Green E-300 DT

Anyone know if the '98 and '99 E-300 diesels come OEM with lockup torque converters the same as the gassers do?

I recently purchased ours, and I want to be sure that the car has a lockup T/C before I get into it with the dealer. It hast he Starmark Certified Guarantee, and if the T/C is bad, I want it fixed.

Anyone, please? Thanks in advance

Green E-300 DT

Just had the complete tranny overhauled, and guess what?

It still does not lockup!

So contrary to what other "know-it-alls" have to say on the subject, they simply don't lockup!

DslBnz

What is the E300 turning at say, 120 mph?

It seems the '97 420 I have is always locked up. I just know that the 12 valve version of the E300 turbodiesel(the '87 model) had a very high stalling torque convertor. You have to get close to redline before she starts locking up.

If you have a higher stalling TC, then at around 80 mph, your gauge should read about 3100-3200 in top gear. Not 2700.

Green E-300 DT

Here is what my '99 E-300 DT should be doing:

3.07 X 0.83 X 814 = 2074 rpm per mile or 34.569 per one mile per hour. So 80 mph should be 2765 rpm. My tack reads about 2800, but it is not steady because the T/C nevers locks up!

Your '97 E-420 which is the same as the kids car which they bought new:

2.82 X 0.83 X 814 = 1905 rpm per mile or 31.754 per one mile per hour. 80 mph should be about 2540. Is your tach steady at that speed?

The older diesels did not have an overdrive and didn't have a lockup T/C either. I think they had rather low gears, perhaps 3.46s?

DslBnz

No, the older six cylinder diesels all had lockup TC's. The one I have in my SDL deals with a 2.88 rear-axle.

The TC is so slippery, I can vary my engine speed at 40 mph from 1300 rpms - 3000 rpms all in fourth gear, depending on how much I push the pedal.

At 120 mph, the engine is turning a healthy 4550 rpms at full lockup(I observed with GPS accuracy).

BTW, on the E420, the tach is almost steady, (+ -)150 rpms depending on throttle.

Rick Miley

The torque converter on the 722.6 locks up fully only when the engine is over 3000 rpm.

Lightman

Nice post Derrel - I thought you were SO SURE they didn't have the converters, lmao.

As Rick has said, it only locks up at speeds old man derrel doesn't reach

The 722.6 definitely has a locking converter, no iffs ands or butts about it. As I posted the CHARTS from the MB tech info cd before, the torque converter is variable - it slips and engages at various rpm. I also posted that chart. Derrel just refuses to believe in the existence of the torque converter thats in his car. I've even posted a picture of the torque converter and it's various parts.

Don't feed the trolls!

Lightman

For those who haven't seen it, here is a screenshot from the tech info cd from mercedes. Derrel has seen this but refuses to believe it.
Torque Converter1

Lightman

Here's another.
Shot2

Lightman

And a third.. This one has the chart showing when the 722.6 locks up and when it slips..

Lockup Chart

Lightman

Here's a cutout view of the 722.6

722.6

Rick Miley

The chart clearly shows that the converter does not lock up below 3000 rpm, and even then only at less than 50% accelerator position. Mr. Green, did you test it in that region? I did (50mph in 3rd gear), and it does lock up.

Green E-300 DT

Thanks Rick for the information. Not sure, but I thought we did try it at higher speeds in all three top gears.

The question then:

Why would the stupid engineers wait until such a relatively high speed for the T/C to engage? That's over 87 mph when in overdrive. Seems practically useless at that high of a speed doesn't it?

Were they trying to insulate the vibrations from the crankshaft to the driveline? Never had that problem with the several stick-shift MBZ diesels I've had beginning with the 1961.

Most car will engage lockup at between 40 and 50 mph when in their top gear. How many of us "cruise" at 90 mph where these cars are supposed to be engaging the T/C lockup?

I'll try it again later today, and report the results here.

Green E-300 DT

You'd be surprised at the speeds I drive. I'm not at all like those other duffers you spoke of when you were on your own down in FL.

My most recent citation just last year cost me about $250 for 86 mph in a 70 mph zone. (That would have almost taken care of Speedtunings tariff!)
Out here, the CHP considers anything over 105 mph to be reckless driving, and they can and do take people directly to jail for that.

BTW, what is the highest speed you had your "Whitey" to, especially now that you've got all that extra power!

Green E-300 DT

Went out for a test-run with an open mind, but mine simply does not do like you guys are saying.

Tried it in all three top gears.

Third speed at over 65 mph (4000+ rpm)

Fourth speed at 95+ (4000 rpm also)

Over 100 mph in fifth (3500 rpm)

The tach is not steady even with the cruise control set. The slightest change is ground level, and the tach will move.

I've no way of knowing what percentage the throttle is, but especially in the lower gears, it dosn't feel like it is anywhere near 50 percent.

The only way to be sure would be to have that expensive tester that the dealer uses, and then what good would that be?

For all practical purposes, if it is indeed working, at such high speeds, it is of no use anyhow.

The question is:

Who knows how to wire around the computer to be able to manually ( electrically) make the T/C engage?
I know this can be done, but without the schematic, I haven't a clue as to how to do it.
Kerma ( Charlie M ) needs to be involved, or someone just like him. He was able to figure it out for his TDI.

michakaveli

Priceless