I have an 86 F-250 4x4 A/T XL with the 351W. My truck has 150,000 miles on it. I just got it a month ago. The truck has been used all of its life for pulling farm equipment and fifth wheel trailers,(and a few Chevy trucks and tractors). I am going to change the ATF in it sometime soon. What brand do you recomend? I still use this truck to haul firewood around in the bed so I would want something that will last. I'm lookin at getting either Royal Purple or Quaker State 4x4 ATF. Which brand would ya use if it were youre truck? Also I think my trans. is a C6.Another thing, do additives such as LUCAS trans. really help the transmission out in the long run? Thanks everybody!

 

As long as you use a name brand fluid things should be just fine. I have customers that swear that Lucas products work. You may want to add a trans cooler to prolong the life of the trans.

 

A few things to consider first, how many miles on the last rebuild, how current is the trans service? If the trans is in bad shape fluid wise, you can drain some off thru the cooler lines and refill, if you get too strong a fresh mix it can cause problems with hard seals and plugging passages with sludge. But if its in good shape any major brand is good if serviced once a year under extreme load.

 

Either brand would be good. If there are no leaks or drips, I might spend the extra money on the Royal Purple.

If the tran<!>smission is in good condition, shifts well and doesn't leak... you're not likely gain anything by using additives. If you are going to be using new high quality fluid, why tamper with the chemistry by using an additive?

The auxillary tran<!>smission cooler is a good recommendation. Especially if you plan on hauling wood or to<!>wing a trailer in the mountains.

 

in my 82 i run type f. the ball and ball wear test was lower, higher in detergants than dexron, higher flash boiling point also. i had type f in my tranny from 32k till 280k, when it was replaced. not for wear, but rather i replaced the 351m with a 460. i still have it in my shop, and with regular maintence it has had a good life. napa sells their brand for one of the best prices, but dont be fooled, it is not cheap barrel oil, but rather it is manufactured for them by valvoline. ask anyone of the napa parts guys, and they will tell you the same. aslo ford had a terrible filter in their trannys, or rather "window screen". those who worry about filtering oil in a c6 should alway think about running an external filter on the return line of the tranny cooler. this will filter out any unwanted item from your tranny fluid. a kit will run you around 35.00. replacemenbt filters are easy to change using the standard ph8a or 1515 wix/napa filter. i change mine every other engine oil change. you would be suprised at what you will see in there. becarefull though a plugged filter line will fry a c6 within 15 miles, so it is filter that should be regularly serviced, and you should think about an trans temp gauge. all these items will help keep your c6 running for along time to come.