Aging transmission
 

Hi all --

Wife recently bought (well, bought a half-interest... long story) a '93 C2500 pickup, 350/4L60E. Truck has about 85,000 miles, we know the original owner (he, wife and co-owner are all friends). It's been used primarily for towing, and wife pulls a horse trailer (>6000 lbs loaded). Co-owner changes oil regularly and repairs as needed, but is not particularly car-savvy.

Just pre-tripped it, the trans fluid is brown and doesn't smell great (though not burned). Trans shifts nicely when light (I haven't driven it while towing, but wife says there are no issues). There is a hydraulic-y whining noise coming from somewhere, but I haven't sussed out the source or circumstances. AFAIK trans fluid has never been changed.

We figure the trans will die at some point, but I want to avoid a breakdown.

What's the common wisdom on doing a complete fluid change and filter? Can this prolong (or shorten) the life of the transmission? Any modifications we should consider to extend its life? (Was considering a finned pan, for example.)

Also -- we don't plan on doing any serious engine modifications -- maybe a K&N or a cold air intake, but that'd be it. She's not worried about going faster. If the trans does go to its earthly reward, should we go with a straight rebuild or look at swapping a 4L65 or 70?

Thanks -- I'm relatively new to GMs -- I'm a Mopar guy, but now with two... well, one and a half GM trucks.

Aaron

'83 GMC Suburban C2500 6.2
'93 Chevrolet C2500 350

Change the oil and the filter and keep on truckin'. They wear compensate.


Allan