On Tue, 01 Jun 2010 13:38:00 -0500
"Lloyd E. Sponenburgh" lloydspinsidemindspring.com wrote:

Leon Fisk fired this volley in news:hu3jgp$krg
:

snip
Oh they're okay if you treat them real nice. No tranny slams, forced
shifts, "passing gear" ... but how many people drive like that?


I never quite understood why they put the 700R4 in towing vehicles. Mine
on my diesel Sub never made it past 60K miles per rebuild.

"BABY" Allison was right. It never grew up. It kept evolving, with
thinner clutch packs with more plates, thicker packs with fewer,
different modulators, etc... but it would still eat the clutches or a
sprag in 50-60K -- every time.

I twisted the guts in the torque converter at ~40,000 miles. Pulled it
out myself and after some preliminary checks took it to a tranny shop.
It looked new inside yet, still had writing on the clutch surfaces.
That meant the torque converter... As long as it was apart I had a mild
shift-kit and special front seal clamp put on. New torque converter, put
it back underneath, been treating it really nice for the past 25 years.
I'm at around 135,000 now. Seems to be okay yet, other than a strange
ticking noise, sometimes. Only while going forward, three ticks per
revolution of the drive shaft. That started around 4 years ago, not
even sure if it is still doing it. Figured it would get worse if it was
serious

They (700R4) were suppose to be a bit lighter (weight wise) than a 350
turbo, which was a good solid tranny. Mmm... another whole gearset and
a few pounds lighter, doesn't sound good for durability. And of course
as we both know, it wasn't. The transmission shops really liked that
tranny. They called it the 60-1000, 60,000 miles, $1000 to repair. Of
course that was 25 years ago...

My brother inlaw has an old (mid 90's) Chevy 1 ton 4x4 with a 454 and
four-speed automatic (the 4L80E). That tranny has taken a lot of
use/abuse and held up quite well.

--
Leon Fisk
Grand Rapids MI/Zone 5b
Remove no.spam for email