Has anyone else had this problem.... The roads were wet and I was towing a fully loaded 4 place snowmobile trailer. I accelerated from a stop light rather hard and the tires lost traction on the white line in front of the traffic signal and regained traction when back on the pavement. When they regained traction the truck made this god awful clunk sound that seemed to hit almost underneath my seat. It almost felt like the transfer case hit the floor of the truck! It was so bad it jarred the whole truck and I thought I broke the drive shaft or something. I lightly got back into the gas and everything was fine. I have felt this happen before, but not as bad, when the truck hits passing gear especially. I've checked underneath and can't find anything broken or out of whack. I hate to take it to the dealer because they will say it's normal and blah, blah, blah, but I guess I don't have a choice, it's really annoying! It also doesn't seem to do it all the time, really weird.

 

My truck does this when it hits the white or yellow lines, metal plates, manhole covers, and anything else it finds slippery in the rain... I get worried about it sometimes but the truck keeps marching along fine. If anything I am just as curious as you are!

 

oldnnew

That's the rear portion of your drivetrain taking a beating. It's no different than if you were driving on a treadmill type track where the car didn't move but the rear wheels spun at a decent rate, and then all of a sudden some device brought the rear wheels to a near stop whilst you were still pressing on the gas. Ever see the RPM's when you're rear wheels are skidding? They are sky-high, probably enough to have your car moving 20-30 mph. Of course, most people concentrate on other things than their RPMs when both wheels are skidding. Because both wheels were spinning but then suddenly found traction, the differential/ring gear took a immediate slowdown while the engine is still kicking out the same power. The centerline of where the two "forces" meet so to speak is the place that gets the ultimate break-for-your-buck, and that would be the transfer case.

But don't worry. I believe if you did damage to the transfer case you would immediately know, as proper function of the transfer case (at least the input shaft and output shaft) is necessary for 2WD, as well as 4WD.

 

The weird thing about it though is that the tires weren't really even spinning, they just slipped slightly, probably didn't even skid a full revolution. And the slam I felt from underneath my seat was incredible to say the least! I think it rattled everything I had in my center storage compartment! I don't know, the truck still runs and drives fine. I guess I just won't worry about it. If it's something bad I hope it breaks before 36,000 miles!

 

nonsequitur- What configuration is your truck? 2 or 4wd, reg or super cab, engine, long or short bed?

 

Did the tranny shift from 1st to 2nd during all this? Could be bad timing on the tranny's part.

 

Sorry I did not add that information...

My truck is a 2wd 5.4L SuperCab Shortbed with 3.31 open diff...

When it rains to avoid the white line slip I have to tap the accelerator and let it coast through the crosswalk. If I take off normally the truck will sit and spin, if I granny it out the truck will spin once it hits the white line. Sometimes when it catches it hits hard and I will get a one wheel hop or the clunk... I try to baby it in the rain, and the open differential does not help wet weather traction (nor does the stock Goodyear Wranglers)...

I am looking into putting a LSD in but have not decided which unit is best. I am hoping Eaton has one for my truck, and when the LSD goes in I will be altering to 4.10s with a larger (probably Mag-Hytec) diff. cover...

EDIT: Another thing to consider is that I live in San Francisco where there are a lot of hills and driving a heavy, open diff truck, with a V8 can get tricky when its wet even with an automatic...

 

oldnnew

I've got the same package as you, except year 2000 with a 4.6, 5sp manual. I get that damn thing all the time too, right in the transfer case. Well, I shouldn't say all the time, as I'm really careful when driving in rain, especially with my LSD (the differential, not the drug). But every time I doo-doo the one-wheel spinarooni I get the infamous THUD right under my rumpus.

Doesn't take much if you think about the forces involved. Under what other circumstances do you have a wheel spin superfast (even for a half-revolution) and then come to a complete stop (relatively speaking since traction has been regained)? It's the same chemical reaction so to speak that makes your engine stall when you release the clutch immediately, it's just that in this scenario the power has made it through gear multiplaction, through final drive multiplaction when the big-bang happens, and thus the bigger bang.

 

i've seen this happen a few times before. I've had my shifter (5-speed mind u) move as much as 6-8" (and smack me right in the leg). It's probablly something with the trans/motor mounts
-Jeff

 

TubaMan

That brings back memories. In High School I had a '69 Plymouth (it wasn't that old back then) and I could dump the clutch (Hemi 4spd and big 'ol Hurst dog leg shifter) and the shifter would end up 6" to the side. I would throw it into reverse and dump it to move it back over. The motor mounts were split in 2 so the engine would literaly spin one direction and land up on it's side sort of. Reverse would reverse the torque and flip the engine back upright. And yes, I did replace the motor mounts and WOW, it sure was much funner then!