Is there a difference between a 1998 Ford F150 and a 1999 Ford F150 transmission? Both 4WD, both 4.6 L engines. The 99' needs a transmission and I have a 98' if it will work. Need some info on this. Thanks in advance!

 

Not really. 1997-98 use a different VSS system, so wiring is wrong, etc. The very best way to go is with a 99 and up transmission. I just replaced a trans in my 98 lil Red truck with another. It had to come from a 98 or 97 to work correctly. There is one write up on here from just a few weeks ago, who changed the transmission and now nothing works correctly.

When you consider any parts for 97=98, make sure they fit first. Lots of things will bolt on, but the differences are night and day. Look at the interior door designs. They moved the handles to the top of the panels, the dash cluster is digital, and the list goes on. Its not a good swap.

 

Check the transmission numbers, should be stamped on or near the pan. I believe it will bolt right in since both are 4 speeds.

There are some differences such as the plug connectors, neutral safety switch, linkage and pan filters. Photograph the electronic connectors and match them to the replacement tranny before you drop it. Make sure the fluid lines are in the same location. Save some time and headache. I know these differences exist between an early '97 and a late '97 and '98.

It's cheaper to have it rebuilt if you pull it yourself and drop it off than have the shop do it, if you need to go that route. If you know someone who has an ATV/motorcycle jack that will help when swapping out.

Since you have the '98 out already I would suggest replacing the front and rear seals and a fluid/filter change after checking your connectors will all hook up.

 

One is the 98' and one is the 99'. According to what I read the U under TR means it's the same transmission. 4R70 W is this correct?

 

From the research I've done, yes it's the same transmission...4R70W.
It should bolt right up.
Just double check your linkage and electrical connections, make sure those match up.
I replaced a neutral safety switch on a '97 Explorer which used a '98 part (late '97 transmission) and the wiring was different. I'm betting you will run into a similar issue. You might be able to swap out some parts like the speed sensor, neutral safety switch and the like.

Easier to check out prior to installing/swapping.

 

The one thing that is being forgotten is the speedo system. 97=98 uses a gear into the tailshaft for the speedo. 99 and later does not. This is a big problem for the 98 to get a signal to read the speedo. 99 and later is electronic. How will you use the 99 in the 98 and make the speedo work. You don't, without changing the tail shaft and possibly the output shaft. Using the 99 into a 98 is a real pain. Both may be 4R70W's, but with the 99, the whole truck went digital.

Ok White.....jump in now and give your 3 cents. lol

 

98 is an odd ball year. It has the new valve body and main wiring harnesses (they are a completely different pinout from the 97). As AK said, the speedo output is different as well.

Technically, the same trans... but not plug and play between 98 and 99.

 

Just went through on my 98 Expy.... Thought I had a pic of the speedo stuff... but this is the trans we put in it. Luckily my Buddy had this one already built when it puked.

 

Yes.... 97-98 use VSS (vehicle speed sensor), 99-03 uses OSS (output shaft sensor). I've seen conversion kits to go from VSS to OSS, but not backwards.

Although this is Mustang specific... this kind of explains what AK is speaking of. Also has conversion kits on this page... http://www.accutach.com/general-how-tos/vss-oss-swaps

See pic below for difference

 

So my plan is to use the 98 and put it in the 99, so I think what you guys are saying is it can be done, just not a 99 to a 98. Is it worth making the swap? Thanks for all the input I appreciate it. I was going to start pulling the 98 out this week.