it works!...well,sorta...

[Ambulancechser]

Just a little update on my trans swap.i was planning to get this thing go-ing by spring,but spring went and sprung without me...last week i finally got the shift linkage settled enough to trust in park and drive and tried for a test run.

shifted into drive and...nothing.blast!after some fiddeling with the controller,i switched to manual shift mode,and got it moving.i have an issue with 1st gear,apparently.it shifts into first,but won't budge in manual or auto modes...have to pull the valve body and do some tests i guess.

luckily i was able to get it on the hi-way in o/d with the converter locked,and man what a difference.i might well have the only 80 mph capable m-1010 in canada.it would go faster with some coaxing,but my rear driveshaft obviously has an issue with the pinion angle,giving an annoying vibe that must be fixed.and the tires aren't to well balanced at that speed either.it's amazing how quiet the truck is when the 6.2 is not trying to spin itself to death.

More tuning to be sure,but i'm on the way to a much more versatile vehicle.

 

[CCATLETT1984]

cool, keep us updated

what controller are you using again?

 

[Ambulancechser]

update...

finally,after a great deal of trial and error (mostly error) i got it to work!here's what i went through...dropped pan 4 times,pulled valve body twice,pulled all wiring twice,continuity checked all wiring twice,replaced all solinoids once,swapped valve body with a good used unit once,finally pulled the works and swapped cases.

and guess what...the last did the trick.turns out that i likely had a case leak in one of the worm tracks that only opens under pressure. rare on a 4l80/thm-400 style trans.but it worked!at least until it overheated .i might have a mismatched pump or a clogged line.(i made the lines myself,so there you go).hoping it's the line.

while it was working the compushift controller shifted very well indeed...shifts were spot on and tunable to a degree.the shift logic is excellent and has a setting for diesel apps as well.rather expensive,but an excellent product.

 

[acetomatoco]

RE: update...

The non electric overdrive tranny would have been a lot easier.. fer sure.

 

[mangus580]

Re: RE: update...

The non electric overdrive tranny would have been a lot easier.. fer sure.

Nowhere near as durable though....

 

[AJMBLAZER]

RE: Re: RE: update...

A well built TH700R4 can stand up to anything even a turbo'd 6.2L is going to throw at it.

A 4L80E is a great transmission but for all these troubles I think I'd just go get a TH700R4 and all the parts from a donor truck and do that swap with factory parts. Actually...that's sorta the plan...

 

[Ambulancechser]

found problem...interesting.

turns out i used a slightly smaller size of line than recomended for the cooler lines i fabbed.the line would not match precisely to the reusable style of hydraulic fittings that i aquired to fab the line.
if the line is slightly to small,the fittings can tear small bits from the inner wall of the line,and clog the fitting.an air test(yes i should have done this before install...live and learn)revealed the clogged return line.no flow at all.i'll get the proper size line this weekend and fab new ones.

the interesting bit is this...everything i've read on the 4l80 says that the front (highest) cooler fitting on the case is the output to the cooler.in this case it appears reversed.
i hooked up a line to what i believed was the output and left the return open...what i got on a brief start was a significant mess as the fluid sprayed out the REAR fitting.perhaps there is a model change somewhere in the 4l80 family tree.

as to cost...the only cost to me for all the fuss was time and bloodpressure.the parts to source the problem were free of charge,thanks to the shop owner/rebuilder,who was just as curious as i was as to the problem.the cost to replace the case was met by myself going to a scrap yard and pulling another 4l80 trans from a one ton van.110 can$ for the core and an hour and a half of my time,payed all the bills.labour for all the trans pulling and install was mine anyway.

ultimate cost?...the jury is still out.a built 700r with all the goodies,is going to run over 2200 U.S. plus adapters for the trans to x case.not counting the price of a good late model core.quite a few shops won't touch an early case.to find a late model"K" case you'd be lucky to score one for under 400 U.S$ from a yard.in the end you still have a 700r.

the 4l80 may be electronic,but it's super strong,and can easily take a turbo 6.2 or 4b cummins stock.with a few simple and cheap add ons,you can flog it like crazy without complaint.mine cost 1700 can$ to rebuild...add in 2 cores for 220 bucks,and a controller for 800 U.S$(skip if going manual shift),plus bits here and there,and the cost is really close .you have to look around for a decent shop.iv'e found that small one or two man shops that advertise mostly by word of mouth are usually the best.

notice i'm not counting driveshafts (same for both) shifters and linkage (ditto) or any change to the x-case you use...thats optional.
the simplest? external o/d boxes...gear vendors or u.s gear.but also not cheap.
Manual? be prepared to shell out major coin for a proper o/d five speed plus adapters.
the best? a heavy 4 spd auto,that bolts direct to a 6.2...ie: 4l80