Differential Housings

[Nishant Jain]

hello...

we're yet to exactly purchase a differential. haven't got one selected. but we intend to replace pinion gear with a chain and sprocket system.

so i assumed we'd need to design our own housing for it. but i dont know what kind of info i need for that. or how its done.

can anyone help with some preliminary info on how to go about building a differential housing??

[Steve O]

Sounds kind of obvious, but I would start with finding a diff and work from there. We use the torsen diff which comes with a diff center that we scrap but make a replica of the portion that houses the gears but lighter and then make an external housing with shear pins to the center. Other than the shear pins the external housing only really needs to be designed for proper oil flow,heat transfer, and load transfer through the sprocket and rotor.

The end caps of the external housing contain the splining for the diff drivers and the mating shear pin holes.

If you want to go with the torsen diff, get it sooner than later because if they run out of stock for the student specials you have to wait I think 6-8 weeks for them to build you one.

Hope that helps.

Steve

[vreihen]

http://www.westhouse.plus.com/chaindrive1.htm
http://www.westgarage.co.uk/chaindrive/chaindrive1.html

If you would rather keep your hands clean, Taylor Race has at least three chain-drive differential options and Scotty is a regular forum participant and FSAE supporter:

http://www.taylor-race.com/part.cfm?category=Chain%20Dr...Drive%20Diff&id=4702 (http://www.taylor-race.com/part.cfm?category=Chain%20Drive&subcategory1=Quaife%20Honda%20Chain%20Drive%20Diff&id=4702)
http://www.taylor-race.com/part.cfm?category=Chain%20Dr...Differential&id=4844 (http://www.taylor-race.com/part.cfm?category=Chain%20Drive&subcategory1=Taylor%20Race%20Quaife%20Chain%20Driv e%20Core%20Differential&id=4844)
http://www.taylor-race.com/framedmap.cfm?drawing=cds&su...Drive%20Differential (http://www.taylor-race.com/framedmap.cfm?drawing=cds&subcat2=Configurations%20With%20The%20Steel%20Endb ell&category=Chain%20Drive&subcategory1=Taylor%20Race%20Chain%20Drive%20Diffe rential)

[Nishant Jain]

@steve: thanks man. hope we aren't too late right now.

@vreihen: cool! nice links!

[Scotty]

Vreihen,

Thanks for the plug....
Just got in our new design diffs.One pound lighter than the last ones.

The Maryland bunch did very well with the diff at VIR.
#1 in acceleration
Set fastest lap in endurance
and #2 in skid pad.

And them Alabama boys did good to.

[vandit]

most of the teams use torsen diff ....

and i guess you are first year team, so most of us would suggest to concentrate on designing proper casing for it rather than directly fiddling with housing....no offense meant, but there our things to worry about first!!

[stealth]

great job guys... http://fsae.com/groupee_common/emoticons/icon_smile.gif

please give me the info about cost and manufacturers of torsen differential....


@ steve
what is "student special torsen diff"...

can u please elaborate....

thank u...

[Nishant Jain]

@stealth: in general, torsen differentials will be quite expensive.

so for students participating in fsae, you have university special differentials at a discounted price. they're sold on torsen.com so take a look.

also, they aren't available throughout the year so plan your purchase quick.

[Steve O]

what he said ^. If I remember correctly, I believe the diff would cost $1600 if you got it out of the audi (it's original application)...torsen charges us $360 for the university special.

[stealth]

thank u guys...http://fsae.com/groupee_common/emoticons/icon_smile.gif

i heard university special comes without the housing...is it difficult to build one??

is Torsen t1 limited slip differential is different from torsen differntial?
i am getting confused as they say the type of differentials are open,limited slip differential(LSD),TORque SENensing differential...
give me some links...
can anyone please tell me.......i ll be very thankful...

@nishant
hey buddy...
do u have any idea abt the custom duty(India) to import any automobile parts??
is there any concession for students??

@steve
can u please give me the details like specifications abt the type of torsen diff used in audi as u mentioned?

[Nishant Jain]

read it up anywhere online. or get a book from your college library on transmissions. it should tell you enough about differentials and the different types there are. just type in whatever you want on wikipedia for starters. it should also find you sufficient links on google. easy enough!

as for duties, they will apply like they do. no concessions as far as i know. check with the people who are selling it to you. they should tell you the exact cost with all duties etc.

[Nishant Jain]

@scotty, steve: i dont want to do more than is strictly necessary right now. it IS our first year so would just like to have something that functions for now.

so im buying the torsen. now, what do i NEED to do? i dont understand very well. they @ torsen say that they're giving me a housing plus internal components. now, what is my end of the work left?

@shanky: what do you mean casing? the gears will be in a carrier as it is. im supposing thats what the guys at torsen are calling the housing, but im not too sure. what do i really need to do?

and how do i go about planning and designing before the actual diff arrives? really unsure about how to proceed at this point.

[B Hise]

i dont want to do more than is strictly necessary right now.

Then buy the Taylor.

We tried making a diff housing our first year. Not the best idea. It's better to source systems like this and to focus on the parts of the car that you can work with to make a good baseline 1st year car.

-Bryan

[Peter]

Originally posted by Nishant Jain:
i dont want to do more than is strictly necessary right now. it IS our first year so would just like to have something that functions for now.


use a spool!

Peter
-Delft 04FSUK, 06FSG

[PatClarke]

Nishaint, Peter is right!

Read this newsletter
http://www.formulastudent.de/public-relations/fsg-news/...ts-column-january-2/ (http://www.formulastudent.de/public-relations/fsg-news/news-details/article/pats-column-january-2/)

Pat

[Nishant Jain]

@pat, peter: i read up on spools online. this says it completely restricts the differential action of the differential! why would i want that?

also, most sites point out that it is used only for drag races, and NOT if i even so much as intend to turn around a corner or two.

dont understand. also, how would this solve my housing problem?

[Nishant Jain]

@bryan: where did you buy your diff housing from? i cant find exact sources.

[James Waltman]

Pat, I really want to jump in and help you here.
I can't figure out how to do it without being an ass to those who need help.
(Good article by the way)

Anyway, I thought that this was an interesting topic: http://fsae.com/eve/forums/a/tpc/f/125607348/m/15910320...10160141#76510160141 (http://fsae.com/eve/forums/a/tpc/f/125607348/m/15910320141?r=76510160141#76510160141)
(Well, I at least thought that my picture collection was interesting.)

[PatClarke]

Thank you James,

One can but help. If people a too dumb to realise people are trying to help them, well thats their problem.
I had forgotten that earlier thread, otherwise I would have pointed him to it.

But feel free to help, and if that means you are going to be an ass.....then maybe thats what it takes?

Cheers
Pat

[Horace]

Originally posted by Nishant Jain:
@pat, peter: i read up on spools online. this says it completely restricts the differential action of the differential! why would i want that?

also, most sites point out that it is used only for drag races, and NOT if i even so much as intend to turn around a corner or two.

dont understand. also, how would this solve my housing problem?

You want it because it isn't more than what is strictly necessary, like what you said before.

And read Pat's article

[vandit]

@ nishant

no housing and casing is different ....housing is something in which all the gears are arranged with proper timing ....

casing is something which you are suppose to manufacture to put the housed diff into it ...the casing actually is keyed to housing and hence rotates with diff and sprocket....also the second function is that it houses the diff in oil bath , which is required for the proper functioning of the diff....

but some teams after having expertise, removes the stock housing and design their own housing cum casing, which is much lighter yet serves both purpose .....

[Nishant Jain]

@pat, horace: i see. thanks.

@james: those were useful pics. and the link. thanks a lot!

@shanky: understood. thanks.

[Steve O]

Originally posted by Nishant Jain:
@scotty, steve: i dont want to do more than is strictly necessary right now. it IS our first year so would just like to have something that functions for now.

so im buying the torsen. now, what do i NEED to do? i dont understand very well. they @ torsen say that they're giving me a housing plus internal components. now, what is my end of the work left?

@shanky: what do you mean casing? the gears will be in a carrier as it is. im supposing thats what the guys at torsen are calling the housing, but im not too sure. what do i really need to do?

and how do i go about planning and designing before the actual diff arrives? really unsure about how to proceed at this point.


Look on the torsen website. Most of your questions are answered there. As you
hypothesized, what they refer to as the housing is just the gear housing. Think of a normal rear end in a car. It has a rear end which the driveshaft connects to and the axles connect to... usually one big thing (http://www.classicchevy5speed.com/images/Currie-Rear-End/Currie_Rear_End_kit.jpg)

You get the differential that is inside of that housing and the thing that holds the gears. Its a big heavy chunk of steel with splining on it and holes that hold dowels that hold the gears in place, if I get a chance I will take a picture.

You need to make a housing that transfers force into this diff using a chain or belt as you are probably not using a drive shaft. Making a case and new gear housing is a lot of work and a lot of man hours; you will need very accurate machining equipment. The very basic concept is the following:

-Sprocket connected to a case that is sealed
-Case physically connected to diff carrier (the thing that holds the gears). This means that the sprocket will physically turn the gear housing and spin the gears.
-diff gears connected directed to diff drivers ("spindles" for the inside of the diff. These stick out and you connect your cv joints or U-joints to them.

The whole very basic concept: motor turns sprocket which turns case and diff gear carrier. Gears spin with carrier, which, in turn, spins diff drivers and wheels. When torque is imbalanced between wheels the gears "shift" and allow the diff to "open" up.

We buy the torsen and use only the gears because the unit they send you weighs probably 8 lbs where as our entire diff. assembly, including sprocket and rotor, weighs about 7 lbs. We used the layout of the gears in the housing provided as a foundation to start our design. As suggested before, look up diffs online. I believe How Stuff Works actually has a decent article with animated gifs. It's not a basis for designing a diff, but its a place to start.

Steve

[vandit]

@ nishant

here are two pics for your better understandings...

first pic is of housing and it's gears ....

second pic is of a casing, inside which there is differential .....

http://i296.photobucket.com/albums/mm190/vanditgoyal/diff.jpg

http://i296.photobucket.com/albums/mm190/vanditgoyal/diff3.jpg