Drivetrain 4r70w acting up

Discussion in 'SN95 4.6L Mustang Tech' started by Rafoo, Feb 6, 2013.

  1. Hello everyone, I'm new here my name is Raphael and I'm experiencing issues on my tranny these days.

    I own a 2002 Mustang GT with an automatic transmission which I beleive is a 4r70w and it has developped issues when shifting from second to third.

    The symptoms are when it wants to shift from second to third, it lags, or it is slow. Sometimes I feel like it is trying but not succeeding so it'll rev up without being in gear and then finally shift a little hard.
    The other thing is if I'm in 4th, and I gas it, it'll drownshift into third perfectly.
    This is my first automatic transmission car, so I don"t know those very well and I don't want to get bull****ed buy a mecanic if he tells me it needs a rebuild when it doesn't.
    From what I understand in the way those trannies work, since it's downshifting correctly, it must be something in the hydraulic system that makes the shift between 2nd and 3rd gear.

    Can you guys help me with that ?

    Thanks
     
  2. Start with the easy stuff, how many miles on the fluid/filter and is the fluid low? As far as you know is the transmission stock? No extra holes drilled or enlarged, etc?
     
  3. As far as I know (bought it almost 2 years ago), it is bone stock, there are 91000 miles on it, the fluid level is good, the color is orange-ish which I think is normal considering it has not been flushed ever.
     
  4. Way too many miles change the fluid and filter and hope that fixes it. If not it needed to be changed anyways.
     
  5. Ok I*ll go for that first. Really thought you'd need changing the fluid every 100 000 miles though. Any other ideas if that's not it ? Because I'm honestly not sure if it has been changed or not, I just assumed it never had been
     
  6. Use the right fluid. Change it and the filter. I have seen this problem before. You have a very good chance a fluid and filter will fix it. Do you have a check engine light on?
     
  7. No the check engine light is not on. What you guys are saying is giving me some hope, can't really afford to rebuild the tranny right now ...
     
  8. Is it chattering (shuttering) when it shifts?
     
  9. None, there are no weird noises when it shifts
     
  10. Ok I took it to a transmission shop tonight, the computer says nothing, the guy says the third is dead and needs full rebuild $2000, told me the fluid looks bad slwhich I beleive is true but also told me that putting new fluid and filter might make things worse which I find weird. He offered to take the pan off this weekend and see whats in there and then change fluid etc. I think Im gon do that. Do you think theres a risk ?
     
  11. Not gonna hurt a thing. Never flush them without dropping the pan to change the filter.
     
  12. Ok that's what I thought. What is the exact right fluid to put in there ?
     
  13. I just got my 02 back from tranny shop yesterday and paid about $1400 and I destroyed third gear. Two thousand seems steep.
     
  14. Same transmission as yours by the way(automatic).
     
  15. Did you get a full rebuild w/ torque converter and everything ?
     
  16. Where are you located. I have a built 4r70w here with a stall in my shop.
     
  17. Start by changing fluid and filter.
     
  18. A little far from you Im in newport beach california. Ill change the fluid and filter this weekend Ill let you guys know what happens
     
  19. Coolant flush, brake bleed, fuel filter, new plugs are also good at that mileage.
     
  20. Duely noted :) the transmission fluid is being serviced but he didnt want to drop the vb and check the accumulator. I brought it to another guy who drove it and told me that the third far from being dead, still picks up pretty good. He gave me another address for transmission work so Ill check it out if its still bad after fluid change.
    Btw sorry if I mispell words Im from France my english is not perfect.
    I really appreciate the help