ATF Leak questions
 

I had my car sitting for about a week while I waited for a replacement antenna mount. Today, I got the car out and took it for a spin to fill it with Diesel, and when I got back to the garage, I noticed that there was a nice little puddle of ATF on my garage floor. It's red, and looks fairly clean. It appears to be leaking from just behind (rear of the car) the place where the trans and motor meet. The leak appears to be on the passenger side.

Any ideas what this might be? I'm not low on fluid, I know that.

Sounds like the seal between the torque converter and the front pump. About a $6 seal but removal of the transmission is required.

Good luck
Robert

Yup. I was recently quoted $1100 for replacement of the same seal on my '83. I elected to wait until I can get back to it and shop around some. I'm more interested in getting it converted to a manual, but I don't have the facilities to do that myself.

is it possible it's a cooler line? I was reading elsewhere these symptoms can be caused by the cooler line leaking as it comes back to the Trans.

That could be and it is easy to check just wipe the lines clean and the fluid will show up. 300K + miles is about the end of the seal life though. $1100 is way too much for a $6 seal though. It is not a difficult job to R&R the transmission though if you rent a transmission jack and can get the car high enough to get it out,

I reused the aluminum seal rings on the cooler lines one time and they will leak every time. They can be sanded back flat and will work till new ones can be bought though.

Good Luck
Robert

Replace o-ring on transmission filler tube
 

I wont say that this is the most likely cause of the leak, but from my experience with two 123 diesels, this is the only place I have ever had a transmission fluid leak....and it is located exactly where you describe....

That is the o-ring at the base of the transmission filler/dipstick tube. This is kind of a pain to get to...because the exhaust front pipe and a hard transmission fluid line are in the way. This o-ring has probably never been changed, so it is hard and brittle. Here is what to do..

1. Do what you can to brush dirt and grime away from this spot so crap doesnt get into the transmission when you remove the tube.
2. Drain trans. fluid from the trans reservoir into clean container.
3. Remove upper bolt holding the tube to the manifold
4. Remove the large bolt holding the transmission line banjo fitting near where the filler tube connects to the trans. reservoir...
5. Remove a second bolt holding this hard line to the transmission housing..this will allow you to pull this out of the way.
6. Use a little piece of wire with a "hook" bent on the end to clean the crud out of the allen bolt holding the dipstick tube to the trans.
7. Use a regular allen wrench to remove this bolt...be patient
8. For the o-ring...get one a little fatter than the one that in there...I recently replaced the o-ring with an actual mercedes part for this, and the thing still leaked. I just repeated the job yesterday with a neoprene oring from True Value...a little fatter for a tighter fit.
9. With your little piece of hooked wire, clean the seat for the o-ring on the transmission housing as best as you can.
10. Push o-ring into the transmission housing seat first...then position the filler tube onto the o-ring...the end of the filler tube is bevelled so this works well....then from up above in the engine compartment, push the tube down gently while turning one way then the other, and you will feel the tube slide into the o ring and seat itself nicely.
11. reinstall bolts and pour in the transmission fluid, and you are done.

Good Luck

I thought so too.

Easier said than done in my situation. I did an R&R of the tranny in my '71 once, and that was in a garage but without a tranny jack. It was not a fun job.That transmission is considerably lighter than a 722.2, and I no longer have access to a garage, unless I take it out to NAS Fallon and use the hobby shop there. Come to think of it, that's probably what I'll end up doing.

I agree --- A concrete floor and a Good transmission jack and it is not too difficult BUT it is getting colder and I am a lot older now and it takes me longer to get over the getting up and down.

I helped another fellow a few months ago, we used a friends truck shop and the trans jack that could handle a Road Ranger. The jack could actually pick up the 300SD without problem but that was what we had to work with. The hardest part is getting the drive shaft out and the wiring off of the shifter. I think that it took about five hours or so without Beer. and it drove away.
My wife and I remover and replaced an automatic in a Pontiac forty years ago (we were dating) with a borrowed 2X10 and some concrete blocks in the back yard of her apartment while she was in college. She stood on one end and I was able to lift the transmission up with her as counterbalance. I was younger and stronger then and felt no pain.

I would not recommend transmission seal restore it will affect every other rubber part in the transmission also.

Good luck and sorry for the cold weather
Robert

I checked the fluid level (warm engine, idling) and it was just at the very bottom of the dipstick. That's too low, obviously. So, I added ATF to it to bring it up to the middle of the min/max mark and I'm going to wait to see how long it takes it to leak out, if the leak keeps happening.

I'll check that o-ring at the filler tube, otherwise, it's probably time to start looking for a used or rebuilt Tranny.

I don't have any sort of lift, so I'd be putting it up on jack stands if I were to remove the transmission.

Mine leaks at that same front seal. We've decided that until it gets a whole lot worse it's cheaper to just add a quart every few months than it is to pay somebody to replace the darn thing. And we're not ready to tackle a transmission removal yet. Not enough tools and not enough nerve.

It is not a bad job at all. The hardest part is getting the drive flange bolts off. I have never had a lift so I use jack stands in the front only. If you plan out what is to be done it can be accomplished quickly with little trouble. Before you jack the car up remove all the bolts from the top of the transmission, the dipstick and the bowden cable. While it is still on the floor remove the fan and the top radiator clips so that the engine can be let all the way down without damaging the radiator. Leave the starter in the car (disconnect the battery before you start any of this) remove the torque converter bolts, rear mount, shift linkage, neutral start switch (it rotates to remove) and speedometer hook up. Cooler lines and two more bolts and it is on the way out.

The thing that most people have trouble with is getting the torque converter back in the transmission ---- I just put an index mark on both and it will slide back in every time. Remove the seal, replace the seal and oil it with ATF and then use green scotch bright on the converter seal area to remove the glaze from the shaft. Clean converter, lube with ATF and slide back in place. There is an odd plastic bolt on the side of the transmission housing that keeps the torque converter from coming out too far so replace it now to make sure that the converter is as far back as it will go (it has three parts to be in alignment) I hate this term ------------- REVERSE ORDER FOR REASSEMBLY ---------

You can do it
Robert

Why would you need to move the engine at all? That part sort of threw me for a loop.

I let it angle down so that it is easier to get to the starter bolts and it just slides out to the rear and you can get to everything easier. The valve cover will rest on the false fire wall (SD). The fan mite touch the radiator and that is why I remove it, the radiator hoses put a strain on the radiator so I remove the clips to let it go where it wants.

I do pressure wash all the underside I hate to work in the grimey mess that can be under there.

later
Robert

Definitely a good idea to pressure wash.

Hopefully, I'll get my hands on a decent used transmission and maybe find some forum friends to give me a hand changing it out. I don't have the $1100 right now to just have my old tranny resealed.

Oh, and just to update, the leak seems to definitely be further back (towards the back of the car) than I thought. It's not leaking from around that area where the engine joins the transmission.

I'm thinking it might now be either that dipstick or a bad pan seal or something like that.