DIY for transmission mount R&R

[greerj1]

Anyone do a tranny mount R&R on a 996/997 manual transmission, How do you remove it from transmission casting? Can you do it in place?

Thanks;

James Greer

[996noob]

Anyone do a tranny mount R&R on a 996/997 manual transmission, How do you remove it from transmission casting? Can you do it in place?

Thanks;

James Greer

I've posted this question a couple of times in the past. Everybody says no, even though I think no one has actually really tried it (fashioning the tools, etc.). Those who have changed the mount did it outside the car, and have said that we're better off removing the transmission than attempting an on-car mounting change. I'm quite determined to try to do it in-place, but need to do more research.

[logray]

Here you go. It was fairly difficult, but if I were to do it a second time it might not be as tough as having to come up with this method.

edit edit: If you are adventurous, WEVO sells a semi solid engine mount for the boxster 986. The boxster engine mount is the same mount used in the 996 6-speed transmission (C2, C4, C4s), and the early tiptronics. The wevo mount will stiffen things up, and as an advantage does not require a press to install (so you only need to worry about removing your existing mount). I haven't tried this mount myself, but am thinking about doing it in the future:

EDIT: doing this without removing the transmission (or transmission and engine) would be very difficult if not impossible. Pressing it out required tons of force, and getting a press with sufficient force in that tight spot would require an incredibly unique welding job and custom fabricated tool. If you don't want to go through all of this, and don't mind a stiffer ride, I've read about some who have "filled" the gaps in their broken mount with windshield sealant. I opted for the factory replacement since I rarely track my car, and would rather have more comfort than performance. It is possible to do the windshield sealant method with unit in car, since with the transmission fully supported by a jack, you would have access to the mount on both sides once you've removed the supports.

With either windshield sealant as well as semi solid mount (there are solid mounts available too), be aware that the stock rubber unit will absorb much more shock for the entire drive train than the other methods. Stiffer mounts means a stiffer ride and potential for more road shock transferred directly to the engine, transmission, and your seat.

You'll need:

- a floor jack of at least 6 ton (recommend 8 or more). If you have access to a shop press, use that instead of a floor jack.

- if you use a floor jack, several very heavy duty tie down or tow straps rated at least 5 tons with a suitable sized tie down ratchet to secure them all.

- something to fabricate a support and secure the transmission safely while it's on it's side during pressing

- a new transmission mount (part # fits all 996 MY 98-04, manual C2, C4, C4S and some early tiptronics): 996-375-055-05

- safety gear, glasses, goggles, gloves, etc.

- 4" section of 3" steel pipe (receiver/support for transmission case to accept the mount and ram)

- 4" section of 2.5" steel pipe (ram to press mount out)

- If you can't get 4" sections at your hardware store, a way to cut the irrigation pipe. A pipe cutter, band saw, or circular saw and "disposable blade".

- grease

Step 1.) Remove transmission from vehicle.

Step 2.) Purchase from your local hardware store (that sells steel irrigation piping) a 1 foot section of 3" steel pipe (galvy or black doesn't matter). This becomes the "receiver" for the mount. Also buy a 1 foot length of 2.5 inch steel pipe - this will become the ram that you press with a floor jack. If the store has the capability, have them cut each section for you down to 4" or sell you 4" you can save yourself the trouble of cutting it. The stores I visited would not sell/cut less than 1' of pipe.

Step 3.) Cut each length of 1' pipe to 4" (be as accurate as possible with the angle on the cut to ensure it is perpendicular to the pipe).

Step 4.) With the transmission VERY WELL secured (I recommend simple fabrication of foam/wood mounts/tie downs) and on it's side (I used a harbor freight trans jack with strap and some carefully placed shims of wood), place the 3" outside diameter "receiver" section of steel pipe on the top side of the transmission with the concave flange surrounding the mount hole (press side). Be careful not to damage the gear selecting arms, reverse light switch, etc.

Step 5.) Using a 6 ton or larger jack (recommend 8 or more), place the 2.5" outside diameter piece of pipe underneath the transmission on the non-press side (flat surface on the transmission casing). The pipe should rest on the cup on top of your floor jack. This becomes the press that will push the mount out of the casing. The jack will press the 2.5" O.D. section of pipe and the mount through the casing into the receiver piece of pipe out on the top side of the transmission. It is VERY important that the press section of pipe is exactly aligned with the outside edges of the mount, otherwise you'll press into the transmission casing. The 2.5" O.D. pipe is a few mm smaller than the outside diameter of the mount so it will slide through the hole in the case.

Step 6.) If using a floor jack, using several very heavy duty tow straps (at least 3 wrapped around) and a tie down ratchet, secure the entire assembly snugly (but not overly tight). The straps should wrap around the bottom of the floor jack, and the top of the receiver on top of the transmission on it's side.

Step 7.) Ensure children and pets are not nearby. Do not do this where flying debris could damage something, although the strap mechanism is most likely to break. Wear safety goggles and suitable protection while pressing.

Step 8.) Gently add pressure to the floor jack to ensure everything is aligned properly before adding too much pressure. (might take a few efforts to align properly). The entire system (jack & trans) might roll a little on the ground (unless your floor jack raises exactly vertically) - I found a point on my jack that raised more vertically than while in the flat or highest position. The more vertical the pressing action the better. This is why an actual hydraulic shop press would work best since it does not move laterally as it presses.

Step 9.) Once you're certain everything is aligned, give it your all - one "pump" of the handle at a time. The mount will break free and eventually press through.

Step 10.) The next part was more difficult for me. You are going to do the steps above but in reverse and with a few notes.

a.) FLIP the transmission on it's other side so you are pressing towards the concave flange around the hole in the case (recommend fabricating a simple wood support to keep the transmission level and secure). Be careful not to damage the gear select arms, etc.

b.) CRITICAL that you align the mount vertically (make note of how it was removed) within a few centimeters (there is a small amount of play in the transmission mounting system). You'll see on the top of the new mount there is an arrow that should point straight up when the transmission is LEVEL.

c.) GREASE the outside of the new mount and inside of the transmission casing.

d.) PRESS the new mount in using the press side of the casing (you'll see one side of the trans casing has a small concave depression while the non-press side is flat against the press).

e.) Don't be discouraged if it takes a few attempts to align it properly. The casing may actually deform slightly and it takes a lot of force (several tons worth) to get the new mount in. Once you get it started though, it will start to slide in with less effort than it took to press it out.

f.) As you press in using the floor jack, SLIGHTLY relieve the tension on the straps when you press the mount in farther (may require a couple press attempts, mine took two and broke a strap in progress). This is because eventually you will be pressing against the strap, and not against the press that pushes the mount in place - preventing you from pressing it in completely. Don't be discouraged if your tow/tie down strap didn't work the first time, use wider or more straps and bigger tie down ratchets the next time you attempt it. Note that you don't have this problem when pressing out (much easier) because once the press has started there will be less tension on the tow strap due to the mount pushing into the receiver section of steel pipe.

Here are the pictures of my success with this procedure. Good luck.

(click pictures to enlarge)

edited for easier reading/accuracy.

Edited January 5, 2012 by logray

[jcb]

I bought a 997TT tranny mount from Pelican Parts to replace my 996TT stock mount....thought this was supposed to be simple and something one could on with it all on the car?

Confused now....please let me know if this thread is not what I am thinking about doing....tia.

jeff

[Loren]

I bought a 997TT tranny mount from Pelican Parts to replace my 996TT stock mount....thought this was supposed to be simple and something one could on with it all on the car?

Confused now....please let me know if this thread is not what I am thinking about doing....tia.

jeff

This for a 996 Carrera transmission NOT a 996TT transmission.

Different transmissions and engines.

Try posting in the 996TT section.

Carrera 6 speed rear mount

996TT 6 speed rear mount

[xmac]

Loren, what about the mount for a C4 6-speed?

[Loren]

Loren, what about the mount for a C4 6-speed?

C2, C4 and C4S share the same 6 speed mounting.

[logray]

Some of the early tiptronics use this same system (first year or two IIRC).

I also edited my post above for clarity and added some more info about aftermarket mounts.