Rear Axle Modification

[TR]

Dalton -- Thank you kindly for the reply.  Sounds encouraging.  You don't think we'd give up much off-the-line acceleration then?  Effectively a non-issue?

Tom in Boise
'71 280SL 4-spd, signal red w/lt. tan interior, restored/enhanced

[A Dalton]

The up-side far outweights the down.
 If one is looking for the cruise , it is a great mod.
 I have seen many use the change with success and seldom , if any , do they go back to stock gearing.
  I also pefer to see it done on manual trans chassis , where the driver has better control of load conditions. But that may also be my own personal taste of not liking 113s  w/autos, regardless of gear ratios.....
 
 

[TR]

Dalton -- Thanks.  This will be part of our winter work.

Tom in Boise
'71 280SL 4-spd, signal red w/lt. tan interior, restored/enhanced

[ja17]

Hello Tr,

The 3.27 seems to be the most popular gear. These units from Mercedes W108 3.5 and 4.5 V-8 sedans must be checked carefully. The pin that holds the spider gears in the differential wears it's mounting hole oblong in the yoke casting.

I find that about half of the used units I find are bad!

Joe Alexander
Blacklick, Ohio

[TheEngineer]

Attached is a picture of when I changed to a 3.27 axle. I have an automatic. I do about 3100 rpm at 62.5 MPH (100 km/hr). My last fill-up indicated about 22 MPG. Acceleration has never been a problem, but if you drive like that, you'll get less MPG's. This morning I accelerated away from a Lexus, up a steep hill. He wanted to race me. Left him in the dust. My file indicates that the picture was taken in Feb. '04. I have had the axle in for that long. I have no desire to go back. I didn't recalibrate the speedo. I can multiply the indicated speed and milage by 1.25 (on good days only) Officer - I was only doing 60!

Download Attachment: RearAxle.JPG
82.67 KB

[TR]

Thanks Joe & Peter. We'll start getting into this, in some depth I expect, over the next several months.

Tom in Boise
'71 280SL 4-spd, signal red w/lt. tan interior, restored/enhanced

[Tom]

I echo the suggestion that once you have a 3.27 rear-end in you car, you will not want to go back.  Went cruising tonight up the GW Parkway in Washington-you know the road Tom, the same one we went along when you were here.  Had the windows up and the windscreen on, but top down.  It was very easy to conduct a conversation at 50 miles per hour in a normal, un-elevated voice.  Of course the windscreen helps a lot, but the low revs from the 3.27 helps a bunch.

1971 280sl Tunis Beige Metallic (restored & enhanced)
1971 280sl Tobacco Brown (low mileage stock)
1970 280sl Deep Red (Project Car)

[mille]

Does anybody have experience with the installation of a later 5 speed MB gearbox into a Pagoda? In this way the brisk acceleration would be maintained and the 5th gear would act as a welcomed overdrive on the highway. I used to drive MGA years ago and a popular modification was to fit a 5-speed Ford gearbox. It really did wonders for this little sportscar when driving on the highway.

Cheers

Finn

1964 MB 230 SL Euro 4-speed manual, silver metallic/black interior

[TR]

Anyone have thoughts on the best source(s) for a 3.27 rear?

(I haven't yet posted a Wanted to Buy message).

Tom in Boise
'71 280SL 4-spd, signal red w/lt. tan interior, restored/enhanced

[Douglas]

Finn,

"Hauser" in this group has a very nice 280 SL with a later-style Getrag 5-spd installed, so he can comment on installing the side-mounted gearbox. I know he likes the unit very much as it shifts better than his earlier ZF 5-speed. There's been some talk about the gearbox on this site so I suggest you run a search on the word "Getrag."



Douglas Kim
New York, NY
280 SL #016220