Rear end noise 8.75 .. 741

[josephqatarcarguy]

Hey lads , I'm getting a whining sound mainly under acceleration 30-40)mph.
It ain't real bad but yea I can hear it over the exhaust... she just recently started doing this ..pull the diff or try changing oil first?

 

[pnora]

Its beyond oil. Could be a bad pinion bearing but you wont know till you pull it and inspect it.

 

[furious70]

What mufflers do you have?
Only during accel? When going straight or turning?

 

[josephqatarcarguy]

What mufflers do you have?
Only during accel? When going straight or turning?

flowmaster , with the windows up and AC on i can hear the whine inside the car
only during acceleration going straight if i let off the throttle sounds goes away , no sound while turning

 

[josephqatarcarguy]

Its beyond oil. Could be a bad pinion bearing but you wont know till you pull it and inspect it.

if i pull the rear ill redo the whole thing , any harm in driving her like this till i pull the rear ?

 

[Aron Gleason]

It will get worse the more you drive it.

 

[Jerry Hall]

As stated it will get worse, and will be worse on your pocketbook the longer you wait.

 

[josephqatarcarguy]

As stated it will get worse, and will be worse on your pocketbook the longer you wait.

If I pull the rear I'm changing the whole lot , gears , bearings etc anything else it might hurt driving her ?

 

[RemCharger]

Inner pinion bearing. Could be gears too
.

 

[tonysrt]

I have a 489 that was making noise and the gears were bad. Replaced gears and no more whining. Certain gear ratios are getting rare with the 8 3/4.

 

[Jerry Hall]

If I pull the rear I'm changing the whole lot , gears , bearings etc anything else it might hurt driving her ?

You pretty well covered it. If you are not happy with the setup you have, go for it. While you are at it, find a 742, or 489 housing to put all new stuff in.

 

[josephqatarcarguy]

You pretty well covered it. If you are not happy with the setup you have, go for it. While you are at it, find a 742, or 489 housing to put all new stuff in.

Do I need a new housing? Can I just keep my 741 ?

 

[68Moparmaniac]

If your going to change it all out, then why not just get the whole package. I got mine from Randy's Ring & Pinion with 3:73 ratio/ 489 (big bearing case).

 

[dadsbee]

Back in the day... we'd find a banana, stuff it in there and then sell the car!

 

[1KoolBee]

Do you know if anyone worked on it previously? If so probably set up wrong. Otherwise bearings, likely caused by ancient oil or low oil level. Either way, time for a rebuilt pumpkin. Bearing replacement relatively easy if you have the proper tools, just use same shims, follow service manual for carrier bearing preload. Check gear pattern and adjust via shims per manual.

 

[Jerry Hall]

Do I need a new housing? Can I just keep my 741 ?

You can, but the 741 case is the weakest of the three. It's still good enough for most applications.

 

[DPeltz]

You could check and make sure the pinion nut holding the yoke on hasn’t loosened. Long shot, but that sets preload. Not sure if 741 has crush sleeve. Others will know. Good Luck.

 

[RemCharger]

No crush sleeve. Torque it up!