Rear Diff. - Honda Foreman Front Diff.

[Patrick]

Does anyone know anything the Honda Foreman front differential? The service rep in our area ( i work at a dealership ) says that it's a non-clutch pack type but that's all he knows. Does anyone know if this uses helical gears like the Zexel or....Also, what kind of power will this diff handle? Wouldn't want it to explode now would we. Torque-Bias numbers would be good too. Thanks guys.

[awhittle]

Look at the Yamaha Big Bear stuff. It is known to be bullit proof

[Sam Zimmerman]

Patrick,

We have a Honda front diff we are not using and I do not know much about it right now. I do know that it does not use clutches or gears, it is very light-weight, and looks cool. I will try to get some specs on the diff, it might take about a week or so as we are still trying to find some information. Email me and I can send you some pics and info. Perhaps we can both learn a bit. racing@uidaho.edu

Sam Zimmerman
Vandals Racing (http://www.uidaho.edu/~racing)

[Patrick]

What type of diff does Yammy use on the Big Bear? I thought it was a clutch pack type... we are trying to stay away from a clutch pack differential. Thanks

Patrick DeGrosse Jr.
RPI

[awhittle]

http://216.37.204.202/Yamaha_OEM/YamahaATV.asp?Type=13&A=62&B=23

It appears all of the 4wd Yamahas have a limited slip in the front dif

Hope this helps

AW

[This message was edited by awhittle on August 28, 2003 at 10:23 PM.]

[Scott Wordley]

Patrick and Sam are you talking about the cam and pawl Honda diff?

Regards,

Scott Wordley

http://www-personal.monash.edu.au/~fsae

[LukeT]

Seeings how I am our team's Diff guy, I can tell you all that I know about the Foreman diff. AP Racing used to make them, but then sold the line to a company in Japan (my contact did not tell me which company that is). There is an SAE paper that was written about them, it includes some of the math modeling for them. I'll post the paper number when I find it in my massive stack of research material... But this is the diff with the 19 cams, using a Belleville spring.
www.gt-classics.com (http://www.gt-classics.com) actually has some old car-sized AP Suretrac differentials for sale, but they weren't much help when I emailed them.
We decided not to use the Suretrac mostly because we have no idea what it is rated for. Also, looking at the size of the splines in it worried us.
Hope this is of some help.


-Luke Thompson
Vandals Racing 2003-04
University of Idaho

[Alan]

http://www.kettering.edu/~lo1224/diff1.jpg
http://www.kettering.edu/~lo1224/diff2.jpg
We've been using the Honda diff for two years now with no problems.

Kettering University FSAE

[Patrick]

Very interesting setup... hmmm.... does anyone know how much this thing weighs? Torque-bias ratings, etc? The cam thing seems a little sketchy to me... but if you guys have been using it for 2 years without problems then I guess it's something to consider. If anyone has some actual pictures of this diff or ANY other info at all... please e-mail me at Xstasy007@aol.com . Thanks alot guys.

Patrick DeGrosse Jr.
RPI
formula student #2

[LukeT]

Alan,

Which ATV is yours out of? Ours is the Rubicon TRX500FA. Did you guys do any testing or analysis of it when you started using it? Like I said, we were worried about such small spline shafts... It sure is a cool looking Diff though!


-Luke Thompson
Vandals Racing 2003-04
University of Idaho

[Alan]

Its out of a Rubicon. We didn't have time to do any testing or analysis before we used it the first time. Although I did get a hold of some engineering data before we decided to use it for sure.

Kettering University FSAE

[LukeT]

Which sort of engr data? The tech papers or did you find something better?


-Luke Thompson
Vandals Racing 2003-04
University of Idaho

[johnnySV]

what is involved in the integration of the Honda Foreman style diff into an FSAE car ?? it appears that in OEM form the front differential accepts a driveshaft input.... how can the unit be modified for co-axial input & output (chain / sprocket drive) ??

also, how much $$ can these things be had for, where, and which model(s) year(s) are ideal ?

thanks
jSV

thanks,

[Nate Notta]

... I am also interested in what other teams paid for the Rubicon diff.

I thought I had a quote for the diff for $400 CDN and the shafts & CV's for $240 CDN, but another guy on our team got a price more recently that has the diff and shafts going for well more than $1000.

Nate