Weird Knocking/Rocking

[CanaMark]

Ok I had an o2 sensor that was hanging loose ever since I bought it. Had 65L/250miles. Its an american truck in canada. Had the jeep 6 months with no o2 sensor connected. Anyways the past week, I had rough idle, running problems when its driving. Almost felt like the timing was off. The thing would stall around corners. Anyway I replaced the o2, its all good now. Runs like my baby should. The rear u-joint went. Broke the rear diff yoke, $100 dealer part it bolted into rear diff. I didn't really torque it down to specs, Just yanked on it tight. This might cause the knock.

Anyways to the knock. I be driving in 3rd gear, and the jeep rocks back and forth, also I can make it happen by tapping on the gas, and it will rock. Almost like the transmission or something is going. Anyway buddy said it might be a slipping clutch, could this be?

Any help would be most appreciated.

[gtmud]

If you replaced the diff yoke and DIDN'T torque it down to spec then this is probably were your problem is coming from. With the tranny in Neutral, take the driveshaft and slowly turn it backand forth, watching the nut on the yoke, it is probably sloppy. Also the proper torque will affect the backlash of the ring and pinion gears. MUST be ( diff yoke)installed correctly or you run the risk of either wearing out another diff yoke or worse trashing the rear end. Also when you replaced the yoke did you reinstall everything that came off with the yoke. Some times there are shims on the pinion shaft that set the backlash, if their not installed this too will had adverse affects on the rear end.

[fredjacksonsan]

More description on the "rocking" is needed to help you out.

[CanaMark]

Ok it only happens in 3rd 4th and 5th. I be driving everything is ok, steady gas is applied (gas peddle is giving it gas, but doesnt move) It starts to knock, I press in cluth it goes away. I can make it happen by tapping the gas and it will knock. To describe the knock, it is kinda hard. But I will do my best. The whole jeep moves forward and back almost like you are rocking the jeep to get out of snow. It has nothing to do with the axle, cuz when the clutch is depress it goes away. I am almost thinking it has something to do with the transmission. I will replace the fluid tommorow. B/c that might cause it as I lost some fluids doing the u-joints. 93 YJ 4L

[fredjacksonsan]

How are your plugs, cap, and rotor? If they're old you could have that rocking, or misfire, that could cause the problem.

[CanaMark]

New plugs gapped puurrrfact, cap is gud, rotor ditto

Sumtin mechanical indeed

[fredjacksonsan]

Throttle position sensor maybe? Fuel pump/system?

[CanaMark]

Ok I found out what the problem was. the motor mounts were gone on one side, causing the engine to sit low and tilted. This put stress on the tranny,TC. This also caused my oil pan to be alot lower, making the axle too close. Thats what caused my damage to the pan. I got a good 3/4 of a foot, compared to an inch or 2 between front axle and oil pan. This also cleared up some other problems.