HELP: Automatic, can move forward. But, cannot reverse.

**lm723** · February 18th, 2013 04:51 PM

Helping a friend..

98 Nissan Sentra can move forward. But cannot do a reverse.

Symptoms:
When cold, car can do a reverse - but needs more rev power (mahina na).
When hot, cannot do a reverse, even revving more, wala na.

What could be the problem? if the car can move forward, pero cannot move backward? -- weird.

Thanks

**battcor** · February 18th, 2013 05:10 PM

I have this same problem. And same experience as posted here : tsikot_dot_com/forums/transmission-talk-141/1995-nissan-sentra-ss-weak-reverse-84424/

Pa help po. Thanks

**lowslowbenz** · February 18th, 2013 05:18 PM

Have you guys tried flushing the ATF and replacing it with new ATF? Do these cars have a transmission filter? If yes, try replacing that along with the ATF flush. Remember that the torque converter should have a drain plug for the ATF too, drain that as well (MB's have them). Valvebody cleaning might also work, but this is best done by a qualified gearbox mechanic. Take note of the ATF appearance when you drain it, and check the bottom of the used oil container for metal particles.

Worse case scenario, reverse brake band and clutches are already worn out, overhaul and replacement is needed.

My 2 cents. Hope this helps.

**battcor** · February 18th, 2013 05:43 PM

Originally Posted by lowslowbenz

Have you guys tried flushing the ATF and replacing it with new ATF? Do these cars have a transmission filter? If yes, try replacing that along with the ATF flush. Remember that the torque converter should have a drain plug for the ATF too, drain that as well (MB's have them). Valvebody cleaning might also work, but this is best done by a qualified gearbox mechanic. Take note of the ATF appearance when you drain it, and check the bottom of the used oil container for metal particles.

Worse case scenario, reverse brake band and clutches are already worn out, overhaul and replacement is needed.

My 2 cents. Hope this helps.

I think it has a transmission filter.

I asked my father-in-law to get a mechanic to replace the ATF and will find the result when I get back home later. I will post an update soon.

In case of overhaul and replacement, any idea how much it will cost and any preferred mechanic that can get the work nicely done?

**lowslowbenz** · February 18th, 2013 07:00 PM

Originally Posted by battcor

In case of overhaul and replacement, any idea how much it will cost and any preferred mechanic that can get the work nicely done?

Hi, I'm sorry but I have no idea on how much for parts and labor. Ang alam ko lang is for european brands, and its not cheap.

**yebo** · February 18th, 2013 07:10 PM

funny that the least used gear (reverse) ang sira. it could be as simple as a loose wire. pag hindi, planetary gear brake band, or the actuating piston, or solenoid. kung hindi pa din, OH na yan or replace.

di ba nabaha yan? baka hindi na-flush ng husto after flooding kaya nasira ang seals ng pistons ng brake band.

**battcor** · February 18th, 2013 07:39 PM

To : lowslowbenz,
Thanks.

Originally Posted by yebo

funny that the least used gear (reverse) ang sira. it could be as simple as a loose wire. pag hindi, planetary gear brake band, or the actuating piston, or solenoid. kung hindi pa din, OH na yan or replace.

di ba nabaha yan? baka hindi na-flush ng husto after flooding kaya nasira ang seals ng pistons ng brake band.

Yes, nabaha siya noong habagat at baka nga hindi na flushed na mabuti. But I'm still wishing for the not-so-worst-scenario.

Sa mga possible causes you've suggested, simple / mura lang ba ang repair?

Btw, shifting is good and smooth for other gears except lang talaga sa reverse.

**lowslowbenz** · February 18th, 2013 08:44 PM

^

The brake bands can be adjusted to specific limits, as in the case of Mercedes Benz. This is done to compensate for wear and tear of the bands due to usage, and is being done by a qualified transmission mechanic. I have no idea if this is possible in a Nissan gearbox, you can ask the opinion of a Nissan casa for this. If the gearbox had water intrusion, chances of rusty/stuck/corroded mechanicals are more likely.

**battcor** · February 19th, 2013 11:44 AM

Update: The mechanic was unable to check my car due to large volume of clients visiting his shop.

lowslowbenz, it is nice to hear that it can be adjusted. I hope this can also be done with my car.

We'll keep you posted. Btw, I already bought 4 liters of ATF and will buy one filter.

**yebo** · February 19th, 2013 12:00 PM

since nabaha yan most probably seals lang ng piston or rust sa piston area. baka palit lang ng seals ok na. hopefully hindi pa pitted ang sealing area. pacheck mo din wiring harness papunta sa solenoids baka naman rusted lang o poor contact.