5 spd auto swap 4 spd

[mcfir7]

hi guys i m driving a 300se w 140 which come wit auto 5 spd in malaysia.i got problem wit my gear selector as it doesn stick to D but stick only at 4.so after using sometime i got to fix this up.

my mech advise to change to the auto 4 spd from a s280.this is much cheaper to mine to rebuilt or replace.n he said will give less problem n cheper to fix in future.

can someone give me advise n any opinion on this pls

[Kaz]

Yes, what your mechanics said was true. The parts require to fix the 5th speed alone cost more than the rest of the transmission rebuilt. However, replace only the 4 speed transmission alone isn't enough, several things you will/might have to replace are

1. Rear differential
2. Rear axle shafts
3. 4 speed trans. is shorter therefore you will need a new propeller shaft
4. If you don't manually shift the transmission then you might still keep the old transmission seclector
5. ECU <------- I'm not sure about this

[deanyel]

Not entirely clear what he swapping (722.5 for a .3/.4?) but I would say if the mechanic thinks he can do it let him try. Clearly the 4 speeds are cheaper to rebuild and to purchase as rebuilt units. I would say most people consider them more durable as well.

[mcfir7]

how bout the performnace guys?n the fuel consumption?will it be bad?

[deanyel]

Originally Posted by mcfir7

how bout the performnace guys?n the fuel consumption?will it be bad?

Fuel economy will likely suffer a little but it shouldn't be that bad - maybe a mile or two per gallon. At the link below you can track some Mercedes that transitioned from 4 speeds to 5 speeds in the 1995 to 1997 timeframe.

http://www.fueleconomy.gov/feg/findacar.htm