QuestionQUESTION: looks like for about three times the cost of the car it might be possible to
drive down the road and look mercedes and yet really be a chevy.
I guess the primary issue is the lowering of the rear end ratio. it is my
understanding that the 420 has 2.47 gears. I am lead to believe that will
produce a 3200 rpm running down the road, caughing up gas milage of 15 or
less. I also am lead to believe that a 15% change in rear end ratio will push
the rpm down, and reduce the fuel consumption to near 25 MPG>.
an alternative suggestion is to replace the mercedes rear end with a ford 9
bolt rear end... how woud it be mounted. the mercedes swings from the
center, the ford would basicly be solid streight across.
Please straighten me out on this...
John
ANSWER: Well you left out some dates ( of the cars) , but you are right. A 380 with a 2.47 rear end and I can cruise at 70 showing approx 3000 RPM. Lower diff gear ratio offers better fuel economy and less zip. It also lets the engine turn less rpm and will make it last longer. Most of the 380's had the 2.47 rear end, not sure all the 420's did. . If you spend a lot of time on the highway, you will be rewarded with much quieter and smoother operation of the car. That being said, the downside is that there is slightly less acceleration off the line and slightly more need for downshifting in hilly areas. YOu probably could expect about 1, maybe 2, MPG more than the 3.07 in highway driving. 25 MPG out of a V8 Mercedes is not common, no matter what the rear end.
I do not believe a Ford rear end will go in the MB,unless you replace the whole drive train and eliminate the half shafts.
I am just not sure because I am not real familiar with Fords. I do know some have repalced Ford 4.0 and 5.0 drivetrain and engines in MB's, but it is quite a job.
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QUESTION: the mercedes is a 1986 4 door
Timing chain broke bent valves driver side
Benz been sitting 4-5 years. Valve job quoted at 2200. New rebuild on fuel
injected 350 $1100 new trans about same... Motor & trans latemodel
I'm lookin to slow the motor down for economy, been drive 4 cyl and v-6
Your turn
John
ANSWER: no matter the rear end you put behind a V8 MB engine from the 70's thru late 80's you are not going to get 25MPG, 16-18 at best with the 2.47
That is providing the D-Jet or later electronic L or K-Jet engine is functioning at its peak
---------- FOLLOW-UP ----------
QUESTION: I think your picturing me putting the gears FROM a 9 bolt ford rear end INTO
the swing axel of the existing 420 mercedes.... no, that's not what I have in
mind, although if it would work the gears for the 9 bolt are readily available.
I was thinking if we took the entire rear end out of the mercedes, how would
the straight axel/rear end mount.
It would be a given that we would have to shorten the drive shaft, i picture
the chevrolet 700 transmission as longer than the existing MB transmission.
CAN YOU POINT ME AT SOMEONE THAT HAS REPLACED THE ENTIRE DRIVE
TRAIN FROM A 400 SERIES MERCEDES SEDAN CAR? I DON'T MIND A
REASONABLY SLOW TAKE OFF, IF I CAN AVERAGE 20 MPG IN AND OUT OF
TOWN.
THANKS
JOHN
AnswerGotcha, Ok I have never heard of anyone doing this but I suspect it COULD be possible. MB have a very sophisticated rear end mount so other than just welding up some brackets to bolt to I am pretty certian there is no other way. Shortening a drive shaft and throwing off the balance would be of some concern.
I will post this question to some of my cyber MB friends and see what I can find out for you.
stay tuned
Ron
