The gearbox refresh - 4L80e
After a bit of reading on the Tinternet it seems these LS motors have been known to punish some gearboxes.
The 2 speed power glide whilst very strong and simple - I thought it would get a bit old revving the poor motor on a run so decided to go for an overdrive box.
The TH400 is known for its strength but it is only available in 3 speed.
The 700R4 is a 4 speed but too many haters online saying they are fragile - whilst Im sure you could build one to last - it probably would not be in my budget.
So the 4L80e seemed to tick most boxes - strong, 4 speed, a bit more modern - the only slight negative for me was it would need an electronic controller and a speedo converter to use the stock gauges.
I managed to source a box “that was running well when pulled” - always a gamble but it was cheap enough to use as a core if it turned bad.
It arrived on a pallet with a converter and no yoke. All looked well on the outside so time to crack it open and fit a shift kit and a few other small mods to help it along - as well as a new harness and filter and gaskets.
Its always a bit scary opening up an auto if you haven’t done one before - the fear of having a ballbearing left over when “you’re done”.
Lots of Youtube videos later and a few parts and I was ready.
It all went surprisingly well - drilling holes in oil galleries isn’t something to get mostly right :-)
I added a deeper sump for some additional fluid and fitted some AN6 fittings to allow an external cooler and fan to keep things from getting too warm.
A sonar forged yoke added on a slip joint to make hooking the prop a bit easier - the tuck is now short so I can run a single prop and loose the centre bearing on the crossmember.
A couple of links to the parts I went with use in case they are useful to anyone else messing with 4L80s :-)
The TransGo Reprogramming shift kit for 4l80e and 4L85e -
https://transgo.com/product-details/4l80e-hd2/
The gearbox controller -
https://www.tciauto.com/ez-tcu-gm-4l...ontroller.html
The TCI deep sump -
https://spike-performance.com/produc...-deep-oil-pan/
The speedo converter box of tricks -
https://www.dakotadigital.com/index....rod/prd886.htm