1983 Mercedes 300D transmission acting up while cold - Page 2 - PeachParts Mercedes-Benz Forum

JHZR2 · #16 02-20-2023, 10:15 PM

Quote:

Originally Posted by tangofox007

Dexron III is obsolete and unlikely to be an option. So you will have to settle for a Dexron III equivalent. I recommend Valvoline Maxlife Multi-Vehicle ATF.

Dexron IIi stopped being licensed long ago. Dexron VI is the new licensed product, and, is a lower viscosity product. GM claims it is backwards compatible, though there were some claims of incompatibility with certain older transmission materials.

Dexron VI and Maxlife are both low viscosity fluids. Our ATs were designed for higher viscosity.

The best modern alternatives are the Allison transmission fluids. I believe TES 295 is equivalent to Dexron IIIH but that would need to be verified as I’m not 100%.

Lubeguard red works well in the MB transmissions too…

JHZR2 · #17 02-20-2023, 10:41 PM

I can’t see the speed, so I don’t know what’s right for rpms… but to me it doesn’t look like a flare. Flaring shoukd happen once and then ideally the AT grabs it’s new gear and progresses. This seems all over the place, amd is probably some kind of slipping of the bands due to low pressure or something not right.

A pan drop is in order to see what residues are present.

A flare or single time slip/over speed is one thing. This looks like something worse to me.

vwnate1 · #18 02-21-2023, 11:23 AM

Until the filter and T.C. have been serviced there's no point in pondering .

Back when W123's were the in thing for hipsters to have I had similar issues and read endless posts about adjusting and so on, none really fixed the problems until the proper service was done then the pressure check was done, then simple adjustments made everything right again .

Roamer24 · #19 02-22-2023, 02:30 AM

Update: I have gone through with the transmission fluid and filter replacement, and torque converter drain. I filled the empty transmission with about 6 and a half quarts of the Valvoline full synthetic maxlife ATF, and it no longer does the “flaring” even while cold. Only thing I notice now is that my 3-4 shift and 4-3 shift is pretty hard, but it may be because I broke a brittle old vacuum line connected to the intake manifold near the firewall. Regardless, thank you all for your help. I will look around to see what tweaks I can make after I repair the vacuum line to see if I can smooth out the 3-4 shift and 4-3 downshift.

psaboic · #20 02-22-2023, 09:39 AM

Fix the broken vacuum line and Ill bet your harsh shifts go away. I've seen vacuum issues cause all kinds of weird transmission symptoms....

vwnate1 · #21 02-22-2023, 10:18 PM

If it's the one on the rear ward end of the intake manifold, it's the ALDA boost signal pipe and it relays pressure not vacuum .

As long as it's broken , take it off and clean it well, the inside is normally nearly plugged up with gooey carbon .

I use the Purple cleaner from Sam's Club and a thin wire to clean it, there's another pipe going down to the ALDA capsule, once those are clean and leak free you should gain power and economy .

Unless the up shifts bang, firm / hash is a good thing .

tangofox007 · #22 02-24-2023, 07:57 PM

Quote:

Originally Posted by JHZR2

Dexron VI and Maxlife are both low viscosity fluids. Our ATs were designed for higher viscosity.

Given that the original complaint here was "transmission acting up while cold," a lower viscosity ATF might be just what the doctor ordered.

In any case, I am completely satisfied with the way my transmission performs with Valvoline MaxLife ATF. 1982 300D. I have owned it for 31 years and the transmission has never performed better than it has since I switched to MaxLife six years ago. (Prior to that, I had minor cold temp issues as well.)