Changed Trans filter-overdrive doesn't work

[springer9861]

I took my 91 Explorer over to my dad's garage today and we changed my trans filter and added 6 qts. of mercon atf. Started it up let it warm up and took it for a test drive and my overdrive doesn't work. I can get the explorer up to 65-70 mph and let off the gas and let the rpm's drop to about 1000 then I can step on the gas and it acts like it's in neutral. When the speedo gets to 55 you can step on the gas and it will kick into drive but it will not shift into overdrive. The fluid i drained out didn't smell burnt and it shifted fine before I changed the filter. I have noticed that the shifter pointer doesn't point right to overdrive but just to the left of the O. I can start in 1st and shift it to 2nd then to drive but when the speedo reaches 55 it will not shift into overdrive. Thanks for any and all help...........Larry

 

[Glacier991]

The first obvious question (no offense intended) is did you make sure the filter was correctly installed using the long washer on the bolt? If not the filter won't pull fluid from the pan as it should. Also, is the Fluid level on the mark?

 

[springer9861]

Washer on bolt

Thanks for the reply Glacier991,
I did use the long washer on the new bolt that came with the new filter but I did notice that the new small O-ring was not as tight as the old small O-ring. The new small O-ring didn't want to hold the filter in place until I tightened the bolt. Think that could have anything to do with my problem?
Thanks for any info.........Larry

 

[Glacier991]

Low line pressure can cause all kinds of hard to solve problems. It is entirely plausible that your line pressure is low (due to the seal on the filter) and the OD servo is not engaging as a result (ONE possibility). An easy test is to put the old filter back in and see what it does then. (messy and unfun I know. Also how is the fill on the transmission.. you on the mark?

 

[springer9861]

The fluid is about 3/4 up the dip stick on the criss-cross marks when up to normal operating temp. I can't put the old filter back on but I can go and get a new from the local auto parts store. The new filter I just installed came from bulkparts.com.. I have been reading about there filters and how good they are. I will try and new filter and o-ring and let you know what happens.
Thanks for the info...........Larry

 

[Glacier991]

if you are in the cross hatch you should be ok, but try and make sure it's to the top of it.