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Post by cp93mm on Nov 15, 2010 16:19:46 GMT 12
[img src="[/img]http://i1006.photobucket.com/albums/af181/bluefluffzzz/058.jpg?t=1289795000 ![]() i1006.photobucket.com/albums/af181/bluefluffzzz/058.jpg?t=1289795000"]Hi im 35 and i was an trade cert mechanic for the 1st 11yrs of my working life but am now a bit behind on the times. I have a hi-perf subaru and have a few certification related questions for my build. My 1st question is about my conversion to rwd.I have a 1996 legacy gt bg5 and have converted it to manual and rwd and need to know the regulaions on the front shafts as ive removed mine and bolted up the outer cv;s to the hubs......what do i have to look out for so far for when i go for my lvvcert?...lots more questions and pics to come |
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Post by p10racer on Nov 15, 2010 21:22:53 GMT 12
What gearbox are you using dude? we did this conversion on a friends WRX a couple of years ago, after breaking 3 locked center boxes we converted a W58 Toyota box to go behind it.
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Post by cp93mm on Nov 16, 2010 3:14:14 GMT 12
What gearbox are you using dude? we did this conversion on a friends WRX a couple of years ago, after breaking 3 locked center boxes we converted a W58 Toyota box to go behind it. ...Im using a v5/6 box which has a stronger casing then the earlia ones converted professionally to rwd (center diff to front diff spline taken away).......rear hubs i will add extra support to aswell to stop flex and twist....do you know the regulations for converting to rwd with a 400hp engine?...apart from 1 or 2 driveshaft loops? |
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Post by Justin on Nov 16, 2010 7:47:57 GMT 12
Hi there LVV don't have regulations as such for gearbox requirements - it's just a matter of working out what will be 'man enough' to do the job. p10racer has suggested a Toyota box as they have learned the Subaru box is inadequate - this could be good info to take on board. (Thanks p10racer). We do have an infosheet which covers 4 wheel drive to 2 wheel drive conversions, but this is more aimed at what needs certification, and doesn't go too deeply into technical requirements. I'll email this to you now. Regarding your rear hubs etc, I do suggest that if you don't already have one, get your hands on a copy of the NZ Hobby Car Technical Manual - there are various requirements you should be aware of, including welding requirements, and in some cases the need for a design approval on certain modifications. To get a copy, follow this link; www.hotrod.org.nz/Merchandise%20Page%20Files/Hobby_Car_Technical_Manual.htmI hope this helps. Justin |
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Post by cp93mm on Nov 16, 2010 17:07:47 GMT 12
Hi there LVV don't have regulations as such for gearbox requirements - it's just a matter of working out what will be 'man enough' to do the job. p10racer has suggested a Toyota box as they have learned the Subaru box is inadequate - this could be good info to take on board. (Thanks p10racer). We do have an infosheet which covers 4 wheel drive to 2 wheel drive conversions, but this is more aimed at what needs certification, and doesn't go too deeply into technical requirements. I'll email this to you now. Regarding your rear hubs etc, I do suggest that if you don't already have one, get your hands on a copy of the NZ Hobby Car Technical Manual - there are various requirements you should be aware of, including welding requirements, and in some cases the need for a design approval on certain modifications. To get a copy, follow this link; www.hotrod.org.nz/Merchandise%20Page%20Files/Hobby_Car_Technical_Manual.htmI hope this helps. Justin Hey cool thanks for that email Justin and for the heads up on the NZ Hobby Car Technical Manual but i still dont understand as to why the front axles have to remain intact on an AWD to RWD conversion when the front diff is no longer in use? Or are they saying to increase the braking ability of that vehicle if awd is removed?. And if an awd gearbox has been converted by way of professionally removing the transfer spline that connects the front diff to the center viscous diff and the center diff welded solid what use are the front axles still?(they do not affect steering or suspension)......so for what reason would they have to remain? Does the lvv certifier judge his certification case by case or do they have to be one sided?(do it by the book even if it doesnt make sence?). Id love it to be case by case as i see lots of descrepancies so far on this one issue unless ive been misslead by others telling me that they have failed a wof or lvv cert cause the front axles are no longer in.....please help |
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Post by Dan on Nov 18, 2010 8:31:08 GMT 12
The infosheet Justin forwarded gives some examples of the need to retain front axle components. These are general examples and won't apply to all vehicles but they will all need to be considered by the LVV certifier when he makes his assessment.
Here are some of the examples:
• The front and rear hub assemblies on commonly-available 4-wheel drive equipped vehicles rely on the constant velocity (CV) joints being fitted and torqued up correctly to keep the bearings pre-loaded and secured onto the hub. The CV, by means of an oil seal, also provides a weather-proof seal for the wheel bearings and hub assemblies. It is critical to ensure that the CV joint remains correctly fitted into the hub, to ensure the bearings are correctly retained and sealed. A nut/bolt/washer combination is NOT acceptable as an alternative to a CV joint.
• In some cases the CV joint may have been modified, so as to remove the ‘cup’ section of the joint, giving a cleaner looking conversion. This is acceptable, provided that the strength and integrity of the main ‘shaft’ and ‘clamping’ (threaded, splined, and stepped) areas of the CV joint is not affected in any way through heat, or grinding.
• It is critical that if the vehicle is equipped with ABS, that the ABS ring is still in its correct location on the CV joint, and that the ring is secure.
• While in its original configuration, the inner CV joints are securely retained in place by a circlip, and the positive engagement of the axle shaft. With the axle shaft removed there is a risk of the inner CV joint popping out while under high load or RPM conditions. It is therefore advisable that the inner CV joint is removed, and a machined plug fitted to the gearbox, to eliminate the risk of gear oil being allowed to exit the gearbox.
There's always more than one way to skin a cat so if you've found an alternative solution to an issue the certifier may recommend that it is put to the technical committee for approval.
Dan
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Post by cp93mm on Nov 19, 2010 2:42:50 GMT 12
Hey thanks so much for that Dan, i do think that there now wont be any issues with getting cert for my RWD conversion without the axles based on the Subaru layout and what you have shed light on (plus my inner cv's are fully removed and female splined(the male splines out of the box are dormant), plus i have not altered the outer cv's at all apart from removing the bearing cages nothing can fall out,no cutting/welding or heat was used on them and i dont have ABS).
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