Auto tranny rear seal change

I have been posting my efforts to change the center drive shaft bearing in another thread. I was under the impression that once the drive shaft was out I could change the rear tranny seal from the back of the transmission. It appears the seal is inserted from the "inside" of the rear Ferrari made housing. To change the seal would mean removing the rear tail piece. Has anyone done this job with the tranny in the car?

Questions:
- How did you support the transmission when doing the job?
- how much fluid will come out if that piece is remove?
- Are any pullers needed to get it off?
- Is there a bearing behind the seal? If so does that need to come out to change the seal?

I have not dug into it yet, but hope some one can get me started.
Ken

 

PT
I have the Ferrari parts manual. When I looked to order the seal I had the impression it came out the back out the back and I would not have to pull the tail piece. Your description sounds right, I will check manual and parts book before going forward.
Ken

 

Gary / others!
Did you actually do this job on a 400? Based on your input I started into the job this morning and was enthusiastic that it would not be to tough. Then I looked at and touched the top two nuts holding the housing. There is no way to get a straight shot with a socket on them due to the rear flange of the same housing. There is not enough space for a box or open end. I have a set of short Facom open ends that I can get one end on but no way to get enough torque to loosen the nut. Has anyone found a suitable tool to get to them from under the car?

I see an access port just above these bolts. This is obviously the intended means to get to the nuts. Has anyone removed that trap door from inside the car? Is this a case of removing the entire interior to get to the two nuts on the transmission?!! My car is on a two post lift and getting inside the car is not too easy or impossible for me, but if the access port is not too tough an answer I am willing to give it a try or hire a very small person to get in.
Ken

 

I got into car and the bolts I need access to are just about below the ash tray. With ash tray out there is a rubber like pad between interior and the chassis below. I thinnk the console would have to be raised to get to the access door.

If there is some combo of socket, u-joint from below I am all for it. The gap between the two flanges on that spool piece is just too small.

Ideas?
Ken

 

Gary
"Just nuts and bolts" does not describe cars that I swear the designers make the jobs tougher so people go to the Ferrari techs, which they must get a kick back from.

In this case there are two flanges 3-4" apart on top of the housing and only less than 2" clearance in any side. A socket and swivel take up most of the gap and any extension runs into the bottom of the car. It is a 17 mm socket so no small torque to get it loose. Come to think of it a socket with the swivel part of it may just work. My 3/8" drive socket and swivel are a bit longer than a combination one would be. Sounds like a trip to Sears tool store!

I am still hoping to hear about the access door above, because this it the plan.

Remember that Luigi Chinetti designed the TH400 conversion not Ferrari. I would have thought a few years in NY would have made him more practical for maintenance.
Ken

 

Al
That is great pic and it will surely get me to the nuts. Now tell me what did you have to do to remove the console? Step by step if possible but I don't need spoon feeding. Where are the key bolts/screws? Can all the wiring remain intact in the console and just lift the console as a unit? Unbolt at dash/AC? That is the scary part when I looked at it.
Ken
p.s. I removed and re-installed my dash a few years ago so I know bolts around the AC, but are they needed. I have a Series 2.

 

Al
I think your car is a series 1 400i one by the details of your post. Do you have the wood panel by shifter and three AC outlets in dash?

I hope someone with a Series 2 car will post procedure.
Ken

 

I tired my two newly purchased tools: swivel direct on 17mm socket and a stubby open end/ratchet box. Neither would loosen the nuts. I pulled out my crow's foot set and after rigging the right length of extensions it turned the top right nut. It took a few more tries on top left. The stubby ratchet got the top right the rest of the way off. The top left needed the crow's foot until loose enough to do by hand.

I had advice last night that getting the console off would be tough, so I am sure glad this worked.

I have an extra bit of work with this job. I found one of the lower studs had pulled the aluminum threads out. It looks like a helicoil job, but will try some other options first like a longer stud.

Now that bolts are undone I am not clear about how to get the piece completely off. I used a rubber mallet to open a small gap and start the oil draining. It does not want to come right off, seems something inside is holding it in place. It gives when pried but springs back. I will be sending PM to Godspeed; he has done this job.
Ken

 

If you want to pull something, use a puller! I just used a general purpose small puller, pushing on the output shaft and out it came, smooth as can be.

Unfortunately, I can now see that I never had to remove this piece to change the seal; the edge of the seal was hidden by a thin aluminum ring in front of it that I thought was part of the housing. As long as it is out I will change the bearing too.

The correct sealing between the housing and the TH-400 is an o-ring. Mine was put together with a gasket (probably from a TH-400) and RTV. I plan to get the o-ring and no RTV if all the faces are smooth.

I sure feel better than 12 hours ago.
Ken

 

GT
I was not clear in that post (just so happy "it" was out). I was struggling to get the housing off the tranny. I used a Craftsman 2-arm puller to ease it out. Once housing was out, seal was just pushed out from back side.

If I was going to pull the seal in place I would have probably used a cork screw. They make such things as seal pullers but they are just a cork screw on the end of a screwdriver, sometimes with a flexible shaft.
Ken

 

Took my time this morning and installed new bearing and seal. O-ring is interesting in that the F-part has a slight larger diameter than the grove. When you get it all into the grove, it pushes to the outer edge of the grove; I thought it would cling to the short spigot on the inside. It protrudes from the face so seal is by compression against the transmission flange. I used some Hylomar to make me feel better.

Housing mounted onto tranny, took a few taps before bolts extended enough to get nuts on. It pulled up okay.

Tomorrow is the big day, putting the diff and tube back in. I'll finish any posts in the the other thread I started, this one appears done.
Ken