(it's a 2001 2wd 4.0 v6) I rebuilt my transmission last year in November and I was able to driver perfectly fine for about 2 weeks and then my forwards gears would only engage if put it in 2nd and and let it engage then I could throw it back in drive and be fine unless i took it out of gear but I still had reverse there's absolutely no problems with it. My fluid is still brand new I dropped the tranny and I see absolutely nothing wrong. I don't know if I may have had something loose but I dont think I did. Any comment help thank you!

 

Welcome to the forum

Should include the year of the Ranger/Mazda, and engine size with questions

If 1995 and up then its a 4R model, 2001 and up 5R, but internally they are the same
44E and 55E are related to OD drum size, but they are the same as far as operation

In any case have a look here: https://atracom.blob.core.windows.ne.../2003_5_50.pdf

This PDF shows what valves(solenoids), Clutches and Bands are being used in each "gear"

Not engaging in D but engaging in 2 points to one-way clutch(sprag) issue, and usually R is also effected, so maybe that doesn't apply