What are my transmission replacement options?

[68_F100_Don]

I have a 1968 f100 ranger. The transmission has issues. I assume it’s a C6 but not for sure. It doesn’t shift properly and, not necessarily a mechanical issue, it doesn’t cruise very well as a result of I assume no overdrive. I had my mechanic look at it. He said it could probably be rebuilt and may just need adjusted to shift properly but if I wanted a transmission that would be better at cruising speeds, instead of dropping money into a rebuild, replacing it with a more modern transmission with overdrive might be a better option. He’s going to do some research but thought I would look into it as well.

It’s a FE360, 2wd, automatic. What are my options for transmissions, with overdrive that I can directly swap in with minimal modifications if any?

Thanks,
Don

[390FE1972]

I'm not sure what modern transmissions you could use, hopefully someone else will give you some info on this, but some of our trucks had overdrive in them from the factory. I believe they did away with the overdrive on the bumps in 1971. Here are a couple of tech items that will help you identify your transmission and older options for transmissions that you can use. The shifting issue might be your shift modulator, that controls your shift points. Hope this helps!

http://www.fordification.com/tech/transID-auto.htm

http://www.fordification.com/tech/trans ... trucks.htm

[68_F100_Don]

If I am reading the charts right, there isn't a transmission with OD that is a direct bolt on to the FE engine. I did find some adapters so you can bolt on these later transmissions but they a $$$. So if I did go this route, rebuilt later transmission, adapter and paying mechanic to put it in it would several thousand. Not sure if it is worth it.

I did some math last night, the C6 with just its 3 gears, no OD should be just fine for me. Should cruise at 55 mph at about 2500 RPMs if my math was right. I think mine is just messed up and not shifting and not hitting the top gear. That is why it seems like it revving really high when you get to speeds over about 35. I don't know how much the mechanic got into it so not sure if he looked at the modulator or not. It would be nice if it was something that simple. A new modulator is cheap and worth a shot before replacing the whole transmission.

[Ohiotinkerer]

Change the modulator (put in an adjustable one), change the vacuum line, adjust the bands, and change the fluid and filter if it needs it and see what that gets you.......alot of times that will fix the problem unless you have a serious internal problem.......and even if it does need rebuilt you'll still be less money than found a complete swap unless that's what you want to do..........they are fairly simple to work on - at least for me but I used to work at a transmission shop in the early 90's..........

[sargentrs]

A lot of information can be found by reading these threads. https://www.google.com/search?ie=UTF-8& ... n.com#ip=1

Don't rule out staying with a C6. I have an '87 F150 with a 5.0/C6 drivetrain. I have to say that I am very pleased with how it drives and shifts. She turns 2500+ rpms at 65 mph but I'm sure the 3.55 gear set in the rear end and 32" tires has a lot to do with the higher rpm.

[68_F100_Don]

my mechanic has told me its a Jasper transmission and wasn't swapped out very long ago. I'm getting the impression he doesn't want to work on it based upon the reputation of Jasper. Don't think he trusts it. I think he is basically coming to the conclusion that it was probably defective from the beginning and doing any work on it would be a waste of time and possibly might come back to bite him in the a**. I've only had the truck for about a year and half. Who knows the story before I got it. I told him to look at the modulator and if that doesn't fix anything we'll look at swapping the transmission out. Probably just stick with a re manufactured C6.