Hi guys,

My 97 F150 SC Lariat 5.4 LB has developed a slight rattle when downshifting from OD under power. It seems to happen when hot, maybe after 30-40 Highway miles. I hear the rattle, and feel it a bit. It does not do it when it's cold.

I'm thinking it may just need a fluid change. I do pull a boat, and the truck has just turned 175K. Last fluid change was 3 years ago, about 45K miles. Any thoughts on this?

I have also noticed a bit of a vibration on hard acceleration. I was thinking u-joints, but I removed the driveshaft, and they are free. I did notice a bit of fluid from the output shaft on the transfer case, and when I reinstalled the driveshaft, I get a bit of wobble on the spline. Is there a bearing there? Is it easy to R&R? ANywhere I can get a blowup illustration of the transfer case?

I have code E on the door jam sticker. E40d, right? What tranny fluid is best for this?

Thanks for the help. If this doesn't fix the problem, I got a smokin' price on a new F150 Lariat SC on Saturday. I might just have to upgrade a few months early!

 

Tranny shop described it as convertor shutter. Could not make it do it today, even after an hour on the road. Should have been hot enough by then. They're going to pull the pan and take a look. If they do not find stuff in the pan, they'll drain the old fluid, replace the filter, and fill it up with new fluid.

If they do find something, I'll be at the dealer tomorrow evening.