Page 1 of 1

Too much castor?

Posted: Thu Jan 22, 2009 2:43 pm
by Z()LTAN
Hey all,

I just pulled my front housing down to check my castor angles and found that i must have buggered up my C&T a little as im gettin around -8deg, as far as i know thats 3-4deg too much.

The reason im checking my castor is from some random low speed death wobbles im getting.

Can too much castor cause this?

PS; The wobble only happens at low speeds (less than 40kmph) and i have to hit a bump for it to set off.

Posted: Thu Jan 22, 2009 7:01 pm
by v8zuki
used to run 6.5 degrees positive castor on my rally car rx3 and it handled supurb
are you sure the castor is the prob as dont you run 3" wheel spacers
which messes up your scrub angle ie- if you draw a line through you pivot points on your king pin nuckle and drop a line down the face of your hub where the wheel bolts on they should overlap or meet not be spaced apart
wheel spacers do that low speed death wobble and also big tyres as there is a lot of rubber spinning around the spindle

Posted: Thu Jan 22, 2009 7:09 pm
by zookimal
Yeah we run massive amounts of castor on the race car too, however, I went through a similar thing to this with my Sierra. I don't know the technical reasoning for it, but figure a leaf sprung solid axle is a very different beast to an independant front end.

Ended up reducing castor by a few degrees and angling the pinion back up towards the transfer. Was the opposite to what I'd expected but corrected the issues it had.

Posted: Thu Jan 22, 2009 7:21 pm
by Z()LTAN
ive brought that castor back to about 5deg

took it for a quick spin, no death wobbles so far.

Cheers fellas

Posted: Thu Jan 22, 2009 9:17 pm
by tuff 75
i had the same prob with my old 75, a bit different to yours tho as yours is spring over, mine was 5in springs and extendard shackles, ended up being lose front u bolts, Not saying this is your problrm but worth a look....... Truck looks great mate................. got any power figures yet?

Posted: Thu Jan 22, 2009 9:35 pm
by Z()LTAN
i need to get this cooler made b4 i can do any sustained power stuff.

But for now its really goes hard!