What Fluid Should I Use In My Transmission - PeachParts Mercedes-Benz Forum

Targa-NF · #1 04-25-2006, 08:42 PM

I have seen a few posts that said to use synthetic. Is there different weights
of trans fluid? If so, what should I use. My trans is acting up lately. Thanks
Jay

ConnClark · #2 04-25-2006, 08:47 PM

Dexron III is what you should use. First and foremost change the filter. One of those $100 presure flush services isn't a bad idea either.

I have no idea how well the synthetics work out, I don't know what it is suppose to get you other than costing you more. I have never seen an independent test comparing it to anything.

pawoSD · #3 04-25-2006, 09:20 PM

My past 7 months of driving has shown a 30% happier driver with synthetic.

It makes it run smoother, much better in the cold, and protects the tranny components better as it can stand up to more heat and has better properties than dino fluid.

I vote synthetic, in fact, I'm changing our '83 (in sig) over to synthetic this friday.

ConnClark · #4 04-25-2006, 09:26 PM

Quote:

Originally Posted by pawoSD

It makes it run smoother

How does transmission fluid make a car run smoother?

Any change in your mileage?

pawoSD · #5 04-25-2006, 10:19 PM

It seems to make it quieter when driving and shifts are smoother.

tangofox007 · #6 04-25-2006, 11:07 PM

Quote:

Originally Posted by pawoSD

My past 7 months of driving has shown a 30% happier driver with synthetic.

.

But it's entirely possible that you might have achieved the same level of happiness with a new filter and fresh Dexron. A transmission will typically work better with fresh fluid, so crediting all of the improvement to the synthetic fluid might not be reasonable.

The placebo effect can be a powerful thing. My engine always seems to run smoother after I wax my car!!!

Hatterasguy · #7 04-25-2006, 11:15 PM

Quote:

Originally Posted by pawoSD

It seems to make it quieter when driving and shifts are smoother.

Noticed the same thing after I switched to Mobil 1 ATF. The generic Dexron that came out was clean and not that old, so was the filter. 10k maybe on it if that.

pawoSD · #8 04-25-2006, 11:19 PM

It really is noticeable, I was very skeptical before I switched to the Synthetic, and it did really make those differences. Less of a "whir" when driving and shifts are nicer. Our '83 still has dexron in it, and you can tell the difference.

ConnClark · #9 04-26-2006, 01:15 PM

I just changed my fluid and filter in my 300SD and it shifted smoother and the tourque converter seems to lock up more. I can't say a thing about transmission noise as I haven't noticed any even before the change. I guess until someone does a dyno test with a transmission fluid change in between runs we will never know if it really makes a difference.

pawoSD · #10 04-26-2006, 01:56 PM

Quote:

Originally Posted by ConnClark

I just changed my fluid and filter in my 300SD and it shifted smoother and the tourque converter seems to lock up more.

These cars do not have a lock-up torque converter.

I think MB added that feature sometime in the early 90's or late 80's, probably with the W124 or something. The W126 did not have it though.

ConnClark · #11 04-26-2006, 02:35 PM

Quote:

Originally Posted by pawoSD

These cars do not have a lock-up torque converter.

I think MB added that feature sometime in the early 90's or late 80's, probably with the W124 or something. The W126 did not have it though.

Perhaps I should have used a different term or said it in a different way. The torque converter seemed more effective at transfering power to the wheels.

tangofox007 · #12 04-26-2006, 03:08 PM

Quote:

Originally Posted by pawoSD

These cars do not have a lock-up torque converter.

The placebo effect strikes again!!!

ConnClark · #13 04-26-2006, 04:10 PM

Actually in my case there is some evidence that the tourque converter was more effective. The rpms turned by the engine going up a hill at a fixed speed dropped after the fluid and filter change. No placebo there.

lee polowczuk · #14 04-26-2006, 04:13 PM

in my son's 300e.... mobil one helped make some smoother shifts....this happened over time...maybe 6 months..

my 300ce shifts great with dexron...but i will switch over to synthetic sometime in the next 6 months... i already have the filter....

flushes---look i once had a flush...and my transmission started slipping in overdrive gear after that... it was a Q45..

i would drain and change the filter...no more flushes for me....

pawoSD · #15 04-26-2006, 05:27 PM

Quote:

Originally Posted by ConnClark

Actually in my case there is some evidence that the tourque converter was more effective. The rpms turned by the engine going up a hill at a fixed speed dropped after the fluid and filter change. No placebo there.

I'll agree with that, I also experienced a "tighter" torque converter, however, they still don't have lockup.

Our '83's slips almost 350-400rpm when in 4th gear and you give some deeper throttle, we'll see how the switch to synthetic changes it....I am very curious...