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Diff Ratio's

Started by AMG69, 21 November 2005, 08:09 PM

AMG69

I'm curious about the advantages / disadvantages and cost of changing the final drive ratio in my 6.9 from 2.75:1 to say something like 3:08 to give it more low down and mid range acceleration. Have many M100 owners done this? I can honestly say my car exceeds 140kmhr about once a year and I really dont care if its top speed reduces from 225km/hr to under 200; I guess the only issue bothering me is that I will do a bit of country cruising (esp down to the Margaret River wine region here in WA!) and would prefer not to have the engine spinning (slurping!) at over say 3000rpm at 100km/hr. In summary I guess I'd love to know if anyone has "played around" with their diff ratio and how easy / expensive is it to swap and was it been worth it, tips, thoughts..........
sigh....sitting back contemplating the next purchase..!

Captain Spalding

Quote from: "Chris M"I'm curious about the advantages / disadvantages and cost of changing the final drive ratio in my 6.9 from 2.75:1 to say something like 3:08 to give it more low down and mid range acceleration.

I am new to the 6.9, but I have two G-Wagens, and have investigated the possibility of re-gearing the diffs on them. The parts are rare and expensive. The ring and pinion must be bought as a matched set. There is a set of special tools required to do the job - only three of those exist in the U.S.. The whole idea turned out to be too impractical and I abandoned it. (of course, the G-Wagen has two diffs, so maybe not as impractical for a sedan.)

I don't know if the rear axle of a standard 450SEL is mechanically compatible with the suspension/driveshaft/et al of a 6.9, but the standard's axle has a 3.07 diff, and the track is identical. Maybe you could get a 450 SEL axle from a yard and swap it into your 6.9. I think you'd be sacrificing the limited slip, though, as I believe the 6.9 has it and the 450SEL doesn't.  I can say with near certainty that it would be cheaper than re-gearing your own diff. Just a thought.

Sorry I don't have any real facts for you. Hopefully someone else will chime in.

? Spalding

Mforcer

Quote from: "styria"Hi ChrisM, check out http://www.sechsneuner.de/fahrzeuge/amg-69/index.html-this thread, whilst in German, will answer some of the queries you raised in your previous post. You may also note that the car DOES Not have the AMG front spoiler.
I can't read German but that car seems to have the same style rims as mine but 17" or possibly 18" rather than my 16". My car is even the same colour :) The rear of the car looks interesting without the three-pointed star.

There is one thing that suggests to me that it is not a genuine AMG is that during the 1970's the AMG logo was just AMG and not ///AMG. Old-school AMG gear does not have the /// stamped anywhere and I suspect that this changed in the late 80s although not certain. The badge on the boot is certainly not old-school.

I am also still trying to work out when the AMG disc wheels commonly referred to as monoblocks were first produced. Does anyone know?
Michael
1977 450SE [Brilliant Red]
2006 B200

AMG69

Def.not an original AMG; Original AMG's deleted the 450 badge and replaced it with old style AMG badge on LHS of boot.  As for the wheels they came out in about 1984 I think - I have an AMG brochure from that year which shows only two types available - up to 17 inch.  The five spoke "Penta" we are all familiar with and the type shown on that car.
sigh....sitting back contemplating the next purchase..!

Mforcer

Not wishing to take another discussion off-topic :wink: , I would not be surprised to see the AMG badge on the RHS of the boot - if the car owner wanted it there AMG would put it there - but one thing AMG would not do is change their logo at a customers request.
Michael
1977 450SE [Brilliant Red]
2006 B200