It looks like I need a transmission rebuild - 986 Forum - The Community for Porsche Boxster & Cayman Owners

Background: Car is a 2001 Boxster S manual. Over the winter, I did the IMS, RMS, and clutch, and changed the transmission lube. When I got it back together and started it, I was getting a noise from the rear of the car. Here's what it sounded like: https://www.youtube.com/watch?v=EWWvBP2g1T4 I ruled out all the engine-related sources, so figured it must be in the trans/clutch. After a couple of cycles of pulling the trans and checking the clutch/flywheel/fork/slave cylinder/release bearing/every other damn thing, I couldn't find the problem, so I took it to a trans shop. They narrowed it down to something inside the trans. Here's what it sounds like turning it by hand on a bench: https://www.youtube.com/watch?v=CXEP9oD8UyU But they aren't equipped to rebuild this trans, so their suggestion was a used trans, but those aren't cheap and you never know what you're going to get. I've accepted that this is going to cost me a good chunk of change, but I want to make sure it's done right. So, what do you guys suggest? I'm not averse to boxing it up and sending it someplace, but something local (southeast Michigan) would obviously be preferable. Thanks!

Unfortunately the S 6 speed is unique to that car and not found on other vehicles, so the only guys who will be familiar with the are probably Porsche specialists. You may want to just try your luck on an ebay pull, or source one through locally through car-part.com that you can check out and pull yourself. Sent from my POCOPHONE F1 using Tapatalk

Did it make noise before you took it out the first time?

Isn't it a ZF transmission? Any good shop should be able to tackle the problem. Check with local Mercades shops on who they have do transmission work. You said you changed the fluid, what fluid did you put in and how much? Also doesn't sound like you have driven it much if any in between all the work so I would start to ask why it started to sound like it does. My first thought (didn't listen to any of the videos)....drain the fluid, look at the fluid, put in the correct amount & type and see if it still exists. There are good videos on how to do this, look for Help Me DIY on youtube.

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Yes, but that particular transmission is specific to the 986 model. Unlike the 5 speed and the later 987 6 speed, which are more widely used in German autos. With that said, stl is right about the fluid. One of the nifty little points about these trannys (5 and 6 speed) is that they are hypoid gear setups with a lot of brass. A lot of EP additives will chew that **************** up, which is why most people use only the oem lube. Sent from my POCOPHONE F1 using Tapatalk

My point is, something about this just isn't right. We are all assuming the noise/issue wasn't there BEFORE any work and that the noise started after being put back in the engine. Just seems off is all. If a shop has worked on ZF transmissions they shouldn't have a problem with this one. parts will be different but it isn't rocket science either. Personally I dont touch transmissions, I would rather just pull one out and replace it then think about tearing into one but these transmissions are pretty bullet proof. It is hard to really break them. I have seen more problems with the chains breaking then the transmissions braking on these cars.

I've got an unusual 3-2 downshift crunch in my CSS 6-spd that I suspect is a 2nd gear synchro. I've been snooping around to see what it would cost to fix and like you have found no one wants to work on it. The only place I found that would was in CO but it was going to cost at least $5K. With my engine rebuild going to cost an astronomical amt, I haven't pursued spending more on top of that. I'm sure I kept the info on the name of the place in CO if you're interested, but it will take me a while to find it.

No, it made no noise before I pulled it. The trans shop I took it to (local place that's done good work for me, but not a Porsche specialist) is thinking something came loose when I pulled it. Here's what it sounds like running: https://www.youtube.com/watch?v=EWWvBP2g1T4 For the record, I get that noise with the clutch out, and when the car is moving (clutch in or out). If the car is stationary with the clutch in, it's nice and quiet. Hence why I have pulled it 3 times looking for clutch/flywheel/release bearing issues. I used Porsche OEM gear oil I got from Pelican. This stuff: https://www.pelicanparts.com/More_Info/00004330549.htm?pn=000-043-305-49-OEM I filled it according to the instructions in the 101 Projects book.

The video link in your first post , that sure sounds like either a belt tensioner gone bad or power steering pump .

Well since you are becoming an expert at removing the trans why not just remove the trans and then start the car, if the problem is still there you know it isn't the trans itself. I highly doubt it is the transmission.

Just listened to the new video. That is NOT transmission noise. Take the belt off, start the car, run it for 30 seconds. Noise gone? If so the RF is on the right track. Sounds to me like PS pump, Alt, pulley but definitely not transmission or clutch

In post #8 OP states that with car stationary and clutch in=depressed the car is "nice and quiet". With car moving and clutch in or out he hears the noise. So with car stationary and clutch depressed the trans main-shaft is not spinning. But with car moving the trans. main shaft is spinning with clutch in or out. The axles spin the main shaft while car is moving with clutch in. If you listen to the vid of the trans. main shaft being spun by hand something is not right in the trans. So very possibly a trans issue. I do agree the the vid of engine running does sound like power steering or idler pulley. Removing the belt and running engine as suggested should tell all.

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+1 on the tranny. I wouldn`t be surprised if the transmission oil was full of steel and metal debris.

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Husker, taking my car (987CS) to the track for two seasons with the POC, I ruined my pinion bearing, perhaps for not installing a transmission cooler and sent the gearbox to GBox in CO, while it was that shop I decided to install an OS Giken LSD as well, but when I received the gearbox I noticed that they stripped the head of one of the bolts of the input shaft flange, and the shop didn't bother to replace it.., This shop also didn't return the open differential when they shipped the transmission back to me and after I complained they simply told me that they could not find it and I could not do anything about it.. however the worse came a few months later after I lost the ability to engage fifth gear (..!!) After removing the transmission I decided to bring it in person to CMS (California Motor Sports) in Lake Havasu, AZ and they kindly open the case while I waited, and reveal that the selector fork for 5th gear had lost it's locking pin, and that pin was loose inside the gearbox for the few days I was using the car without been able to engaging 5th gear Needless to say I would Never consider sending a gearbox to GBox for their poor craftmanship and terrible customer service.. In the other hand many of the SoCal speed shops praise the quality and professional support they get from CMS, give them a call and you will be surprised that you may not need more than 2-3k to rebuild your gearbox https://californiamotorsports.net/ Good luck!

Send it to these guys: https://californiamotorsports.net/collections/porsche-986-boxster-5-speed-transmission-parts

Thank Gilles (and harnishclan), you're awesome! I had no experience with GBox (found the link I had and it was them) but they were the only facility I'd found who would work on my trans. I will defn check out CMS and let you know what I find out. My budget could absorb $2-3K. You guys rock!

Thanks, folks. I did find CMS when Googling, but I wasn't sure about their reputation. It looks like I might have a line on a used trans from someone on another forum, so TBD on that. By the way, I made a post yesterday about the steps I took to investigate the noise, but it never got posted for some reason. In any case, removing the accessory belt was the first thing I did. And, as I said, there is zero noise with the clutch in. It's 100% a transmission issue.

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Yes pretty obvious it is a trans issue when you listen to the trans. when the main shaft is being spun by hand.

To continue this thread, and for future reference, I got another reference for CMS from a trusted source so I contacted CMS and described the issue with my trans. Roger quickly responded and said replacing 3 items (he listed them) would most likely solve my issues. He had the parts and they'd cost $1330. When I asked how much he would charge to do the repair himself, he said $600. I had my shop drain the trans fluid and ship my trans to western AZ. It just left on Thu. I will follow up when I get it back.

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No, it's a Getrag transmission and it's a miserable POS that no one will touch. I was told by GBox that the pinion bearings are only good for about 60k miles and then need to be replaced for around $2000-4000. And then there's the 2nd gear synchros.... Any updates on your dilemma? What happened with your tranny? That's good to know as I'm in this boat now unfortunately. I would love to hear an update on how the repair went and hopefully the tranny is working well.