HELP!!!

I am very frustrated by a transmission fluid leak on my 1990 300E. After a transmission service, it started leaking.
I have replaced two pan gaskets and an O ring but my mechanic(who is pretty good) can't stop it. I really don't want to pull the transmission(it works really well) which he is suggesting now. Any help anyone can send my way?

Richard

Rich,
Can't help, but my 86 300E has had a tranny leak since I first got the car.Even 2 trips to the tranny shop hasn't stopped my leak. $600 later and I still have a leak. Good luck.

__________________
Richie
1986 300E

Richard,
I've got the exact same thing going on with my 92 300E. Took it back to the mechanic and dropped the pan. Put another gasket on it and re-affixed. Kept leaking. So, after some discussion I'm going to try solving it this week-end. It appears that the middle bolt on the right side may not be gripping the way it should due to some sort of "flaw" in the pan. Could be that the lip is bent or that the hole through which the bolt slides has somehow enlarged itself. The leak is definitely coming from this particular area. I'll post once I've looked at it Saturday morning.
John CH
92 300E

that it is real easy, in your exuberance to halt the leaks, to overtighten the pan which can damage the gasket resulting in leaking.

Jim
'85 300D
'95 E320
'97 CRV

A flat, straight level pan and a torque wrench may be the answer???

I found it leaking around the base of the dipstick tube on my 300E. it was leaking alot too... Replace the o-ring and make sure its a metric.

I have had a transmission leak for the past 7 years on my 87 300E at the main seal. Replacement requires removal of the tranny, so it is obviously quite expensive. My dealership actually recommended to NOT replace this seal, because the leak is fairly minor and has never worsened. Remember, this leak has been around 7 years, and my car has never had a trans problem and it now has 170,000 miles on it and she still shifts perfectly as long as I keep her filled with fluid. It only takes me checking the fluid once a month and adding a few ounces. I don't know how severe your leaks are, but if they are not very severe, I would not worry about fixing it and simply keep a watch on it.

Ditto Engatwork.

722.3 tranny pan bolts are torqued to only 5-6 lbs. Many people over-tighten and this may cause leaking.

__________________
Mike Murrell
1991 300-SEL - Model 126
M103 - SOHC
"Fräulein"

I have noticed a similar leak after I replaced the transmission filter. At first, I saw a rather large puddle but now only a drop leaks everyday. Thanks for posting the torque specs for the bolts. Would gasket sealer help when assembling or is it simply a question of proper torque? I tried to tighten in a sequence that was logical to me.

__________________
VR
1967 250SL

Don't use sealer, tighten in a "cross" pattern.
Jim
'85 300D - with leaky front tranny seal
'95 E320 - currently no leaks
'97 CRV - never any leaks

Hello Everyone,

Thanks for all of the feedback. I'm going to leave the car with the shop for a week while I'm out travelling. Hopefully, they can track down the problem and cure it.
I travel a lot, and the leak is more severe when the car sits for three or four days. When I drive it every day, the leak nearly disappears. Keep, those comments comming.

BR,

Richard

Have you checked the fluid level? Cold, it should be about 1/4 inch below the mark (at least on my 88, 300TE-check your manual). If it leaks more when sitting for a few days, perhaps it is overfilled.
To be sure the leak isn't above the gasket, wipe the pan, then tape strips of newspaper around the pan, above the gasket area. A leak will show fluid on the paper.

__________________
'76 240D-Sold
'78 240D-Sold
'85 300 SD, 165K-Sold
'88 300 TE, 165K-Sold
'64 Porsche 356C Cabriolet- under restoration
'86 560SL 124K Miles-Sold
'94 320E Wagon, 74K Miles-128K Miles JUNKED
'06 E350 Wagon, 84K Miles
07 SL550, 14K Miles

Brother of The Benz.
A oil leak from any area/item above the oilpan flange presents itself as a pan leak.
I'm positive you have checked other areas as well.
My W124030 at 165,000 miles developed a small leak that appeared to be from the oil pan.
Cleaning the tranny's sides and pan area helped to isolate the possible leak area.
On the drivers side of the transmission case is a large plug with a 17mm allen socket(double check the size).
This is the band strut retaining plug and on it's pass through of the housing has 2 "O" ring seals.
After years these seal become hard and leak.
There may be a technique to replace tese without removing the tranny?
In my case I backed the plug out approx 2 turns and sprayed it with brake cleaner for cleansing.
Using electrical solder(0.015"dia), I wrapped a turn around the plug(clockwise) over lapping the ends and applied RTV and tightened to compress the solder.
I've been told by one of our Moderators that damage can occur repairing this leak this way.
It has been 9,000 miles and the leak is stopped and, cross my fingers no damage.
Happy Trails beep Beep from the Spiderman in Houston!!!

I'm keeping a close eye on my leak. I too add about once a month. It's been a year since the last time I brought the car back to the tranny shop. The car shifts fine, still leaks, not a major leak,so I'm just going to keep adding and monitoring, adding and monitoring. My next project is to have the complete valve job and seals done. Every once in awhile I notice a puff of blue smoke, I guess i'll have the rings done also. Can anyone advise?TIA

__________________
Richie
1986 300E

Brothers of the Benz
Rich, your 1986 300E has one of the strongest if not the strongest bottom end of any of the Benz engines.
Unless you have an untold amount of miles, 200,000 or more, or has been grossly abused, your rings should be just skuffing the machining marks off the cylinder walls.
The valve stem seals my need replacing, this is a routine repair above 100,000 miles.
Have the valve stem seals inspected and replaced if needed; then check your little puffs of blue smoke. Chances are you will have corrected the problem but if not, what will be an acceptable oil consumption rate?
My 1987 300E W124030 and the same engine has 175,000 miles and it uses a quart of oil between changes.(3500-4000mi).
Being the original owner I know how she has been maintained. Sometimes when we purchase pre-owned, we gamble on the care our beloved Benz has had.
My engine has the original valve stem seals. I attribute the long life to regular oil changes. I've always used dino oil, if I could do it over I would have choosen synthetic. Who knows what mileage I would obtain considerring what I have to date.
I'm hoping to get 200,000 miles before any cylinder head work. It appears I may make it if the valve seats and valve angle don't wear out.
Oil is cheap and seals ain't.
Happy Trails Beep Beep from The Spiderman in Houston!!!