No 4th gear

[Endless]

I rebuilt the transmission in my girlfriends 02 Mazda Protege 5. It's the same trans as a focus 4f27e with some slight differences. It has 80k on it and lost 3rd and 4th gear. Her mechanic pulled only a slipping code and the a/t light never came on. He said it would need a rebuild costing $2k+.

I decided to do the work myself since I have experience with older A/Ts. Using the ATSG 4f27e manual and the factory Mazda manual, I pulled it apart and all the soft parts looked good with maybe a slight glaze on the clutches. Absolutely no signs of any problems besides very black fluid.

I rebuilt it with a full soft parts kit and rebuilt t/c. All the clearances were within spec. It now runs fine in 1st -3rd but when it shifts into 4th it holds for a second and then slips and revs like its in neutral. It shifts fine back down into 3rd no problem.

Based on the Trans go manual they suggest this is likely a bad solenoid and to switch the 4th gear and lockup solenoid. I did this with no change to the 4th gear problem. My scanner picks up no codes and during the rebuild the solenoids all ohm'd perfectly.

My next step would be to drop $200 on new solenoids but would rather not throw parts at it. I don't have a line pressure gauge but that may be my next step instead of the solenoids.


Anyone have any ideas?

[Sponsor]

[05focusST91]

i'd try the solenoids first, if not it could be a bad valve body

[Endless]

Thanks for your input. I went ahead and ordered a remaned valve body with solenoids on eBay. It ran $189 shipped which is only $10 more than the solenoids by themselves.

I'll keep this thread updated and if anyone has any more input it would be greatly appreciated!

[CBen]

I can't offer much, other than I've had a similar problem that was fixed by replacing solenoids. I, however, did not do it myself:(

[Endless]

Any little bit helps! Im hoping it is the solenoids, although i will be a little pissed that I took the 20hrs it took to do the full rebuild.

[rotarypwr]

Did you look close where the rings on the rear cover ride. Any melted piston in reverse drum? Luckily if it is
Internal you can drop mounts and remove rear cover and drum in vehicle.

[rotarypwr]

One more thing.. can you shift manually through gears? Not being rude but you did snug down adjuster for
The band correctly. That it shifts then looses the gear makes me think fluid pressure loss

[Endless]

I inspected the rear cover and the ring seat looked fine, replaced the rings that came with the kit. I did not measure the ring seats so i cant confirm there was no wear. The molded piston in the drum looked good along with all of the other pistons.

Manually shifting has the same problem, no 4th. Not sure how the focus manually shifts but on the protege you move the shifter to the manual position and forward for down band backwards for up. This is all electronic and not linkage shifting.

I didnt have a band select guage so i reused the bolt and adjusted it by feeling the band tension with the valve body removed and welding the tip of the bolt to make it longer. I had to add 1/16" to get the tension right.

I was guessing pressure loss too. Any ideas on trouble shooting that?

I was hoping i could pull the cover by tilting the trans down. Thanks for confirming that

[Endless]

I found that band adjustment procedure in the transgo manual. There is alot of good info in that manual.

[rotarypwr]

Your atsg manual should tell you where to hook wet gauge up and specifications for idle and stall pressure