Posted by Fat Boy on December 12, 00 at 08:03:14:
In Reply to: Re: Front Differential Problems? posted by Lee Correll on December 12, 00 at 06:59:18:
: Yes, I understand the whole theory on different speeds at the wheels when turning. What I don't understand is why it is so extreme in the '93 - my '78 is no where near as bad! Did GM put a locking front diff in with the tow package? I know the rear is an open diff.
No, a locking front diff was never an option in any Suburban, though there are a couple available from the aftermarket. It's unlikely the previous owner went to the trouble to install one unless the truck sees significant off-roading.
The reason the bucking is more pronounced is probably because the Sub has a longer wheelbase than your older truck. The longer the wheelbase, the more pronounced the difference in turning radius front to back. That gives you more driveline bind, as the others have mentioned. Another possibility is that because this rig weighs so much more it has much better traction, which resists the hopping/bucking/slipping a little longer, allowing the driveline to bind and twist a little more before something finally gives. When it does finally go, the effect is more pronounced.
If you do want to be able to run four wheel drive all the time, there are companies out there (like Mile Marker) who make a full time conversion... Basically, it's a viscous coupling that mounts to the front output shaft on your transfer-case (requires shortening the front drive-shaft a few inches). This allows you to run in four wheel drive (actually, now it would be all wheel drive) without the driveline bind.
To see if you do have the locking rear differential, check for an RPO code (sticker inside the door of the glovebox) of G80.
In my personal experience, I've found that after about 5 years, a GM locker is just about useless anyway. I have one in my '94 Sub (and if memory serves, there's also one in my '89 Sub), and you'd never know it was there... I can plant one tire on ice and floor it. Theoretically, the stationary wheel will recieve more power after the slipping wheel is spinning a couple hundred RPM faster than the one with traction... Mine will spin all day.
Hope this helps...
Fat Boy