My 94 F150 4x4 has 83k on it. I've owned it for one year. Doesn't appear that the tranny, xfercase or diff lubricants have been changed. Should I go ahead and do this? I drive about 70 miles one way to work each day, all interstate. It has the 4.9 inline six too. I read that article in the Four Wheeler mag about Pro-Tech synthetic additives. Any experiences with such products?

Chris

 

I would deffinitely replace the gear oil in both differentials and the tranny.You will be amzed at what may come out of the diffs.Often times you will find water from stream crossings from who know how long ago.I use synthetic gear oil in the front and rear diff,and I would suggest it for at least the rear.The front is hard to open with the Dana 44 or 50 due to the IFS system.To drain without doing a major mechanical project you will need a pump to pump it out.The front doesnt take that much of a beating due to its infrequent use,but they are expensive to rebuild if they fail.I have been using synthetic motor oil for about 10 years,and I beleive it has helped my motors to all last long and happy lives.Check for metal shavings in the used fluids that you remove.This can often point to potential problems before catastrophic failure.No one wants to rebuild something when its still running OK,but if you let them fail they always take out more parts with them.Also ckeck all of your U joints,if you dont have grease fittings,systematically begin changing them to high quality Spicer U Joints,(when they go they almost always take something out with them),(Drive shafts,axle shafts,steering knuckle joints,etc.).Oh dont forget the transfer case,you might want to even look into a rebuild kit if the truck looks like its been 4 wheeled hard.Maintenance time is when you really get to know your rig and its components.Enjoy it and do it often.
Happy truckin,
Jeff

 

If your differentials have limited slips don't forget to add the friction modifier when you change the fluids. (it sure quieted down my rearend) My 96 4.9L came with a factory Limited slip in the front axle too. The Ford mechanic said a bottle in the transmission will make for a smoother shift so I put four ounces in my trans when I changed all my fluids.

 

I'm in the same boat as you with my 93 4.9L 4x2. I'm definitely going to use synthetic oil (Mobil 1)for all my lubrication purposes and would consider using the additives in the tranny, radiator, and differentials. But I think it would be too costly to use the engine oil additive in conjunction with synthetic oil. (Remember that the total cost of the additives they use in the article comes to about $160.00.)

Those guys in Four Wheeler definitely are not living on a budget with their truck. So far they've spent $2,222.00 and still havn't gotten to the elusive 13mpg mark. Just my .02

 

If you are using synthetic gear oil then you dont need to add the limited slip friction reducer.Its really not that expensive for the differentials.I have been using Mobil 1 synthetic,it sells for about $8.50 quart,(aprox 4 quarts in the rear and 2 quarts in the front).I used to change my gear oil once a year,But it should be changed much more often if you do a lot of water crossings,(remember to keep your differential vent tubes,in good repair and high up into the frame,this can reduce water intruding into your axle assembly).It is also a good idea to use a magnetic filler hole plug to collect any stray metals from ruining bearings,and seals.For motor oil I also use Mobil 1 synthetic(0W-30) at about $4 a quart,but they say you can go 7K miles between changes,I usually change at between 4 & 5K,"General Consensus"seems to be that there is no need to use additives when using a qaulity synthetic oil.The expensive one is the tranny,with a high capacity tranny fluid pan,my E4OD holds 20 quarts at $7/qt.and although I have been told that it is really great for the tranny,I still feel like the tranny fluid needs to be changed to often(just to remove metal shavings),not necessarily due to viscousity break down.I am running synthetic in my brand new performance built E4OD,but the jury is still out on weather or not I will continue to use it.It is also a good idea to in stall a tranny fluid temp gauge,if you have an auto.One thing everone agrees with, is that if you change your lubricants often your components will last longer.
Jeff