Where's a safe place to go for transmission flush?
 

I don't trust some of these franchise places, where you go in and they do a "20 point inspection" on your transmission. Then their price of $99 for flush and fill just went up to $278 or something. Some of these places, if you don't have a problem when you go in, you will by the time you go out.

What's been your experiences? I was thinking about getting a whole thing, drain, flush, fill, or whatever they do. But what about these places that suck the old fluid out, are they any good?

Not sure I'd want to try changing a filter, etc. by myself. Looks hard. I don't know anything about adjusting bands, etc., either.

Thanks,

Jeff 1991 300d, 118k

The best place anywhere is your own driveway:cool:

Yeah, it's called not falling for the hype and doing it in your garage or carport!;)

Just to be clear, are we talking about a transmission flush (which I would not recommend doing), or replacing the fluid and filters (which I do every 30-40K miles)? I just have my indy do the tranny service, do it yourself if you feel like getting dirty.

Don't do a flush, do a normal change. Flushes are risky for your trans, and your car has a TC drain so you can simply drain all of the fluid to change it, no point to a "flush".

I wouldn't flush an old trans your just asking for trouble. Any decent shop should be able to no screw it up. On these cars it really doesn't get any simpler.

I was talking about ....
 

I was talking about doing a complete flush, filters, fluid, the whole bit. What about those places that suck the fluid out? Is that better?

jeff

That won't get the fluid out of the torque converter.

Flushing is where they hook it up to that machine and run it forcing fluid through the cooler lines. I would not recomend that on an older transmission, chances are it will start to fail soon afterwards. If this was a rebuild with 30k-40k on it or a new car, and you wanted to go nuts, go ahead.


With these old trans a drain and filter change is all that is needed, every 30k-40k miles. Don't forget to drain the TC. You get 95%+ of the old fluid doing it that way.

Again MB has almost idiot proofed them, so any decent shop should be able to do it. Their is nothing MB specific about them, they are as complicated as a 70's vintage Ford.

ATF + Filter change
 

Jeff,

Pick up a set of ramps+large drain pan(10 QT.)...get a tranny filter here and
get the fluid locally...drive that baby up and chock it with the "E" brake on.
find your torque converter drain plug underneath and drain (replace gasket
on the drain plug).Then drain the pan(replace the gasket on the pan plug
too)...remove the pan ...replace the filter...replace the pan ,torque to specs
in expanding sequence...refill tranny and check when warm on absolutely
level ground.Enjoy
OR let a professional Independent do it.
DO NOT,"Flush It".The chances of damage are
not worth it.

Why does a flush hurt transmissions?
 

[QUOTE=Hatterasguy;1796243]Flushing is where they hook it up to that machine and run it forcing fluid through the cooler lines. I would not recomend that on an older transmission, chances are it will start to fail soon afterwards. If this was a rebuild with 30k-40k on it or a new car, and you wanted to go nuts, go ahead.


With these old trans a drain and filter change is all that is needed, every 30k-40k miles. Don't forget to drain the TC. You get 95%+ of the old fluid doing it that way."


Why does it mess things up to do a flush?

Jeff

Old transmissions can be full of crap, and have a lot of wear. Forcing new fluid through cleans everything out, which is bad because that crap is needed to keep it shifting. A lot of good shops won't do it because of this.


Just change the fluid and filter every so often, don't beat on it, and it will last for a long time.

There is also a risk of over or under filll during the flush, and of contamination. The crud is in the pan, you drop the pan when you replace the filter, it is then GONE instead of flushing around the system.

I have a friend with transmission shops, he loves the flush places because he's the next stop after a flush, a rebuild.

Also added, it that when the flush is done, you still have the OLD filter in place. Would you do oil flushes on your engine and not replace the filter?

[QUOTE=jbach36;1796252
Why does it mess things up to do a flush?

Jeff[/QUOTE]


not to beat a dead horse.... but flushing implies that only oil is replaced and possibly dirty filters are kept in place.... and per everyone's comments, they should be replaced...... its really not that difficult to do it on your own. This way, you know its done right.

I'm glad I read this. I have heard mechanics say the the BG flushes are really good to have done. Perhaps they were speaking of newer cars, though.

In a new transmission, done every 30k-40k miles they are probably good. Provided they drop the pan to change the filter.

In a transmission without a torque-converter drain (most don't have a drain plug), you are changing less than half of the fluid when you drain the pan. In those cars, there is a justification for "flushing" to change substantially all of the fluid.

However, the change intervals on these cars do account for the fact that the fluid is only half-changed at each change interval, so you're okay. It would of course be better to change it all, thus the fluid flush business. Still, both of the AT service business owners I know (both in it for over 30years) say don't flush, just change, the flush causes more problems than it is supposed to prevent. Further, the Mercedes transmissions with the drain plug on the torque converter drain substantially all of the fluid which is BETTER than pumping new in and old out until it has diluted the old enough to call it changed (the "flush" method).

When you do change it, don't use paper towels on anything internal. Use lint-free towels and only dab at the bottom of the valve body or just let it drip. Clean the pan thoroughly, install a new gasket without sealers and don't over-tighten or you'll warp the pan.

Ditto what Jeff said (above). Flushes are used on transmissions that don't have a torque converter drain, because on those trannies, there's no way to get more than a few quarts out. There's no need for this procedure on an MB.

Mercedes 722.x transmissions can get 90% of the fluid out because you have two drains... the pan, AND the torque converter. You'll get about 2-3 quarts out of the pan, and 3-4 more quarts out of the torque converter. No need for a fancy flushing machine. Draining the converter can be messy, but is doable as DIY. Order a new seal for both drain plugs (they are different sizes), about a buck each from the dealer.

Your 1990-1993 300D turbo, with 722.418 tranny, will take 6 quarts of new fluid when both the converter & pan are drained, and the filter is replaced. I would recommend using synthetic fluid, the 722.x tranny does seem to prefer synthetic (improves shift consistency from hot to cold). The Red Line Synthetic ATF was officially approved by MB a few years ago, but their D4 fluid would also be ok, ditto Amsoil or Mobil-1 (although I'm personally boycotting M-1 ATF since they recently removed the Dexron label.)

If you pay to have this job done, either have it done by a place that is familiar with Mercedes (i.e., local German car indy shop), or take it to the dealer. DO NOT take it to a "transmission" specialist.

:stuart:

If you decide to do this job yourself, make sure that you clean out the plug allen holes with a pick before inserting the allen bit. The plugs are a lot "softer" than the bits and will strip easily if you do not get the bit all of the way in.

A few years back, I worked for an independent Goodyear franchise. They owned several locations. One of the stores decided to do a "flush" on a Grand Cherokee with 104,000 miles that never had the trans serviced. When they were done, it had no reverse. If that vehicle came to my location, I'd have done:
A - declined to do it OR: B - told him the only wad I'd do it was to flush AND replace the filter AND not be responsible if the trans "does not work" afterwards. I'm always leary when someone that has never been to my shop before, walks in to have a trans service done at 100+K when it's never been done before. If doing a "flush" on any car, all they're doing is forcing that dirty fluid thru the trans and replacing it with clean fluid, and ramming more dirt into an already dirty filter. Hence the no reverse on that Jeep.