Yes, the transmission was originally made for 30W oil regardless of the temperature but then they
started to fail way to often in cold climates, so they changed the Lube Order to specify the use of
10W oil below a certain temp instead. This improved their reliability by a major factor. Later on
the use of ATF was specified but only after a complete rebuild. The disks in the clutch pack had to
be replaced with ones that were compatible with ATF. Just changing fluid would cause a failure in
short order due to the old disk material not being compatible with ATF. One other thing that can
kill an auto transmission is heat. Under a heavy load the ATF can get hot enough to cause it to
break down and not lubricate things properly. I used a Dodge Caravan to tow a '67 CJ5 (I had planned
on converting it to an M38A1 till I fell in love with big trucks) from South Dakota to Alaska.
Several people kept telling me my transmission would be scrap before I got half way due to the
mountain passes that I would be traveling through. At the time I had already driven the ALCAN twice
so I knew the road. First thing I did was install the largest tranny cooler I could find and then
added a tranny temp gauge to help keep on eye on the fluid temperature. Whenever the gauge got in to
the yellow zone I pulled over for 5 minutes to let it cool down. That was two years ago and after
putting another 22,000 miles on the van the transmission still works fine. Plus as David pointed out
be sure to use low range when in reverse. I have come to find out that this is a common weak link in
many auto transmission, not just the one in the M135/M211 series. I had a Dodge 4X4 with a 727 auto
behind a mild 440 that was rebuild to drag racing specs. While trying to back it through a snow bank
under heavy power in reverse I heard a loud snap and the truck quit moving. I had not thought of
putting the transfer case in low and when the tranny shop asked about it the guy looked like he
wanted to smack me. That's when I found out what not to do. :-)
Bryan Rupp
Anchorage, AK
1952 GMC XM211 2 and 1/2 ton Cargo
1953 GMC XM220 2 and 1/2 ton Shop Van
XM105E3 Trailer (built by Checker Cab Co.)
Note: all for sale for $1,000
DDoyle9570@aol.com wrote:
>
>
> The transmission was built for non-detergent crankcase oil, not ATF fluid.
> The weight of this oil varies with the climate, as specified in the MANUAL.
> The data plate on dash is a little misleading here. What I have read/heard
> from other (non-GM, non-military) sources indicates that ATF will work OK, so
> long as the transmission is COMPLETELY drained of motor oil first. DO NOT
> mix ATF and engine oil.
>
Snip
> Avoid the use of high range, reverse, when loaded.
>
> my .02,
> David Doyle
>
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