reverse " BANG " sound

[rokes]

ok so while reversing my jeep ( 99 Sahara Wrangler 4.0L 6cyl w/4"in Skyjacker lift ), it'll make a loud BANG sound coming from either the transfer case, differential, or maybe the trans but i can't tell as i'm driving when it happens. it doesn't always do it, but it's pretty annoying when it doesn and i get looks sometimes from people who think i've struck their cars while i'm just trying to reverse and it gets pretty embarassing

anybody else have this issue and know what i can do to fix it ????

 

[Saddle Tramp]

Total stab in the dark but have you checked your u-joints? Maybe something is loose in the drive train system like the transmission mount that allows everything to move when you put reverse pressure on it or the suspension system doing the same? If not one of those items could the chain in the x-case be slipping? Like I said, total stab in the dark.

 

[60biscayne]

I vote for: Take a look at the "U" joints especially if you have raised it up or are running taller tires. These factors change the geometry & put new strains on things plus its most likely the cheapest fix!

 

[rokes]

alright thanks guys, i'll try and check that out and keep you updated. it really boggled my mind and i was freakin out the first time i heard it :lol:. hopefully it's not too serious

 

[Bigcountry10]

that exact thing happens to me. I changed the rear diff fluid and found a tooth from one of the spider gears in the bottom. :x

 

[jps4jeep]

is it only when backin gup from a stop, and is it a continuous sound?

sounds like something is binding, My best internet guess with the info supplied is it is not a U-joint.. they only go Bang once and you will know it.

if you have a CV shaft, it could very well be a junk CV

definately could be the gears in either the rear, t-case, or transmission.

and my last guess.. if your rear drum brakes are really worn, they will sometimes stick and then slap back and it will make a obvious nosie, I have found it only does it in one direction and not the other.

 

[Gennybro]

motor mounts, not the rubber you see , but directly under that,Is a flimsy mount that is probably broke.Just replaced one yesterday,To find out jack your engine up a little,and look at that area. I made my own to replace it out of 1/4" steel,cause the original is to flimsy,and it was much cheaper. Good luck,let us know what happened.

 

[rokes]

that exact thing happens to me. I changed the rear diff fluid and found a tooth from one of the spider gears in the bottom. :x

i'm hoping not to go through that situation

is it only when backin gup from a stop, and is it a continuous sound?

sounds like something is binding, My best internet guess with the info supplied is it is not a U-joint.. they only go Bang once and you will know it.

if you have a CV shaft, it could very well be a junk CV

definately could be the gears in either the rear, t-case, or transmission.

and my last guess.. if your rear drum brakes are really worn, they will sometimes stick and then slap back and it will make a obvious nosie, I have found it only does it in one direction and not the other.

yes, just in reverse from a dead stop. and it only does it once in a while, not all the time, and it's just one loud short bang when it does happen

motor mounts, not the rubber you see , but directly under that,Is a flimsy mount that is probably broke.Just replaced one yesterday,To find out jack your engine up a little,and look at that area. I made my own to replace it out of 1/4" steel,cause the original is to flimsy,and it was much cheaper. Good luck,let us know what happened.

don't have a high lift jack at the moment, so i'll figure something out and try that one but it sounds like it's coming from the rear somewhere which is why i was assuming either rear diff or transfer case

 

[Gennybro]

you dont need a high lift jack, use a bottle jack and put a piece of 2x4 between the jack and the oil pan and lift it up a littie,while looking at thje area under the rubber motor mount, if the mount is busted the weight of the engine will be ok on the bottle jack