Are 124 transmission interchangeable? - PeachParts Mercedes-Benz Forum

babymog · #1 10-04-2009, 05:04 PM

What is wrong with the transmission, perhaps we can help.

They are interchangeable, but:

The 300E transmissions start in 2nd gear, extremely annoying IMO. If you can find an E320 transmission for the 1st-gear-start, or another '87 300D it would be simpler.

Also, is your torque-converter good? The torque-converter will have a different (higher) stall-speed on the 300E, not a deal-breaker but you will probably lose just a little fuel mileage.

If the valve-body is okay in your 300D, that is another option, use the 300D valve-body in the 300E transmission to retain the 1st-gear start.

If I remember the gearing is also slightly different, but 4th-gear is 1:1 (minus TC losses) on both so you'll be fine there.

Last, I'm not sure where the speedometer ratio is changed for the different diff-ratio, likely in the speedometer but I'm not sure, someone else might know if this swap will affect your speedometer.

bsmuwk · #2 10-04-2009, 05:17 PM

Quote:

Originally Posted by babymog

What is wrong with the transmission, perhaps we can help.

They are interchangeable, but:

The 300E transmissions start in 2nd gear, extremely annoying IMO. If you can find an E320 transmission for the 1st-gear-start, or another '87 300D it would be simpler.

Also, is your torque-converter good? The torque-converter will have a different (higher) stall-speed on the 300E, not a deal-breaker but you will probably lose just a little fuel mileage.

If the valve-body is okay in your 300D, that is another option, use the 300D valve-body in the 300E transmission to retain the 1st-gear start.

If I remember the gearing is also slightly different, but 4th-gear is 1:1 (minus TC losses) on both so you'll be fine there.

Last, I'm not sure where the speedometer ratio is changed for the different diff-ratio, likely in the speedometer but I'm not sure, someone else might know if this swap will affect your speedometer.

The speedometer will be effected when the differential is changed. Changing just the transmissions won't effect the speedometer. From reading his Benzworld post, he's using 225/55 tires so he's off on his speedometer anyway.

pawoSD · #3 10-04-2009, 06:22 PM

Quote:

Originally Posted by babymog

What is wrong with the transmission, perhaps we can help.

They are interchangeable, but:

The 300E transmissions start in 2nd gear, extremely annoying IMO. If you can find an E320 transmission for the 1st-gear-start, or another '87 300D it would be simpler.

Also, is your torque-converter good? The torque-converter will have a different (higher) stall-speed on the 300E, not a deal-breaker but you will probably lose just a little fuel mileage.

If the valve-body is okay in your 300D, that is another option, use the 300D valve-body in the 300E transmission to retain the 1st-gear start.

If I remember the gearing is also slightly different, but 4th-gear is 1:1 (minus TC losses) on both so you'll be fine there.

Last, I'm not sure where the speedometer ratio is changed for the different diff-ratio, likely in the speedometer but I'm not sure, someone else might know if this swap will affect your speedometer.

The torque converter on the 300E is a higher stall speed? What is it on the diesels? Its only 1600rpm on the M103 300E's.....too low in my opinion....