w124 transmission problem
 

Hi,

300TE

it used to take a while to engage reverse. Today it refuses to engage at all, going forwards is OK, but sometimes I want to go backwards as well.

Thanks.

Those 4 speed automatics are usually bullet proof. A missing reverse gear is probably a clutch issue.
First check with an auto is of course fluid level.

I've not had the car long, so i dont know if the fluid was changed recently, I checked the level and it seems to read a good 2 inches above the marks on the dipstick, but looks clean and clear.

Common issue and happens to ALL of us at some point. PO probably sold it to you because he knew it was about to go out!

Other than living with it, only option is to pull it out and replace the B3 bands. Transmission must come completely out.
(Reseal the tranny while its out).

Changing fluid will make it worse unfortunately, so don't waste the money. What's done is done. So plan for removal, no way around it.

ps2cho,

My car has had very little reverse for six months now and I have learned to deal with it. My 400E had the very same problem and when the dealer pulled it out, they found that only the B3 was worn--the forward discs and bands were perfect. In fact you could still see the Mercedes logo on the discs after over 200,000 miles. The tech recommended just doing the B3. It was stil $3,600 and I probably overpaid for it (that's to be expected at a dealer).

Now, when I take my existing car to an indy to have the transmission done, I am thinking of only having them do the B3 and seals, but for my own information, what seals are you referring to? Can you get to all that will likely need replaced without going too deep into the transmission? Approximately how much time would be saved by just doing the B3?

I want to compliment you for taking the initiative of diving head first into your 722.3xx without hesitation and getting it done. That's a job many of use here wouldn't dare tackle.

True. From what I have read, if the reverse goes out slowly, usually its the disks, if it goes out all of a sudden its the b3 piston.

Seals that are imperative are front pump seals. I recommend doing the kickdown switch and rear output cover seal. Those are the most common leak places especially after fresh fluid.

Thanks. I'll get an estimate for the full overhaul versus the B3 piston and discs. I suspect a tech will discourage doing just the B3 and refuse to warranty the transmission if he doesn't do the whole overhaul.

It doesn't need a whole overhaul unless you have shifting issues. These transmissions are pretty bulletproof other than leaks and the reverse bands.

What I discovered today though -- if you replace the b3 bands, change the fluid + filter after 5k miles because your pan will be dirty filthy with the bedding in on the new bands.
First time I've pulled mine today and its been ~15k since I did it.

Find a shop that knows these transmissions and you won't have those questions. If they refuse warranty, find someone else because they probably have no idea.

I agree with Ph2cho...I did my b3 bands about a month ago. I'm in transmision bliss now. Did you ever hear clicking when driving in reverse?

Ph2cho, That's a good idea to replace the fluid and filter after 5k miles.

No clicking, but it is exhibiting the same characteristics as my old 400E as far as reverse goes. The forward gears seem fine. I'm just getting tired of having to look for a parking spot on a hill or a space I can drive forward to get out.

Mine was also the B3 bands. Transmission tech said everything else looked great. Replaced those and whatever other little cheap parts he saw and transmission has been super solid with no reverse noises or problems.

Thanks for the input.