3,27 axle checkout, reseal, repair & install

[jeffc280sl]

Picked up the first of two 3.27 axles I purchased recently.  Took 5 to 6 hours to drain it and take it apart.  Work completed:

calipers and emergency brake parts removed
axles shafts removed
Pivot bolt/shaft removed
trunk mounted carrier arm removed
pinion support arm removed
axle tubes removed from differential

Tomorrow I'll try and remove the gears inside the diff housing.  Need to figure out how to do that.  Once this is complete I can look at the casting hole Joe has talked about to see if it is worn.  Bearings look good.  Plan to replace all seals and rubber pieces.

Will pick up another axle later this month.  Decided to buy 2 in case
parts were worn or casting hole was elongated.  If I can refurbish 2 good axles I will and consider putting the second one up for sale.

Will post some pictures soon.


Jeff C.
1970 280SL 4-speed

[jeffc280sl]

This is a picture of the diff casting and ring gear.  Joe has advised us to be mindfull of an elongation in the casting that can take place in high mileage rear axles.  You can see from this picture that the casting hole is round and the gear shaft fit is snug.  Will post more pics as I can.

Download Attachment: OH Casting1.jpg
15.85 KB

Jeff C.
1970 280SL 4-speed

[jeffc280sl]

Thought I would post a couple more pictures of the swing axle.  You are looking at the hinge assembly and bushing for the swing axle.  Note the X channel and hole in the assembly.  The X channel helps distribute grease throughout the connection. There is a hollow space behind the brass bushing that is connected to a grease fitting.  As grease is pumped in the X channel helps force it out to needed locations.  It's hard to see but this joint was dry at one point and there is some scoring on the bushing and axle assembly.  

Download Attachment: swing hinge bushing.jpg
35.92 KB

Download Attachment: swing hinge.jpg
38.01 KB

Jeff C.
1970 280SL 4-speed

[skrmetti]

Jeff,

I am thinking of swapping my 3:69 rear end on my 1967 250SL 4 speed for a 3:27. I am wondering where you found your axles ?

Any info would be appreciated.

Thanks,
Tom

[jeffc280sl]

Check ebay in the W113 and W108 sections and be patient.  Also check your local bone yard, you may get lucky.

Jeff C.
1970 280SL 4-speed

[Ben]

Good stuff Jeff..............keep us up to date, I'm hoping for more and more photos !

Regards,
Ben in Ireland.
'64 230SL 4sp.

[jeffc280sl]

Hi Ben,

Anything in particular you would like to see.  The first axle is in pieces awaiting new seals, rubber boot and the like.  Just couldn't put it back together without replacing these parts.  Now is a good time for pics.  I'll also take some as I put it back together.  Need an in/lb torque wrench to preload the pinion gear.  Anyone know where to find a reasonably priced torque wrench?

Jeff C.
1970 280SL 4-speed

[Naj ✝︎]

Jeff,
How are the two outer axle bearings lubricated?
Do they need to be packed with grease or do they get lubed by the diff oil?
Beleive there are oil seals either side of the bearings...

naj

68 280SL

[Ben]

Jeff, just general photos really. I plan to do tyhis job next year, so dont really want to know what to ask for yet !

I suppose the more photos the merrier !

Is it possible to see that elongated hole without so much stripping !

Regards,
Ben in Ireland.
'64 230SL 4sp.

[al_lieffring]

quote:Originally posted by naj

Jeff,
How are the two outer axle bearings lubricated?
Do they need to be packed with grease or do they get lubed by the diff oil?
Beleive there are oil seals either side of the bearings...

naj

68 280SL

The outer axle seal is on the park brake mounting plate. Sometimes replacement bearings will have metal shields on one or both sides but they should not be sealed bearings. The bearings do get lube from the differential but I do pack them with wheel bearing grease before installing them just to make sure.

Al

113-042-10-014715
built 11 Jan 66
904/396 blue, Ivory Tex
condition- rust bucket

[Vince Canepa]

quote:The bearings do get lube from the differential but I do pack them with wheel bearing grease before installing them just to make sure

There are inner and outer seals at the bearing.  Although rear axle lube can travel down the axle tube, it should not reach the bearing due to the inner seal.  The bearings are lubed by packing them with grease.

Vince Canepa
1967 250SL
113.043-10-001543
568H Signal Red
116 Caviar MB-Tex

[al_lieffring]

Vince, nice save

I was completly wrong on this one.

I guess I am relying on memory from far too long ago.
I of course now remember the inside-out inner grease seal on the axle shaft.
The shielded bearings were parts we ordered from a bearing distributor just to keep the  diff. lube out of bearings if the inner seal did fail. We mounted them with the shield to the inside. The reason for many wheel bearing failures was the inner seal leaking and washing the grease out of the wheel bearing.

al

113-042-10-014715
built 11 Jan 66
904/396 blue, Ivory Tex
condition- rust bucket

[jeffc280sl]

Ben,

Here is a better pic of the casting and hole for the spider gear shaft.  In my case the hole was in great shape.  Hope this is what you were looking for.

Download Attachment: OH castingb.jpg
44.29 KB

Jeff C.
1970 280SL 4-speed

[jeffc280sl]

Had to make a couple of tools for the axle.  A tool is needed to tighten the slotted nut on the axle shaft after the bearing is pressed on.  I welded this tool together using a 1 1/2 inch steel pipe as the starting point.  Two pins were added to fit into the slots and not shown in the picture is a 3/8 square fitting on the bar for my torque wrench.  I need to apply 150 ftlb of torque to secure the nut.

The second tool is simple and is needed to hold the pinion shaft secure while torquing the pinion nut into place.  The bar is bolted into place using holes in the flange.

Download Attachment: pinion nut bar.jpg
12.66 KB

Download Attachment: slotted nut tool.jpg
24.52 KB

Jeff C.
1970 280SL 4-speed

[Naj ✝︎]

Thanks Al and Vince for info on the lub.

 

naj

68 280SL

[jeffc280sl]

Here are 3 more pics.  They include the diff case, fixed axle shaft and ring gear assembly.  Each side of the ring gear assembly has a tappered bearing pressed on.  These bearings mate with a beveled surface in the diff case and fixed axle as the axle is bolted to the diff case.

Download Attachment: diff case bearing surface.jpg
79.51 KB

Jeff C.
1970 280SL 4-speed

[jeffc280sl]

Download Attachment: Diff case w-ring gear.jpg
46.12 KB

Download Attachment: fixed axle bearing surface.jpg
39.99 KB

Jeff C.
1970 280SL 4-speed

[Ben]

quote:Ben,

Here is a better pic of the casting and hole for the spider gear shaft. In my case the hole was in great shape. Hope this is what you were looking for.

Yep ..........all good photos............thanks Jeff !

Regards,
Ben in Ireland.
'64 230SL 4sp.

[jeffc280sl]

As I reassemble the 3.27 rear axle I thought I'd take some more pics to document oil seal and rubber bushing replacements.  These pics show the trailing arm bushings going in.

Download Attachment: trailing arm bushing.jpg
60.86 KB

Download Attachment: trailing arm complete.jpg
45.53 KB

Jeff C.
1970 280SL 4-speed

[jeffc280sl]

Here are some pics of the pinion gear shaft oil seal going in place.  I've taken pics from different angles so that you can see the detail.  Pay particular interest to the raised metal lip on the oil seal.  The drive shaft mounting bracket is the actual part that is sealed by this oil seal.  This bracket has a neat dirt and debre cone which extends over the metal oil seal lip to keep it protected from road grime etc.  It is a very neat design that I hope everyone can see clearly.

Download Attachment: pinion seal underside.jpg
54.34 KB

Jeff C.
1970 280SL 4-speed

[jeffc280sl]

More pinion shaft seal pics.

Download Attachment: pinion seal install.jpg
51.34 KB

Download Attachment: Pinion seal.jpg
42.49 KB

Jeff C.
1970 280SL 4-speed

[jeffc280sl]

Last pics for the evening.  Note the inner seal and the extended base for good oil seal inside the axle tubes.  The last picture is of the installed outer grease seal.

Download Attachment: inner seal.jpg
51.43 KB

Download Attachment: inner seal complete.jpg
26.18 KB

Download Attachment: outer seal complete.jpg
58.14 KB

Jeff C.
1970 280SL 4-speed

[jeffc280sl]

Spent a couple of hours this morning putting the rear axle housing and differential back together.  Need to align the carrier, preload the pinion, press bearings on axles, install axles,  brakes, trailing arms and put oil in the diff case and that should about do it.  Here are some more pics.

Download Attachment: axle parts.jpg
15.51 KB

Download Attachment: conn bolt & wedge screw.jpg
39.14 KB

Download Attachment: diff case and right uni.jpg
29.2 KB

Download Attachment: conn bolt.jpg
17.28 KB

Download Attachment: assembled diff.jpg
19.5 KB

Jeff C.
1970 280SL 4-speed

[ja17]

Hello Jeff,

Good job and lots of nice photos!
Thanks!

Joe Alexander
Blacklick, Ohio

[jeffc280sl]

Thanks for the kind words.  I can't tell you how many times during this project I have looked back on your rear wheel bearing tour for advice.  Thank you!

Jeff C.
1970 280SL 4-speed