Fishtailing

I need a little help here:

My back end torque's drastically to the right when I step on the gas, then back to the left when I let off, and I'm not talking about the rear axle, I mean the whole darn Jeep!

It doesn't matter if I'm driving on dirt or dry pavement. When I'm going around 20 MPH or more, and I step on the gas to pass someone or build up speed for a hill, the rear end jumps to the right. Then when I let off the gas, the rear end will twist back to the left.

I dismissed the problem for quite a while as just a "Jeep thing", but it is darn right scary to have your whole rig twisting and jumping around the road every time you accelerate or decelerate.

Is this torque normal, or is it a symptom of a bigger problem???

 

almost sounds like the rear axle is loose from the spring mounts. Maybe someone else can give some input....

 

My first thought was springs as well...

Check for broken spring or mount on the passenger side. I suspect that's your culprit. Let us know...

 

Definately sounds like a spring/rear axle issue. Mine did the same thing until I changed the rear springs and found a broken spring but I havs a spring over so I expected it.

 

Broken frame?

 

I performed a visual inspection of springs and mounts a little while back and didn't see anything to cause alarm.

I have not thought to check the springs or mounting bolts for tightness though. I'll put a wrench on them when I get home and see if I have a few screws loose

Thanks everyone for your input, I don't know where I'd be without this forum

Allan

 

You might not be able to see the crack when the JEEP is static. When I took my springs off to put new bushings in they looked great till I took the weight of the jeep and axle off the spring, one just snapped into two. the other took one hit from a hammer trying to drive the bushing out to break into about 6 pieces.

 

My TJ started doing the same thing your describing when I put in the rear lockrite. The jeep will shift to the passanger side when I get on the gas and back to the driver side when I let off the gas. So it may be that a PO put in a rear locker of some sorts and thats causing the prob.

 

R/H Axle shaft sheared at the inner end. :? With locker or LS only one side is getting power. Extreme brake drag? :? Engine putting out too much torque? LOL :v6: R) R) R) R) :hurrican:

 

My vote goes to bad bushings and/or shackles.

 

I'll put my $ there too. When I pulled my axle the drivers side rear spring had a few inches of side to side sway.

 

normal V6/V8 torque on hard accel will do the same thing
mine with 5:38s will scare you
and.........nothing is bent, broken, worn out, ect........
it's a Jeep thing

 

Mine does the same thing if I'm cruising and suddenly let off the gas.

 

Don't listen to Joe he's from Cincy...you know where the Reds are R)

 

Check Motor and Trans mounts too, could be causing strange frame flex if these are bad.

 

Jim: Strange! :? Mine doesn't do that--except I have a Detroit Locker in the rear. It has mild "trailing throttle" oversteer and "on throttle" understeer. In other words, if you accell. you will go a bit wide; you back off and you will tighten up. We used to try to "build that in" in our sports cars. Comes in "handy"! R)

 

used to hang the tail of the car out through the corners I see

 

I had a 66 cj5 with a 225,sm420, and a full floating d44 with a detroit locker.It would almost change lanes when i hit the gas or let off. I was told the locker was worn out. But it worked flawlessly off road

 

I found that the bolt that goes through the spring pack was broken on mine. The head of this bolt is supposed to ride in a hole in the spring pad. The spring pad hole on mine was warn into the shape of an oval. Had to weld it and redrill.

I would recommend taking off the u-bolts and checking it out. You may end up needing new u-bolts.

 

I would check the tightness of the rear spring u-bolts. If they are loose then the symptoms you describe would occur.