J-Boy Posted May 23, 2006 Share Posted May 23, 2006 Hi there...anyone has any idea how to tell a dogbox or aftermarket gearbox from a standard GTR gearbox without taking the gearbox out? Link to comment https://www.sau.com.au/forums/topic/119194-how-to-tell-if-my-gearbox-is-a-dogbox-or-an-aftermarket-box-without-taking-it-out/ Share on other sites More sharing options...
jantolis Posted May 24, 2006 Share Posted May 24, 2006 If it's a dogbox it usually makes a whinning sound all the time. They are also alot harder to drive at first. After market gearboxes i'm not sure if they make the same sound. Link to comment https://www.sau.com.au/forums/topic/119194-how-to-tell-if-my-gearbox-is-a-dogbox-or-an-aftermarket-box-without-taking-it-out/#findComment-2196782 Share on other sites More sharing options...
T04GTR Posted May 24, 2006 Share Posted May 24, 2006 first off give me an exact speed reading at 4000rpm in 1st ,2nd,and third Link to comment https://www.sau.com.au/forums/topic/119194-how-to-tell-if-my-gearbox-is-a-dogbox-or-an-aftermarket-box-without-taking-it-out/#findComment-2198334 Share on other sites More sharing options...
J-Boy Posted May 25, 2006 Author Share Posted May 25, 2006 Ok here is wot i observed... 1st gear: 32km/h @ 4000rpm 2nd gear: 59km/h @ 4000rpm 3rd gear: 83km/h @ 4000rpm Link to comment https://www.sau.com.au/forums/topic/119194-how-to-tell-if-my-gearbox-is-a-dogbox-or-an-aftermarket-box-without-taking-it-out/#findComment-2202502 Share on other sites More sharing options...
Bass Junky Posted May 25, 2006 Share Posted May 25, 2006 try this. Put it in first. Flatten right foot on floor. Accelerate to 7500 rpm, change gear as quickly as possible without using the clutch. If it goes into gear and makes a bang but keeps going, she's a dog box. If it doesn't go in, or goes in then shits itself all over the road, it's not a dog box. Then try it without the taking your foot off the throttle! On a serious note, you' know from the V8Supercar whine that they give off. The faster you go, the higher the whine. Like the diff of a fu(ckarsed old taxi Link to comment https://www.sau.com.au/forums/topic/119194-how-to-tell-if-my-gearbox-is-a-dogbox-or-an-aftermarket-box-without-taking-it-out/#findComment-2202612 Share on other sites More sharing options...
kasanoff Posted May 25, 2006 Share Posted May 25, 2006 i thought the whining is more to do with straight cut gears rather than dog engagement... Link to comment https://www.sau.com.au/forums/topic/119194-how-to-tell-if-my-gearbox-is-a-dogbox-or-an-aftermarket-box-without-taking-it-out/#findComment-2202696 Share on other sites More sharing options...
J-Boy Posted May 25, 2006 Author Share Posted May 25, 2006 Sheesh...then if its not a dogbox, wouldnt i have done damage to the gearbox switching from 1st to 2nd without the clutch? Link to comment https://www.sau.com.au/forums/topic/119194-how-to-tell-if-my-gearbox-is-a-dogbox-or-an-aftermarket-box-without-taking-it-out/#findComment-2202704 Share on other sites More sharing options...
saliya Posted May 25, 2006 Share Posted May 25, 2006 Hi, There's a heap of info at the PPG or PAR websites. In particular, have a read of the PAR FAQ A dog-engagement box has no synchromesh/synchronizers on one or more gears. Rather than gradually selecting a gear (and allowing the synchro to work) you basically slam the gear in as fast as possible with a dog box. This needs to be done while the box is unloaded. You definitely need to find out - driving a dogbox like a synchro box apparently causes rapid dog wear. You can't tell a dog-box by the whine - when the dogs are engaged (with or without synchromesh) they are not moving relative to one another and should be making no noise. The gearbox whine in racecars is created mainly by the gearset - most racecars have straight-cut gears (because of strength and no-lateral-load reasons, amongst others), and it is the teeth of the straight-cut gears meshing and unmeshing that makes the whine. Helical gears (like those in an OEM gearbox) make much less noise; and you can have helical gears with synchros or without (that is, you can have a helically-geared dogbox). A dog-engagement box will feel just like a box without synchros : ) One of the ways you can tell by noise is if it makes a noticeable 'clunk' when you select first gear from a standstill. I'm sure there are others... Regards, Saliya Link to comment https://www.sau.com.au/forums/topic/119194-how-to-tell-if-my-gearbox-is-a-dogbox-or-an-aftermarket-box-without-taking-it-out/#findComment-2202829 Share on other sites More sharing options...
Bass Junky Posted May 25, 2006 Share Posted May 25, 2006 J-Boy. Yep, but that's half the fun. saliya. I was under the impression that you wouldn't have a dog engagement box on anything other than a straight cut gearset. There's not much point in changing to og engagement with normal helical cut gears as there is no strength advantage. Straight cut gears is much stronger because there is considerably more meat in the gears. Link to comment https://www.sau.com.au/forums/topic/119194-how-to-tell-if-my-gearbox-is-a-dogbox-or-an-aftermarket-box-without-taking-it-out/#findComment-2203081 Share on other sites More sharing options...
saliya Posted May 25, 2006 Share Posted May 25, 2006 (edited) J-Boy.Yep, but that's half the fun. saliya. I was under the impression that you wouldn't have a dog engagement box on anything other than a straight cut gearset. There's not much point in changing to og engagement with normal helical cut gears as there is no strength advantage. Straight cut gears is much stronger because there is considerably more meat in the gears. Hey, according to some, it's actually helical gearsets that have a strength advantage on a strict size-for-size basis - this kind of makes sense, because with a helical gearset there are more teeth engaged at any one time (which translates to less push on any individual tooth). But yes, at very high loadings the side loads become significant - so in theory, right at the top of the strength tree is a straight cut box that has no lateral loads. According to PAR, the 'strength' advantage of dog vs synchro is more to do with gear size rather than engagement method; the dog-engagement arrangement takes up less room than synchro, allowing more space for a wider gear. This extra width can then be used for either helical or straight gears... I'd guess that because they're harder to make, helical aftermarket gearsets have been around for less time and probably cost more, so yes, you're "more likely" to see a straight-cut aftermarket gearset than a helical set statistically. But straight-cut gears != dog-engagement, is the point I was trying to make. Dog engagement has the advantage of virtually requiring high-speed shifting - apply pressure to the shifter, unload the box and wham, you're in the next gear. You can unload either electrically (ignition 'blipper' or similar) or mechanically (lift throttle for long enough). I'm certainly considering going down the path of a dog-engagement helical gearset sometime in the not-too-distant future; I don't want the noise of straight-cut gears but I love the high-speed shifts that are possible. It will depend primarily on how long my current box lasts, what the service/rebuild intervals for the dogbox are, and whether I can live without synchros in real life Regards, Saliya Edited May 25, 2006 by saliya Link to comment https://www.sau.com.au/forums/topic/119194-how-to-tell-if-my-gearbox-is-a-dogbox-or-an-aftermarket-box-without-taking-it-out/#findComment-2203165 Share on other sites More sharing options...
Beer Baron Posted May 26, 2006 Share Posted May 26, 2006 the real question is why do you think it has anything other than a standard box? i would think if it had a dog box in it you would know about it as the first time you jumped in it would have been practically undriveable. Link to comment https://www.sau.com.au/forums/topic/119194-how-to-tell-if-my-gearbox-is-a-dogbox-or-an-aftermarket-box-without-taking-it-out/#findComment-2203293 Share on other sites More sharing options...
LANFOH Posted May 26, 2006 Share Posted May 26, 2006 Like what Bass Junky said you can work up the gears without using the clutch for fast engagement and only have to use the clutch for down shifting. Popular upgrade for wrxs. Link to comment https://www.sau.com.au/forums/topic/119194-how-to-tell-if-my-gearbox-is-a-dogbox-or-an-aftermarket-box-without-taking-it-out/#findComment-2203341 Share on other sites More sharing options...
J-Boy Posted May 26, 2006 Author Share Posted May 26, 2006 Well i do get sorta like a clunk sound going into first...sometimes when shifting fast from 1st into 2nd i get a loud "bang" kindda sound and the gear engages, but i am using the clutch...every gear change feels like as if it goes in very hard somehow...like a very bare metal feeling...no cushioning on impact wotsoever....it does whine as well...somehow i dont really dare to slam it from 1st into 2nd without the clutch.... Link to comment https://www.sau.com.au/forums/topic/119194-how-to-tell-if-my-gearbox-is-a-dogbox-or-an-aftermarket-box-without-taking-it-out/#findComment-2205385 Share on other sites More sharing options...
Ronin 09 Posted May 28, 2006 Share Posted May 28, 2006 could just be a shagged gearbox with fcuked synchros... Link to comment https://www.sau.com.au/forums/topic/119194-how-to-tell-if-my-gearbox-is-a-dogbox-or-an-aftermarket-box-without-taking-it-out/#findComment-2207380 Share on other sites More sharing options...
predator Posted May 28, 2006 Share Posted May 28, 2006 w3rd.. your gearbox is a special "Knacker" gearbox Link to comment https://www.sau.com.au/forums/topic/119194-how-to-tell-if-my-gearbox-is-a-dogbox-or-an-aftermarket-box-without-taking-it-out/#findComment-2207404 Share on other sites More sharing options...
Links Posted May 28, 2006 Share Posted May 28, 2006 Does it whine in every gear? or just 1st and 2nd.. Have you changed the oil lately? noticed any teeth when you have? Maybe take it to a gearbox specialist.. they should be able to help you out.. Link to comment https://www.sau.com.au/forums/topic/119194-how-to-tell-if-my-gearbox-is-a-dogbox-or-an-aftermarket-box-without-taking-it-out/#findComment-2207816 Share on other sites More sharing options...
Guest Mashrock Posted May 29, 2006 Share Posted May 29, 2006 if all else fails. give me $5000 and i will sell you a fully rebuild trust dog box. Link to comment https://www.sau.com.au/forums/topic/119194-how-to-tell-if-my-gearbox-is-a-dogbox-or-an-aftermarket-box-without-taking-it-out/#findComment-2211563 Share on other sites More sharing options...
9krpm Posted June 6, 2006 Share Posted June 6, 2006 let me take it for a spin next time and I will let you know if it's a dogbox or not. Like beer baron said if it's a dogbox you will know it aldready. It's not that simple to drive a dogbox but not very difficult once u learn what to do. one quick test is while the car is idling, clutch in and put it into first gear. If it goes in smoothly and THEN bang ==> dog box If it's difficult to go into gear or make noise as it goes in ==> stuffed synchro. This is bad new because if your first gear syncrho is stuffed then more than likely the others are not healthy either! Link to comment https://www.sau.com.au/forums/topic/119194-how-to-tell-if-my-gearbox-is-a-dogbox-or-an-aftermarket-box-without-taking-it-out/#findComment-2233583 Share on other sites More sharing options...
T04GTR Posted June 7, 2006 Share Posted June 7, 2006 shes a stocker mate Link to comment https://www.sau.com.au/forums/topic/119194-how-to-tell-if-my-gearbox-is-a-dogbox-or-an-aftermarket-box-without-taking-it-out/#findComment-2237289 Share on other sites More sharing options...
T04GTR Posted June 7, 2006 Share Posted June 7, 2006 Ok here is wot i observed...1st gear: 32km/h @ 4000rpm 2nd gear: 59km/h @ 4000rpm 3rd gear: 83km/h @ 4000rpm yeah its stock. Link to comment https://www.sau.com.au/forums/topic/119194-how-to-tell-if-my-gearbox-is-a-dogbox-or-an-aftermarket-box-without-taking-it-out/#findComment-2237296 Share on other sites More sharing options...
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