I've done a little bit of research on the 3.69 on this site but still am unclear how the different rear end ratios work. Can someone tell me what the positive and or negative effects of a 3.69 rear end would be on a 617 turbo. Thanks.

70 mph @ 4000 rpms,and 12 mpg.I love my 420 rearend

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1999 w140, quit voting to old, and to old to fight, a god damned veteran

Can somebody kindly post the vehicle, year, and model in their signature?

3.69 gear ratio is for a 240D

to the orginal poster:

You want a lower gear ratio since the engine will be screaming in terms of rpms. You want more of a ratio 3.46 and lower

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1986 300SDL, 211K,Dealership serviced its whole life
1991 190E 2.6(120k)
1983 300D(300k)
1977 300D(211k)

The question was not related to which vehicles have the 3.69. I've figured that out by now...........

The question was related to which vehicle is possessed by the OP.

You cannot tell the OP what he wants until you figure out what he has...........

why would someone want to switch to a 3.69 diff who has a something other than a 240D

The diff ratios for each model werent randomly picked, it was figured out by engineers for a reason...

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1986 300SDL, 211K,Dealership serviced its whole life
1991 190E 2.6(120k)
1983 300D(300k)
1977 300D(211k)

Clearly he has done some research and is interested in the 3.69. You might conclude, therefore, that he doesn't currently have a 3.69...........because, if he did have a 3.69............he wouldn't be asking about a 3.69.

Another clue for you: "617 turbo"..........in the OP.

Thanks for your help oracle. To make Brian happy, I have a 84 euro 240d. I didn't list that in the original thread because it really wasn't relevant to my question. I know how the 3.69 works in the 240d. I wanted to know how it would work with a 617 turbo regardless of the model. Now I know it is not an ideal choice.

Guess he thinks hes smarter than the mercedes engineers...

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1986 300SDL, 211K,Dealership serviced its whole life
1991 190E 2.6(120k)
1983 300D(300k)
1977 300D(211k)

It would make a 617 turbo be an absolute screamer around town. If you won't be going 70 mph on the highway, it'll be excellent.

The downside is that any highway trips above 50 mph will cause the engine to turn excessively fast with resulting noise and wear.

It's a perfect differential if the transmission had a .70 overdrive gear.

Simple: A 3.69 with a 617 turbo would give you rapid and awesome acceleration up to about 85mph....then you'd be nearing redline. At 70 the rpms would be way too high.

Ideal is a 2.88......for slightly slower performance but even better economy (and even quieter)....a 2.47

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-diesel is not just a fuel, its a way of life-
'15 GLK250 Bluetec 118k - mine - (OC-123,800)
'17 Metris(VITO!) - 37k - wifes (OC-41k)
'09 Sprinter 3500 Winnebago View - 62k (OC - 67k)
'13 ML350 Bluetec - 95k - dad's (OC-98k)
'01 SL500 - 103k(km) - dad's (OC-110,000km)
'16 E400 4matic Sedan - 148k - Brothers (OC-155k)

You'd have a creeper first gear.

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[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.

Which could come in handy for hauling heavy equipment around a farm!

__________________
-diesel is not just a fuel, its a way of life-
'15 GLK250 Bluetec 118k - mine - (OC-123,800)
'17 Metris(VITO!) - 37k - wifes (OC-41k)
'09 Sprinter 3500 Winnebago View - 62k (OC - 67k)
'13 ML350 Bluetec - 95k - dad's (OC-98k)
'01 SL500 - 103k(km) - dad's (OC-110,000km)
'16 E400 4matic Sedan - 148k - Brothers (OC-155k)

I have a 3.69 behind my 617 turbo...the gearing is too high. I am planning to swap it out.

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1979 240D- 316K miles - VGT Turbo, Intercooler, Stick Shift, Many Other Mods - Daily Driver

1982 300SD - 232K miles - Wife's Daily Driver

1986 560SL - Wife's red speed machine

3.69 will give great acceleration until it hits redline at 85mph. MPG will be worse, but not severely bad.

I swapped a 3.46 into my 300, while its tolerable ("sweet spot" cruise speed is 75mph/3500rpm) I'm definitely going to switch back to a 3.07.