1995 E300D transmission and brake behaviour - PeachParts Mercedes-Benz Forum

Zulfiqar · #1 04-20-2011, 12:44 PM

Sorry for the noob question - but when driving on the freeway the car feels powerful YES - but the engine spins up to 3000 rpm while cruising, and seems that the torque convertor never locks. Mind you I have been driving Japanese A/T cars mostly. e.g. in my old 97 camry you could feel the convertor lockup at 45 mph.

This car feels like it needs another gear to shift or needs its convertor to lock

on the brake bit - what should be the ideal pedal height on this car - the FSM tells you to put in certain amount of force etc. Comparing to a jap equivalent it feels a little low - any easy way to adjust?

babymog · #2 04-20-2011, 02:20 PM

The brake pedal is self-adjusting I believe, you might need to bleed the system.

There is no lockup torque converter on your car.

Chris W. · #3 04-20-2011, 05:28 PM

Zul,

Why not post the exact speed you are going when your tach reads 3000 rpm, or 2500 rpm or whatever benchmark you want. The the rest of us with this car can comment. This assumes you still have the stock tire size of 195-15.

Rgds,
Chris W.
'95 E300D, 338K

Skippy · #4 04-20-2011, 08:08 PM

Quote:

Originally Posted by babymog

There is no lockup torque converter on your car.

That's surprising, considering the level of technical sophistication Mercedes had even way back in the day (ie 4 wheel independent suspension and 4 wheel disc brakes on my '71). Ford had a form of torque converter lockup* as early as 1980.

*Instead of an actual lockup clutch, the AOD transmission used two input shafts, one inside the other. The outer shaft transferred the output of the torque converter into the transmission and was used for first and second gears. The inner input shaft turned at engine speed with the torque converter housing and provided power when in third and fourth gears.

babymog · #5 04-20-2011, 10:34 PM

It is a bit annoying, I'd like to have a little better fuel economy. On the other hand, every time I drive my wife's Oldsmobuick GM crap, or the Suburban, or the Phord E150, all with AOD and lockup TC, I remember how annoying it is to have the damn thing drop out of lockup and sometimes even downshift on such light grades on the freeway, ... where the '87 will chug up a 3% in 4th without any drama on the cruise control.

Each has its disadvantages.

vstech · #6 04-20-2011, 10:51 PM

remember this vehicle has a low horsepower high torque engine. it also has a steep rear end gearing for lower cruise RPM's but the low HP needs a torque sweet spot and 2-3500 is it. American cars went the way of lockups to eek additional economy from their vehicles with ancient pushrod carbed, then throttle body injected engines... which pushed their beasts from low teens to high teens in economy... the MB had mid to high 20's then 30's and 40's in your vehicle... during the same time period...

babymog · #7 04-20-2011, 11:08 PM

I wouldn't say too low HP and torque, even stock at 148/195 it is probably close to a 5.0L V-8 in the mid-'80s.

I sold cars back in the early '80s. It was always fairly well-known back then that an American car rated at 25MPG would seldom do that well, where a German or Japanese car rated at 25MPG would usually do 10%-20% better. Same with HP, the Germans usually rated a car based on testing series engines and calculations that all cars should be able to meet or exceed, where the US numbers pretty much came from hand-built test engines.

It seems that the 302 & 305 engines were rated around 155hp in the mid-'80s.

Anyway, since fuel mileage ratings were so important back then, anything that could get the engines turning slower (overdrives and lockup TCs) was good for the EPA test cycle, even if they were annoying and somewhat impractical in the real world.

vstech · #8 04-20-2011, 11:16 PM

good point... but I don't think I remember the 80s boats with under 150HP. the 90s boats SURELY did not have less than 250HP
also, the turbo motors have to spool past 2000rpm to be at the rated HP, and the american boats did not. so even if they (5.0's and such rated at 150HP, had it at very low rpm's and a broad range of power... )
I sure do remember the 70s boats, and they sure did have pitiful 5.7L motors with under 150HP... a sad time for cars...
the MB's were always leaders in economy and engineering.

Quote:

Originally Posted by babymog

I wouldn't say too low HP and torque, even stock at 148/195 it is probably close to a 5.0L V-8 in the mid-'80s.

I sold cars back in the early '80s. It was always fairly well-known back then that an American car rated at 25MPG would seldom do that well, where a German or Japanese car rated at 25MPG would usually do 10%-20% better. Same with HP, the Germans usually rated a car based on testing series engines and calculations that all cars should be able to meet or exceed, where the US numbers pretty much came from hand-built test engines.

It seems that the 302 & 305 engines were rated around 155hp in the mid-'80s.

Anyway, since fuel mileage ratings were so important back then, anything that could get the engines turning slower (overdrives and lockup TCs) was good for the EPA test cycle, even if they were annoying and somewhat impractical in the real world.

JimmyL · #9 04-20-2011, 11:35 PM

Quote:

Originally Posted by Zulfiqar

Sorry for the noob question - but when driving on the freeway the car feels powerful YES - but the engine spins up to 3000 rpm while cruising, and seems that the torque convertor never locks. Mind you I have been driving Japanese A/T cars mostly. e.g. in my old 97 camry you could feel the convertor lockup at 45 mph.

This car feels like it needs another gear to shift or needs its convertor to lock

Over-thinking that a bit maybe?
I never had a similar feeling in my '95, of course I've never had a Jap-slushbox I can compare it to.
Drive it, enjoy the smooth power and the 32-35mpg on the hwy.
Worry more about your next glow plug change........

Skippy · #10 04-21-2011, 12:09 AM

Quote:

Originally Posted by babymog

I wouldn't say too low HP and torque, even stock at 148/195 it is probably close to a 5.0L V-8 in the mid-'80s.

It seems that the 302 & 305 engines were rated around 155hp in the mid-'80s.

My '86 Lincoln Town Car was rated at 150hp@3200 rpm and 270 ft-lbs@2000. Straight line performance was about even with my 300D. This was the first year of SEFI and hydraulic roller cams in that particular platform. The previous couple of years had a flat tappet hydraulic cam and CFI (Ford's term for throttle body injection) and were rated at something like 130 hp. I don't remember the torque, but it wasn't great either.

As late as 1989, GM was putting out a 307 V-8 that made all of 140 hp. My dad had one in a Cadillac Brougham. The performance wasn't as abysmal as the numbers make it sound, but it wasn't winning any races (unless my 240D was around

).

babymog · #11 04-21-2011, 12:17 AM

I was selling (among others) Fiat in '81. We also had Oldsmobile and others. The Fiat Spider 2000 (2liter Bosch L-Jetronic injected DOHC I-4) had more torque below 2000rpm than the 305 V-8 that we had across the parking lot in the Oldsmobile store. The Fiat Brava (sedan, same engine) was a pretty decent performer in comparison.

We kept an Oldsmobile in our Honda showroom to sell Hondas and Fiats by comparing the quality, it even made the Fiats look good.

Sad years.

chazola · #12 04-21-2011, 06:06 AM

Vstech explained it best, also remember these are German cars designed mainly for German roads- i.e the autobahn with sustained cruising at high speeds coupled with the need to make fast overtaking at speed safely. The engine's are not really designed to pootle along at 55mph, they're at their happiest at 2500-4000rpm or so sitting at 80-90mph, they can feel 'flat' at low speeds and have pretty average performance 'till you hit that 'autobahn sweet spot'.

Skippy · #13 04-21-2011, 09:48 PM

It was explained to me as, "Mercedes and BMW's are built carefully, with good components, by people who seldom drive below 30 mph."

The same source indicated that Fiats are made poorly out of cheap parts, by people who can't afford cars, but would drive Ferraris if they could.

Zulfiqar · #14 04-21-2011, 10:10 PM

update - to the question

I have 3000 rpm at 70 mph.

Skippy · #15 04-21-2011, 10:15 PM

That's about what I get in my 300D. I think-the tach only works once in a while. I believe the W210 has a considerably taller rear end. How many shifts are you getting from a dead stop?