I have a 96 E150 w/E40D tranny, I am going to do a fluid and filter change. Was looking for advise on possibly changing over to synthetic. The van has 285,000+ miles and Tranny was rebuilt at about 100,000 miles. I thought I read somewhere not to switch with high milage trannys.

Any thoughts, recommendations?

 

If I had 285k miles on regular transmission oil I wouldn't even consider any change to the oil. Why change what works?

 

well, only 185,00 since rebuild. I have been using Syn. motor oil and just switched to Syn. Diff. was going to make a total switch, but you raise a good point.

 

You can switch to synthetic with no problems. New fluid will help extend the life of the trans. If you don't work the trans real hard there isn't much benefit to synthetic over dino.

 

Thanks Mark, I tow occasionally, but mostly hwy miles. My main reason is to make it last longer.

 

Mark is of course correct. Also, if you change the fluid regularly (and aren't running it very hard) then there is virtually no gain from synthetic.

The benefit from synthetic is increased fluid life at higher operating temperatures (like when towing) and longer intervals between changes.

 

I'm torn, the extended fluid life of course is still a plus. I generally have my van loaded with 500-1000lbs of gear and this is gradually changing but most of the miles to date are hwy miles running up and down the east coast VA-North western NJ. so some mountains. (for you Colorado people, big hills) But I run about 7 hours non stop. very rarely pulling a very small trailer a little 4x6 enclosed trailer.

I have been reading a thread elsewhere about adding a external filter using regular oil filters. My purpose in all this is to get as many miles out of the van as possible. Given the price of new vans and the fact that I tend to be hard on the interior in the back where all the gear is loaded. I can't see spending the money on a new van when this one is still strong and I want to keep it that way.

 

Skip the external filter. Engine's and transmissions are very different and oil doesn't have the same function in either application. The only thing that could be in the oil for such a filter to remove would come out of the transmission itself. And if that were the case, you would have a bigger problem than dirty fluid.

If you want to extend the life of the transmission, install an additional cooler and change the fluid regularly. That is the proven method.

 

X2 I am surprised it needed to be rebuilt after the first 100K tho. The 2 E4ODs I've had went over 400K without anything but regular fluid changes every 50K or so.
Just change the fluid more often and stick with dino fluid. Why risk messing up the way the trans is with synthetic?

 

I stuck with Regular. Not gonna mess with it. I change regularly and usually everyother one is a full flush.

Yeah first one was a mess and it was still a mess after 2 rebuilds. finally demanded they assign someone else to it and it's been great since. 185,000 (ALmost) miles since rebuild.

 

Good to hear. My miles were 90% hwy. but I often carried loads up to 3K lbs. I always added a drain plug to the pan during the first fluid/filter change. After that it got a complete drain (converter and pan) every 50-60K with a filter change added in every other time. Good luck with this one, it sounds like they got it right!