1985 300D TD Transmission (california) - PeachParts Mercedes-Benz Forum

wagonhorse · #1 02-26-2013, 09:26 PM

I hope your evening is going better than mine. My transmission went out as I was pulling on the interstate. Now only first gear and reverse work. When shifting into d or second the engine starts in first and then at the shift point where second gear should kick in it starts to shift the nothing. Any ideas before the tranny shop?

mach4 · #2 02-26-2013, 09:59 PM

I'll let others comment on the troubleshooting aspects.

The only thing I would suggest is, that if you get to the point of needing to rebuild, consider getting an earlier transmission to rebuild. The '85 Cali uses the far weaker 722.4x transmission. The 722.3x used on previous years is considerably stronger.

When my 722.4 went out on my '85 Cali setup (different symptoms from yours), I replaced it with a 722.3 that came from a junk yard. I took a chance and installed it and it's working fine, but if it turned out to be bad, I'd have rebuilt the 722.3 and not the 722.4. There was some question about whether the modulator setup on the '85 would work with the earlier transmission and I can confirm that it is plug-and-play.

Good luck

turbobenz · #3 02-27-2013, 12:06 AM

Quote:

Originally Posted by wagonhorse

I hope your evening is going better than mine. My transmission went out as I was pulling on the interstate. Now only first gear and reverse work. When shifting into d or second the engine starts in first and then at the shift point where second gear should kick in it starts to shift the nothing. Any ideas before the tranny shop?

You can have a seized B2 piston or a broken valve body spring. Do not let a trans guy tell you it needs a rebuild, something obviously broke that just needs fixing.

And the 85 trans being weaker is, in my opinion, a myth. It shifts softer, so the clutches probably wear down at a faster rate. The 85 transmission has an updated TC with a better stall speed which makes the car feel stronger. I prefer the 85 trans over the earlier ones for the stall speed, more modern shifting and it seems to have an excellent ability to gauge what grade the trans is at and prevent the car from rolling backwards even on a decent hill.

ROLLGUY · #4 02-27-2013, 12:45 AM

Quote:

Originally Posted by turbobenz

And the 85 trans being weaker is, in my opinion, a myth. It shifts softer, so the clutches probably wear down at a faster rate. The 85 transmission has an updated TC with a better stall speed which makes the car feel stronger. I prefer the 85 trans over the earlier ones for the stall speed, more modern shifting and it seems to have an excellent ability to gauge what grade the trans is at and prevent the car from rolling backwards even on a decent hill.

Would that be the case only if ALL of the related vacuum and electronic components are in play and working correctly? The reason I ask, is that if someone was to take an '85 trans and use it in say, an '82 without all the goodies, would it perform the same as it did in the '85 chassis?

mach4 · #5 02-27-2013, 12:58 AM

Quote:

Originally Posted by turbobenz

And the 85 trans being weaker is, in my opinion, a myth. It shifts softer, so the clutches probably wear down at a faster rate. The 85 transmission has an updated TC with a better stall speed which makes the car feel stronger.

I'm no transmission expert. My statement was based on what seemed like consensus on this forum.

One reference in particular seemed to have data to back up the claim

Quote:

Originally Posted by wyldemannn

Torque capacity
The designation W4A0xx tells us the maximum input torque in kpm (kilopondmeter).
1kpm=7.23lb/ft.

722.0 (W3A040)- 290lb/ft
722.1 (W4B020 or W4B025)- 145/180lb/ft
722.2 (W4B025)- 180lb/ft
722.3 (W4A040)- 290lb/ft
722.4 (W4A020)- 145lb/ft
722.5 (W5A030)- 216lb/ft
722.6 (W5A580)- 578lb/ft

And threads -
722.3 vs. 722.4
722.3 or 722.4 transmission difference?

I'm happy to be wrong if that is the case... I used the above data in making my own decision as I expressed above in the form of a consideration for the OP. Is it accurate? Who knows, it just seemed like solid consensus at the time. And case size would tend to support the assertions.

wagonhorse · #6 02-27-2013, 10:28 AM

Thanks for all the help. This forum has always been a great place to get help. This forum has never let me down but does make me feel guilty for taking and not feeling like I give back. I just wish I had the knowledge to contribute more than I use.

Thanks Again

whunter · #7 02-27-2013, 10:32 AM

Quote:

Originally Posted by wagonhorse

I hope your evening is going better than mine. My transmission went out as I was pulling on the interstate. Now only first gear and reverse work. When shifting into d or second the engine starts in first and then at the shift point where second gear should kick in it starts to shift the nothing. Any ideas before the tranny shop?

Regarding your shifting issue...

I suggest you look through this link
Transmission:

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pawoSD · #8 02-27-2013, 12:04 PM

I have an '85 transmission from a 300D in my '82 300SD. I only connected the normal vac modulator line and bowden cable. It shifts and drives great compared to the older transmissions. The high stall speed really helps, and the shifting is flawless and smooth. I have put 40,000 miles on mine so far, so the trans is at about 202,000 at this point, 0 issues. An '82 with an '85 trans is a city-rocket as I still have the 3.07 differential and not a 2.88. Off the line acceleration to about 65mph is quite quick!

I will probably be retiring the car this summer season at some point due to rust. The trans will probably end up in my dad's mint '82SD, and the engine I will put in a shed as a generator.

Quote:

Originally Posted by ROLLGUY

Would that be the case only if ALL of the related vacuum and electronic components are in play and working correctly? The reason I ask, is that if someone was to take an '85 trans and use it in say, an '82 without all the goodies, would it perform the same as it did in the '85 chassis?

DeliveryValve · #9 02-27-2013, 12:47 PM

Quote:

Originally Posted by turbobenz

...

And the 85 trans being weaker is, in my opinion, a myth. ...

If I recall, turbobenz has a Federal '85. So he's talking about a 722.315 trans. The weaker trans is the California version 722.416

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mach4 · #10 02-27-2013, 04:50 PM

Quote:

Originally Posted by DeliveryValve

If I recall, turbobenz has a Federal '85. So he's talking about a 722.315 trans. The weaker trans is the California version 722.416

That's what the OP has, and that's what I was referring to.

Just for the record, you're supporting the apparent consensus that the 722.4 Cali transmission from '85 is indeed a weaker transmission?

DeliveryValve · #11 02-27-2013, 05:46 PM

Quote:

Originally Posted by mach4

That's what the OP has, and that's what I was referring to.

Just for the record, you're supporting the apparent consensus that the 722.4 Cali transmission from '85 is indeed a weaker transmission?

I do support that statement. I put the .4 and .3 side by side. The .4 is a physically smaller trans compared to the .3 plus the center input diameter of the torque converter is smaller which makes it interchange with the .3 version impossible.

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