300TE transmission removal (front pump seal)
 

I need to get the transmission pulled on my 300TE very soon. Over the last 2 years the fluid loss is gradually increased. I am sure its the front pump seal based on my readings. It only leaks after the engine stops and leaves a nice puddle on the ground. I'm losing ~ about 1 quart every 500 miles...

I read that transmission removal takes 6-9 hours. Anybody really think it takes this long? :eek: The rear main seal is an extra 30mins work too so I might as well do it as well.

I plan to overhaul the transmission when its out. I know its only shy off 100k miles, but its out and I'm in this car for the long haul so I see no reason not to do it. I read that it only needs new seals, o-rings and friction disks. I believe my transmission is the 722.3 in the wagon.

Anybody got any other input?

Thanks

I pulled one in about 2hours from a '92 300E.

Did you use a hoist?

I have never done one, but can't see why it would take longer than the 2 to 3 hours it would take with any other standard RWD car. I would get a tranny jack from Harbor Freight...

Definitely NOT 6-9 hours. If you're taking it out with only 2 guys make sure you PREP the area you're working in! Set everything off to the side and make sure you know where everything is. It'll make putting it back in EASY and PAINLESS!

I used a piece of cardboard to cover the dirt under the car in a junkyard.

Unhooked the driveshaft
dropped the cross-member
unhooked the linkage
unplugged the wires and vacuum line
disconnected the bowden cable
un-bolted the cooler lines from the sides of the bellhousing
pulled the drain plug
un-bolted the dipstick tube
removed bell-housing bolts (several extensions for the top bolts)]
Pulled it off.

Took about two hours with hand tools.

I am way slower than that, and take the hard route. On my W126 I pulled the engine to swap the trans!

Well, I hope you took care of some maintenance items/major items while the engine was out!

Well....not much actually.....all I replaced was the boost line and waste gate hose.....it has been a very reliable engine, just keeps on going with very little work.....I've driven it nearly 80k so far. I adjusted the valves today for the first time in 20k, and only 2 were slightly tight, the rest were still perfect! :)

That sounds much better...

Anything else I should inspect when its out?

I've decided to save my money and leave the transmission alone. It has no problems at all, never has overheated on run low on fluid so I see no reason to spend $400 on a rebuild when it could last 100,000 more miles without a peep of problems.

Engine-wise: I am assuming the radiator has to come out...Any other parts need to be removed?

--

So I got the front pump seal and rear main seal. Anything else?

With the tranny out the B2 piston will be a delight to at the very least inspect! You'd only need a couple inexpensive seals if everything is intact, but if there is any question regarding the integraty of the piston replacing things on the bench is a dream compared to doing it in place.

How about upgrading the K1 shift kit also again the parts from the dealer is only $11 dollars and again doing it out of the car is easier than with the tranny in place unless of course you actually do enjoy an ATF shower once in a while!

my seal start leaking badly at 121k.... previously i had done all the work on our 124's..but i drew the line here..

the mechanic said if i wanted to do it right, i should replace the pump as well... and the front flex disk was shot...

all in all 1500. it would have been 800 just to do the seal.... they had the whole job pegged at 8 hours... i think it took them a bit more.... of course i got hosed for parts... labor was 95 dollars an hour for 8 hours...

i think i am set for another 80k

Taking the tranny out can be more than a bit easier than putting one back in my experience. Whether you're on a lift or on your back an adjustable tranny lifting fixture is indispensable, because you need the tranny right at the correct angle and height to get it together without a fight. It can be extremely frustrating trying to accomplish this by any other method. You can get a fixture that mounts on a standard floor jack for $40 or less.

I have found that taking some fine emery cloth to the “nose” of the torque converter and to the inside of the hole in the flex plat where it fits is sometimes the difference between it sliding together and a ball breaker getting it to slide together, takes only a couple minutes before hand to quickly knock of any rust or scale that could come between these parts.

Last thing before moving the tranny onto the engine is to double check that the torque converter is correctly situated and seated on the tranny input shaft, is this gets out of whack as you jostle things around getting the tranny into position, when you start pulling the tranny into place onto the engine you can damage the front pump.

There is a plastic plug on the lower driver’s side of the bell housing that you turn and pull out also. This plug extends into the bell housing in front of the torque converter. When you’re pulling a tranny some times the torque converter separates from the tranny input shaft easier than from the flex plate. If this happens as you pull the tranny rearward it will start to come and then the plastic plug will hang it up on the torque converter which is still stuck to the flex plate. If you can loosen the torque converter from the flex plate, not just the six bolts you access from the hole on the oil pan, but actually the torque converter turning freely from the flex plate you can avoid this. It’s just hard to get the nose at the center of the torque converter free from the hole in the flex plate most of the time. This plastic plug helps hold the torque converter from moving forward of the tranny input shaft when installing the tranny.

I took a tranny out of a an sdl in about 2 hours. I used an 88 300te for the doner transmission, and it was much more difficult. The clearance for the wagon was much tighter, and getting the bolt out of the housing took much more time.
When I did this I didn't use a lift, but just used jack stands. I also made a jig for the foor jack to hold the tranny.
I still have this parts car, if you need anything, let me know.

Don't touch the engine and don't rebuild the trans for the same reason; they ain't broke, so don't invite trouble.

You're going to be dropping the exhaust, so visually inspect it and get whatever rubber bits you feel need to be replaced. Definitely replace the nuts and bolts that secure it to the manifold. Been smog checked lately? after all, you'll be disconecting the O2 sensor. Once the system is down, eyeball the state of the precats (or whatever you CA emissions encumbered car owners have).

The aluminum crush seals on the transmission cooler lines are cheap, replace them (four I believe). Eyeball the rubber hoses at the front of the cooler lines too. I have seen the long metal line that runs up along the radiator to rust badly. How is yours?

Need a new donut between the transmission and the drive shaft? The books say not to reuse the bolts. Though I've never seen the bolts sold without the donut. Go ask your favorite parts supplier about that when you order the front seal and the replacement torque converter bolts (I think they too are use once only). Filter kit too while you're at it. Also the dipstick seal.

Removal of the transmission is easy.
- Disconnect the battery!! You're going to be messing with the starter.
- Put the car on jack stands in front. Rear too if you have four stands.
- Get a creaper for yourself
- Get a piece of 2x12 about a foot long for the transmission. This will go between the jack and the pan.
- Unbolt the torque converter from the driven plate.
- Drain the transmission pan a bit.
- Disconnect and seal the cooling lines from the transmission. My preferred seal is the rubber gloves I wear when handling slimey stuff like transmission fluid. You should be able to undo the lines from both ends and loosen the clamps that hold them to the oil pan and then slide them forward a bit. Removing them entirely works too.
- Unbolt everything from the transmission that impeeds its removal.
- With the jack holding up the weight of the transmisison, you should be able to pull it back from the engine. You want the torque converter to go with it.

Reinstallation is about as simple. The hard part is lining up the bolts. Use an extension rod or two as a guide. Just position the transmission about 2" from the engine and man-handle it to place with a pair of long 3/8" extension rods guiding it home (I think those fit. I may have used a pair of 1/4" rods when I did this last year).

It's a lot of work for one little seal, but it's fun work.

HTH -CTH