First gear slipping all of a sudden - PeachParts Mercedes-Benz Forum

phinsup · #1 09-18-2009, 01:39 PM

It just starteddoing this it's when I first get going Basically I put it in drive I have accelerate a bit then it clunks in and starts going. It doesn't do it any other gear but first and doesn't seem to do it when it warms up. Vacuum issue? Where do I start?

Thanks

rrgrassi · #2 09-18-2009, 02:16 PM

Clogged filter?
When was the tranny last serviced?

winmutt · #3 09-18-2009, 02:38 PM

Checked your fluid?

DocSarvis · #4 09-18-2009, 03:17 PM

B2 piston??? Thanks

pawoSD · #5 09-18-2009, 04:31 PM

You should have made sure you have proper fluid level and a recent trans service before you even asked the question....

First gear slipping is usually low fluid, clogged filter, or a bad B2 piston.

71inka02 · #6 09-18-2009, 04:50 PM

Quote:

Originally Posted by pawoSD

You should have made sure you have proper fluid level and a recent trans service before you even asked the question....

First gear slipping is usually low fluid, clogged filter, or a bad B2 piston.

That kind of feedback makes a novice or new comer not want to ask questions. We're all human and have busy lives and sometimes don't think clearly, and simply overlook the obvious.......Seems to be some 'attitude' and 'anger' in some of the threads recently..........Maybe there's a full moon or something.

Just my sincere opinion.

pawoSD · #7 09-18-2009, 04:59 PM

I suppose I was being a bit mean.....but I tend to be sarcastic as well. I'm actually a nice person though.

71inka02 · #8 09-18-2009, 05:05 PM

Quote:

Originally Posted by pawoSD

I suppose I was being a bit mean.....but I tend to be sarcastic as well. I'm actually a nice person though.

No worries -- But honestly, there does seem to be some 'stress' expressed recently....I have those days too, but enjoy this forum to get away from that type of stuff...The information, even sometime repeated stuff, is informative, interesting and sometimes very humorus...

leathermang · #9 09-18-2009, 07:38 PM

While the other suggestions are correct..
you might put a couple of cans of Trans-x in there ( follow can directions ) ...
all those movements inside the trans....like the clamping down on the clutches which change the gears in an Auto Trans are operated by hydrualics..
and those are controlled by the valve body which has small bb size spheres used to block reverse pressure... when the varnish builds up over decades in those tiny openings a sphere can get stuck or sluggish in its movement...
So the Trans-X is just a varnish solvent....not some snake oil...and I have had it cure cars which would only drive in ONE gear....
Using it does not hurt anything and is cheap.... and you can have more than one problem at once... so this is a good one to get out of the way first and cheaply...

babymog · #10 09-18-2009, 08:12 PM

Not really just a cleaner.

The solvent swells seals, making them seal better. The transmission is operated hydraulically, if the hydraulic pressure is leaking past some/all of the seals then there won't be enough volume to operate the clutches/bands via hydraulic actuators. At idle the pump volume is the lowest, therefore most susceptible to leaks bleeding down the pressure.

As LM says, it can help and has helped many a dying transmission make more miles or even years. Once in there, you'll always need it though, the seals wear in at their new dimensions and will not seal well without the solvents to swell them. Harm? If seals leaking is the problem, they needed replacing anyway, so this will do no (additional) harm.

Different manufacturers use different solvents, napthalene, xylene, acetone, ... almost all carcenogenic and flammable so pouring it in with a hot manifold below is not a good idea.

The right way would of course be to put gauges on the transmission and test the operating pressure, possibly increase the modulator pressure if it is low and within the adjustable range of the modulator, but that's a bit more complicated than pouring in a bottle of nail-polish remover. It can also be a piston sticking in its bore, if you don't have a manual search here and the tech forum for "B2 piston" and you will find reading material to learn about the operation of the transmission.

pawoSD · #11 09-18-2009, 08:18 PM

Having to use things like Trans-X usually means the trans is near rebuild time....I say its better to just fix it and get it over with than to limp it along, because then it is not a trustworthy vehicle....especially if its a daily driver.

leathermang · #12 09-18-2009, 08:30 PM

BabyMog,
A few months ago I had a serious leak on my 95 Lincoln transmission... a quart per 75 miles.... I put Trans-X in it and it has not leaked in the months since...it took a couple of cans over a week to swell the seal ... but that is all I did to the trans.... and those kinds of leaks don't seal themselves in my experience...

daw_two · #13 09-18-2009, 08:56 PM

Original Poster ---- If you need a transmission, let me know. I have a few.