5R55E with no reverse or drive... now it works WHY?

[Buckeye Yooper]

Longtime lurker/reader but first time poster. My son has an 03 ranger with a 5R55e that had the no reverse or drive for a month. He lives ~9 hours away and yesterday I met him halfway and swapped cars so I could drive it home and swap out the trans from my 01 Explorer Sport. Funny thing is after driving for 5 hours ( using LI, L2, D and OD) when I got home I didn't have the room to turn around in the driveway to face the road, so I put it in R to see what would happen. It backed up fine! I thought might be because it was hot from the long drive. This morning I go out and Drive works (all gears) and reverse works. I cleared the codes and none have returned. I plan on driving this daily this until any codes come up or it loses R or D.

This causes me to think it is electrical or in the computer. Anyone else had this issue self correct? Any ideas or thoughts on what to check out? I really don't want to swap transmissions and have the same issue remain.

Any input would be appreciated.
Cheers.

 

[JK080]

A common failure with this transmission is the input sprag, its a part that allows the certain parts to spin one way and lock the other way. When this input sprag fails with this transmission it will lose forward and reverse but low and manual 2nd will engage and one up to speed you can shift to the higher gears. Sometimes these sprags fail badly all at once and other times they just wear down and cant hold at times but they will eventually fail and not work at all.

I would think that in your case the sprag is just very worn and is operating for the moment and will fail completely in the near future.

This transmission should have reverse and forward engagements even if the computer is disconnected completely so unfortunately you can rule out any electrical issues causing this. You will end up having to put another transmission in the truck or having that one rebuilt in the end.

 

[Buckeye Yooper]

Thanks for the response JK080. I knew the issue might have been the input sprag, but was hoping that since it corrected itself there might have been another cause. I just got through a rebuild of a 4l60e for another vehicle and wasn't looking forward to another transmission R/R. I guess it is easier than tracking down electrical gremlins.

Oh well, off to verify the tag # on my on my explorer sport to ensure it is a good donor.

 

[410Fortune]

how many miles on the 2003 5r auto?
How does the fluid look?
Have you checked fluid level? at temp, while running in P or N
If the fluid level drops you will lose gears, I know I know but we have to state the obvious

did you have to rev it up to get R to go? or did it just shift?

Is it a 4wd ranger?

 

[Buckeye Yooper]

The 2003 5R has about 217K on it. The fluid is red with a brown hue. When the vehicle is at temp and in P the fluid is at the top of the crosshatch on the dip stick. Yes it it s 4x4 ranger.

I did not have to rev it up to get reverse, it worked at idle speed. My son said he had to rev it to get some reverse and was surprised when I told him it was working. I literally pulled in the drveway put in R and it backed up and has worked since.

He had the condition of no drive or reverse for about a month. We had guessed it was the input sprag and planned to do a tranny swap but figured I ask around to see if there was a chance it was something else.

 

[410Fortune]

With those miles and these symptoms it is time for a rebuild or swap with low mile unit

 

[Buckeye Yooper]

Thanks, I figured it was unavoidable. My donor has only 113k on it.

 

[410Fortune]

What year is the donor from? I ask because The 03 ranger has a second OSS sensor in the 5r55e transmission, so you must use a 01+ 5r that has the second OSS. Earlier units did not have the second OSS

 

[Buckeye Yooper]

What year is the donor from? I ask because The 03 ranger has a second OSS sensor in the 5r55e transmission, so you must use a 01+ 5r that has the second OSS. Earlier units did not have the second OSS

The donor is out of my 01 Sport. They both came up 1L5P-EA and appeared to have the same wiring connectors. I'll double check before pulling the trans. Thanks.

 

[410Fortune]

should have it I think the second oss was added somewhere between 98 and 2001? I cant remember
Just make sure it has it before installing!!! Been there seen that one a few times....

 

[Buckeye Yooper]

should have it I think the second oss was added somewhere between 98 and 2001? I cant remember
Just make sure it has it before installing!!! Been there seen that one a few times....

It wouldn't be much fun finding it out the hard way.