rear end swap 4.08 to 3.27

[n/a]

I forgot to mention that I checked with John Olson re purchasing just the compensating progressive-rate spring, since I can't afford all five springs at once and the others are relatively easy to get at later on. He does sell just that one spring for $175, for your planning purposes.

He'd appreciate any orders as he's in Europe skiing and wouldn't mind your subsidizing his Glüwein tab.

John

John Livingston
Newport News, VA
1968 280SL 4 speed manual

[A Dalton]

Two  we checked here  are also stamped 3,27.
 The 4.08 with orig size tires [185/ 80 profile] will get you 17.01 mph@ 1 K..
 The 3.27 will change that to 21.22 mph@ 1 k..so approx 4 mph per 1K tach...

Slightly less if using  the shorter 195/75s..
 
 Some that have gone the 3.27 go w/lower profile to take the edge off.

 Here is a nice calculator to make any comparisions.
 http://pw1.netcom.com/~sgalaba/mph.htm

Note that the German ratio stamp uses a comma in place of the colon for ratio punctuation...

 


 

[jeffc280sl]

A. Dalton,

Are you interested in selling a 3.27 axle?  If so email me at lax882@aol.com.

Jeff C.
1970 280SL 4-speed

[ja17]

Hello,
Yes that is a 3.27 and not a 3.23 for sure. I guess even Mercedes factory manuals have some rare mistakes!

Joe Alexander
Blacklick, Ohio

[A Dalton]

On the subject of 113 rear swing axle ..
 I posted a tool that is easily and inexpensively made to centralize the axle to factory specs.
 This is done w/cross strut adjuster and allows the axle pivot pin to be located to the proper factory spec. offset distance of 36mm [ +/-2 mm] to the right of the Center-Line of the Chassis.
 This can be done by dropping plumbs from the pivot and chassis C/L Bore Holes ,etc. , but  this tool has those geometrics in the design and allows one to simply hold the tool ends up to the Thrust arm mounting Step Bearing  bolt heads and lining the pointer up on the center of the pivot bolt head.  It can also be used for a dimensional check without  jacking the car up.

 ftp://members.aol.com/ajdalton7/113tool.jpg
 

 I have cleaned up what was previously posted , so if anyone is interest, go here for a copy. May want to blow it up from there , as I have included the 3 pages into one...

[n/a]

I've very interested in your tool and sure do appreciate your having posted it. Would it be possible for you to mail me a hard copy? The print I got from your on-line version wasn't clear enough to make out the details. I'd be happy to scan a higher-resolution version and put it on the web for members to access.

John

John Livingston
Newport News, VA
1968 280SL 4 speed manual

[jeffc280sl]

A Dalton,

Great tool for calculating speed after gear change. Assuming it works here is a brief summary of my 4 speed manual with 205 70R14 tires in 4th gear.

rpm          3.27 rear          3.92 rear

1000         20.92 mph          17.45 mph
2000         41.85              34.91
3000         62.77              52.36
3500         73.24              61.09
4000         83.7               69.82
5000         104.62             87.27

So currently a 70 mph cruise is about 4000 rpm.  With the 3.27 rear it will drop to 3300 rpm.

Jeff C.
1970 280SL 4-speed

[A Dalton]

Jeff

 You are somehow not entering the correct info in the speed cal.

 Tires 205/70-14 should get you :
  1K rpm = 17.45 mph w/3.92 rear
  1K rpm = 20.92 mph w/3.27 rear
 This is in top gear - you must therefore list  the trans spec as 1.1 in the calculator.. I think you are just using 1., giving you false readings

[jeffc280sl]

Arthur,

Thanks for the info.  I've corrected the table below.

Jeff C.
1970 280SL 4-speed

[n/a]

Updating everyone on my progress, or lack thereof:

I've been working on the compensating spring, following Joe Alexander's instructions (up to a point!). I've got both shocks and coil springs out, the exhaust system hangers removed (still supporting the exhaust slightly as i've not attempted disconnecting it at the manifolds), the right caliper unbolted, and the outer 19mm bolt of the spring perch removed. This is where I erred: Joe had said, "Remove the 19mm inner most spring bracket bolt first. The bracket will now hinge out of the way releasing the spring. To be on the safe side, use a spring compressor which should fit now that the spring is so far extended." Even though I removed the wrong bolt,  the bracket tilted out and released most of the spring's compression (see attached pic). However, I still couldn't get  my compressor on it, so I took the fool's way out and levered the thing off the rest of the way. It came off with some enthusiasm, but without mishap. Keeping a compressor on it would certainly be advisable!

I'm hoping the Samstag.com drive shaft wrenches will be in next week, which will allow me to disconnect that. That won't leave much, except the cross struts (?), some of the remaining brake lines, and then the central mounting bolt.

Thanks again all the sage advice.

John

Download Attachment: comp_spring2.jpg
42.57 KB

John Livingston
Newport News, VA
1968 280SL 4 speed manual

[jeffc280sl]

Hi John, Sounds like progress to me.  You may noy need upper coil spring pads but I imagine the bottom are pretty bad.  Make sure you order the correct thickness pad.  The BBB tells you where to measure for pad thickness.  Are you planning on installing new seals etc. on the old axle?  Now is the time to replace bearings as well.  How do you know if they need to  be replaced?  I'm thinking that I'll replace every wear type part I can when I do the job.  Did you get a readable copy of Arthurs tool diagram?  I have one if you need it.

Jeff C.
1970 280SL 4-speed

[n/a]

Jeff,

I've tried to order every rubber-type part and bushing I could think of. I ordered both upper and lower spring pads. I didn't know about measuring pad thickness. I'd better check that and see if I have the right ones.

I haven't done anything about seals and bearings on the "new" axle. I guess I'd better look at that, too. Do you have any part numbers handy?

The version of Arthur's tool drawing that I have measures 621x687 pixels, which doesn't print very well on my printer. Have you got a higher-resolution version?

John

quote:Originally posted by Lax882@aol.com

Hi John, Sounds like progress to me.  You may noy need upper coil spring pads but I imagine the bottom are pretty bad.  Make sure you order the correct thickness pad.  The BBB tells you where to measure for pad thickness.  Are you planning on installing new seals etc. on the old axle?  Now is the time to replace bearings as well.  How do you know if they need to  be replaced?  I'm thinking that I'll replace every wear type part I can when I do the job.  Did you get a readable copy of Arthurs tool diagram?  I have one if you need it.

Jeff C.
1970 280SL 4-speed

John Livingston
Newport News, VA
1968 280SL 4 speed manual

[jeffc280sl]

John,

There are three different pad thicknessess for the upper rear springs.

18 mm thick #108 325 01 85
24 mm thick #108 325 02 85
30 mm thick #108 325 03 85

Springs and spring pads including the compensating spring were specifically matched in the factory to achieve correct ride height and rear wheel camber.  I could read the part number off my old pad.  I didn't know any of this until after I installed my new rear springs with the wrong pads.  At least I did it faster the second time.

The compensating spring pad comes in two thicknessess.
6 mm #110 329 01 85
3 mm #110 329 00 85
Sometimes you have 2ea 3mm pads sometimes 2ea 6mm pads and sometimes one of each.  If you spring has white markings on it you have 2ea 6mm pads.  If red you need one of each.  If blue there both ends are 3mm.

I have not found a detailed parts summary of the rear end with Mercedes part numbers.  The BBB on page or job #35-0/5 says the 280SL has a grooved ball bearing #183 981 00 25 on the left and a self aligning roller bearing #000 981 05 06 on the right.

That's all that I have found at the moment.

Jeff C.
1970 280SL 4-speed

[n/a]

Jeff,

This is a huge help. Thanks.

I checked and my original upper pads are the 30mm jobs. The compensating spring has the white marking, so it looks like 2 6mm pads.

How does all this work out if one goes to Olson's progressive springs?

John

quote:Originally posted by Lax882@aol.com

John,

There are three different pad thicknessess for the upper rear springs.

18 mm thick #108 325 01 85
24 mm thick #108 325 02 85
30 mm thick #108 325 03 85

Springs and spring pads including the compensating spring were specifically matched in the factory to achieve correct ride height and rear wheel camber.  I could read the part number off my old pad.  I didn't know any of this until after I installed my new rear springs with the wrong pads.  At least I did it faster the second time.

The compensating spring pad comes in two thicknessess.
6 mm #110 329 01 85
3 mm #110 329 00 85
Sometimes you have 2ea 3mm pads sometimes 2ea 6mm pads and sometimes one of each.  If you spring has white markings on it you have 2ea 6mm pads.  If red you need one of each.  If blue there both ends are 3mm.

I have not found a detailed parts summary of the rear end with Mercedes part numbers.  The BBB on page or job #35-0/5 says the 280SL has a grooved ball bearing #183 981 00 25 on the left and a self aligning roller bearing #000 981 05 06 on the right.

That's all that I have found at the moment.

Jeff C.
1970 280SL 4-speed

John Livingston
Newport News, VA
1968 280SL 4 speed manual

[jeffc280sl]

John,  

I can't really say for sure.  For me the original pad thickness worked the best.  I had 18mm on the rear and you were using 30mm.  I think modern technologies would make for more uniform springs across productions runs.  I suspect all of the pad matching stuff had to do with spring variations from one production run or supplier to another.  But that's a guess.  Maybe John Olson has more insight into the matter.  Email me at lax882@aol.com and I'll sent you Arthurs sketch.

Jeff C.
1970 280SL 4-speed

[n/a]

Jeff,

My primary concern would be the compensating spring pads, as they are the tougher ones to get to. It'd be easier to make adjustments on main coils, if needed.

I'll see what Olson suggests.

Thanks for the thought that it's the springs' variations that the pads allowed for. I'd thought maybe I just had a very heavy W113!

quote:Originally posted by Lax882@aol.com

John,  

I can't really say for sure.  For me the original pad thickness worked the best.  I had 18mm on the rear and you were using 30mm.  I think modern technologies would make for more uniform springs across productions runs.  I suspect all of the pad matching stuff had to do with spring variations from one production run or supplier to another.  But that's a guess.  Maybe John Olson has more insight into the matter.  Email me at lax882@aol.com and I'll sent you Arthurs sketch.

Jeff C.
1970 280SL 4-speed

John Livingston
Newport News, VA
1968 280SL 4 speed manual

[W14]

Has this been discussed yet:

Are the compensating springs the same for the 280SE 4.5 and the Pagoda?

If not, should you use your Pagoda comp. spring in your new 280SE 4.5 rear end?

Will W14
1965 230SL 4spd
Victoria,BC

[n/a]

Will,

It's a moot point on mine as the "new" rear came w/o the spring. It's either use the original one from the SL, or get one of John Olson's progressive ones. I'm leaning toward the latter, primarily because the darned thing is a nuisance to replace.

John

quote:Originally posted by W14

Has this been discussed yet:

Are the compensating springs the same for the 280SE 4.5 and the Pagoda?

If not, should you use your Pagoda comp. spring in your new 280SE 4.5 rear end?

Will W14
1965 230SL 4spd
Victoria,BC

John Livingston
Newport News, VA
1968 280SL 4 speed manual

[W14]

My new 3.27 rear axle did come with the comp. spring, so I would appreciate any advise on which one to use.
Thanks,

Will W14
1965 230SL 4spd
Victoria,BC

[n/a]

Take my advice with a large grain of salt, as I'm just midway through this process.

I'm not a fan of 30-year-old springs in general, so I have decided to replace my compensating spring with a new, progressive one from John Olson. I plan to replace the other springs as funds allow, but wanted to get this one done since I find it a nuisance to pull.

If I were to stick with one of the old springs, I'd lean toward the one that came with the SL, since your spring pads were matched to that and getting the correct replacements should be a bit easier.

Hopefully more experienced folks will chime in here with their advice.

John

quote:Originally posted by W14

My new 3.27 rear axle did come with the comp. spring, so I would appreciate any advise on which one to use.
Thanks,

Will W14
1965 230SL 4spd
Victoria,BC

John Livingston
Newport News, VA
1968 280SL 4 speed manual

[n/a]

Just a "short" update.

I got the 41 and 46mm wrenches from Samstag.com this week. I just tried them out and was disappointed by how easily that slip nut on the drive shaft loosened. I could almost have turned it by hand!

I've disconnected the brakes and lines from the axle. You can tell which flex line I've already replaced as it drips readily when loosened, whereas the original one is so constricted that virtually nothing drips out of it. Time to replace that one!

I hope to do the pinion coupling nuts in the morning, then move the drive shaft out of the way. I'm pretty sure I'll then be about at the point of lowering the axle.

I've lowered the exhaust by removing the donuts, but still have the front pipes attached to the manifolds (I've got a support under the system, so there's no great stress being put on the manifolds at present). Getting to those manifold bolts would be tough with the car in its present, rear-up stance. Can I realistically expect to be able to get that rear end out of there with the exhaust merely lowered and not removed?

John

John Livingston
Newport News, VA
1968 280SL 4 speed manual

[Cees Klumper]

John - I use pipe wrenches to undo and tighten the nut on the driveshaft. On the exhaust, it's hard for me to visualize it being much more difficult to get to the manifold-to-downpipe bolts with the car jacked up in the rear. I think you should be able to get to them ok and drop the exhaust a lot further down. It will be very difficult to remove the system altogether though, unless you have a car lift that goes up high enough.

Cees Klumper in Amsterdam
'69 white 280 SL automatic

[n/a]

Cees,

I think I've come up with an alternate plan. I need to replace the forward of the two resonators, so I'm thinking about using a reciprocating saw to cut the back half of the exhaust off. I'm hoping that'll leave enough exhaust in place that I can drive the car (assuming I ever get the rest of it back together) to the exhaust shop and have them put in the new forward resonator and pipes to the rear (fairly new) resonator. This should let me drop the axle w/o having to fuss with the manifold bolts.

quote:Originally posted by cees klumper

John - I use pipe wrenches to undo and tighten the nut on the driveshaft. On the exhaust, it's hard for me to visualize it being much more difficult to get to the manifold-to-downpipe bolts with the car jacked up in the rear. I think you should be able to get to them ok and drop the exhaust a lot further down. It will be very difficult to remove the system altogether though, unless you have a car lift that goes up high enough.

Cees Klumper in Amsterdam
'69 white 280 SL automatic

John Livingston
Newport News, VA
1968 280SL 4 speed manual

[Cees Klumper]

Hi John - your plan will work for the rear axle I suppose. For the exhaust system - since you need to replace part of it, have you considered getting a complete new system? If one of the resonators needs replacing now, how long will it be before other parts / pipes are worn out? Driving with half a system may attract more (police) attention that you may care for.
I had to replace part of my system and decided to get it over with 'once and for all', and I bought a stainless system front-to-back from Van Dijk. It cost around $750, seems very well made and it should last 20-some years? It clamps together; this way, it will be much easier to remove if there is ever any need in the future. Just a thought.

Good luck on the job at hand!

Cees Klumper in Amsterdam
'69 white 280 SL automatic

[n/a]

Cees,

I did look at stainless systems. How do you feel about the sound of yours? Is it close to the original exhaust note? Right now I'm pinching pennies hard, so salvaging some of the existing system seemed the way to go. I only plan to drive it to a nearby muffler shop to have the new pieces welded in, therefore missing the rear muffler shouldn't get me in too much trouble.

Anyhow, I finally sawed through the last pipe minutes ago. I'm now moving to the drive shaft bolts, which are a bit problematic as the car isn't in gear, the shift levers are all out waiting for the last bushings to arrive, and the drums are off and the cables are disconnected, so I can't use the parking brake to keep the driveshaft from rotating. Maybe I can wedge my 41mm wrench in place, or put something through one of the wheel bolt holes.

Did I mention that my 54-year-old back is getting pooped?

BTW I've got a fun story about Pagoda hunting in the Netherlands I hope you'll appreciate, but I'm trying to track down a photo first.

John

quote:Originally posted by cees klumper

Hi John - your plan will work for the rear axle I suppose. For the exhaust system - since you need to replace part of it, have you considered getting a complete new system? If one of the resonators needs replacing now, how long will it be before other parts / pipes are worn out? Driving with half a system may attract more (police) attention that you may care for.
I had to replace part of my system and decided to get it over with 'once and for all', and I bought a stainless system front-to-back from Van Dijk. It cost around $750, seems very well made and it should last 20-some years? It clamps together; this way, it will be much easier to remove if there is ever any need in the future. Just a thought.

Good luck on the job at hand!

Cees Klumper in Amsterdam
'69 white 280 SL automatic

John Livingston
Newport News, VA
1968 280SL 4 speed manual