Front tires locking
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Freshman User
Joined: Apr 2004
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Front tires locking
Second time this month, first needed to be last. I have a 97 F250 xcab 4X4 8800 lb gross with 175400 miles. Goodyear Wrangler HT 235/85R/16 E, 80# rear 70# front. Trailer is 18ft flat10000 gross, twin 6000lb Dexter axles, electric brakes. Tires are Goodyear Marathon Radial ST225/75R15 rated 2540lb @ 65 psi. First time the load was a 96 F250 xcab 4X4. Second time the load was a 91 Suburban 2500 4X4. I have hauled these types of vehicles before with no trouble. The first incident was on I 75 Knoxville, TN. The semi in front and I were running around 55mph when everyone, all three lanes, stopped. The semi flashed his brake lights then got on them hard. I was on my brakes hard with the flash. My front brakes locked, got off then on, locked again . We both were smoking, cars in right lane cleared we both did a stage right which gave us time to stop. Tires are now on the back a bit rough but ok. The second incident was north of Atlanta, GA I 75. Three lanes, again running around 55 mph right lane stopped center and left lane slowing . I was in the center lane behind a pick up and we had more than enough room to stop when a guy with a boat in tow decided he wanted to be in the center lane we had slowed to 45mph. The boat pulled into the center lane and stopped which left the pickup and me with no room to stop. I was going to push the pickup right up the boats motor and the pickup new it. so did the lady in the car to my left, she gas it and cleared the left lane. Stage left, get things straight, stage left, on rumble strips and shoulder passed eight cars before I stopped. Right front is down to metal, left front almost. Right front was 6/32, left 5/32. The truck with trailer loaded handles properly. I can apply just the trailer brakes and they will stop the truck. ANY and ALL help (suggestions) will be appreciated.
Fleet Mechanic
Joined: Nov 2003
Posts: 1,372
Likes: 14
From: West Cornwall, CT
In a panic stop it is easy to lock up the front wheels. (I'm assuming that you have only the rear ABS system in your truck.) I'd check out the adjustment on your rear brake drums. The self-adjusters sometimes do not self-adjust.
If the rear brakes check out OK, you might try increasing the braking power to the trailer brakes.
Making a panic stop when towing a load that outweighs the tow verhicle *always* gets your attention....
Lou Braun
If the rear brakes check out OK, you might try increasing the braking power to the trailer brakes.
Making a panic stop when towing a load that outweighs the tow verhicle *always* gets your attention....
Lou Braun
Cargo Master
Joined: Dec 2003
Posts: 2,182
Likes: 7
From: Saint Augustine, FL
I am assuming your trailer is a tag not a gooseneck/fifth wheel. If so, there are a couple of things that will cause the front brakes to lock. First, as in all panic stop situations, if you stab the brake pedal really quick and hard, the fronts will lock before the car/truck has a chance to transfer enough weight to the front axle to prevent lockup. So instead of stabbing the brake, squeeze it. I know this is tough to do in a panic situation, but it will result in shorter stopping distances.
Second, if you are hauling a very big load on the trailer, like the 4x4 f250 and suburban you mentioned, then when the trailer brakes come on hard, it causes the trailer weight (with the big vehicle atop it) to shift forward. This transfer's a great deal of weight onto the rear of your truck thus lifting the front end and unloading the front tires. A load equalizing hitch will help this problem greatly.
Steve
'95 Clubwagon XLT
Second, if you are hauling a very big load on the trailer, like the 4x4 f250 and suburban you mentioned, then when the trailer brakes come on hard, it causes the trailer weight (with the big vehicle atop it) to shift forward. This transfer's a great deal of weight onto the rear of your truck thus lifting the front end and unloading the front tires. A load equalizing hitch will help this problem greatly.
Steve
'95 Clubwagon XLT
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Freshman User
Joined: Apr 2004
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Thanks for the info. The self adjusters were not working. The load shift and putting down force on the hitch , I think, is my major source of trouble. These two trucks were not running and I loaded them with the winch. The Suburban is still on the trailer, using the bathroom scale with the brick and pipe the static tongue weight is a 875 lb. I'm going to research the load equalizing hitch.
Elder User
Joined: Oct 2002
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What he said.......
60 percent or more of your brakes are on the front tires. You need 60 percent of the weight to transfer to them to stop without lockup. You need a 5th wheel, gooseneck or load equalizing hitch that is tight.
60 percent or more of your brakes are on the front tires. You need 60 percent of the weight to transfer to them to stop without lockup. You need a 5th wheel, gooseneck or load equalizing hitch that is tight.
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Freshman User
Joined: Apr 2004
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Thanks to all for the insight! The hitch on the truck is Rease Hitch V rated at W.C. 600/6000 & W. D. 1200/10000. Before I put another truck on the trailer I will have a load equalizing hitch. Now the dilemma is which one.
