DIY Transaxle / Transmission mount bushing with AGA tool

A quick demo on how to use the AGA tool for pressing out and replacing the bushing that serves as the mount on the forward end of the transaxle. This whole operation took me 2.5 hours, working casually. It was easy, like a 3/10, and I would say I am a moderately experienced wrench. Not as hard as dealing with ball joints but tougher than, say, an oil change. Two strong pieces of advice: 1. Use a lift. Obviously this is easier said than done, but being able to stand under the car while working the tool, removing all the plastic, etc, was really nice. It's doable on jack stands but would take longer. 2. Place the new bushing in the freezer overnight and then put it in a cooler full of ice to take with you to the place of work. Bonus points: place refreshing beverages in the cooler. Another piece of time-saving advice is use an electric impact (or air if you'd rather) to remove all the 10mm plastic nuts holding on the plastic undertrays. Don't use an impact to reinstall them (you'll destroy the nuts). Special tools: 1. AGA transmission mount tool. ( http://www.agatools.com/part/porsche...nsmission-tool ) It's $300 or you can hop in my other thread and get in line to rent it. There are a few clever design points in this tool that make it so good. Namely, some intricate machining bits that add clearance and make it easy to properly align the bushing coming out and going in. Additionally, they didn't skimp on the materials and threaded rods, so it's a "professional level" tool that can stand multiple uses. 2. 7mm socket or wrench. I mean honestly why does Porsche love the weird sizes? I already had one from my 944 days but they don't come in any kits. 3. Grease. Bearing grease, moly grease, etc for lubricating the threads on the tool. Also useful for a light layer when installing the bushing. 4. Cooler with ice, for keeping the bushing cold right until install. 5. Tall jack stand, for supporting the transmission while working. 6. Torx bits for removing the plastic under-trays. If you own a 996, these should be common to you by now anyways. I think it was a 30 and a 27 that I needed.

Step 1 is remove the plastic under-trays. If you need more detail on how to do that...maybe reconsider this job. Just undo all the torx bolts and 10mm plastic nuts for the two center plastic pieces and the one plastic shroud on the aluminum cross-brace. Remove the aluminum cross-brace (I threaded the bolts back into the chassis as not to lose them). Step 2 is support the transmission in such a way that it unloads all stress on the two bolts going through the mount. Remove the nuts (15mm) and adjust the jack until the bolts just easily slide out.

Step 3: Remove the four nuts holding the forward bracket onto the chassis. The bracket compresses the mount a bit, so it won't immediately fall off the car. Step 4: Remove the nuts holding the truss-shaped hanging bracket. These nuts (15mm) are on studs (7mm). In the photos, I removed the nuts first and left the studs; you'll actually need to remove the studs to swing the truss bracket out of the way, so go ahead and remove them both. If the forward bracket hasn't already come loose, pull it off the car. Swing the truss bracket up and out of the way. We won't be removing it; just moving it out of the way is fine.

Here I'll point out some good engineering that went into this tool. The large spool has a flat cut in it; the flat allows the spool to be centered up over the hole without contacting the transmission housing on the left/driver side. The AGA-RIM-996 piece also has a notch cut in it, and its face is likewise machine in such a way that it will only go on in the correct orientation. 5. Setup the tool as shown in the first picture: Place the AGA-RIM-996 cap on the passenger side and slide the two threaded rods through it and the bushing, then place the spool and AGA-CC-996 cap on the other side and put the washers and nuts on. Hand-tighten as you ensure that the tool is totally centered. Being completely centered is really important! The AGA instructions mention trimming any extruding rubber on the existing bushing if it has failed, as to not interfere with proper tool seating. I did not have to do any trimming.

More pictures demonstrating the fitment of the tool upon removal of the old bushing The caps are fitted with slots that hold the bolt heads; no holding of the bolt heads with tools is required.

6. Tighten on the two 13mm nuts; the AGA instructions say to alternate between top and bottom. When I did this, I used a ratcheting wrench and got about one flat on the nut before I'd have to switch to the other. Don't use a big wrench or breaker bar or you'll risk putting too much torque on one rod and getting the bushing crooked as you press it out. I recommend using a ratchet and 13mm deep socket in conjunction with a 13mm ratcheting wrench so you can pull on both threaded rods at once. It is MUCH faster this way. Eventually you'll feel the bushing pop out into the big spool piece. Disassemble the tool and remove the old bushing.

7. Clean up the hole in the transaxle with a clean rag. Place a light film of grease on the left/driver side of the hole. 8. Set up the tool to press in the bushing from the driver side: Make sure the flat part of the bushing center piece is up. There is an arrow on the rubber that points up also. Once you remove the bushing from the cooler, work quickly to get the bushing started before it warms up. You won't use the big spool piece on installation; the "CC" cap goes on the passenger/right side on the "RIM" cap goes on the driver/left side. 9. As before, hand-tighten the nuts and make sure everything is centered. If you buy the mount direct from AGA, they machine a lip on the bushing to help it center during this part. The transaxle body itself has a bit of a chamfer to help center the bushing. With the bushing cold, I didn't have an issue with this part, even though my bushing was bought elsewhere, without the machined lip. 10. Using the same method for tightening the rods evenly, drive the new bushing in. You'll feel the tools bottom out, and then you know you're centered. Disassemble the tool.

11. Reinstall both brackets loosely. Put the studs back in for the truss mount, but not the nuts. The only remaining tricky part is using the jack to position the transaxle, and manually manipulating the two mounts in order to get the new transaxle bushing bolt holes to line up so you can drop the bolts back in. Once the bolts are in, start tightening up the four nuts on the forward bracket and the two nuts on the truss-shaped bracket. I recommend using the 7mm wrench to hold the studs while you fasten the nuts on those; you want to put tension on the stud not rip it out of the body of the car as you tighten its 15mm nut. 12. Reinstall the plastic under-trays and the aluminum cross-brace.

Nice write up. Thanks for sharing.

Well done, thanks!

Thanks for the great post! Quick question: Freezing the new mount makes sense and mine is currently in the freezer, but does it help to heat up the transaxle a bit so it expands a little? I'm trying this project without the AGA tool, so I need all the help I can get. Thank you in advance!

It's really going to depend on the tool you're using to press the bushing in. It's a very tight fit, so make sure your tool has enough "guts" to get the job done without failing and leaving you with a half inserted or crooked bushing. IMO heating the transmission side isn't going to help you much, and will just warm up your bushing that much quicker - making it more difficult to press in. Good Luck

Well, after spending a great deal more time and energy than I anticipated, I managed to complete the job. The most important lesson learned: BUY THE AGA TOOL! I thought I had a good work-around tool but it didn't take long to learn that it didn't have the "guts" needed to adequately press in the new mount. The amount of force needed to press in the new mount, even after freezing for 36 hours, was exceptional and unexpected! I'm tired, sore, and cant tell you how many times I thought to myself: "I should have bought the AGA tool". Think about it...the cost of the tool+the cost of the mount would still have been less than paying a shop to replace it. Huge lesson learned for me! Thanks for your input!

My AGA tool is SOOLLLLLLLDDD

Well heck - too late now..Thank you! By the way I did notice a big difference in the way my car feels now with the new transmission mount. It made a big difference to me.

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Hi, is it still? Thanks, Martin

Tool still for sale??

I have the tool for rent: https://rennlist.com/forums/996-foru...-for-rent.html Followed up to your email!

Dave, I am a new member, and not able to PM currently. I have a 99 996 C2 Tip and would like to rent your tool. Do I need anything extra or different since my car is an automatic? Ben Schulte [email removed] [phone removed]

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You'd need the Tiptronic adapter in addition to the regular mount tool. I only have the regular tool for manual transmissions. http://www.agatools.com/part/porsche...ic-adapter-kit

[QUOTE=dkraige;15731226]You'd need the Tiptronic adapter in addition to the regular mount tool. I only have the regular tool for manual transmissions. http://www.agatools.com/part/porsche...ic-adapter-kit [/QUOTE Ok! I can purchase that through AGA. May I rent your tool?

dk, are you still renting the tool? I know someone had issues with renters damaging it but can't remember who...If you are, PM me please.

I have the the tip adaptor from AGA to use with their transmission mount change tool for sale. I bought it and used it once. You still need to rent the mount change tool from the guys on this thread. Pm me for shipping and payment details. Ben [phone removed]

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If I were dporto or dkraige I�d buy it to increase the number of potential renters... I own the aga tool, but don�t ever imagine a time where I�d own a tiptronic.

As Porsche apperently doesn't sell the bushing as a spare part I bought the part made by ZF Lemf�rder. Turns out they supply Porsche as it read 996 blau (=blue) 986 gelb on the rubber, had a blue paint mark on it and an erased porsche part number. The color coding is most probably to discern the different characteristics (Shore hardness) of the boxster and 911 parts. I have seen this color coding on the engine mounts too.

I just used these instructions to replace the two cushions on each side of the transmission mount between the transmission and the brackets. To do this when I got to step #4 above I removed the drivers side nut completely but only loosened the passenger side one. This gave me enough play to pull out the one remaining cushion and reinstall the two new ones.

Thread revival - but thought useful to update if anyone in the UK is looking to rent the tool / do this job. I found this thread very useful to do the job and agree - trickiest part was the bracket / bolt alignment after install. Using the AGA tool was the easy bit. For this looking to do the same I�d say go for it. Found the rental via Facebook market place - just search - Aga porsche gearbox mount tool. Friendly chap called Darren rented it to me. He has both manual (that I used) and the tip parts of the tool. Straight forward job (on axle stands in the garage) much improved shift now. Very good piece of kit.

@knfeparty I discovered you once owned a 955 CTT, and replaced the cross member bushing in that as well. Did this same AGA tool do the trick? Thanks!