1985 300D W123 Transmission Fluid
 

Way too much info here!! Just a couple of questions. I am going to change my transmission fluid including the torque converter drain and new filter.
I am looking for a recommendation (brand name) of a modern DEX 3/4 fluid to use for this change. I do want to go synthetic, but not this time around.

2, a lot of threads include tranmission type, 722.xxx etc. What type is the transmission in my car? it has not ever been changed.

I am going to buy a case of transmission fluid, 12 qts. That should be enough. I am also going to do this withthe car on ramps, that OK?

185,000 miles, shifts hard but no slip or flare. I'll play withthe modulator after I get the underside cleaned up a bit.

You should have a 722.3 transmission

I only use Kroon oil - but I'd be shocked if you could get it!

I think you need Dexron 2 by the way...

12 qrts is that really about 13 litres? Well if so yeah that's enough - almost twice as much as you'll need.

You could do the change on ramps if you wish - but when you remove the sump for the filter you might get more of a shower than you would with the car on the level.

In my 722.1 that I'm rebuilding I estimate there was about 1 litre left in the transmission when I dismantled it - so you'll never get it all out anyway... and there's the oil cooler...

I'm sure I can't get Kroon here! New name to me. I can't get Dex 2 either, only Dex 3/4 as far as I can tell. I'm going to poke around a bit more but I think that Dex 3/4 should be OK, I've read about folks using Amsoil in their boxes but I'm reluctant to go this way the first time in case I screw up. I'm pretty sure I'm going to get pretty dirty here anyway.

Castrol manual gear box oil and differential oils seem to be good. I've never tried their ATF though - but I use their engine oil all the time => GTX diesel and GTX diesel magnatech. I've only had good experiences with Castrol despite them having a reputation in the 1980s in the UK of being sludge forming oils... if that was the case they've certainly sorted themselves out now for motor oils.

Many here, including I and my ASE tranny-shop-owning buddy, suggest NOT to drain the converter, lines, etc on an older, condition-unknown transmission. Wayne's contention is that such "violence" rapidly dislodges accumulated detritus, leading to seal and valve-body trouble soon after. He says that something like 20% of his rebuild business got a recent flush (at Jiffy Lube, etc).

Just drain the fiveish that will come out of the pan, and slap on a new filter.

Any brand-name DexIII should be fine.

You have a 722.3xx (where xx indicates modulator style, speedo drive, etc). Look on the right side of the transmission body, JUST ABOVE the pan. You will see a long string of numbers with "722.3xx" hiding in the middle.

12 is more than enough, ramps are fine.

Fix your vacuum leaks before you do any tuning.

Your new filter should also come with a pan gasket; make sure it's the right type (six or four bolt) before you drop the pan.

I guess I'll get the Castrol DEX 3/4 fluid. I've used their products for years. A drain, filter swap and refill it is. The transmission is working very good and I want to keep it that way. I broke the vacuum line from the booster to the vascuum pump. I put in the new one and the car is shifting a bit smoother. I am thinking the old vacuum lines one-way valve may have been getting tired. I am not sure when the fluid was last changed but overall the car appears to have been cared for so I don't think I'm draining 100K mile fluid. It is still red and smells OK. Doing a front bumper to back bumper maintenance on the car just to give me peace of mind next winter. I drive it in the very cold but try not to use it in the snow and ice. My 26 year old daily driver :-)

I run trick shift or sync atf.both cars

Should be a 722.315 if it's not a California spec car.

Is there a Dex 3/4? I hope you don't mean ATF +3/+4 equivalents for Mopars.

Sixto
87 300D

You know, I'm not really sure about he DEX 3/4 question. I'm stopping in Napa after work and will talk to the folks there about what I want to do. Barring that, I may just buy fluid from MB but I think any modern DEX is supposed to be OK.

That's a lot like saying a hamburger should come with fries.

What you get depends on what you order.

Someone probably had a problem decoding Roman numerals. Dexron III was superceded by Dexron VI.