weird whine in summer months

[bsalz]

my 1996 ranger makes a whining sound in the summer months. it sounds a little like the teacher on the peanuts cartoon, only a higher pitch. I thought it was the a/c pump, but it sounds like it is coming from the engine itself. when the temperatures are cooler, it doesn't make the sound, only when the temps get around 80 or higher. I can't seem to track it down, has any one else had this problem? I would greatly appreciate any help.

[Earlyboomer]

I had this problem with my transmission, a 5 speed made by Mazda, in a 4x2 Ranger XL. The problem was the front main bearing. Mazda starting using a fully caged bearing on the bottom shaft of the transmission. This "cage" was Nylon and it completely filled up the bearing so no oil could flow down through from the top bearing. this allows the lubricant to totally break down like water and fills up the space between the front cover and the transmission. this causes insufficient lubrication and heating of the top main shaft bearing. The cure was to drill a hole in the case near the lower caged bearing, I used a 1/2" drill, and used a steel plate to make sure the drill didn't get to the first gear and damage it. The top bearing was getting hot and "singing". Also the lubricant lever is way too low as specified by Ford. They say you will blow the seals with too much lubricant, bulloney -because there is a vent on the top of the transmission. I replaced the top bearing, plus the front and back seals, while I had the transmission out, and I filled the transmission with synthetic transmission fluid to cover both shafts, while I still had the shifter out. I did this 100k miles ago and that solved that problem.

Now I heard that the Mitsubishi manual transmission used in the 4x4s had a problem of some kind with the rear bearing in that transmission, but that is all that I know about that. I originally learned about both problems from a Trucking magazine.

Ford has a service bulletin on drilling the hole, but I never saw it. I drilled the hole at the lowest point in the access slot to the bearing, somewhat close to the corner bolt hole for the front cover.

This might be way off, because you didn't give more info, but maybe this decades old info will help someone else.