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| MED SC Dropgears and Deafness- Avoid or tolerable? https://ausmini.com/forums/viewtopic.php?f=2&t=101471 |
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| Author: | watsupskip [ Sun Aug 07, 2022 6:58 pm ] |
| Post subject: | MED SC Dropgears and Deafness- Avoid or tolerable? |
I bought a set of these when i thought it sounded good at the time, but i do want to keep my hearing and need to conisder the wife and daughter who love going for drives too. They were intended for a 1360 we’re building but im thinking of just using the mk2 pArts again. What’s everyones thoughts to these and has anyone got experience with the MED product in particular? Should i sell them and run and never look back? Or give them a go?? How loud are SC drop gears really? Like ear next to petrol leaf blower motor loud? Or is it a whine / high pitch? Youtube doesnt seem to give it justice when trying to gauge the dB level. Appreciate everyones thoughts no right answer i suppose. Car gets used about 20 times per year and generally coffee runs or club events. |
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| Author: | lomin [ Sun Aug 07, 2022 7:31 pm ] |
| Post subject: | Re: MED SC Dropgears and Deafness- Avoid or tolerable? |
Hi, my personal opinion, and some will disagree. Normally most people fit them to race cars, because of perceived strength and the fact they do not have thrust loads into the casing, which helical gears can damage. After you come into the pits after a race with very hot oil, you would think the gearbox is exploding, incredible whining/ chatter, and the majority of that is idler gears. there is the odd racecar thats not bad. I am building an engine for my rally car, with est. 140- 150 hp. I have 2 sets of MED straight cut idlers, one with a broken tooth where they drill down into bearing area, and this hole is right at the bottom of 2 teeth, a lovely weak spot where there is a point of propagation for breakage. and the other set has a fair bit of wear on teeth, and done very little work. I am fitting the best genuine all synchro helical idler gear system I can build up. It will be quieter by a mile and imho outlast any MED product. The other point you may not realise is helical gears make contact with about a tooth and a half with the adjacent gear, straight cuts one or less. Unfortunately the material and heat treating, and surface finish of new replacement gears leaves an awful lot to be desired. This is not unique to MED. With helicals, make sure you polish the shafts, and examine with a magnifying glass for any sign of flaws in the hardening. A 1275 will deteriorate that very quickly. Always use new Japanese or german idler gear bearings In all my years of racing (about 50) I never fitted straight cuts until I got over 130hp, then I thought I will need them.I had also never had a helical failure. I now wish I hadnt, because I have had a few straight cut fail. cheers Lindsay Siebler |
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| Author: | Cooper_Matrikon [ Mon Aug 08, 2022 3:58 pm ] |
| Post subject: | Re: MED SC Dropgears and Deafness- Avoid or tolerable? |
I went down this path. I fitted a set of MED s/c drops and I stopped the car 50m down the road and got out the car and kicked myself. It was literally mind numbing. I've since removed them and added a set of s/c standard ratio gears to the box. Mini Sport in Adelaide sell them and they are spectucular. Enough whine in 1st, 2nd & 3rd to satisfy the boy racer and barely perceptible in top. I would drop the drops. |
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| Author: | simon k [ Mon Aug 08, 2022 9:49 pm ] |
| Post subject: | Re: MED SC Dropgears and Deafness- Avoid or tolerable? |
I've never understood why people think straight cut gears sound good... it sounds like metal being tortured to me lomin wrote: I am building an engine for my rally car, with est. 140- 150 hp. I have 2 sets of MED straight cut idlers, one with a broken tooth where they drill down into bearing area, and this hole is right at the bottom of 2 teeth, a lovely weak spot where there is a point of propagation for breakage. and the other set has a fair bit of wear on teeth, and done very little work. .......... I now wish I hadnt, because I have had a few straight cut fail. is this the kind of failure you experienced Lindsay? happened to a friends car a couple of weeks ago (ex-Grinter car at PI) Attachment: 20220802_171908.jpg Attachment: 20220802_171937.jpg
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| Author: | TK [ Mon Aug 08, 2022 11:37 pm ] |
| Post subject: | Re: MED SC Dropgears and Deafness- Avoid or tolerable? |
what brand? |
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| Author: | watsupskip [ Tue Aug 09, 2022 5:52 am ] |
| Post subject: | Re: MED SC Dropgears and Deafness- Avoid or tolerable? |
This was great feedback thanks for the straight answers. Gonna stay stock instead. |
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| Author: | simon k [ Tue Aug 09, 2022 8:39 pm ] |
| Post subject: | Re: MED SC Dropgears and Deafness- Avoid or tolerable? |
TK wrote: what brand? Don't know, just about everything else on the car is the expensive stuff so it would have been some well known manufacturer, but it was in the car when he bought it. Engine builder didn't know |
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| Author: | lomin [ Sun Aug 14, 2022 6:53 pm ] |
| Post subject: | Re: MED SC Dropgears and Deafness- Avoid or tolerable? |
Hi Simon, I finally took a couple of photos. Not supper clear. 1 shows hole drilled through the middle of idler gear in 3 places. This creates an extremely weak spot a the base of 2 teeth. and result broken tooth Second photos is not super clear, but through the hardening right across the tooth face, on a little used primary gear. cheers Lindsay Siebler |
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