Can anyone recommend a lite-weight but strong OEM diff suitable for at least, say, 300 hp? I'm not at all interested in an expensive traditional style American racing QC. At this point, all bolt patterns and brake styles in the hunt, foreign or domestic. Thanx, Gary
Width and ratio? Auto or stick? OD? Any drag racing? Most of smaller import ones will be 4.XX ratio which may be too low if going behind a Mercruiser. I think you will end up with an 8", 10 bolt or 8.8. If weight is main issue and running 30"+ tires then Alfa Romeo Spyder looks neat, but taller tires put even more strain on rear.
This reminds me of an experience I had in 1961. I was building a roadster to run C/Altered back then. Had a homebuilt square tube frame, the front half of a "T" touring for a body, and a 241 Dodge Hemi with a stock three speed. I thought I could save a little weight by using a Henry J rear end (it had 4:56 gears too). Scattered it on the first attempt.
Volvo 240 its a Dana 30-31 strong compared to wheight disc brakes some are limited slip most are 3.xx-1 some 4.10-1 4 1/4 x5 bc handles 300 hp easy in a light car if you dont do one wheel burnouts
Some Jeep Cherokee and Grand Cherokee SUVs use a Dana 44A that has an aluminum center section with pressed-in steel axle tubes. The aluminum center section saves a bunch of weight compared to a standard iron-cased Dana 44 axle housing, but if you want a limited slip differential, you'll need to use a factory Jeep-Dana 44A limited-slip unit because the commonly available ones for conventional iron Dana 44's wont fit the 44A aluminum case. The 44A is also not as strong as a standard iron-case Dana 44, but it should be fine and even overkill for 300 hp in a light or medium-weight car, even if you pound on it quite a bit. By the way too, as fitted to the Jeep Cherokee and Grand Cherokees, the 44A's come with disk brakes and 30-spline axles with a '5 on 4.5 bc' wheel pattern and a good selection of factory-available gear ratios ranging from 3.07 to 1, all the way down to 4.56 to 1. Mart3406 ============
Curb weight is what will break it, not HP. In a really light car, you can get away with almost anything. I'd stick with the 8" Ford. Lots of tech and parts available; it's a proven piece. Toyota truck would be another good choice, but I'm not sure how the weight compares to an 8".
Ford 7.5" axle out of a Ford Ranger truck or Mustang is also light weight (135 pounds without brakes). Pre-93 Ranger is narrow-est, 93 and later Ranger is 1-1/2" wider, Mustang wider still. Strong enough for a small block v8 Mustang if you don't get crazy. Piper106
Anyone ever put one of these on an actual scale?? I'd be interested seeing how one of these would compare to some of the other 'lightweight' axles. Piper106
Thanx for all the inputs and please keep them coming. I can't really estimate widths as I'm considering cars a tad narrower than what you'd use on a Model A and another several inches wider. Strange, I know. But a mildly huffed I-4 Ecotec is the plan, so 300 lbft of torque might be a good estimate of the damages that could be done but I'm thinking of some fairly narrow tires, so... they'd probably go up in smoke before any damage could be done. I hope to keep the car very light, 1800 lbs perhaps + pax and the usual road trip trappings. Gary After I left this AM I got to thinking that perhaps I asked this question before, but the damage is already done if I did. Sorry.
Currie works with 8": Ford axles. They also offer an alumiunum diff housing. Winters has a Mini-Banjo that is light and has no quick change. It's a nice piece, and can be ordered to your needs, but it's not cheap.
Your information may be correct for Canadian Jeeps but is inaccurate for US versions. The Cherokees never used the 44A, only Grand Cherokees in 2nd generation ('99 up) and the bolt pattern is 5 on 5". As for gear ratios, have never seen Gr Cherokee lower than 3.73. The 44A was a problematic rear end in it's early years...often noisy. Ray
6 lug. I see '95 up 2 WD Tacoma is 5 lug. http://www.vehicle-bolt-pattern.com/toyota-lug-reference-guide.html
Two wheel drive Toyota pickups are typically 5 lug on 4 1/2". Four wheel drive use the six lug on 5 1/2" BC. However, later model two wheel drive "Pre-Runner" models use 4 x 4 chassis/suspension components, and are six on 5 1/2" BC as well. Ray
I'm going through the same thing with an off topic car. My case is a Mercruiser 3.7 bored and stroked with a Boss head. I want- -3.73 gears- no flexibility b/c it has to match the front. That excludes Ford 8.0 - a limited slip in either a clutch or a Torsen type, available new - strength for 330 lb ft- about the same as yours, - about 55-57 inch wide, lightish weight, - disc brakes, not the the kind with the park brake cable pulling on the calipers- we have too much problem with those in the rustbelt. has to be internal drum type for park brake. - strongly prefer 5 on 4.5 bolt pattern. Toyota Previa (the egg shape minivan) have a disc brake 7.5 Toyota. You'd be cutting off a lot of oddball brackets, but it's a good piece. It might be a little light duty for 335 ft-lbs, though some of the drift crowd put that through them. The Previa never had more than a supercharged 4 @ only 160 hp. I think around 180 lb-ft? And they did have occasional issue with them. The Ford 8.8 is heavy. If you really really research it there are light weight tube versions which will drop the weight a little. The lighter weight ones don't have discs. The heavy Explorer ones have discs and LSD's OE. I am not sure if you can mix and match to make one with all the feature I want. The Volvo is good. I would say 335 lb ft is just beyond what is is good for. The bolt pattern (5 on 4&quarter) is rare, and very few aftermarket value priced wheels exists, none are vintage looking. You can redrill to 5 on 4.5 but there's not much meet in the flange. Best to use a screw in stud, so when you drill out the holes big and pound in the studs, the studs' onions do not put strain on the edge of the flange. See attached pic. Clutch type LSD's did exist but are NLA from Volvo, torsen (Trutrac) are available. Jeeps use these, mostly in the front? I'm not sure how really light the Volvo one is. I was toting one around, and seems a bit more than I thought? I was not aware at all that there was any kind of LSD for the 44A, but being a Jeep I guess I could have guessed there was. Might be rare and expensive. And though it has discs, they have the 5 on 5 bolt pattern. The Toyota 8 inch seems to have an awful lot going for it. There are roundy round guys using them behind V8's and they stand up. Some racers that hate using anything non US-sourced seem to begrudgingly admit there's nothing better, and circle track LSD's are available, both clutch and gear. Ford 7.5 mostly came with drum brakes, up until around 94-95 when rear discs started as OE on all Mustangs. Before that there were the turbo 4 cars like a Mustang SVO turbo 4, and Thunderbird Turbo Coupe. Rangers didn't get rear discs until 2010. You can get Truetracs and good clutch limited slips for the 7.5 (and 8.8, both), though the 7.5 clutch type was recently phased out by Ford, good for existing stock only. Though some ares are 4 lug, if you stick with Ranger/Aerostar/sn94+ Mustangs, they are consistently 5 on 4.5 Right now, I'm leaning toward getting smart about 8.8 and seeing what I can piece together. Looks like an Explorer brakes/ring/pinion/diff, in a Ranger housing is a possibility, though I don't know about end weight or axle length/spline compatibility.
Ok not sure how long it's been- couple hours for sure, but I have researched this a lot, and am more convinced the 8.8 is not for me. Nor is the 7.5. This because of my demand that it not use the cable-pull-to-caliper "external" park brake, and because of the Explorer 8.8 excess weight. The 8.8 in the 96-on Explorer has the nice brakes. It also has 3.25 axle tubes of 0.25 thickness, & has 31 spline axles. These are both massive massive overkill. The center housing along is about 12-15 lbs more. It's definitely a porky piece. To get an 8.8 out of a Ranger, or a car (Mustang or either generation of Full size sedan), you get lighter-wall-thickness 3.0 inch axles tubes and lighter 28 spline axles. But first thing is that the Explorer brakes don't bolt on. On the Rangers you can hack on late model mustang brakes by cutting up the bracket. Or just get a Mustang axle- either 8.8 or 7.5 and narrow it (they are wide). But then I'm stuck with the calipers I don't like. Pinion offset is another concern. You *can* mix and match components very well with the Ford 7.5/8.8 family, so that in most cases you do not need a custom axle and you only need to shorten it on one side. For me I'm thinking the Previa is the way to go. Just looking at it, it uses higher quality materials in a more intelligent way and I can't believe it's not going to be significantly lighter. Just found out it's wider than I thought and than I want, though. Being able to pick and chose width and pinion offset is an advantage of hte Fords. The Mustang 7.5 was used up through more recently than I though and as the Mustang v6's got more powerful and the care heavier, they got to a point where I feel they would last for me. links (best 3 of several hours reading): http://www.ranger-forums.com/showthread.php?t=95557 http://grannys.tripod.com/TASAinstallguide2.htm http://www.mgexperience.net/archive/Scored_today_on_my_search_for_a_rear_axle/2015779
If you are using a lightweight car then just about any of the rears mentioned earlier would be fine...Most likely you'll smoke the tires before it hooks up and goes.
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