| Author | Message | ||
     Lawrence Heasman Frequent User Username: lheasman Post Number: 56 Registered: 5-2008 |
'89 Spur - SCAZN00A5KCH24747 Occasionally when starting the car I get this gut wrenching shriek with no turnover or ignition at all. If I leave it a few seconds sometimes it does it again or starts normally. Today it did it 4 times in a row causing a few to almost choke on their Café Latte's. Of course it never makes this horrendous noise in the privacy of ones own garage. Is this signalling the end of the starter motor or is it something else? | ||
| Paul Yorke Grand Master Username: paul_yorke Post Number: 584 Registered: 6-2006 |
Does it sound like an angle grinder on a bell or a miss selected gear? If so - probably the starter. Get it changed before and damage to the ring gear occurs. (And to spare the blushes!)  | ||
| Lawrence Heasman Frequent User Username: lheasman Post Number: 57 Registered: 5-2008 |
Definately more like the angle grinder on the bell!! Can these be re-conditioned or am i up for a new RR part? | ||
| Lawrence Heasman Frequent User Username: lheasman Post Number: 58 Registered: 5-2008 |
The starter motor turns out to be OK, all be it an obscure model that only had a short run from Crewe. The bad news is there is a worn spot on the ring gear that is causing the noise. It's about 10% of the area that has worn. As this is a costly job, will delaying the work have any negative impact on the engine, other than that awful noise when it lands on the worn patch? As this model appears to be fitted with a less then common starter motor and ring gear it's going to take while to source a part. Does anyone know if ring gear can also be reconditioned? | ||
| Richard Treacy Grand Master Username: richard_treacy Post Number: 2134 Registered: 4-2003 |
Lawrence, Although it won't hurt the engine, best stop driving your car right now. The ring gear may still be repairable. It is a special for your car. You can buy a complete secondhand motor and transmission for far less than the price of a replacement ring gear. This is potentially a big $ matter. There are several places around Australia which can do a proper repair, but don’t risk using the starter given the state of the ring gear unless you really need to do so. New ring gears, actually a flywheel assenbly with the ring gear and all, UE72403 for your car, are priced at a staggering £5,000 plus taxes in the UK. Used are priced at £2,500, all plus VAT/GST. Look it up on the web if you don’t believe me. That means that a new ring gear would cost you at least A$11,000 delivered in Australia with GST applied, and more if customs hit you with another 10% as they would on anything above A$1,000, or half the total secondhand. Yes, A$11,000 or more. I hate to think what the local outlets in Australia are charging. Part of the price is because the ring gear has special patterns and fittings which control spark timing and all the rest of the Motronic engine management system. There is no alternative to the correct unit. Removing the flywheel-ringgear thing is not a big job: just pull back the transmission. If you are familiar with the job, it should all take no more than four hours, a ring gear set, a new transmission filter and gasket ($7 for the pair at Supercheap by the way) and new transmission fluid. Replace the transmission front seal while you are at it. As a guide, my transmission shop charges just A$600 to remove and refit the transmission, so you must consider whether there is any real saving of DIY in this case as in all cases. The starter itself is a Nippondenso, not particularly special, and there are a few sources around A$500 if you ever need a brand new one. ps: chances are that the starter is loose in the bellhousing and has chewed up the ring gear. RT. | ||
| Daniel Diewerge New User Username: didi13109 Post Number: 8 Registered: 11-2009 |
Hello Lawrence, I would weld some material to the worn teeth on the ring gear and then file or dremel the teeth into the proper shape and finish. | ||
| David Gore Moderator Username: david_gore Post Number: 956 Registered: 4-2003 |
"Hello Lawrence, I would weld some material to the worn teeth on the ring gear and then file or dremel the teeth into the proper shape and finish." Unless you can match the hardness of the weld to the parent metal as well as controlling the heat input during welding to minimise distortion, this suggestion could cause more problems and expense over time than the once-off cost of replacing the ring gear assembly. The possibility of uneven wear patterns on the motor pinion and gear teeth and distortion of the ring gear itself gives me great concern. | ||
| Daniel Diewerge New User Username: didi13109 Post Number: 9 Registered: 11-2009 |
The ring gear teeth are already electricaly hardened, the hardness of the welded teeth will very probably not cause a problem. The ring itself is quite beefy, so the welding heat can be transported away safely if you do it slowly and give it some cool down time after each tooth. Considering the price of a replacement ring gear, this is really worth a try. But then again I have more of a shadetree mechanic's attitude and you might just prefer to bite the bullet and replace the ring gear. If you should decide to weld to the ring gear, it is very important to attach the ground directly to the flexplate so the current does not have to travel thru the crankshaft possibly damaging the main bearings. | ||
| Omar M. Shams Prolific User Username: omar Post Number: 133 Registered: 4-2009 |
If you tell me what the material is, I will contact our material scientist at work and get the correct weld procedure for you. He will also ensure we specify the correct welding rod and any pre heat requirements. Give me the details and I will gladly provide the procedure. If you use any old rod with any old procedure it becomes like Russian Roullette. | ||
| David Gore Moderator Username: david_gore Post Number: 957 Registered: 4-2003 |
Daniel - I am a metallurgist which some experience in this field hence my concern. The welding process will affect the structure and hardness of the base metal which may have adverse consequences if the welding techniques are not properly carried out by someone who knows what they are doing. Omar, the teeth have been induction hardened. The welding techniques have to ensure underbead cracking and hydrogen embrittlement does not occur. The material is most likely AISI/SAE1045 or AISI/SAE1050, possibly AISI/SAE4150. The tooth hardness will probaby be around 50Rc. A post-weld stress relieve not exceeding 250 deg C would be advisable especially if it is 4150 grade [this is prone to temper brittleness in the range 250/450deg C] | ||
| Richard Treacy Grand Master Username: richard_treacy Post Number: 2135 Registered: 4-2003 |
I have seen a few tooth repairs to ring gears on many makes of cars. I am sorry, but I put them almost exclusively into the used car lot basket. Durability is not generally a virtue of built-up teeth. Metallurgist or not, the results always seem to be poor. A convincing industrial repair outfit could just potentially do a good job. I called the guru at my trusted transmission shop yesterday about this particular case (he rebuilt my 3L80 Turbo R transmission last week). He confirmed this approach nervously. Maybe the best result from a gear repair would be almost as good as a new one with a lot of luck. However, and as he suggested, would it not be wisest to have a new ring gear fitted to the existing wheel ? That way, a proper gear with contiguous teeth would offer the same robustness as a new wheel, but at a fraction of the cost. Fortunately, the gearwheel diameter and pitch are fairly common, so it would be a machining, fitting and dynamic balancing job resulting in a perfect outcome. RT. | ||
| David Gore Moderator Username: david_gore Post Number: 958 Registered: 4-2003 |
Richard, I was not condoning this form of repair just pointing out the pitfalls involved. I stand by my originsl advice: "Unless you can match the hardness of the weld to the parent metal as well as controlling the heat input during welding to minimise distortion, this suggestion could cause more problems and expense over time than the once-off cost of replacing the ring gear assembly." I rest my case m'lud.... | ||
| Richard Treacy Grand Master Username: richard_treacy Post Number: 2136 Registered: 4-2003 |
Agreed, David. Hence my scepticism of all but a new ring gear, whether fixed or shrunk onto the existing wheel or a new wheel (but not a complete new wheel at that price thank you). I hope that you agree that a repaired set of teeth may be at best almost as good as a new fitted ring to the existing wheel ?? RT. ps: my guru at the transmission shop in Canberra confirmed that he had inspected the ring gear on my Turbo R last week. It is still unworn at 320,000km, a prerequisite for the 3-year unlimited-km warranty on the transmission job, and with the aftermarket Nippondenso starter replacing the original Nippondenso unit. | ||
| Lawrence Heasman Frequent User Username: lheasman Post Number: 59 Registered: 5-2008 |
All very interesting gentlemen. At present there appears to be no second hand part available in OZ so the search must go O/S. Thank goodness for the strength of the $AU at present. Still looking at $5k plus at present to get this wee matter sorted. In for a penny in for a pound eh!! | ||
| Lawrence Heasman Frequent User Username: lheasman Post Number: 60 Registered: 5-2008 |
Just as a foot note, I've been quoted 2 days labour to get this job done, so the 4 hours mentioned by RT, is this 4 hours to just take it out or 4 hours all up and is this a 2 man job? If so i can understand the quote of 16 hours labour. | ||
| Bill Coburn Moderator Username: bill_coburn Post Number: 1240 Registered: 4-2003 |
Richard/ I am confused! The first replacement for the old Lucas starter by the Factory I thought occured in '87 with the installation of a Nippondenso. I had two Lucas starters fail on '84 and '85 Spirits and replaced them with Nippondenso's cobbled together by a team of doctors of all people at Brith Starters Inc in the States. RA Chapman used them for a while and then decided to manufacture his own so developed a more powerful Nippondenso motor with the necessary adapter. These are apparently very successful. So what are you using now? | ||
| Paul Yorke Grand Master Username: paul_yorke Post Number: 598 Registered: 6-2006 |
Bill, I assume that Richard is using "Nippondenso" as the generic term for the newer reduction gear permanent magnet motor starter motor - and meant "replacing the old Lucas one". Can't imagine anybody fitting a Lucas one these days! | ||
| Richard Treacy Grand Master Username: richard_treacy Post Number: 2137 Registered: 4-2003 |
The car I mentioned is my 1987 Turbo R, which of course had a Nippondenso as original equipment. The one-way roller clutch collapsed, so I replaced the starter by an aftermarket Nippondenso one. Incidentally, the most reliable starter I know has been the Lucas in our 1972 T-Series. It has never given the slightest trouble. The Nippondenso ones that were OEM from 1987 are electrically fine, but the roller clutch (sometimes called a sprag incorrectly) is far weaker than the Lucas equivalent. Lawrence, to remove the transmission and the flywheel, then to refit it should take one person 4 hours, max 6. A few years back, I removed the transmission, fitted a replacement torque converter and front seal, new engine mounts, new filter and fluid. It took 4 hours drive-in, drive-out. I have the receipt from the rented workshop space to prove it. The flywheel-ring gear will take another 30 minutes to R/R compared to my job. A professional shop should be quicker than I, so 4 hours should be plenty all in. Of course there is the repair to the wheel itself to cost. RT. | ||
| David Fairbrother New User Username: davidf Post Number: 5 Registered: 2-2010 |
Lawrence, I dont know of any ring gear repair companies in Australia but there are a couple in New Zealnd that that I have listed below and they may be worth contacting. The $AU to the $NZ would certainly help Possible we may have a few NZ readers who know of these firms and could comment. David http://www.finda.co.nz/business/listing/qt9f/ring-gear-recovery-ta-lon-laggon-engineering/ http://www.ringgear.co.nz/index.shtml | ||
| Douglas Majors Experienced User Username: rollerman Post Number: 19 Registered: 12-2006 |
Hello Lawrence and David, Re the ring gear recovery company trading as Lon-Laggon here in the Manawatu in New Zealand. While I haven't personally had any any dealings with them in regards to getting ring gears fixed, I do know the owner of the company, a Mr Rob Pettigrew who is very well know in motoring circles here in NZ. He is also a member of the Mercedes Benz club to which I also belong so I meet up with him quite often. He is a very likeable and approachable man with years of experience in his field. As I also live in the near vicinity to his workplace, if I can be of any assistance to you, please send me a personal email. As for the other company listed, I have no knowledge but their listing suggests that they are knowledgeable in their field. Good luck, Doug Majors. |
