TCI 6x 6-Speed GM 4L80E Automatic Transmissions

[gmenor]

My transmissions shudders in OD under load. I was looking at prices online and saw this from Summit. Has/does anyone tried mating this to a 6.5 and if so what are the results?

[john8662]

I had a friend call me earlier this week about this transmission, for a project that's in the beginnings (already putting a 4L80E in).

First, it won't work in a factory 4L80E truck with factory programming. It will physically mount in, but the computer won't know how to use it. TCI did put it in an old school 4L80E case, it's likely got some internals from the 6L80E trans.

Second, the disappointing part, it's got the same OD gear ratio as the 4L80E (0.75), you just have more gear splitting going on. I was originally looking at it to determine whether I could get a double over drive out of it, not the case.

Third, It's $4k by itself, if you want to run it, it costs another 2k for the kit to run it.

Looks neat though, might work well for something with tall gears/tires to get rolling (lower first gear).

[gmenor]

John,
Thanks for the reply and information. I just wanted to know if anyone had installed the two and their results. As of right now I was planning on either dumping more money on the beast or buy a Duramax. Leaning more on the Duramax but keep the Burb once the transmission is fixed.