Mercedes-Benz Forum banner

Manual transmissions and differential ratios

3K views 3 replies 3 participants last post by  Dr.Grillz 
#1 ·
I'm trying to see what I'm getting myself into and would like some expert opinions from the peanut gallery.

My understanding is the stock differential for a M110 6-cyl 280 is 3.58. These motors came with automatic, 4-speed and 5-speed manual transmissions but retained their 3.58 differential ratios.

My question is, besides the speedometer reading issue which can be corrected with the correct speedometer, what would I expect to happen if the 5-speed manual transmission is mated with a 2.88 differential ratio? I should expect lower RPM's at higher speeds, but would this make the car very slow at acceleration?
 
#2 ·
I think you have answered your own question. Your shift points will be higher speeds, and 1st gear may end up feeling pretty sluggish off the line. The m110 engine is not very torquey, so you may end up stalling in first, maybe burning up the clutch a little faster.

The m110 is most impressive around 4000-6000 rpms, the reason it is so great to have mated to a stick shift.

I have a 280sl 5-speed, and used to have a 280slc 4-speed, both with 3.58 I think. While highway cruising, I did find myself trying to shift into a non-existent 5th gear in the 280slc. But on the contrary, I find myself downshifting to 4th for highway passing in the 280sl 5-speed.

If you've got overdrive, I think you are best to stick with the 3.58.
 
#3 ·
What he said.

The tall gearing may improve matters for the slush 'box, or even the 4-spd manual. But the only thing the combination of overdrive gearing with a tall final drive will cause is lugging the engine. You will not have an improvement in fuel consumption, and you will not be doing the engine any favours, as these engines prefer running between 3000 and 4000rpm. Yes, they are fantastic at higher revs, but also thirstier.

While my car was still a M102-powered 200, I never even contemplated fitting s W124 5-spd manual, even though I had one lying around, and it would bolt up with no issues. Why? Because the car is optimally geared for the gasser.
 
#4 ·
Thank you, gentleman for the responses.:grin

Good to know as currently I have a 2.88 ratio with a 4-speed manual and although its "OK", I feel it would benefit from a performance sake to go back to a 3.58 with a 5-speed. I was worried, and rightfully so, that a 2.88 with a 5-speed on a 280 may not be a good idea.


Fonzi, do you have any 3.58 diffs for sale? I know of one about an hour from where I live.
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top