1999 C4 noisy transmission vs Porsche magic grease absence

Hi all, I bought my 1999 Carrera 4 in september. The p.o. specified that the transmission was a bit noisy and I bought it like that cause I do all my mechanics myself (usually). The car was in excellent general condition. Cause we have looong winters here, I planned to take out the drivetrain as my winter project. So now that I'm in, I'll do some maintenance on the engine like changing the o�l separator, IMS bearing, RMS, and everything I can to have peace of mind. My post is about the tranny. I'm aware of the Pinion bearing failures and everything I read about noisy transmission was followed by: The first check to make is to drain the o�l and stick your finger in the drain hole to see if there is the Porsche magic grease that came off the pinion bearings. That is the first thing I did when I drained and saw nothing like that. I just had a bit of black deposit just probably normal due to the age and mileage of the transmission. The car has 100k miles on it by the way. I opened the transmission and did'nt see any grey magic grease like I saw on other related posts or Youtube. The condition of internal parts of my transmission look excellent. I would like to know if my pinion bearing could be the problem of the noise I hear from the transmission even if I don't find the magic grease that should have come out from the bearings? Since I'm not on an open budget I would'nt change these bearings without beeing sure cause first it's very expensive and second it's a huge task. I found a cool DIY about changing the bearings but it's for a C2. Mine beeing a C4 there is no hole at the end of the primary shaft where I need to put the special tool used not to break the shaft while I press out everything to the bearing. Is the shaft of a C4 also hollow ? Does anyone did that in a Carrera 4 transmission? I called a specialist and told him what I wrote and he told me that it could be noise coming from the differential part of the tranny. He also told me that there was not much to do with that. I did'nt find anything on the net about other reasons than the bearings that make trannies noisy on these cars. Could someone help me please?

Ok I'll change my question for a shorter one: Does anyone already rebuilt or heard of a rebuilt of manual transmission for a Carrera 4 ???

I know of a good indi if you live anywhere in S E PA. I had a noisy gearbox and now it is amazingly quiet. He also did a new basic clutch and AOS at a shade under $5000.

Too bad I'm in Canada You have a C2 but mine is a C4. My main concern is that in the excellent DIY thread to rebuild those trannies the procedure is for a C2. They put a special tool in the hollow shaft before pressing not to break the shaft but in a C4 the end of the shaft is not alike because of the front drive shaft output. I wonder how to do not to break anything and if it has already been done in a transmission of a Carrera 4.

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A search didn't turn up any DIY write ups/videos of a C4 transmission rebuild. A couple of places that appear to do Porsche transmission rebuilds did turn up. There's this place that you might find of some interest: https://californiamotorsports.net And: https://www.vertexauto.com/porsche-9...n-p-10736.aspx

Did you find the long Sticky by Nick Hend and 2 Angels(?) There are lots of threads on this subject .Few/none(?) are C4 specific. Read all and that may narrow down your questions. Photos help.If you are lucky ,an attractive post will catch the attention of experts like GTGears or GBox. Have you priced out the bearings yet ? Which organ will you sell?

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Thank's a lot Macster, I already found the two links but since I'm in Canada the shipping will be very expensive (rebuilt tranny and core) and it's a bit over my budget. I also searched a lot and also found nothing on C4's. Thank you very much.

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Yes I did find the stickies but both are for C 2's. I tried to pm Nick without success. I just removed the nose cone for now. Sorry but what do you mean by : Which organ will you sell? Thank's a lot for your help

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Meaning it will cost a lot of money...how much can you get for a kidney these days?

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the most expensive "organ" by weight is bone morrow...in essence, we are all millionaires

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A place up near the Oakland Raiders coliseum pays IIRC $400 for a bone marrow sample.

Perfect pricing ! Each bearing is around $400,then there are the tools to extract/replace. Kukko. Recently a forum meber was offering some for $300 each. It is just a deep groove, ball ,double row, grease-sealed bearing - sound familiar ? Yes, one mode of failure is that it's grease washes out ! Remove seals on replacement bearing or rig a DOF?? We really,really need a generic crossover/interchange # for the 6-speed gearbox bearings.So far nobody has even posted the bearing dimensions so we could get started on finding a generic alternative. Whoever discloses the secret dimensions or the generic part number would be a legend on this Forum !

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Try to find Erik Johnson on the Porsche Forums or GT40. He may be able to help you.

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LOL Sorry I understand fast when you explain a long time I'm french native so sometimes I sound odd and sometimes I understand the same Thank's

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I have'nt decide yet to do the job myself cause of lack of infos on C4 tranny rebuilds. If ever I jump into this adventure I swear I will do my best to give the dimensions of the bearings. Thank's

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Thank's a lot I'll try.

Just a few words that I'm in the process of chaning the pinion bearing by myself. As soon as I can I will follow with the bearing dimensions.

Well done for persevering with this project. The lack of much info on the Forums indicates what a daunting task it is. I hope you succeed and can indicate the risks to others who follow. Thank you for taking the time to share your experience and knowledge. Did you read this link kindly supplied on a related thread by Robin 993dx ? Interesting that he removed the seal on the replacement (sealed+greased)pinion bearing but no follow up on if it helped. https://rennlist.com/forums/996-foru...project-5.html

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Yes someone just write me the same thing on Nick Hends threads. Just a little hint about the fork shafts. I gave them number from 1 to 5 before removing. #1 was the shaft near the drain plug and #5 the fartest. In order you must remove #1 then #2 then #4 and #5 togheter. And the last to go is #3 (the one in the center) For #5 we must remove 2 pins to take it out. Everything is in the d�tails If that could help.

These ar exactly the tedious details we need to learn ! Imagine trying to pull off #5 and only removed one of the two pins . More force on the puller- something would eventually bend or break. So pile on with the details please ! I wish someone like Pelican would show an interest in subjects like this and do a video . There is certainly plenty of money to be made selling the $300 bearings !

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Thank's I don't make magic. It's just deduction during the work. By the way you don't need a puller to remove the fork shafts. It's just by hand. Oily hands cause everything slips. Yes someone should make a video but just a little mistake in there and the tranny may get more expensive damages so it's risky business

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Here are a few infos on the bearings as I continue the procedure to change them. The number on the primary shaft double ball bearing is : 572548C.H84 The dimensions are 72mm O.D. 35 mm I.D. and thickness 34mm. I also found this old thread where they mention Porsche parts numbers for 2 bearings. Probably for the main shaft and the pinion. It's a post of 2006 so maybe things have changed about availabilities. Also the O.D. of the pinion bearing is 93 mm. The other dimensions will come in a few days when I'll will be done disassembling them (I hope).

Here is some info on the bearing part numbers you mentioned: A finders fee offered ! It is an *** Volvo or Mercedes truck axle bearing ? https://rennlist.com/forums/996-foru...-bearings.html http://forums.pelicanparts.com/porsc...-bearings.html These come up as 964 /993 bearings? Hopefully others are better than me at hunting for you.

I did found those 2 threads a few minutes ago but they lead to nothing

Which is why we are still fighting to make this job easier for the future. If you google "572548C.H84 bearing" the hits are all Chinese. That is where I saw the reference to the truck axles. To me that suggests that a good Bearing dealer who specializes in truck bearings would be able to track down the parts.

A friend of mine who's an engineer will help me searching. He has a contact directly at NTN or NSK bearings. I wonder if a double bearing of the same dimension but in a single piece casing would fit? The one I removed tonight was had one inner race but in 2 outer cases.

That is a very odd bearing configuration !

Yes and beeing in the disassembly I think it's a very odd mounting configuration in there too. If I find something I'll post I thought a bit about the 2 rows and one of them stayed in the tranny aluminum casing but the other half is not even held anywhere? Unless it goes in the steel plate that holds both shaft? I'll check that tomorow or after tomorrow. I'll sleep on that. Thank's

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The pinion bearing has a unique notch on the outer race for select fit shims, I have searched extensively for another application for this bearing, none are to be found. The split outer race is where the bearing gets its pre-load when the bearing retainer plate is tightened, no other design will work (ie split inner race, one piece ) wheel bearings with split inner races get their pre-load when the axle or stub axle nut is torqued.