Do I really need the rebuit tranny

[chc]

My 89 300e is leaking the fluid very bad, the shop quote me 650 to replace the main seal or 2,200 for replacing the whole thing with a rebuild unit since it is already taken apart. This car has close to 120,000 miles on it and run really smooth, do I realy need to spend 2,200 to get it done? Or just fix the leak and hope the tranny to work another 30k, how long will the tranny normally last on W124? Any suggestion?

[md21722]

They should last at least 175Kmi. Mine has 273Kmi and still shifts Okay, no leaks yet. One of my mechanics will recommend resealing until the tranny gets 175Kmi and they their recommendation varies.

[keithed]

I would opt for the seal replacement and drive with the extra 1600 dollars in my pocket. Of course make sure that you get a warranty in writing for the seal work being done.

K

[ILUVMILS]

If the transmission has been properly serviced and the shift characteristics are currently good, I see no reason to spend $1500+ just for the heck of it. Fix the leak and keep the cash in your pocket. You might want to have them look at the rear crankshaft seal while the trans' is out. If it shows any signs of leaking, now is the time to address it. Additional labor should be around 1.5-2.0 hours at the most. I re-built a 722.4 transmission as a favor for a friend when the car had 150,000 miles on it. It currently has 415,000+ miles on it, and other than a slight harsh engagement into DRIVE it still shifts fine. I've never replaced a tranmission because of leaks.

[ctaylor738]

I've got to file a minority report on this one.

The issue is getting the most value out of the $630 in labor for the r/r of the transmission (the seal is about $20 list). If you plan to keep the car and drive it into the 250K range, you should go for the rebuild. If you plan a new ride before that, go for the seal.

All IMHO.

[chc]

Thanks for all your information. Just wondering is there anything need to be checked/replaced beside rear crankshaft seal mentioned by ILUVMILS while the tranny is open.

[blakeF]

Clearly no correct answer on this one. How bad is your leak?

Mine leaks about a pint every couple months and I just top it off. Shifts excellent. Reverse delays somewhat. I'm happy with it for now.

-Blake
'86 300E

[keithed]

I also agree with ILUVMILS do the real seal also. You did say the transmission shifts and preformes great? That being the case after close inspection everything looks good, the new seal job should last another easy 100,000. MB trannys are well built like the rest of the car. Regular fluid and filter changes, and engine tempertures kept to normal operation will provide you with good service.

K

[chc]

It started with one drip a day several years ago. Now every 30 miles of drive to work, park, and before I getting in the car on my way home, I can see a puddle of transmission oil at about 6"x12" ground surface. How about those "Leak Stopper", will it help? Any concern about using them?

[engatwork]

I might catch some heat for this but I will put some Lucas transmission additive in a high mileage automatic transmission to stop a leak. Keep in mind that this is the last resort before a rebuild and is just used to get me another 50-100k miles or so. I've used TransX successfully too. Both of them will stop a tranny leak.

[chc]

Last Question, is that necessary to replace the transmission mount while the tranny is out?

[keithed]

I would if it is the original with the miles and age on it, why not.

K