3.46 Differential - PeachParts Mercedes-Benz Forum

rudolfgreen · #1 12-15-2007, 10:29 AM

Picked this up to put in my 240 Manual..but then ended up selling her. $50+S&H.

jkoebel · #2 12-15-2007, 11:18 AM

Would a 3.46 be an upgrade or downgrade from whatever is in my '83 240D Auto?

t walgamuth · #3 12-15-2007, 11:23 AM

It will slow your engine at highway speeds and sacrifice acceleration. Probably will give a little better fuel economy too.

Tom W

Hit Man X · #4 12-17-2007, 08:16 PM

Quote:

Originally Posted by rudolfgreen

Picked this up to put in my 240 Manual..but then ended up selling her. $50+S&H.

Get me a shipping quote to 77079

Mustang_man298 · #5 12-17-2007, 09:53 PM

Quote:

Originally Posted by jkoebel

Would a 3.46 be an upgrade or downgrade from whatever is in my '83 240D Auto?

Your 83 should be the same as both my 80 and 82, which have 3:69's in them. As Tom said, you'll get a bit better mileage, little slower on the takeoffs, and the engine won't be running as hard on the high speeds.

I found an 80 300SD out in the wrecker a little bit ago, wasn't sure if the diff would fit in my 240 or not, it had a 3:07 in it, I probably should have jumped on that...especially since I'm going to do a manual conversion.

Hit Man X · #6 12-17-2007, 09:55 PM

Quote:

Originally Posted by Mustang_man298

Your 83 should be the same as both my 80 and 82, which have 3:69's in them. As Tom said, you'll get a bit better mileage, little slower on the takeoffs, and the engine won't be running as hard on the high speeds.

I found an 80 300SD out in the wrecker a little bit ago, wasn't sure if the diff would fit in my 240 or not, it had a 3:07 in it, I probably should have jumped on that...especially since I'm going to do a manual conversion.

With 62-67hp, 3.08:1 isn't enough gear.

t walgamuth · #7 12-17-2007, 10:57 PM

Right. IMHO, on a 240d a 346 is pushing it but probably will work on an automatic, but the acceleration will be galcial. Since the acceleration is glacial with a 240 automatic already it probably will not make all that much difference.

but I would not not not recommend a 307 with a 240. taking off will be very very hard on the clutch and you will probably fine fourth gear all but unusable.

I would recommend sticking with the 369 in a 240, really.

Tom W

jim16671836 · #8 12-18-2007, 07:38 PM

I think it will make about a 8 percent difference in distance traveled at the same rpm at highway speeds... traveling 30K a year getting 25 mpg you could save approx. 100 gallons of fuel... Some one needs to check this... Jim

rudolfgreen · #9 12-18-2007, 08:00 PM

Quote:

Originally Posted by Hit Man X

Get me a shipping quote to 77079

a quick ups estimate (@40lbs) was $40.59

actually find the 2.47 matched to the 617 turbo actually provides quicker overall acceleration due to staying in gear longer..
this would be an ideal mod for a manual trans for the same principle.. 1st gear is near useless with the 3.69, having to change gear..

t walgamuth · #10 12-18-2007, 11:48 PM

First gear with a 240 and 369 is not useless.

Were you by chance talking of a 617 conversion using the 369 diff?

Tom W

rudolfgreen · #11 12-19-2007, 06:36 AM

Tom.. we always have battled this viewpoint.

the stock gearing is just too short.
And would not ever be thinking 617.952/3.69.. unless the goal was burnouts.

t walgamuth · #12 12-19-2007, 07:13 AM

I would like to see your acceleration test to verify the claim of faster acceleration with the taller diff. Please tell that to anybody involved in running the quarter mile for acceleration. I think you will be laughed out of the place.

Tom W

fast68 · #13 12-19-2007, 10:25 AM

do these cars have a typical conventional rear axle such as like american cars and so on ?

or are they different/unique ?

anyone got a pic of a rear axle under one of these cars ?

thanks for anything

t walgamuth · #14 12-19-2007, 10:42 AM

Quote:

Originally Posted by rudolfgreen

Tom.. we always have battled this viewpoint.

the stock gearing is just too short.
And would not ever be thinking 617.952/3.69.. unless the goal was burnouts.

Come to think of it I did have a 74 240 in which the first gear felt too low. I have never felt that way in a stick though.

Tom W

rudolfgreen · #15 12-19-2007, 07:54 PM

Quote:

Originally Posted by t walgamuth

I would like to see your acceleration test to verify the claim of faster acceleration with the taller diff. Please tell that to anybody involved in running the quarter mile for acceleration. I think you will be laughed out of the place.

Tom W

agree with that statement..but find the taller ratio is seemingly always in the sweet spot of the power band and just works out.
in the 240, would always be travelling a little too fast for third, and a little too slow for fourth..the 3.46 would have solved this.