some bolt the same thread as the valve body bolts, only longer and cut the heads off. Use them as alignment pins to hold the gasket in position when you set the valve body in place.

I can tell you from experience that TransGo is very conservative on shift firmness. I like my transmissions to shift with a good solid “thud”, not necessarily a hard shift, but firm enough that you know it shifted. TransGo caters to the soccer mom shifts, if you follow the recommended hole sizes it’s going to be pretty soft shift. I guess they feel it’s easier to make a hole bigger than to try and make it smaller.

 

[yevgenievich]

I drilled the holes in the plate for selection transgo set as HD tow use. For my 97 burban, felt firmness was enough.