transmission questions
 

I have a 92 5.0 automatic that the other day I noticed a hard thud when driving and now I have a hard shift into each gear and my speedometer doesn't work. I was looking up and was wondering if it would be the speed sensor that is the problem?
2nd question I was already planning on switching it from 2wd to 4x4 and thus don't want to put to much in this transmission, I did find a c6 transmission from a 86 5.0. I was wondering if it would be a straight bolt up no problem kind of deal or will I have to do some fabricating? thanks in advance for any info

Tons of things to change to change to a C6.
Your speedometer not working is probably what's wrong with your transmission. Sort out the speedo problem first.
Start with the fuse. Vehicle speed sensor is next to check; if replacing it motorcraft only.

ok thanks, ill check the fuse during my lunch, then ill check the sensor when I get home. is the sensor located on transmission or else where?

On top of the rear differential.

even the one for the speedometer?

Click this & read the caption:

https://www.supermotors.net/getfile/...ster-front.jpg
(phone app link)

Even MotorCraft new speed sensors don't work right on these old trucks, but a failed sensor can't cause a THUD, so it's NOT likely you need to worry with yours. If you can't find what made the noise, pay someone who can. Check U-joints, U-bolts, suspension bushings, frame rivets & bolts, frame cracks, engine/trans mounts, springs, body mounts, bed bolts, spare tire, bed cargo, and any aftermarket parts (lift, hitch, ladder rack...). Pay close attention to wiring harness damage from road debris.

The more we know about your truck, the more-likely we can help you. So click this, read the caption, study the truck, and see how MUCH detail you can fit into your signature:

https://www.supermotors.net/getfile/...oorsticker.jpg
(phone app link)

Pics help, too.

I know its been over a month but I wanted to close this out, that being said the problem was the backyard hanger that the previous owner put on the exhaust broke and the pipe landed on the wiring harness for the speed sensor and melted/ cut the wires. fixed the wires and works like new, thanks for the help!

That's what I was thinking....