Do I have differential trouble ?

[lurtch]

Hello All PagodaMen - - - got a tough one for you - -

I just took my 66 230SL out of service till spring in order to do an engine change. My work space is cramped so I will

need to push the car in and out of the garage as the work  progresses. While doing so on a practice run (auto trans in

neutral, parking brake off, slope = dead flat) I discovered that the car moves easily backwards, but requires way too

much effort to roll it back in the garage. I got it up on jack stands and determined that the right rear wheel rotates as

it should, but the left rear wheel strongly resists turning the forward direction. It will, however, turn freely in the other

direction. I also verified that the rear calipers are  releasing like they are supposed to.   Any Ideas ?  I am stumped.

 

I further found out that I have the problem illustrated by Joe Alexander in the PUB 2007 video about slop in the

junction where the right  axle is pinned into the pinion gear casting. My car has one of those 3.27 ratio rear ends

that was installed by a previous owner. I have no clue how many miles it might have on it.



The car has performed very well for the last 5K miles, with no indication that something is not-quite-right  in the rear

end. There have been no unusual noises, no leaks, and lots of fast freeway miles.

  - - - -  IS DISASTER LOOMING ?


Got plenty of time now to fix it,      Larry in CA

 

[waqas]

I also verified that the rear calipers are  releasing like they are supposed to.

Larry, how did you test this?

Also, have you inspected the condition of the brake shoes of the parking/hand brake? One of the springs may have come loose or broken, causing the shoes to apply uneven force on the inside of the the disc/drum.

The only way you can rule out brakes is to completely remove the brakes: hang the caliper from the axle with a wire hanger; remove the brake shoes completely. Then, place the car back on it's wheel and see if you still have the same rolling resistance issue. Then panic.

[w113dude]

I'm with Waqas, I had a similar problem with my car (w114), it turned out to be the that emergency brake shoe was broken in half causing the wheel not to spin freely.
This would be by far the least expensive scenario.

Good luck,

[ja17]

Hello,

Yes, check the rear emergency brake shoes for sure.

As far as the slop in the diff gears, make sure that the drive shaft is stationary during the test.  The slop may not be an immediate problem. If you are not having any clunks clunks in the drive train, you may just want to live with it for now.

[lurtch]

Thanks Joe    - -  Thanks Waqas - - - Thanks Shaun

The fix was obvious and easy!     The brake rotor/drum would not come off easily ( like it should  )  which told me that the shoes were somehow jammed. When the BMF pry-bars were able to overcome the resistance the rotor/drum came off, and the emergency brake shoe retention spring fell out on the driveway. I made a tool for reinserting it.

I love the easy fixes - - - Larry in CA