Changing the axle seals on the transaxle is reasonably easy but requires a couple of tools and some muscle (and a few beers).
By the way I would change both of them - these things usually screw up in pairs.
Here are the steps:
What you doing here is trying to compress a little circlip/snap ring (which is mounted on the axle spline inside the trans) enough to get it out of a groove which is machined into the bore (inside) of the trans output shaft.
The problem is that this snap ring is pretty stiff and the groove seems to have a fairly steep taper on it - thus the ring doesn't want to ride up the taper very easily. When you reinstall the axle you will feel the snap ring pop into that groove with a distinct "click" - and this holds the axle in place in the trans output shaft.
Anyway, I finally went into the workshop at school and made a very large pickle fork - just like a ball joint splitter but much larger. I put it up on the inner joint from below and hit the little stem of the fork one light rap with a 2 pounder and this popped the inner CV joint out like magic.
You must be careful not to beat on the joint itself or tear the rubber boots at all (if torn they MUST be replaced NOW!!!). You must also never pull on the axle from the end (ie. outboard near the wheels) since this will just pull the joints apart and it will not result in removal of the inner joint from the trans.
Once the axles are out, you need to remove the old seals. The best way to do this is with a cheap (< $10) little seal puller tool which looks like a crowbar with a nasty tooth on the end.
The seals are really tight in there so don't spare the horses when pulling the old ones out. I think that they over-did the press fit but oh well.
DO NOT scratch the trans housing when getting the seals out - the new ones could leak if you do.
Install the new seals - this will be tough since they are REALLY tight fit. You need to use a seal installer which is a handle (on which you hammer) with an endplate which transfers the load onto the outer (steel)portion of the new seal. Some manuals suggest the use of a large socket - but I couldn't find one in my kit with fitted the seal well so I made my own plate.
It wasn't all that good - I ruined 1 seal and had to buy another one but they are cheap (>> $10 each).
The seal must go in square and it must be driven home (ie. all the way into its bore in the trans. If you warp it or damage the flexible part of the seal - throw it away and get a new one.
Take out the speedo drive unit and refill the trans - and hope to God that the stupid little plastic gear doesn't fall off the drive unit shaft (like mine did). If this happens you need to fish it out with a piece of wire or the like.
BTW - when this gear fell off it made me so burned that this was the only time I actually considered selling my car. When this darned gear fell off - I thought that I would have to start the clutch job all over again. I just can't imagine why GM designed it to have no visible means of being fixed positively to the speedo unit shaft.
In my view this is the most dumb and irresponsible piece of design that I have found on the car. It is also sort of dumb to combine this unit with the trans dipstick - I wish I had a Getrag which has a separate dipstick.
The next time I have to take out the trans on my car - I am going to make a drain plug through which I can pump the refill fluid back in and then close off just so that I can avoid removing that stupid little speedo unit again!
(Can you tell that this problem made a big impression on me?)
From: Peter Frise
Our good friend in Canada (Peter) recently pened a superior article that involved pulling and replacing the rear axles on all Fieros. He advised replacing the transmission to axle oil seals anytime the axles were out.
I totally agree. But, extreme care MUST be taken when driving in the new seals so as not to disort them.
A very sophiscitated tool for this purpose is a piece of 2" ID (2.5" OD) Schedule 40 DWV Plastic (PVC) pipe. The pipe fits perfectly on the seal flange, and a tap on the other end of the pipe with a hammer does the job. You only need a few inches of pipe to make this tool. One caution, the pipe MUST be cut perfectly square, so use a factory end or saw it in a miter box. It is also helpful to place a short piece of a 2x4 on the hammer end of the pipe before giving it a wack - keeps things aligned and makes it easier to drive the seal in straight.
I do not advise driving the seal without this tool, or something similar.
From: Randy Agee