I know dick about posi type rear ends. I wanna build one for my 36 for a 9 inch Ford. Do I have to have a traction-lock carrier or can I just convert one from a dogleg rear end? What parts are required for the conversion? Currie wants like a grand for a new complete pumpkin.
You can buy the carrier which is the best way but be prepared to pay $400-500 for a new one. There is a company that make a racheting limited slip that uses the original open carrier also, but they are not very tough. I can't remember who makes them...
maybe this is what you're thinking of? http://store.summitracing.com/partd...925134+4294839047+4294918887+115&autoview=sku
You dont want a lock rite or one of the "replace your spider gears with this" type locker in your street car. Full lockers make a lot of racket and can be interesting to drive, especially in the rain. On the street I would rather have a clutch type limited slip. Auburn pro is a decent unit for a 9". You can get the trac lock for about $300. Auburn and traclock are both rebuildable. However I rebuilt the one in my 77 bronco and it cost quite a bit for the parts from ford. I had some non-wear items bad,though. Or for something a bit different, a detroit truetrac for $400. http://www.broncograveyard.com/bronco/c-399 The grand sounds like a big bite at first but at least $300 for the diff, $100+ for bearings and seals, $200 for R+P, press work for bearings and set up labor, plus they are supplying the housing. Pretty easy to see how they get up to that range if they want any profit.
And you can stab an Auburn in an open case. The hard part is finding the right install kit for it. They make like 12 kits depending on if it was open or trac-loc from the factory and the carrier bearing sizes. The common side bearings are 2.891 and 3.062" Figuring that stuff out is the hardest part.
There are probably more diff selections for 9" fords than aything else. Drop-ins like EZ-lockers are actually pretty strong, but noisy. I'd look into Eaton. Clutch type posi that is rebuildable. Be aware that 'some' of the Auburn type 'cone' posi units are not rebuildable due to there design. Get a 4x4 magazine....they're FULL of choices.
I don't have any experience with the powertrax locker, but the Detroit locker in the 9" in my 55 seems to work just fine, and I don't have any problems driving it...over 50k miles so far. Any powerful car with a limited slip rearend can surprise you on wet roads, it's not locker only thing.
Powertrax are good pieces. Their design is good and I have not had any defects come back. The only feedback I have is from a good customer with a 8.5" in a later model GM truck with a hopped up Caddy 500 (seriously) that runs 12.20s on nitrous. Has about 40 passes under his belt plus 6,000 street miles and its fine. Its a little noisy around corners if he gets on it before he is straight. Otherwise he loves it.
locker will not let a tire turn slower than the differential, a limited slip will. To have a difference in rotational speed between the tires with a locker, one tire has to "speed up". Oh heck, wikipedia can explain it better than I can: "A locker locks both wheels under normal conditions i.e. the default state is locked. If a wheel is externally forced to rotate faster than the diff centre (the outer wheel in a corner) the mechanism unlocks that wheel and allows it to turn freely. Thus the locker has the extremely unusual characteristic of applying drive torque through the inner wheel in corners. If one wheel starts to spin (therefore rotational force is being applied internally) the pinion cross shaft locks the centre more firmly. Often used in off-road 4WD applications. Can be very noisy. The traditional American racing diff is a Detroit Locker. Difficult to control under power in corners as the two actions of the mechanism are contradictory, the car will unpredictably alternate between one wheel and two wheel drive.[4]" I've experienced this a few times. Only cleaned out a fence row and destroyed my truck once. Your 55 is a nice HEAVY car with a decent weight balance. The 36 is probably a bit more front heavy. My truck, light as crap in the back just like they ll are. Not knocking detroits, there's none better, but if your not racing...
Anyone run a Detroit TruTrack? http://store.summitracing.com/egnsearch.asp?N=700+314530+4294900976+115+4294790783
I run a Trac-Lock in my 9" under my '35 sedan. It was pretty noisy until I dumped some of the GM Posi additive in it. I "made laps" at LACR during the Rat Fink Party earlier this year, I think like 9 back to back runs. It worked great and still drives good on the street. You have to be careful on the street in the rain if you drive anything with good horsepower.
After further research, it looks like a lot of the Mustang guys have gone the way of the TruTrack and have logged some serious miles and time at the strip. Not cheap but what is.
The "gear driven" posi units like the Tru-track and Zexel Torsen work best in road race cars. in an all out drag application, the clutch or locker posi's work better, but because of the way the gear driven type works, it's ideally suited to road courses. The gear driven posi not a true posi, as in it doesnt spin both tires at the same time. Power is transfered to the tire with the MOST traction. When you do a burn out, as soon as a tire spins, it has less traction, so power is transfered to teh other tire. the moment that one breaks loose, power is transfered back to the non-powered side. so, only one tire is getting power at a time. However, in the real world, it switches so fast that you can't see it happen and both tires appear to spin teh same speed. ok for drag use, excellent for road racing because the tire with the best traction gets teh power. This type was what the factory used in the 98+ Firebirds and Camaros, and they have very few longevity problems(they last much longer than the previously used Auburns)
I just got done putting a Powerlocker unit in my old car and it works great. I had to go with this locker because I had a Dana 44 with 19 spline axles, and like you said the only other thing I could go with in this application was a detroit lockerfor $700. I found the one I needed on E-Pay, luckily, for $200 and still wound up spending around $600 to $700 on the whole thing, bearring, seals, ring gear, and the kit to set it all up with. I would go with the pre assembled center section if you have the $$$$ because me being a novice I had the availability of all the tools from work and took my time and it still took a long time. I did however find a very very good instructional video on line and it walks you through every step of the setup, ford, chevy, and chrysler.Below is the shortcut to this company and you rent the video by the week for $9 a week or you find someone who has the tech stuff to duplicate it and send it back and keep the dupe as a refrence guide. MONEY WELL SPENT if you are goint to attempt this your self. The only other option is to watch the local papers around town, there is always someone trying to unload one of these from your local tracks, or E-Pay!!!!!!!!! TIIIIIMMMMMMMMMYYYYYY!!!!!!!!!! https://technicalvideorental.com/index.php?main_page=account_history_info&order_id=207449
YES! I run one in my green truck and have installed them in several customers vehicles. NONE of the side effects of a locker or friction type limited slip in adverse weather conditions, NONE! It drives just like an open diff around corners and such. Does not require any special additives and makes no noise. in low traction situations it will allow the low traction tire to spin while turning the higher traction tire at a percentage of the low traction tire speed. They call it torque transfer or what ever, but the two tires are linked together through a planetary gear system that does allow differential action but will not allow one wheel to stay stationary and transfer all power to the low traction side as in a normal spider gear system.
the tru-track has been around for decades, and has recently made a big comeback. interesting. Does anyone know how tough it is behind a big motor with sticky tires?
I just want one for my 36. It's going coast to coast and I didn't want a dang spool or a locker for something that's gonna see that much driving.
The way the TrueTrak works is very slick. It's similar to the Torsen differential used in a lot of high end sedans & sportscars. It's based on the ability of a worm & sector gear setup to turn easily in one direction but not in another. Take an early steering box which frequently have simple worm & sector type gearing. You'll notice that it's very easy to turn the worm which is attached to the steering input shaft but very hard to push on the pitman arm which is attached to the sector gear. Steering boxes use a low pitch worm gear which allows some push back of the wheels to aid in self-centering but worm/sector gears can be designed which make it virtually impossible to reverse direction by turning the sector. In a TrueTrak/Torsen differential torque is transferred from the pinion shaft to sector gears which are attached to worm gears attached to the axles. When torque is applied the sector gears "bind" against the worm and drive both axles. In a turn the outside wheel, turning faster than the inside, can spin it's attached worm gear easily and smoothly around its coincident sector gear to achieve the greater turning speed without the need for dog clutches, clutch packs or other such mechanisms. If one wheel spins with lost traction the reverse occurs. Through it's bound up sector it turns the other axles sector and forces it's worm gear to turn in concert. This effect can be varied in its intensity across a fairly broad range depending on the specific design of the gearsets, from a fairly "soft" and smooth torque transfer to very a very abrupt aggressive action. The Torsen is designed more to aid handling in high performance sports, touring cars, and 4X4s whereas the TrueTrak is presumably more tuned to provide an aggressive level of torque transfer in high power muscle cars and rods. It's a very good solution but the precise machining of the spiral gears involved usually mean that this type of differential is more expensive than most others. It's also likely not preferred for monster torque drag motors that require extremely beefy components and very aggressive axle control. It would be a pointless expense in a track car where a spool is what may be called for. Presumably the TruTrak manufacturer has a max torque rating it recommends.
Factory Torsen rear ends in Camaro/Firebirds are running mid to low 12s, quicker than that, the guys are switching to clutch type posi's Figure that to be 350ish RWhp in 3500 LB cars, so it would be pleanty strong for your 36
TrueTrac® Operation: Truetrac® differentials are unique in that they increase traction but do not affect steering or wear out prematurely; these problems are common with limited-slip differentials that use clutch plates and springs. TrueTrac performs like a conventional (open) differential, until there is a loss of traction. Only then will the torque transfer occur - when it is needed. TrueTrac Differential : Internal ComponentsA typical TrueTrac differential is shown above. As with an open differential, the TrueTrac side (or spider) gears are interconnected by pinion gears, which allow one wheel to slow down or speed up as required. TrueTrac gears have spiral teeth and the pinions are mounted in pockets in the case. If one wheel begins to lose traction , the pinions separate slightly from the side gear and wedge in the pockets. As torque increases, the separating force increases, thus slowing or stopping the spin-out. This allows torque to be distributed to the wheel with the best traction. Notes: TrueTrac differentials require a certain amount of resistance at the ground (i.e. traction) in order to start the torque transfer. A TrueTrac differential may not transfer torque if the spinning wheel is off the ground or on a very slippery surface. If spinning occurs, often a slight application of the brakes, while carefully applying power, will slow the spinning wheel enough to allow the TrueTrac differential to transfer torque to the other wheel. In low traction situations, like snow and ice, I find the TrueTrac works very good. Unlike automatic lockers, which require a speed difference between the axles to lock up, the TrueTrac begins to transfer torque before any wheel slip occurs. In turns, a limited slip diff biases torque to both wheels, with a bias towards the slower turning inner wheel. An automatic locker puts all the torque on the inside wheel in a turn, as the outer wheel automatically unlocks. An open diff transfers torque equally, but combined with the extra steering load on the outer wheel, it may become overloaded and cause a push or understeer. A similar product on the market is the Torsen Differential which is the model used in the Hummer. On the Toyota 8" front axle, if you are or intend to make use of the "Marfield" axle or the "Marlin-tack" c-clip eliminator, be advised that the TrueTrac diff is approx. 3/8" narrower on each side than a stock carrier. As such, instead of setting the tack-weld at 1-1/2" from the end of the axle, you should set it a 1-1/8" from the end. If this is not set here, the axle can slip into the differential spline far enough to cause the oil seal in the axle tube to miss the sealing surface on the axle shaft. In any event, check that the axle shaft can not slide into the axle tube too far. If you use the stock c-clip inside the Birfield joint, you do not need to worry about this.
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