Rearend Noise?

[hack343]

Hi ya'll,

I'm having issues wih my 85 CJ7 . Originally I thought I had problems with engine running rough at higher speeds.

But, I've come to the conclusion that my tranny or my rearend is going out.

When hitting speeds of 35+ the rumbling begins, at 55 it levels out( theirs still a rumble but not as bad). The warmer the jeep the worst he noise. When I let off the excelerator the rumble is not as bad.

When I first started hearing the rumble, It was light, it has become progressively louder.

Any help would be appreciated.


AMC 258 i6 / 4.2l
T-5
AMC20

 

[thiswontbetooexpensive]

U-joints maybe? Check that before you get into other stuff.


This won't be too expensive Dear! That's what I keep saying. Over and over again.

 

[hack343]

I gave the U joints a good shaking, they seemed solid, very little play.

 

[Torxhead]

The first thing I think you should consider is gear oil. Replace it, look for the larger parts in the used fluid, and check your results. The T-5 first used automatic Transmission fluid which was a mistake, that was later corrected. I use magnetic plugs for the drain and fill with a base magnet inside the diff.

 

[hack343]

Thanks,

I checked the fluid yesterday........the color looked OK. I guess I'll have to remove that cover and inspect........After driving the CJ for a mile or so, I can smell warm/burnt gear oil.

 

[hack343]

New Noise's............still can't determine Transmission or rear diff, now the Transmission or clutch makes metallic screeching sound when coasting.


Anybody?

 

[OEM1984CJ7]

It sounds kinda what I have. It rumbles when under way but not when coasting g. I have pulled the cover to change fluid and do t have any wear on the gears and fluid looked fine. It has been doing this for 3 yrs now and I drive it daily. I have noticed lately that sometimes when turning sharply either way the rear end kinda pops and shifts a little. Carrier bearing? I don't know.

 

[NorthwestCJer]

pull the rear driveline. Leave hubs out. Let out clutch. Does it still do it? If not. lock front hubs. Drive in 4 hi. does it do it now?

 

[Old Dog]

sounds like a bad bearing to me. which one is for you to find.

 

[Redman]

Everything you have listed tells me it is your U-joints. I have seen more than once that I couldn't fell any slop in the drive lines until I pulled them & had the roller bearings (if there were any left) fall in a crimble of dust or dirty grease. 10 minutes of time could save you some money.

 

[NorthwestCJer]

Many years ago, an old farmer gave me some info regarding u-joints.
U-joints have 4 stages.

First stage; new
second stage; very tight
third stage; very loose
fourth stage; broken

just because a u-joint feels tight does not mean its good.