Author Topic: Rear axle refurbish (Read 14978 times)

Larry & Norma · « **on:** January 06, 2011, 16:54:17 »

Ok the axle is out, that was fun. The trailing arms are off that was more fun, so now I
need to order a mountain of parts my question is the what size of rubber pad should
be above the springs - there seems to be several sizes? ('70 280SL)

Thanks To James Howard and David Brough and others for their posts which have helped a great deal
in getting the axle out and apart, not sure how I am going to get it back in, but that is for another day $:-\$

ja17 · « **Reply #1 on:** January 07, 2011, 01:22:13 »

Hello Gnuface,

Check to see if the Mercedes part number is still readable on the old rubber, otherwise you will need to make a good guess.

Larry & Norma · « **Reply #2 on:** January 07, 2011, 12:04:09 »

Thanks Joe, when I had a closer look at the top ones they looked pretty good
so will probably put them back in, the bottom ones are shot.
I am about to pull the right axle shaft to change the bearing, which is why I pulled the axle in the first place
I have noticed quite a lot of end float compared to the left axle shaft, is this normal?
What should the end float be? Is it an indication of bearing wear?
Thanks

DavidBrough · « **Reply #3 on:** January 07, 2011, 12:31:41 »

Hi Larry,

You seem to be getting on well with your axle work and putting it back isn't too difficult if you make sure that the axle is well supported when you offer it back up and ensure that no undue strain is placed on the axle carrier as it can lose it's setting if you are not careful, try and enlist a second or third pair of hands if you can. I found it better to put the comp spring in before I refitted the axle but you do need some extra height on the body to do this. Also, leave the main springs out until you have fully mounted the axle then remove the trailing arms one at a time to fit the springs.

I wouldn't worry about the upper spring pads at the moment as they are very easy to do afterwards and should really be used to set the ride height which is dependent on the correct camber angle. However, I would replace the pads on the comp spring now and as this will definitely affect the ride height you should put everything back first to double check exactly where you are with it. If you search on ride height or camber you should find a lot of information and a neat tool to do the measuring.

Not sure about the end float but could well be due to the worn bearing.

Good luck.

Larry & Norma · « **Reply #4 on:** January 07, 2011, 14:24:55 »

Hi David,
Thanks for that. The support arm is pretty close to vertical with respect to the left axle maybe 1 degree off
but the distance to the universal flange is about 154mm and not the prescribed 158mm.
(I must make up a jig to measure it accurately) Is it worth trying to move it the 4mm as it seems
very solid where it is?

mbzse · « **Reply #5 on:** January 07, 2011, 16:32:13 »

Quote from: Gnuface

The support arm.../... the distance to the universal flange is about 154mm and not the prescribed 158mm.
(I must make up a jig to measure it accurately) Is it worth trying to move it the 4mm as it seems
very solid where it is?

Yes definitely. The geometry of the rear axle arrangement is quite intricate, and the dimensions specified in the workshop
manual (or book of Tables) should be adhered to
Others and myself have written on this when James was doing work on the rear axle in his car, see: http://www.sl113.org/forums/index.php?topic=9060.0 and http://www.sl113.org/forums/index.php?topic=12503.0
/Hans in Sweden

.

Larry & Norma · « **Reply #6 on:** January 12, 2011, 15:15:28 »

I have now taken the right half shaft out ready to replace the bearing. The Haynes manual refers to
a circlip on the spline but my half shaft does not have a circlip or groove for a circlip

Is this a later modification?

Larry & Norma · « **Reply #7 on:** January 12, 2011, 18:54:52 »

I have adjusted the carrier position to 158mm (Thanks Mbzse) I am confused as to the torque value
of the pinch bolts, Haynes indicates 87 lbft (seems high) whereas the Mercedes workshop manual
says 4.5mkp which equates to 33 lbft? (Haynes page 139 diagram 8.20 bolts 19 & 20)
Also are the locating strut bolts really 144 lbft (Haynes page138 diagram 8.14 bolts 7 & 9) that is high!
Cheers

mbzse · « **Reply #8 on:** January 12, 2011, 23:35:57 »

Quote from: Gnuface

I am confused as to the torque value
of the pinch bolts, Haynes indicates 87 lbft (seems high) whereas the Mercedes workshop manual
says 4.5mkp which equates to 33 lbft?

Yes follow the factory specification (45Nm for the M8 pinch bolts, just as you have read)
These bolts must be high strength (=10k spec)
Please note the Haynes has mis-references and inaccuracies, this book should be used with some care
/Hans in Sweden

.

ctaylor738 · « **Reply #9 on:** January 13, 2011, 13:30:31 »

My infiormation is that the sedan rear ends have the circlip, but not the 113s'. The sedan rear end I refurbished did have one.

Larry & Norma · « **Reply #10 on:** January 13, 2011, 16:56:37 »

Is it possible to get a rear brake caliper piston? MB do not stock them now.
New caliper is 250 Euros!!

mbzse · « **Reply #11 on:** January 13, 2011, 21:39:47 »

Quote from: Gnuface

I have now taken the right half shaft out ready to replace the bearing. The Haynes manual refers to
a circlip on the spline but my half shaft does not have a circlip or groove for a circlip Is this a later modification?

There is some reference in this posting. http://www.sl113.org/forums/index.php?topic=3666.0
As Vince C writes, info in the Mercedes part list is that Circlip on axle was introduced from 280SL No17 888 onwards (sometime mid April 1970)
/Hans in Sweden

.

tel76 · « **Reply #12 on:** January 14, 2011, 08:44:56 »

Hello Larry,
S/S pistons can be purchased from the following(if they do not stock them they will make them).
www.ssbrakepistons.com

Larry & Norma · « **Reply #13 on:** January 14, 2011, 09:16:40 »

Hi Eric,
SS was a possibility I had in mind but then I found 'seekpart24.com' who
do a new piston for 19 Euros they also do other parts for our cars, it is always good to
have another source!
Cheers

GGR · « **Reply #14 on:** January 14, 2011, 12:17:33 »

Quote from: Gnuface on January 12, 2011, 18:54:52

I have adjusted the carrier position to 158mm

You should replace the rubber mount on which the arm is tightened as you're there. That rubber mount deteriorates with age and oil and is quite hard to replace once the rear end is back in place. That's the cylindrical rubber mount in which the axle around which both halves of the rear end pivot slides (sorry for my English).

Larry & Norma · « **Reply #15 on:** January 14, 2011, 12:52:38 »

Hi GGR
I had considered replacing this but it seems to be in pretty good condition and as
the costs are mounting up decided not to.

Larry & Norma · « **Reply #16 on:** January 25, 2011, 09:34:59 »

At the risk of maybe repeating an observation made by someone else the picture of the brake backplate shown in
the technical manual under handbrake section and labelled 'Clear view of the emergency brake assemblies (axle removed)'
is incorrect on several points. The small diameter spring should be at the top by the pawl and mounted from inside the shoes, the
larger at the bottom mounted from the outside also the expander mechanism at the bottom is 180 degrees out.

ja17 · « **Reply #17 on:** January 26, 2011, 14:39:03 »

Hello GGR,

You are correct, on the springs, but I suspect that the position of the "paw" would depend on which side of the car the assembly is for. Other note, I believe that the small spring will function fine either mounted on the inside or outside of the screws?
It looks like the other photos in the TM are correct.

Peter van Es · « **Reply #18 on:** January 30, 2011, 22:20:11 »

Quote from: Gnuface on January 25, 2011, 09:34:59

At the risk of maybe repeating an observation made by someone else the picture of the brake backplate shown in
the technical manual under handbrake section and labelled 'Clear view of the emergency brake assemblies (axle removed)'
is incorrect on several points. The small diameter spring should be at the top by the pawl and mounted from inside the shoes, the
larger at the bottom mounted from the outside also the expander mechanism at the bottom is 180 degrees out.

Can you please correct that section of the Technical Manual then...

Peter

Larry & Norma · « **Reply #19 on:** January 31, 2011, 09:55:27 »

Ok, incorrect picture has been deleted. Joe was correct in that the cable expander orientation depended on
which wheel you were dealing with but the springs were definately incorrect. The spring by the adjustment pawl
will work either side but if fitted, as they should be, behind the shoes they will hold the shoes towards the backplate
making it easier to install the small springs which pass through the shoe and backplate.
I do not have a correct picture as my half shaft is now re-installed.

Larry & Norma · « **Reply #20 on:** February 04, 2011, 16:06:23 »

Should the cheese head bolts which secure the flange of the drive shaft to the differential have washers under the nuts, and if so what type? (spring, flat etc).
Thanks
Larry

ja17 · « **Reply #21 on:** February 06, 2011, 06:42:22 »

Hello Larry,

The special rear drive shaft bolts, are flat on one side. They align with the flat on the drive shaft flange. The special thin nuts on the other end have a lockplate which keeps them from coming loose. No washers anywhere.

Larry & Norma · « **Reply #22 on:** February 06, 2011, 08:34:51 »

Thanks Joe, I guess a PO had left the lock plate off but had used some threadlock compound.
Do you have a part number for the lock plate please?

ja17 · « **Reply #23 on:** February 06, 2011, 15:13:44 »

Hello,

Lock plate #111 994 02 09 only two required since each plate locks two nuts.
special round head bolt #111 990 00 20 four required
special thinner than std. nuts #000 990 77 51 replaced by #111 994 02 90 four required

A picture of the lock plate can be viewed in the rear differential diagram of the owner's parts catalog but the individual part numbers for the lock plate, bolts and nuts can only be found by reading the part descriptions in the drive shaft section of the dealers parts catalog.

Larry & Norma · « **Reply #24 on:** February 06, 2011, 15:47:38 »

Thanks Joe, as usual expensive for what they are

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Author Topic: Rear axle refurbish (Read 14978 times)

DavidBrough