Better gear ratio for W123 Diesel – What axle would fit ?? - PeachParts Mercedes-Benz Forum

t walgamuth · #1 11-14-2008, 07:32 PM

you need to calculate your effective gear ratio. if it actually reduces rpm 10% then the actual mileage is 22. likewise the speed will be higher so if it reads 60 the actuak would be 66.

the 81 is na so the diff would be 346.

charmalu · #2 11-14-2008, 10:21 PM

Look in the resources tab above and click on DIY articles. A good write up on R&R a Diff.

See Post #2 above for 2:88.

Charlie

#3 11-14-2008, 10:57 PM

Quote:

Originally Posted by t walgamuth

the 81 is na so the diff would be 346.

For the 300D/CD, yes. The 300TD was the first non-300SD turbo in 81 so it should be 3.07.

t walgamuth · #4 11-15-2008, 12:00 AM

Actually, according to my mb illustrated buyer's guide the cd was turob in '81 too. I wouldn't be surprised if it was a mid year change over.

#5 11-15-2008, 12:21 AM

Quote:

Originally Posted by t walgamuth

the cd was turob in '81 too.

I have yet to see a genuine one.

t walgamuth · #6 11-15-2008, 08:44 AM

Quote:

Originally Posted by t walgamuth

Me either, thats why I quote the book. I do have an 82 300cd though. Its a turbo.

of course the coupes are even more rare than the wagons.

I seem to remember a road test of the first turbo and in my mind it was a coupe, but I have not searched for the magazine......it may be in a road and track in my basement.

I would have said neither the 126 msd, coupe or wagon came with the turbo to the states until 82.... but it may also be kindof a model year thing too....an 82 model year built in 81, though benz generally ignores model years.

I wrote this to respond to forced last night but forgot to hit submit apparantly.

H-townbenzoboy · #7 11-15-2008, 12:57 AM

Quote:

Originally Posted by t walgamuth

Actually, according to my mb illustrated buyer's guide the cd was turob in '81 too. I wouldn't be surprised if it was a mid year change over.

There were no 1981 model year 300CD turbo diesels. All 1981 model year 300CDs were normally aspirated. Around 8/81 or 9/81, production switched from non turbo to turbo 300CDs, and while they made a few hundred 300CD turbo diesels in late 81, they were all 1982 model year vehicles.