Harsh shifting on rebuilt transmission

[Nickrogers610]

so my car had its transmission rebuilt a couple years ago, but the car was parked for 2 years and only got about 20 miles on it. In this 2 years, the battery went complete dead and sat like this for over a year and a half. Well now that the car is driven again, the transmission seem sot shift odd, when coming to a stop it will downshift hard, and when doing 40 or so and you floor it, it will jerk forward. what could be the issues?

[Oday0111]

so my car had its transmission rebuilt a couple years ago, but the car was parked for 2 years and only got about 20 miles on it. In this 2 years, the battery went complete dead and sat like this for over a year and a half. Well now that the car is driven again, the transmission seem sot shift odd, when coming to a stop it will downshift hard, and when doing 40 or so and you floor it, it will jerk forward. what could be the issues?

Honestly just sounds like a atf fluid issue. If your car sat for awhile maybe your fluids went bad. Try changing your trans fluid. I would even go ahead and change all fluids just because gas goes bad in itself about a year sometimes sooner depending on weather conditions. Either that or there might be something wrong with your ecu yelling the car when to shift and what not. The computers might get messed up from your battery draining. If you have any type if scanner I would check for codes. Other then those 2 the only other option I see is maybe the rebuild wasn't done right.

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[HOFFMANN707]

Check the operating temperature of your tranny. Especially if those symptoms aren't there when cold.

[Nickrogers610]

SO i went on a short drive today, it shifted fine until the fluid was warmed up, it doesn’t slip at all, but the gear changes are harsh, especially when slowing down like said, but it’s almost like is hunting for gears more then anything.

[kouks]

If it works when cold and not when warm, it could either be a valve body issue, or a fluid issue, since the fluid is less viscous when warm. It could also be a cooling issue, it the fluid is getting too hot the shifts will be rough.

- Start by checking fluid level (there are plenty of threads and info on youtube how to do it).
- If thats OK, make sure the fluid is Pentosin ATF1 or Lifegaurd5 (OEM fluid). Thats what the trans was built to use. There are other oils, like Valvoline MaxLife that other use that work OK too. The OEM fluids are clear or slightly tan, the others are red. You need to ask what type of fluid they used. There is a transmission thread in the DIY section above that details fluid in the 5hp24.
- If fluid type is OK, then check fluid temp. If its getting too high, the oil cooler has an issue, there are threads on that too.
- If thats OK, then you have to start getting into the trans, like take it back to the rebuilder and find out what the warranty is.

It definitely sounds like a fluid issue though, if the trans was broken it would work badly even while cold. The other mechanical problem could be the valve body, since it uses different passages for cold versus warm operations.

[chrisn7]

From 1/97 on, the 740i/iL original gearbox oil was Esso ATF LT 71141 - and that was the only fluid to be used. This was subsequently re branded as Mobil LT 71141 which is still available.

I would re-check the fluid level which has to be done with engine running, on a level surface, when the box oil temperature is between 30 and 50C - the nearer to 30 the better.