4r70w Tranny swap - 97 Mounty to 98 Explorer?

[mredd21]

Hello all, here's my main question: What needs to be done to make a transmission from a 97 Mountaineer 5.0 work in a 98 Explorer 5.0?

I have a 98 Explorer XLT 5.0. My transmission would not going forward or in reverse. I took it out and saw that the gears in the torque converter were wore down. ( i noticed this after I parted the tranny out)

I went to the junkyard and took a transmission out of a 97 Mountaineer with a seized motor. I assumed they were the same. After bringing it home, I realized the pins were different in one of the electrical connections. With both transmissions next to each other and upside-down, I replaced the old wiring and electrical components in the 97 tranny with the parts from the 98 tranny. I just noticed a post on here saying you could do that (after I did it), so I hope from that standpoint that the transmission would work.

So working alone for the past two days, I got the junkyard transmission in place and mounted to the the engine. When I went to spin the crankshaft (to install the 4 nuts that attach the TC to the flywheel), I found I could not spin it. Everything spun freely before I mated them together.

With a closer look, I found that the bolts protruding out of the TC are hitting the flex plate between the tranny and engine. Sure enough, I measured the bolts from the old torque converter and found that they were a little shorter than the one i pulled from the 97 Mounty!!

I'd really hate to pull that transmission out again since I've been working on hit for a week and was so close to being done. I am thinking of loosening the tranny from the engine a bit and then grinding the 4 bolts down a little to gain some clearance.

Does anyone have any thoughts on why the bolt lengths are different? Will the balance be way off if I grind some of each bolt down? If I absolutely have to buy a new torque converter, which one do I buy? There are 5 listed for the 97 Mounty and 4 listed for the 98 XLT on Oreillys.

I appreciate any help that can be provided in this matter, and this is my second post here, even though I've lurked for quite awhile.

 

[wood1]

You using the flywheel that went with the JY trans?

 

[mredd21]

Hello, thanks for replying!

I am not sure what you mean by "JY Transmission" but no, I did not take the flywheel from the Mountaineer. But when I think about it, the flywheel might be different also. Maybe if the one off the Mountaineer was thicker, or if it was positioned a bit differently it would cause my problems.

I went back to the Junkyard and got the VIN off the Mountaineer. Then I went to the Ford dealership with some questions. They said that if someone was looking for a torque converter for a 97 Mountaineer 5.0, or a 98 Explorer 5.0, this is the part number they would give for both vehicles: f85z-7902-aarm, at nearly $400.

I think they were trying to tell me that it is the original part number for the explorer, but not the Mountaineer. They said that there was an improvement between 97-98 and the 97 Mountaineer's original torque converter was phased out for the newer ones.

 

[wood1]

JY=Junk Yard .

I would get the flexplate off of the Mountie and try it rather than bugger around with the studs on the converter.

If your trans didn't grenade maybe you could use your original converter. Absolutely not a good idea though if your trans blew up. The contaminants in the old converter will destroy your new one.

Also, you need to clean out the cooler and lines. Some times overlooked with terrible results.

 

[mredd21]

Ok, i guess my skills have improved with this job, since I was able to drop the transmission, put a new Torque Converter from O'Reillys, and reinstall the transmission in a total of 7 hours instead of 14 last night!!

I got a Pro King Torque Converter, Part # (FM69C) and the studs were the same length as my original one. It took me all day to start it today. It wouldn't turn over. It ended up being the Neutral Safety Switch wasn't seated all the way.

The transmission took 11.25 quarts of fluid to fill it. I prayed as I slipped it into gear and it actually moved! I just got done test driving it, and it ran pretty good. It shifted gears very smoothly, and all gears including overdrive work. It seems a little less powerful than my last transmission, but maybe I just got used to being thrust into the back of my seat every time it shifted gears rather than the smooth shifting I have now.

I have a new problem now, which I haven't had a chance to troubleshoot. The truck shakes like crazy when i turn the steering wheel left or right. It seems worse when it is in gear. I'm pretty sure the transmission has nothing to do with steering, but stranger things have happened!

My transmission died at 248,000 miles and the Junk Yard one has 158,000. It would be great if I can make another 90,000 out of this one! Thanks for your replies Wood1

 

[wood1]

If it was fine it is something you have done since the last time you drove it likely. Wheel nuts tight?

 

[mredd21]

It was my power steering pump as I learnt from this post:

http://www.explorerforum.com/forums/showthread.php?t=277120

...I turned my steering wheel while the truck was not running and jacked up.

 

[mredd21]

I have a different problem with the transmission. Not sure if I should start a new thread or not, but here goes:

After a cold start, when I put the transmission in either reverse or drive, it does nothing. It is like it is in neutral. So I put it back into park or neutral and rev it up a bit. Then when I put it into gear, it works.

Another issue, which is likely related: Every now and then, when I am driving, it slips out of gear and then back into gear when I give it more gas.

It has a new torque converter, filter, and I put 11.25 quarts of transmission fluid. When It is hot, the fluid reaches the middle of the hot indicator on the dip stick.

Other than that, the transmission is running pretty good. Any ideas?

 

[wood1]

Plugged filter or the filter o-ring is leaking maybe, you did use a torque wrench on the valve body bolts? You could check the pressures, it could mean you have an internal pressure leak, check for codes too.