Rear tires smoking at the line??
- Thread starter jbone
- Start date
Black Knight
I Glow Therefore I am
Re: Rear tires smoking at the line??
You might need to adjust up your rear brakes or upgrade them with larger wheel cylinders and shoes. Dont have those part #'s in front of me, but if you look under Hood's posts I think he's put them up before.
Cant think of anything you might break on the back especially if tires are spinning because that force is going away as the tires spin. Now im sure you know the damage that can be done to the tranny and front prop from boost launching.
What are you running anyway, time wise??
You might need to adjust up your rear brakes or upgrade them with larger wheel cylinders and shoes. Dont have those part #'s in front of me, but if you look under Hood's posts I think he's put them up before.
Cant think of anything you might break on the back especially if tires are spinning because that force is going away as the tires spin. Now im sure you know the damage that can be done to the tranny and front prop from boost launching.
What are you running anyway, time wise??
Robert Lone
MUTANT
Re: Rear tires smoking at the line??
How's your "VICIOUS" clutch in your t-case?
How's your "VICIOUS" clutch in your t-case?
Black Knight
I Glow Therefore I am
Re: Rear tires smoking at the line??
WHAT???
T-56 said:
WHAT???
Robert Lone
MUTANT
Re: Rear tires smoking at the line??
It's actually called a "viscous clutch" and it is responsible for smoothly transmitting the 35% power to the front tires. If it takes a crap on you it could lead to the rears getting 100% and breaking loose.Black Knight said:
QUICK STORM
B.A.M.F. BMW Tech
Re: Rear tires smoking at the line??
i thought our t-cases were chain driven
i thought our t-cases were chain driven
gkrcr882
SyTyless......for now!
Re: Rear tires smoking at the line??
There is a chain to transmit power to the front propshaft, but there is a viscous clutch that allows differential action between the two axles. If it locks up it has the same effect as a regular part-time 4wd system in 4wd mode.:2cents:
There is a chain to transmit power to the front propshaft, but there is a viscous clutch that allows differential action between the two axles. If it locks up it has the same effect as a regular part-time 4wd system in 4wd mode.:2cents:
QUICK STORM
B.A.M.F. BMW Tech
Re: Rear tires smoking at the line??
thanks, i thought it had a viscous clutch but i wasn't sure, so i asked.
thanks, i thought it had a viscous clutch but i wasn't sure, so i asked.
Robert Lone
MUTANT
Re: Rear tires smoking at the line??
This thread shows how little I really know...:eyes:
This thread shows how little I really know...:eyes:
myclone
Donating Member
Re: Rear tires smoking at the line??
Was there any "popping" or "rattling" sound coming from the trans/xfer case area while the rear tires were spinning? If so then the chain is stretched and just needs replaced (cheap) but if no noises were noted your viscous clutch is scrap (new/rebuilt xfer case time....not cheap).
Over the years Ive seen various ppl on here have viscous clutch failures and some had symptoms of binding like a reg 4wd does on dry pavement when you turn sharply while others failure symptoms were just like the thread starters (lots of rear tire spin). Basically from what Ive gathered from others on here theres two ways VC fails....locked in "4wd mode" or lighting up the rear tires.
Was there any "popping" or "rattling" sound coming from the trans/xfer case area while the rear tires were spinning? If so then the chain is stretched and just needs replaced (cheap) but if no noises were noted your viscous clutch is scrap (new/rebuilt xfer case time....not cheap).
Over the years Ive seen various ppl on here have viscous clutch failures and some had symptoms of binding like a reg 4wd does on dry pavement when you turn sharply while others failure symptoms were just like the thread starters (lots of rear tire spin). Basically from what Ive gathered from others on here theres two ways VC fails....locked in "4wd mode" or lighting up the rear tires.
QUICK STORM
B.A.M.F. BMW Tech
Re: Rear tires smoking at the line??
try the brake upgrade first
try the brake upgrade first
myclone
Donating Member
Re: Rear tires smoking at the line??
While thats by far the cheapest route to keep the rear tires from spinning thats not the problem. If the rears are spinning hard enough that the truck dances around while the fronts arent moving the VC is trash or the chain is stretched and slipping on the gear teeth (you'll hear that....it sounds horrible).
If he puts sticky/good/upgraded brakes on the rear whats gonna happen as soon as he's at 10lbs and lets off the brake pedal? The rears are going to light up since very little tq is getting thrown at the front wheels since the VC is trashed.
With a healthy VC theres enough power being fed to the front end to break the front drive shaft. Seen it happen when someone on here was filmed trying a burnout with the rear tires in the water box and the fronts on dry pavement. The rears did about 4 revolutions rather slowly and then bang...front drive shaft pieces went everywhere. BTW, dont ask me why they were trying that IIRC they were old guard and should have known better :roll: .
QUICK STORM said:
While thats by far the cheapest route to keep the rear tires from spinning thats not the problem. If the rears are spinning hard enough that the truck dances around while the fronts arent moving the VC is trash or the chain is stretched and slipping on the gear teeth (you'll hear that....it sounds horrible).
If he puts sticky/good/upgraded brakes on the rear whats gonna happen as soon as he's at 10lbs and lets off the brake pedal? The rears are going to light up since very little tq is getting thrown at the front wheels since the VC is trashed.
With a healthy VC theres enough power being fed to the front end to break the front drive shaft. Seen it happen when someone on here was filmed trying a burnout with the rear tires in the water box and the fronts on dry pavement. The rears did about 4 revolutions rather slowly and then bang...front drive shaft pieces went everywhere. BTW, dont ask me why they were trying that IIRC they were old guard and should have known better :roll: .
QUICK STORM
B.A.M.F. BMW Tech
Re: Rear tires smoking at the line??
well then get the t-case rebuilt and still do the brake upgrade
well then get the t-case rebuilt and still do the brake upgrade
qbnkiller
Conflaguration Specialist
Re: Rear tires smoking at the line??
depending onhow bad it really is, sometimes you can remedy a sticky coupler by replacing the fluid in the xfer case 2-3X with the Smart-Trac-2 fluid they sell at the stealership. You drain what is in your t-case, fill it with the ST-2 fluid, run the truck around for 15-20 minutes (getting the fluid warm), go back, drain it, re-fill it again, drive around for 15-20 minutes, flush it once more, and see if it helps. I have brought back 2 t-cases this way, and there is also a Tech Bulletin on it for the Bravadas.
Q
depending onhow bad it really is, sometimes you can remedy a sticky coupler by replacing the fluid in the xfer case 2-3X with the Smart-Trac-2 fluid they sell at the stealership. You drain what is in your t-case, fill it with the ST-2 fluid, run the truck around for 15-20 minutes (getting the fluid warm), go back, drain it, re-fill it again, drive around for 15-20 minutes, flush it once more, and see if it helps. I have brought back 2 t-cases this way, and there is also a Tech Bulletin on it for the Bravadas.
Q