Rear end problem

P

pea_jay

New Member

Oct 8, 2009

6

0

0

Oct 21, 2009

#1

• Oct 21, 2009

• #1

Well i had this howling/roaring noise that i thought was comin from the front end. I replaced both side hubs and that noised seemed to be covering the noise from the rear end. The thing is, when i turn to the left the noise stops. Also i put the car up on a lift, and i can grab the rear of the driveshaft and it has slack in it where it goes into the rear end. Anyone have ne imput before i start tearing things apart?

 

wmburns

SN Certified Technician

Aug 14, 2009

5,892

514

204

Houston Texas

Oct 21, 2009

#2

• Oct 21, 2009

• #2

Check pinion bearings & pre-load

Assuming that no recent work has been done on the rear end. The pinion bearing is wore out. The fact the pinion can be moved in/out says there is NO pre-load.

The excessive play in the pinion causes whine as it changes the mess with the ring gear. The pitch changes as the car switches between power and coast.

 

P

pea_jay

New Member

Oct 8, 2009

6

0

0

Oct 21, 2009

#3

• Oct 21, 2009

• #3

well i recently bought the car used and he said that a set of 3.73 gears was installed. So the pinion bearing seems to be the culprit?

 

wmburns

SN Certified Technician

Aug 14, 2009

5,892

514

204

Houston Texas

Oct 21, 2009

#4

• Oct 21, 2009

• #4

You could try installing a new crush sleeve and reestablish the pinion pre-load. However, that assumes that the ppl who did the 3.73 install were less than capable mechanics.

If the bearing is worn out, you will not be able to establish correct pre-load. Possible that it will pre-load correctly but still make noise. Only way to know for certain is to inspect.

 

P

pea_jay

New Member

Oct 8, 2009

6

0

0

Oct 22, 2009

#5

• Oct 22, 2009

• #5

Well i just got back fromt he garage, took the cover off and everything was still in great shape. I pulled the driveshaft and the nut that holds the yolk that slides on the pinion was only hand tight, apparently they didnt tighten it up.....so im thinking that may have been my problem, as i havent driven it since ive tightened it up. But could that have been the cause of the howling noise?

 

wmburns

SN Certified Technician

Aug 14, 2009

5,892

514

204

Houston Texas

Oct 22, 2009

#6

• Oct 22, 2009

• #6

YES........

Will assume that the pre-load was set correctly.

If the nut was never tightened, then the crush sleeve is still good. If on the other hand, the nut backed off, the Crush sleeve must be replaced. Otherwise, the pinion pre-load will not be correct.

When I replaced the front pinion seal on my ride, I over torqued the pinion nut. This made the pre-load too high. Months later, the rear end started making noise. Upon tear down, found the bearing wore out on the edges. A direct result of excessive pre-load. Leason learned ($650).

 

K

Kilgore Trout

Fried or Broiled ?

10 Year Member

Mar 30, 2005

4,749

95

134

Oct 22, 2009

#7

• Oct 22, 2009

• #7

Pinion damage can also occur when the car is lowered to a mad tyte level and the pinion agle is not adjusted to compensate. Is your car excessively lowered OP?

 

P

pea_jay

New Member

Oct 8, 2009

6

0

0

Oct 22, 2009

#8

• Oct 22, 2009

• #8

wmburns said:

YES........

Will assume that the pre-load was set correctly.

If the nut was never tightened, then the crush sleeve is still good. If on the other hand, the nut backed off, the Crush sleeve must be replaced. Otherwise, the pinion pre-load will not be correct.

When I replaced the front pinion seal on my ride, I over torqued the pinion nut. This made the pre-load too high. Months later, the rear end started making noise. Upon tear down, found the bearing wore out on the edges. A direct result of excessive pre-load. Leason learned ($650).

Click to expand...

do u have any idea what is supposed to torque at? I looked in my repair manual but it didnt say. Also yes my car is lowered 2 inches with eibachs

 

wmburns

SN Certified Technician

Aug 14, 2009

5,892

514

204

Houston Texas

Oct 22, 2009

#9

• Oct 22, 2009

• #9

The pinion pre-load for USED bearings is 8-14 INCH POUNDS.

Tighten the pinion nut to say 60 Foot pounds. Test the pre-load. Add 5 foot pounds to the nut and retest the pre-load.

Continue until the pre-load is within the specification.

A beam style inch pound (or electronic) torque wrench is needed. You are measuring the turning force of the flange. Note, remove the wheels and brakes.

Note, the crush sleeve is a one use thing. Do not reuse. It will give incorrect pinion pre-load.