4r70w shifting problems - Ford Forums - Mustang Forum, Ford Trucks, Ford Focus and Ford Cars

ford2002 · 07-22-2011, 20:29

Hi Guys.Well after my last post about my 1994 thunderbird s/c I had a stroke.Side lined me for a bit but am now back at working on the bird.Got my exhaust done,went with new down pipes 21/4 to a flowmaster Y then 3 inch all the way back to another y and into a set of flow masters.Sounds different,but wooke up the 3.8 and still has lots of boost.Installed the Ebachs and did the bolt pattern conversion.BUT!! here is my problem.The stock trans was working fine but had the slow 1-2 shift and 3-4 shift and delay going into reverse(Typical stock 4r70w trans)So I installed a transgo hd kit.When the car was up on the stands after the install,I was putting in the oil and shifting thru the gears.When the dipstick said full all I had was 2nd and reverse.So next morning out comes the valve body to check everything I did,all was fine.Reinstalled the valve body and reinstalled oil.Trans needed more oil than I took out,possibly an air lock.Once the tranny was full,had all the gears with car on stands.Lowered the car on the ground and tried to go for a test drive.NO REVERSE.Pushed the car out of the shop and put it in drive,Seemed to shift fine going down the street till I came to a stop sign.Went to pull away a little quicker when the shift from 1-2 did not happen right away semmed to go into nuetral then bang hard into 2nd.Shifting manually shifts Hard into all gears.Also when you stand on it,when it shifts into second it seems to be holding back.Any thoughts?

NoLeaks2001 · 07-22-2011, 20:49

I don't know much about these modern transmissions but I do know that when a transmission (or any machinery) is malfunctioning, the last thing you want to do is go for a test drive. When you noticed the lack of reverse then you should have gone back to the drawing board. Serious damage usually occurs when a malfunctioning auto trans is driven. That neutral-like phenomena while in "D" could be the clutches or a band slipping badly,generating loads of heat and ruining the friction material.
I realize this isn't much help.I noticed there were no responses yet and I needed to exercise my fingers.
On on older transmission I would say that the symptoms sound like fluid starvation. Pick-up not installed correctly,clogged filter,low fluid.
If you were noticing less or more fluid going back in than you took out then you need to find the cause. I don't know about air bubbles. I do know that if fluid drained out of the torque converter and you just replaced the fluid that was drained from the pan,then you would get the lurching,slipping that you describe. You should of course check the level after going through each selector position (engine running) a few times while parked with the brake on.
I'm not at all familiar with the kit you used.I just know that at my age I wouldn't necessarily trust myself to do such an install without screwing something up. Go back and carefully review your work.-Brian

ford2002 · 07-22-2011, 22:26

Thanks for your insight,I have pulled the valve body out twice and found nothing wrong with the install I did. The last transgo hd kit I installed was in my 2002 ford f150 stage2roush.Took all of 1.5 hrs and the truck performs great(350rwhp and 400 ft.lbs torque)Under normal driving conditions the truck shifts FIRM not HARSH like the bird.Under boost(10lbs vortec) You know the trans is working correctly.The bird was a daily driver but did not like the sluggish shifts these trans have.No the trans did not overheat on the test drive and I did not install the hardest springs for hard shifts.I am so chocked right now that I am thinking of pulling the trans and throwing in the scrap metal heap at work and ordering a new one!!!!

NoLeaks2001 · 07-23-2011, 22:18

Again, I know zilch about these electronic units,but "back in the day" if you forgot to put in the O-ring in the pick-up or otherwise failed to have it properly installed then it would suck air and you would get slippage and then a big jerk into gear. No reverse would result from low fluid or a bad pump or mechanical problems.
I am still wondering why the fluid replacement amount would differ from what was taken out.
Is there a gasket for the valve body and did you replace with a new one?