trm Posted 23September, 2022 Report Share Posted 23September, 2022 Hi all, I have a 911 SC that has some rumbling at high load/low rpm especially when cold which I think is bearing noise. It has previously been rebuild 70,000kms ago with new gears, synchros and sliders + clutch and machined fly wheel. But the bearings were not replaced at this time. Still shifts and drives nicely apart from the bearing noise. The oil was replaced every 30,000kms since rebuilt and has been done 3000kms ago (by previous owner). I intend on replacing it this weekend with some Kendall 80W-90 that I have and seeing if it makes a difference and inspecting the oil and magnetic drain plug. Will report back with the findings. I am located in Sydney and would like to hear some suggestions on who to use for a rebuild and expected cost. Ideally feedback from anyone from Sydney who as has their 915 rebuild by a Sydney based shop in the last few years. I am aware that the cost will be heavily dependent on what needs to be replaced as parts are expensive. But at this stage I am hoping its bearings and that the other components done 70,000kms ago are hopefully ok (fingers crossed). Thanks trm Mike D'Silva 1 Quote Link to comment Share on other sites More sharing options...
Zelrik911 Posted 23September, 2022 Report Share Posted 23September, 2022 Check first that this noise is not from the rear wheel bearings. My faithful old SC had rear wheel bearing noise that I originally thought was the gearbox. Its a less complicated job than a 915 rebuild !!! The wheel bearings are the same size as used in some BMW models (& less expensive) . In your model, 4th gear should be direct (1 to 1) so the least gearbox bearings in use & least noise?? The 5th gear can get noisy as it a bit starved of oil however its not a bearing & is a less complex repair. Good luck. Quote Link to comment Share on other sites More sharing options...
trm Posted 23September, 2022 Author Report Share Posted 23September, 2022 Thanks for the feedback. Good point on the wheel bearing. I think the noise stops when I put the clutch in. But I will change the oil and try and report back which gear is most pronounced Quote Link to comment Share on other sites More sharing options...
LeeM Posted 23September, 2022 Report Share Posted 23September, 2022 4 hours ago, trm said: Thanks for the feedback. Good point on the wheel bearing. I think the noise stops when I put the clutch in. But I will change the oil and try and report back which gear is most pronounced Thrust bearing is my guess. Quote Link to comment Share on other sites More sharing options...
mal911 Posted 24September, 2022 Report Share Posted 24September, 2022 The gearbox in my SC was absolute cactus and I had it rebuilt by Ralph at RPMS in Arncliffe. I was extremely happy with his work and could not believe a 915 gearbox could shift so well. having said that it cost me aprox 11k about 2 years ago Mike D'Silva 1 Quote Link to comment Share on other sites More sharing options...
rminc Posted 6October, 2022 Report Share Posted 6October, 2022 Most people that say the 915 is a bad box, haven't driven a car with a good (newly built) 915. Unfortunately they degrade and progressively get worse. I think the G50 transmissions would just not shift at all instead of that progressive decline. Has anyone had to rebuild a G50 transmission? If the 915 bill was $11k, I'd hate to see what a G50 would cost to refresh. Quote Link to comment Share on other sites More sharing options...
trm Posted 8October, 2022 Author Report Share Posted 8October, 2022 My car actually shifts really well with the 915 despite the bearing noise. It is infinitely better after I put a jwest shifter and stomski coupling in it. I have put a stomski coupling in all 3 of my previous cars. It's a must have in my opinion. First time I have had a shifter on these cars. I was tossing up between the wevo and the jwest and went with the jwest just because. It's fantastic. I havent got around to doing anything with my car yet as I am on holidays at the moment. Will likely call BWA and Michael Newton once I'm back and see what they say rminc 1 Quote Link to comment Share on other sites More sharing options...
Peter M Posted 8October, 2022 Report Share Posted 8October, 2022 On 07/10/2022 at 10:30, rminc said: Has anyone had to rebuild a G50 transmission? If the 915 bill was $11k, I'd hate to see what a G50 would cost to refresh. Funny, someone asked me that last week Sean! My gearbox had nearly 250,000km on it and had slow synchro on 2nd gear (the main issue for me) and 5th gear had a barely noticeable whine. Autowerks at Wyong rebuilt mine in 2017 @ $135/hr. I'd expect the going rate for most independents will now be between $150 and $200/hr but I can give the following durations they charged that would allow a more current calculation to be completed: Remove and separate engine and transmission - 3 hours Rebuild G50 - 13 hours Replace various synchro rings, bearings, oil etc. - Around $800 Replace 5th gear set - $2,500 - I scoured the world for the best price and this was it! However I would expect most rebuilds would not require this expenditure. Reinstall transmission - say 4 hours By my reckoning that works out to be 20 hours or $2,700 of labour at the time. Total with parts $6,000. Allowing for cost increases but no 5th gear set replacement, I'd expect a current G50 rebuild to cost expect $4000 + $1600 = $5,600 ish However! Expect to spend extra on the clutch, whether that is a simple replacement of the plate or a full replacement of flywheel, pressure plate, throw out bearing and clutch plate. Expect to replace the yoke bearings to the upgraded version. Beware that replacing the standard rubber centered clutch plate with the commonly available spring centered plate will considerable increase the gearbox noise of a G50. (Rubber centered plates are still available as new old stock but you'll need to search for one and will cost you about $800 delivered) Actual cost will depend exactly on what needs to be replaced and you won't know that with any certainly until it's in bits on the bench! I'd happily recommend Autowerks for this type of work. Quote Link to comment Share on other sites More sharing options...
rminc Posted 10October, 2022 Report Share Posted 10October, 2022 On 08/10/2022 at 17:59, Peter M said: Funny, someone asked me that last week Sean! My gearbox had nearly 250,000km on it and had slow synchro on 2nd gear (the main issue for me) and 5th gear had a barely noticeable whine. Autowerks at Wyong rebuilt mine in 2017 @ $135/hr. I'd expect the going rate for most independents will now be between $150 and $200/hr but I can give the following durations they charged that would allow a more current calculation to be completed: Remove and separate engine and transmission - 3 hours Rebuild G50 - 13 hours Replace various synchro rings, bearings, oil etc. - Around $800 Replace 5th gear set - $2,500 - I scoured the world for the best price and this was it! However I would expect most rebuilds would not require this expenditure. Reinstall transmission - say 4 hours By my reckoning that works out to be 20 hours or $2,700 of labour at the time. Total with parts $6,000. Allowing for cost increases but no 5th gear set replacement, I'd expect a current G50 rebuild to cost expect $4000 + $1600 = $5,600 ish However! Expect to spend extra on the clutch, whether that is a simple replacement of the plate or a full replacement of flywheel, pressure plate, throw out bearing and clutch plate. Expect to replace the yoke bearings to the upgraded version. Beware that replacing the standard rubber centered clutch plate with the commonly available spring centered plate will considerable increase the gearbox noise of a G50. (Rubber centered plates are still available as new old stock but you'll need to search for one and will cost you about $800 delivered) Actual cost will depend exactly on what needs to be replaced and you won't know that with any certainly until it's in bits on the bench! I'd happily recommend Autowerks for this type of work. Thanks for the insight Peter. I'd honestly expected a higher cost than the 915. Good to know. Quote Link to comment Share on other sites More sharing options...
trm Posted 17December, 2022 Author Report Share Posted 17December, 2022 Thought I would report back on this issue I had. I took the car to Michael Newton for him to have a look. What an awesome guy. He spent more than an hour with me, test drive the car, discussed all the things that it could be and the possible alternatives I had. He even took me into his back room and ran me through all the components within the 915 and the typical issues. After driving the car he said that he didn't think it was bearings but it did have an noise that it would be hard to pin point without pulling it apart. He didn't push the rebuild route with me but did suggest I change the transmission oil and monitor the noise. I knew the previous owner had just changed the gearbox oil about 2000km ago. But it was worth a try. I took the car home and changed the oil. The swepco 201 that came out was bright blue and in perfect condition as you would expect given how recently it had been changed. I replaced it with Kendall and well guess what. The noise is gone. Well not completely gone but I would say it's 20% of what it was. Certainly something I can live with and no louder than the level of noise that Michael indicated to me was normal during parts of our test drive. The car did not like swepco for some reason. Potentially some wear in there that showed up with the swepco but for now I am happy to drive it with the Kendall in it and see how it goes. I also fixed the shift fork cover leak while I was changing the oil so happy that is done. Anyway that's the story and I must say I was impressed with Michael Newton, his knowledge and his customer service. I was honestly astonished that he spent an hour diagnosing the car and talking it through with me and didn't charge me a cent or try and sell me on anything. What a guy, his knowledge of these cars was unbelievable. woot woot, Stockydude and Yeatesy 3 Quote Link to comment Share on other sites More sharing options...
Quackers Posted 18December, 2022 Report Share Posted 18December, 2022 that’s fantastic news, Thanks for posting the recent update and great experience you had with Michael. Do shoot me a message if your searching for 915 parts in the future and also check out Tom Perazzos “ahh garage time” you tube updates if you wish to see the transmission rebuild process as his currently doing a 915 right now after just finishing his 356C 741 trans rebuild. Cheers Brendan trm 1 Quote Link to comment Share on other sites More sharing options...
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