1972 280 CE increasing final drive ration / lower RPM for cruising

[Joker]

Hi Guys

This may be a straight NO but when I was into VW's it was relativly straight forward to swap the transaxle to increase/decrease final drive. I am looking at a 280CE that has been fitted with Air suspension and 13 inch wire wheels (pimped but still nice looking) Anyway, my 300SEL running 14's already revs to 3000 at 60MPH and I asked the guy what his car is like at 60mph and he says it is revving higher as you would imagine. This is not good for fuel/noise so...

Is it possible to up the final drive in the trans by swapping things round in the transaxle? or by swapping the transaxle for a different model? (Its a 4 speed floor shift auto btw)

Im not talking about swapping the whole gearbox here just the back axle where the diff is?

Your help appreciated

Rich

[t walgamuth]

i dont know from experience about your specific car but in general there is a wide interchangibility between benz models. so there is amost certainly another rear end that you can swap in pretty easily to lower your cruising rpm. you probably will need to change the speedo too.

tom w

[Mark DiSilvestro]

My reference gives a 3.69 rear axle ratio for the W114 280CE. You may be able to fit a 3.07 rear as fittd to the '70s W107 450SL or W116 450SE, though I'd also get rid of those 13-inch wires and change back to the original 14 inch rims, or maybe go with Mercedes 14-inch bundt-cake alloys.

Happy Motoring, Mark

[t walgamuth]

marks suggestion will yeild the equilivant of about 17% OD, which will be noticable but probably wont kill acceleration too much.

good luck in finding one. i suspect they are around but not thick on the ground (as the brits would say).

tom w

[Joker]

Originally Posted by Mark DiSilvestro

My reference gives a 3.69 rear axle ratio for the W114 280CE. You may be able to fit a 3.07 rear as fittd to the '70s W107 450SL or W116 450SE, though I'd also get rid of those 13-inch wires and change back to the original 14 inch rims, or maybe go with Mercedes 14-inch bundt-cake alloys.

Happy Motoring, Mark

Hi Mark

Cheers for that, very informative and just the information I was looking for. I will begin to monitor ebay UK for these two vehicles. There are some places that break the older Mercs here but prices are loaded up!

Gotta keep the 13's I think due to the air suspension... although maybe 14's at the back and 13's up front would still be ok... might investigate that option first seeing as it would be much easier

Thanks to all others who replied as well

Rich

[dieseldiehard]

I am using a 3.07 (removed from my '83 300D turbo) behind a little 220 (W115 chassis w/ stick shift) and its great not having the engine all wound up revving at 60 MPH. I can live with a little less acceleration as a trade off and get better fuel mileage as a bonus.
A 3.07 should work well and the 123 chassis differentials fit the 114/115 chassis fine.