Author Topic: Replacing my 230sl differential...  (Read 54435 times)

ja17

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Re: Replacing my 230sl differential...
« Reply #25 on: April 26, 2005, 20:12:26 »
Hello Dan,
I also have a method for removing and installing compensator spring without a spring compressor. But the method could be dangerous in the hands of non professionals so I hesitate to recommend it.

Joe Alexander
Blacklick, Ohio
Joe Alexander
Blacklick, Ohio
1969 Dark Olive 280SL
2002 ML55 AMG (tow vehicle)
2002 SLK32 AMG (350 hp)
1982 300TD Wagon turbo 4spd.
1963 404 Mercedes Unimog (Swedish Army)
1989 flu419 Mercedes Unimog (US Army)
1998 E430
1974 450SLC Rally
1965 220SE Finback

Benz Dr.

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Re: Replacing my 230sl differential...
« Reply #26 on: April 26, 2005, 21:42:46 »
Uh, yeah. I suppose you have a point there Joe. I'm more than aware of how coil springs can hurt you because I've been a victim........

 After setting fire to my car once and other assorted screw ups I'm much more carefull as I age. Amazing that I've lived this long ( 50 )

Dan Caron's
 SL Barn
benzbarn@ebtech.net
 slbarn.mbz.org
1966 230SL 5 speed, LSD, header pipes, 300SE distributor, ported, polished and balanced, AKA  ''The Red Rocket ''
Dan Caron's SL Barn

1970  3.5 Coupe
1961  190SL
1985   300CD  Turbo Coupe
1981  300SD
2013  GMC  Sierra
1965  230SL
1967 250SL
1970 280SL
1988 560SEC

waqas

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Re: Replacing my 230sl differential...
« Reply #27 on: April 27, 2005, 00:20:15 »
Well, I just finished cleaning up the mess I made. It seems my differential supplier decided not to drain the oil before shipping. That, coupled with my brilliant assumption that they had indeed done so, resulted in lots of cat-litter on my garage floor. And all I was trying to do was check the boot and differential housing for cracks (as per Joe Alexander's suggestion). It seems the boot may have been replaced in the past ten years or so-- the rubber appears to be fairly supple. That, and the fact that there was no apparent oil leak around the entire differential housing, lead me to believe I can probably spare myself the headache of messing with axle removal and boot replacement. If something happens later, I can always use the split boot (too many people have voiced their confidence in them for me to ignore).

My question of the hour: anyone know how to replace the tubular mount in the differential carrier/hangar, without removing or unhinging the right axle?  The bushings in the right axle hinge seem fine, but the tubular mount appears suspect.  I already tried to remove the wedge screw so I could partially slide out the long connecting bolt (until it reaches the right axle hinge portion), but the wedge screw wouldn't even budge!  Does it make sense to instead remove the differential front "cover with clamping eye" and slide off the carrier mount? (I'll need to remove the flange for pinion seal replacement anyhow)

Waqas in Austin, Texas
Waqas (Wa-kaas) in Austin, Texas

A Dalton

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Re: Replacing my 230sl differential...
« Reply #28 on: April 27, 2005, 07:25:40 »
You can change the hanger lower mount either way.
If you remove the wedge lock bolt, you can push the pivot pin back without removing it from the axle casing enough to change the mount.
Careful with the wedge, they are very brittle.........
 The other way, [ which I do if doing a pinion seal at the same time],
  you will have to take the pinion nut off to remove the flange.
The trick here is to index this nut in relation to the pinion shaft
for re-assemby, as you do not want to overtighten the crush bushing
any further than spec torque. This will get you back to where you started , which is a safe way to do it.
 However , I prefer to set the torque preload on the pinion to Spec. , so i use the inch lb conversion of 24-26 in/lb to set the crush load.
 The reason this is a better way is that by indexing, you are only assuming the preload was correct before you removed the nut , whereas I find that most used units have some bearing wear and can use a little more load to come back to factory specs. This can only be done with touque readings and is a tricky little job [ until you have done one]
 Most I have done usually wind up requiring about a 1/16th to 1/8'
more turn, but do not use that info without taking torque readings and doing it the correct way.
 If you go the flange removal route, index the flange also and change the seal while you are there , for sure.
Most hanger mounts deterioration is caused by a long time leaking/seeping pinion seal, anyway.  [ aside from the inferior design of the early 2 piece ones]
 A word of caution:
 If you over -tightened the pinion nut and cause the crush bushing to be to tight, you can NOT loosen the pinion nut for correction... the crush , once crushed, will not return by loosening the pinion nut and MUST be replaced if this happens, so use care...
 Also remember, the torque of the pinion nut is a very high torque , whereas the torge spec for the bearing load measure is very low, so do not confuse the two.
 The load spec I talk of [ 24/26 in/lbs]is the force required to turn the pinion shaft with no load on the differential [ brakes,etc], whereas, the pinion nut torque is the actual tightening torque of the pinion nut with the flange locked.. [ pry bar ].. and the torque
on that nut determines the load on the crush/bearings, so it is not a specific torque, but rather, what ever it takes to get the load spec correct..
 A little long winded on this subject, but another important item to consider with the new hanger installed ... it is best to position the hanger before hanging the rear end. the important setting is to have the hanger at 90 degres in relation to the left/rear axle [ the fixed axle].. it is best to use the center line of the axle casing rather than the axle casing itself, as they have a slight taper.
 Other measures are lateral, but thay can be close enough by measuring the old one before removal. Once therse are established , you can tighten the cinch bolt.
 The last measure is axle centering after the whole axle has been installed . This is done with the cross link/strut adjuster nuts and I have a pictoral somewhere here on the site explaining that and a diagram for an easy to make diyer tool...
 
« Last Edit: April 27, 2005, 08:24:47 by A Dalton »

Benz Dr.

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Re: Replacing my 230sl differential...
« Reply #29 on: April 27, 2005, 19:53:54 »
It's important to get the pin going up into the trunk at a 90 degree angle to the axels. I use a level and do it with the compensating spring removed.

 Place small pieces of wood or cardboard under the centre of the axel until it sits level on both sides. Place your level on the pin ( verticle ) and move it either way until the bubbles sit dead centre. Not 100% accurate but better than by eye or not at all. Never had a problem using  this method.



Dan Caron's
 SL Barn
benzbarn@ebtech.net
 slbarn.mbz.org
1966 230SL 5 speed, LSD, header pipes, 300SE distributor, ported, polished and balanced, AKA  ''The Red Rocket ''
Dan Caron's SL Barn

1970  3.5 Coupe
1961  190SL
1985   300CD  Turbo Coupe
1981  300SD
2013  GMC  Sierra
1965  230SL
1967 250SL
1970 280SL
1988 560SEC

waqas

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Re: Replacing my 230sl differential...
« Reply #30 on: May 13, 2005, 05:15:04 »
A quick update: still waiting for all parts; was able to completely remove old diff/axle assembly with ease on a wooden plank contraption thingy mounted on my floor jack; also, I made a simple little compressor with a single threaded bolt and a couple metal plates for the compensating spring that allows safe and easy spring removal without the petrol tank hindering in the least; one end mounts directly onto and through the differential portion of the spring mount; once the axle side of the spring mount has been removed, the spring can slowly be de-compressed while still mounted on the differential portion. I can post more details if anyone is interested.

For now, I've a few brain-dead questions about parts. Thanks in advance for any and all guidance.

(1) When I removed the differential mount (trunk), it looked ok to me. In fact, the new one looks a bit different than the original. I suspect the new one (on the right) will lower my riding height by a bit (seems minor). Should I worry about alignment issues if I use the new one, or should I just play it safe and keep the old one?
Download Attachment: 113-diff-mount-sidebyside-close.jpg
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Download Attachment: 113-diff-mount-top-close.jpg
44.55 KB

(2) The new muffler hanger rings seem different from the originals. For example, my old rings from the centre hanger look triangular (part # 113-492-0082), while the replacement rings are smaller and completely circular. Can these rings stretch so much?? Or did I get the wrong parts...?
Download Attachment: 113-muffler-ring-closup.jpg
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Download Attachment: 113-muffler-ring-sidebyside.jpg
50.08 KB

(3) My old rear muffler hangar rings were of two different kinds. What is the correct part number for these rings? #107-492-0082 (on the left) seems pretty soft, while #116-492-0182 (on the right) seems pretty hard... shouldn't they be the same??
Download Attachment: 113-muffler-ring-small.jpg
60.36 KB

(4) Regarding the upper rear spring mounts, I have read somewhere that replacing with the 30mm version is recommended, especially when the old springs are to be re-installed. My old pads look quite alright, except that one of them is about 23mm, and the other is about 18mm (both measured at the same thickest point, and where the centre-line of the spring coil wire sits). I never really noticed any difference in how level the car sat (5mm is pretty subtle). Should I just bite the bullet and order the 30mm pads? Or can I stick with my oldies?

Thanks again and kind regards,

Waqas in Austin, Texas
Waqas (Wa-kaas) in Austin, Texas

A Dalton

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Re: Replacing my 230sl differential...
« Reply #31 on: May 13, 2005, 12:41:50 »
The triagular shape of the old hangers is just the results of long term position memory of the rubber.....

George Davis

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Re: Replacing my 230sl differential...
« Reply #32 on: May 20, 2005, 08:42:16 »
Waqas,

Please post more information on your compensating spring removal method.  I want to replace the rubber pads on mine.

I don't know where you are on the rest of your work, but here are some thoughts:

Use the new diff mount, it will settle pretty quickly to a lower height anyway.  If it affects ride height at all, it will be by a very small amount.

On the rear spring pads, these are (or should be) select-fit to achieve proper rear camber (which also sets rear ride height).  If your current pads are the correct thicknesses, no need to replace them.  Unfortunately, this may involve reassembling, checking camber, and if you need taller pads then you get to do it again.

Rear camber should be positive 1.5 +/- 0.5 degrees, measured with hardtop installed, full fuel tank, and spare tire and tools on board.



George Davis
'69 280 SL Euro manual

waqas

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Re: Replacing my 230sl differential...
« Reply #33 on: May 20, 2005, 11:03:09 »
George,
I'll post more details when I get home tonight. Regarding the whole project, I haven't been able to get one of the trailing arm bolts off, rounding it off in the process. I think I may need to weld a socket to it. But I've been too busy at work to pay any more attention.

Waqas in Austin, Texas
Waqas (Wa-kaas) in Austin, Texas

waqas

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Re: Replacing my 230sl differential...
« Reply #34 on: May 20, 2005, 22:44:04 »
George,
In order to remove the compensating spring, I had to make my own crude little spring compressor. Having never removed the spring before, I had no idea of the fully extended length of the spring (mine turned out to be 11"), and hence the amount of energy stored therein. All the commercial spring compressors I found had grappling hooks too thick to fit comfortably between the coils, and I felt uncomfortable grinding them down. Compounding things further was the close proximity of the petrol tank, pump and hoses. I then noticed that the differential side (left side) of the spring mount was hollow (had a through-hole). This gave me an idea. I used a 15" long 0.5" diameter threaded bolt (Home Depot, about $3/ft), some washers and nuts, and a couple of home-made metal plates.

Download Attachment: pagoda-comp-spring-parts.jpg
52.8 KB

The plate holding the spring (on the right in the photograph) is about 5"x2"x0.25", with a 0.5" hole drilled through the centre. The plate on the left is about 3.5"x2"x0.25".

(0) As a prerequisite, relieve as much tension from the compensating spring as possible. An old post by Joe Alexander mentioned removing the shock absorbers, and slowly lowering the axles, always keeping them fully supported. Also, slightly loosen the two spring mount bolts on the right (axle) side.
(1) slide the threaded bolt through the spring from the differential side of the mount (left to right).
(2) slide the 5" long plate through the spring, a few coil turns from the end, and slide the bolt through the plate.
(3) carefully slide a nut through the spring, on the right side of the plate, and screw-in the bolt until it almost hits the mount on the right. This was the painful part, but a thin pair of clamping pliers holding the nut really helped.
(4) place the smaller plate on the left side, along with any washers, and tighten with a nut. Be sure to grease the bolt threads on this (the left) side before tightening, as this is where the spring will be decompressed from.

Download Attachment: pagoda-comp-spring-side.jpg
28.39 KB

(5) tighten the left nut until you hear the spring compress ever so slightly. now tighten a little more.
(6) carefully remove the two bolts (inner one first) holding the right mount, and remove the mount. The spring will now be compressed against the differential side mount.
(7) slowly loosen the left nut (remember the grease?) until the spring has completely decompressed (this is where the 15" bolt length comes in handy), and remove the spring.

Download Attachment: pagoda-comp-spring-rear.jpg
50.46 KB

Hope this helps,

Waqas in Austin, Texas
Waqas (Wa-kaas) in Austin, Texas

A Dalton

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Re: Replacing my 230sl differential...
« Reply #35 on: May 21, 2005, 07:36:09 »

 << carefully slide a nut through the spring, on the right side of the plate, and screw-in the bolt until it almost hits the mount on the right. This was the painful part, but a thin pair of clamping pliers holding the nut really helped.
>>

 ..you may want to cut a slotted hole on this plate so you do not have the problem of starting the end nut. or you may just use a little thicker plate and tap the hole...

 ..Good job, either way.

waqas

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Re: Replacing my 230sl differential...
« Reply #36 on: May 21, 2005, 18:48:46 »
Alright, I have a dumb question: when you turn the driveshaft flange on the differential, the wheels are supposed to turn, right? If I hold the wheel drum still, and then turn the flange, should it not also resist turning? My "new" differential flange keeps turning... regardless of whether I hold the drums still or not. When I received it, I turned the flange, and both wheels turned also. I never tested it like this-- by holding the wheel drums still (the lug bolts are in there). Now, while preparing to change the pinion seal, I stumbled upon this behavior. Am I nuts, or is my "new" differential messed up...??  (when I turn the flange, the grooved nut and centre drive bolt both turn with it, as I would expect)

A Dalton, did you mention the driveshaft/flange turning torque as 24-26 inch-lb? Where is this listed in the BBB? I can't seem to locate it in section 35-0.... or maybe I'm going blind AND nuts!

Waqas in Austin, Texas
Waqas (Wa-kaas) in Austin, Texas

Naj ✝︎

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Re: Replacing my 230sl differential...
« Reply #37 on: May 22, 2005, 04:30:26 »
quote:
If I hold the wheel drum still, and then turn the flange, should it not also resist turning?


No, you're not nuts  ;)

It means your diff is working correctly. When on the car, power goes to the wheel with the least resistance (just as is happening here), so if one wheel is on say wet grass and the other on tarmac, the one on the grass would get the power and spin...
Now, if you had a limited slip diff,...

naj

65 230SL
68 280SL
68 280SL

Douglas

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Re: Replacing my 230sl differential...
« Reply #38 on: May 22, 2005, 05:59:48 »
Naj,

Didn't you just describe the characteristics of a limited slip differential?

Douglas Kim
New York, NY
280 SL #016220

A Dalton

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Re: Replacing my 230sl differential...
« Reply #39 on: May 22, 2005, 07:52:26 »
<<-- by holding the wheel drums still (the lug bolts are in there).>>

 If you have BOTH drums locked and both with the lugs in them, the flange has also got to lock...if not, you prob have a bad slip joint or broken axle.

 The turning torque is in the old Original BBB.. the new reprints have eliminated much of this info [ which is really too bad], so I suspect you have the later reprint version..
 If you ever see the old ones on ebay, grab it .. they are invaluable..

Naj ✝︎

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Re: Replacing my 230sl differential...
« Reply #40 on: May 22, 2005, 08:17:47 »
Doug,
 
quote:
Didn't you just describe the characteristics of a limited slip differential?




With the limited slip diff, power to the spinning wheel would be reduced and applied to the stationary wheel, allowing the vehicle to move on. This is acheived with two multi-disk clutch packs, one on either side in the diff casing.

In modern cars with electronic stability control, the abs sensors are used to apply brakes on the spinning wheel allowing transfer of power to the stationary wheel.

naj

65 230SL
68 280SL
« Last Edit: May 22, 2005, 11:18:35 by naj »
68 280SL

waqas

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Re: Replacing my 230sl differential...
« Reply #41 on: May 22, 2005, 14:06:17 »
Phew!  Talk about needless stress!  Having just taken Drivetrain 101 (they give you a new splined unversal as your completion certificate), I went back and re-attached the lug bolts, wedged both drums, and tried to turn the flange... voila!  resistance!  (wedging just one side produces motion on the other).

And here I was feeling all proud of my new trailing arm bolt (the final one to come off)

Download Attachment: pagoda-trailing-arm-bolts.jpg
42.99 KB

So how many points do you think I'll get docked for re-using this?  :D

Waqas in Austin, Texas
« Last Edit: May 22, 2005, 14:07:10 by waqas »
Waqas (Wa-kaas) in Austin, Texas

A Dalton

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Re: Replacing my 230sl differential...
« Reply #42 on: May 22, 2005, 14:40:53 »

 Is that Gorrilla glue ???  (:

waqas

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Re: Replacing my 230sl differential...
« Reply #43 on: May 22, 2005, 17:39:27 »
haha! I should've tried gorilla glue first. I call this technique "brazed and confused" (TM)

Waqas in Austin, Texas
« Last Edit: May 23, 2005, 20:50:54 by waqas »
Waqas (Wa-kaas) in Austin, Texas

George Davis

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Re: Replacing my 230sl differential...
« Reply #44 on: May 23, 2005, 08:26:10 »
Waqas,

very clever method for removing the compensating spring, and thank you very much for posting pics and description!  I'll be trying it soon.

George Davis
'69 280 SL Euro manual

waqas

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Re: Replacing my 230sl differential...
« Reply #45 on: May 23, 2005, 20:49:32 »
George, you're most welcome-- it's the least I can do to start repaying all the kind guidance I've received here.

Speaking of guidance, regarding the breather tube on the top side of the differential, how can I make sure it isn't clogged?  (while the diff. is still out and accessible). It looks a bit oily around the edges...

Also, any recommendations for 'sealing compound' for the new pinion seal?

Waqas in Austin, Texas
Waqas (Wa-kaas) in Austin, Texas

ja17

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Re: Replacing my 230sl differential...
« Reply #46 on: May 23, 2005, 22:56:29 »
Hello Waqas,
The vent can be unscrewed and flushed clean with solvents or replaced.

I like to use Permatex #2 sealing compound.


Download Attachment: permatex2.JPG
57.79 KB

Joe Alexander
Blacklick, Ohio
« Last Edit: May 23, 2005, 23:03:08 by ja17 »
Joe Alexander
Blacklick, Ohio
1969 Dark Olive 280SL
2002 ML55 AMG (tow vehicle)
2002 SLK32 AMG (350 hp)
1982 300TD Wagon turbo 4spd.
1963 404 Mercedes Unimog (Swedish Army)
1989 flu419 Mercedes Unimog (US Army)
1998 E430
1974 450SLC Rally
1965 220SE Finback

waqas

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Re: Replacing my 230sl differential...
« Reply #47 on: May 27, 2005, 17:14:23 »
My springs are slightly different sizes (~5mm difference). I've no plans to replace them any time soon. Any recommendations as to whether I can successfully adjust spring height using the spring retainer adjustment holes?

Here's a photo of the spring retainer after grinding off all the rust/crap before I apply POR-15. You can see faint numbers (1,2,3) for what I assume are height adjustment settings. Can I make up for the difference by setting these differently on each side...?
Download Attachment: pagoda-spring-retainer.jpg
41.15 KB

Waqas in Austin, Texas
Waqas (Wa-kaas) in Austin, Texas

A Dalton

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Re: Replacing my 230sl differential...
« Reply #48 on: May 28, 2005, 14:24:24 »
Regardless of spring dimension, you want to take ride heigth from the floor on both sides of the car.. this will tell how the springs are setting.
 The plate adjusters will only slightly change the height [ each click only changes camber 0 degrees 10', whereas a 3 mm addition on the  rubber on the comp spring will change 30'.
 Most guys using old springs just get new 6mm comp spring rubbers
 [ one on each end] and start from there.
 if the camber is out from each side , you can then tweak it in with
individual notch positioning.. [whereas the comp spring dimension affects both sides]..#1 is the highest notch settimg.
 Most old suspensions have all they can do to go with full bottom plate notch #1, 6 mm comp spring pads and thick upper spring pads/mounts... and a new hanger mount [trunk] to get close to original
height/camber..............
« Last Edit: May 28, 2005, 14:29:38 by A Dalton »

waqas

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Re: Replacing my 230sl differential...
« Reply #49 on: June 02, 2005, 01:50:00 »
My snail's pace continues with this job. Somehow the scope keeps expanding, and new parts must be awaited with patience. My question of the hour: when I first removed the differential carrier/mount from the long connecting bolt, the bolt was covered in oil (this was the case for both old and "new" differentials). I initially assumed that oil must have seeped in from a leaky pinion seal or axle boot, but while reading section 35-5 of the BBB (cars starting 1968) regarding installation of the right axle supporting tube, I came across the statement "grease connecting bolt and slide through from the rear...". This implies that the surface between the connecting bolt and the tubular carrier mount must also be greased. Is this correct? Note that I'm doing this from the front (having left the connecting bolt undisturbed within the axle/differential hinge). So why was the bolt oily and not greasy when I pulled things apart? (or perhaps it was both and I did not notice) So do I use regular grease or something special?   (BTW the old tubular mount rubber was completely shot!)

Waqas in Austin, Texas
Waqas (Wa-kaas) in Austin, Texas