169k Mile Tranny Question

[adeadhead]

I have a 1990 K1500 "K" engine, 4 speed auto trans with 169k miles on it. The truck was initially loaned to me at 113k 3 yrs. ago and I am dubious of it's prior maintenance history. Over the past 3 years I have maintained & repaired as needed: New starter, water pump, U-joints, front differential, brakes, alternator, coil, distributor cap, ECM, cat back exhaust, fuel filter, ignition wires, along with normal PMCS including 3-5k oil & filter changes, yearly plug replacement, air filter, coolant flush, differentials & transfer case drain & fill, PCV, etc. I also gained full possession of the vehicle.

 

My question regards the tranny. Do I drain & fill, along with filter change (not a flush) or just drive it till it dies and replace. My instinct is to maintain the trans but several people have told me not to touch it. I feel changing the filter and replacing a few qts. of Dexron would only help. Others have told me that a change in a unit that has already outlived its service life is looking for trouble.

 

The fluid is not dark and smells good. I am about to have a sample tested ($23) to see if I can get a better idea of the fluid & tranny's condition.

 

I like the truck and intend to keep it going. I think the repair and PMCS record shows that. I am hoping that those who know transmissions can offer some advice.

[txab]

Sounds like you like to take care of what you drive. Good for you.

 

2 ways to go on this.

 

1. Drop pan, change filter, fill it up. Drive it a while and then just change the pan fluid again.

 

2. Drop the pan, replace the filter. Fill it up and then do a flush of the rest of the fluid yourself. This write-up should give you an idea what how to do it

 

Post your results of your trans oil sample test. It will be interesting to see what it shows