3.27 axle

[paulr]

So, I found an axle from a 3.5 and as I'm off to France for a month now next week I have had it put in along with a complete retune/mixture done on an analyser, new ht leads, spark plugs, gear box pressures fine tuned etc. I pick the car up tomorrow. I can't wait. Will report back.

paulr
lovely 1970 280 SL

[paulr]

update.
I have the car back and it's amazing. In my opinion it is amongst the best things I have done to it. As you may know I do an awful lot of long miles in my car and although as yet I haven't been on the motorway, I have been fast enough for long enough today to immediately know what a huge difference it's made.

It may have given me the thing that I always wanted from my car and it's just so different to drive. I know that most want originality and that's fine, but for me as much as I want all that and mine is nearly there except electronic ignition and now this axle, I need a car that is beautiful to look at and beautiful and practical to drive. I had rather got the impression from the wonderful forum that it made take off a fairly big issue, but it doesn't really. I don't think there is anyone here that drives their car in a way that take off would be compromised.
I would recommend this to most and as much as I quite liked the torquey "always in third" feeling, I did always want an extra gear. Actually, it was the defining thing in making me think that I would eventually have to buy something a little less frantic.
Now I think I have it in my special little car, always there and always keen, and never do I run out of room cramming cameras, lighting, dogs,clothes, muddy boots, antiques, we even had a proper sized chaise longue hanging out of it recently ...the lot in it. I think I will keep it always.

quote:Originally posted by paulr

So, I found an axle from a 3.5 and as I'm off to France for a month now next week I have had it put in along with a complete retune/mixture done on an analyser, new ht leads, spark plugs, gear box pressures fine tuned etc. I pick the car up tomorrow. I can't wait. Will report back.

paulr
lovely 1970 280 SL

paulr
lovely 1970 280 SL

[philmas]

May I ask how much you paid for this job, including rear axle purchase?

Philippe from Paris
'71 280SL manual 4sp

[paulr]

sure, I have the bill in front of me:

rebuilt axle £1000
labour £480
various bushes £70.31
radius arm kit £128.78
rear discs £69.08
disc pads £22.90
 brake hoses £67.20
all + 17.5%

I know our American friends will find this figure alarming but that's how it is here and anyway, I needed it doing and I don't really mind how much it costs as I rely on my car and my condition when I arrive at a job too much to worry.

I had some extra things done down there whilst the wheels were off, so discs aren't nessesary although like all these things they always find something else to do. There was a chassis modification to do as well regarding an oil cooling pipe that comes with the new axle. The boys will sell my axle on as it had been rebuilt recently and we will put this money towards the next project. I have just come in and I am truly delighted with the ride. It's amazing. The car is just fantastic and I'm annoyed with myself for not having done it earlier. I was put off, with respect, by misunderstanding various posts about the dire consequences on the speedo and take off performance. I thought that the car would crawl away from lights and I have to admit I was nervous when I collected the car, but it's just like it was, if not better somehow.

I hope this helps.

I see you're in Paris. I am often there but I rarely drive in Paris. I am over on the coast / Toulouse / Aix for a month from next week in the car if you happen to be in any of those regions
.

quote:Originally posted by philmas

May I ask how much you paid for this job, including rear axle purchase?

Philippe from Paris
'71 280SL manual 4sp

paulr
lovely 1970 280 SL

[hill]

I just purchased a 3.27 axel. When my mechanic has time he will install it. My car is automatic so performance might suffer on the lower end. Hopefully if my broke arm heals will take a benchmark of perf and mpg and report the changes.

Happy Benzing
Darryl, Hill
350 SL4.5 #60
1967 250sl "California"

[paulr]

It doesn't really suffer, it is amazing how quickly you get used to it. I think you'll be delighted.

quote:Originally posted by hill

I just purchased a 3.27 axel. When my mechanic has time he will install it. My car is automatic so performance might suffer on the lower end. Hopefully if my broke arm heals will take a benchmark of perf and mpg and report the changes.

Happy Benzing
Darryl, Hill
350 SL4.5 #60
1967 250sl "California"

paulr
lovely 1970 280 SL

[JamesL]

who did the work?

Mats - come back to you tomorrow

[paulr]

Paul at Roger Edwards. He does everything for my car. I think they are pretty good and I trust their mechanical judgement.

quote:Originally posted by Tosh

who did the work?

Mats - come back to you tomorrow

paulr
lovely 1970 280 SL

[Benz Dr.]

If you look at the weight of the 280SL and compare it to the 4.5 you'll see that they have identical power to weight ratios. The 4.5 has a lot more torque but you can expect that from a V8.
So the 280SL has more than enough power to push the car along with the 3.27 axel. If you live in hilly country then starting up hill will make it groan a bit. I still think this is best suited to a car with a standard trans but is really does work well on the open road. Very long legs on that girl......

Dan Caron's
 SL Barn
benzbarn@ebtech.net
 slbarn.mbz.org
  1 877 661 6061

[rob walker]

Paul, where did you get the 3.5 axle from?

Rob Walker
1968 280SL papyrus white/green leather
Spain and Turkey

[philmas]

Paul, you're talking of a 3.5 rear axle-am I right?
I thought the 3.27 ratio was only for the 4.5 i.e. the US version, never been sold in Europe. Was it an option on the 3.5 as well?

Philippe from Paris
'71 280SL manual 4sp

[Benz Dr.]

The 3.5 car used a 3.69 axel for the most part. The 3.27 axel was used mostly on US  280SE/SEL and 300SEL 4.5 cars. It's hard to find a 3.69 axel that was used on a few 280SL's and is supposed to be standard on the 250SL's. The 3.5 coupe used a 3.69 axel as well.
These are fairly desireable axels today and only the limited slip axels are more rare and hard to find. Now thats an axel you would want if you could find one!

Dan Caron's
 SL Barn
benzbarn@ebtech.net
 slbarn.mbz.org
  1 877 661 6061

[DavidBrough]

After much dithering and pondering I’ve finally taken the plunge and collected my new axle today a 3.46 from a 1971 280SE 3.5, it needs a fair bit of cleaning and refurbishment before I can think about fitting it  but from the reports so far I can’t wait to try it out.

David Brough
1969 280 SL auto with A/C

[Dick M]

quote:Originally posted by Benz Dr.

The 3.5 car used a 3.69 axel for the most part. The 3.27 axel was used mostly on US  280SE/SEL and 300SEL 4.5 cars. It's hard to find a 3.69 axel that was used on a few 280SL's and is supposed to be standard on the 250SL's. The 3.5 coupe used a 3.69 axel as well.
These are fairly desireable axels today and only the limited slip axels are more rare and hard to find. Now thats an axel you would want if you could find one!

Dan Caron's
 SL Barn
benzbarn@ebtech.net
 slbarn.mbz.org
  1 877 661 6061

Hi Dan..
My 280SL has 3.69 and I'm swaping it out for a 3.27..How much sense does this make? (I bought the 3.27 thinking I had 4:11...)

Dick M
1970 280SL

[Benz Dr.]

The 3.69 axel is a pretty good fit for the 113 car and I'd be inclined to leave it in there. It's a good trade off between acceleration and lower RPM's at speed. You will be running 230 RPM less than the standard 3.92 axel and 390 RPM less than a 4.08
This may not sound like very much but it really does make a difference that you can hear and feel.
The 3.27 axel would run 650 RPM less than the 3.92 axel and is simlar to a 5 speed trans that would run about 550 RPM slower engine speed in high gear. The only thing about the 3.27 axel is you will loose a certain amount of grunt at lower engine speeds but it will work really well at higher speeds and it's great for high speed travel. It's a trade off. I wouldn't want one in mountain areas and definately not with an auto in the car. A 4 speed would be best for that aplication. A weak or worn out engine will really suffer with this high ratio.

5 speed cars have the 4.08 axel as standard equipment so they really pull hard off the line. I can start out in second gear with my car and usually do around town because it leaves nice and easy. If I start in first it will jump too hard.

Dan Caron's
 SL Barn
benzbarn@ebtech.net
 slbarn.mbz.org
  1 877 661 6061

[paulr]

This one was bought from another customer of Roger Edwards that had bought two different ones to try. This was the one that was left over and it was already rebuilt and ready to go in. Thats why the round figure of £1000 was plucked out of the air I suppose.

By the way. It would be very useful to know of friendly 113 mechanics in France. Do you know any, both in and out of Paris?

quote:Originally posted by philmas

Paul, you're talking of a 3.5 rear axle-am I right?
I thought the 3.27 ratio was only for the 4.5 i.e. the US version, never been sold in Europe. Was it an option on the 3.5 as well?

Philippe from Paris
'71 280SL manual 4sp

paulr
lovely 1970 280 SL

[philmas]

There are not many places I could recommand
IMHO, one of the best ones is probably L'atelier SL
48 Bd National 92250 La Garenne Colombes tel.01 56 83 73 50
 http://pagesperso-orange.fr/ateliersl/index.html

This is very close to Paris.There are probably other adresses in France, but these guys are SL specialists, and very friendly.
Just tell me if you need more info.

Philippe from Paris
'71 280SL manual 4sp

[paulr]

thats good to know, thanks.

paulr
lovely 1970 280 SL

[rob walker]

Dan and group. On a European version 280SL build date early 1968 which axle ratio would have been fitted?
Mine runs around 4000 rpm at 70 mph, which I still find a little high and would love to get this down by 500 rpm.

Rob Walker
1968 280SL papyrus white/green leather
Spain and Turkey

[Naj ✝︎]

quote:Originally posted by rob walker

Dan and group. On a European version 280SL build date early 1968 which axle ratio would have been fitted?
Mine runs around 4000 rpm at 70 mph, which I still find a little high and would love to get this down by 500 rpm.

Rob Walker
1968 280SL papyrus white/green leather
Spain and Turkey

Hello, Rob,

My '68 has a 3.92.

17.5 to 18 mph/1000rpm sounds about right.

naj

68 280SL

[rob walker]

Thanks Naj, yes that then seems right.
Rather than changing the axle route, the 15 inch Bundt alloys would offer some relief and also make it easier to obtain new tyres, any idea what this would bring the revs down by?

Rob Walker
1968 280SL papyrus white/green leather
Spain and Turkey

[Naj ✝︎]

quote:Originally posted by rob walker

Thanks Naj, yes that then seems right.
Rather than changing the axle route, the 15 inch Bundt alloys would offer some relief and also make it easier to obtain new tyres, any idea what this would bring the revs down by?

Rob Walker
1968 280SL papyrus white/green leather
Spain and Turkey

Hi, Rob,

I make it about 7% if you use 205/70x15 tyres using the site below.

http://www.1010tires.com/TireSizeCalculator.asp?

A 3.46 diff will give 15% reduction in rpm.

A 5 speed Getrag box is another consideration...

naj



68 280SL

[paulr]

I feel a little embarrassed

Philippe, your question made me phone Roger Edwards garage this morning and I am SO wrong about the ratios. The one that has been fitted to my car IS A 3.69.!! Not a 3.27.
I don't really get that involved in the details and the 3.27 was just mentioned in our conversation about the axle donor customer and I just made the assumption, so please accept my apologies.
I stick by what I said however, it is the best thing I have done and would recommend it to all. DR. Benz, thanks for your diplomacy in your posts.

paulr
1970 280 SL

[hill]

quote:Originally posted by Benz Dr.

The 3.69 axel is a pretty good fit for the 113 car and I'd be inclined to leave it in there. It's a good trade off between acceleration and lower RPM's at speed. You will be running 230 RPM less than the standard 3.92 axel and 390 RPM less than a 4.08
This may not sound like very much but it really does make a difference that you can hear and feel.
The 3.27 axel would run 650 RPM less than the 3.92 axel and is simlar to a 5 speed trans that would run about 550 RPM slower engine speed in high gear. The only thing about the 3.27 axel is you will loose a certain amount of grunt at lower engine speeds but it will work really well at higher speeds and it's great for high speed travel. It's a trade off. I wouldn't want one in mountain areas and definately not with an auto in the car. A 4 speed would be best for that aplication. A weak or worn out engine will really suffer with this high ratio.

5 speed cars have the 4.08 axel as standard equipment so they really pull hard off the line. I can start out in second gear with my car and usually do around town because it leaves nice and easy. If I start in first it will jump too hard.

Dan Caron's
 SL Barn
benzbarn@ebtech.net
 slbarn.mbz.org
  1 877 661 6061

I thought about the gearing being to high. One possibility is to run 205/60/14. The top of the fenders covers the top of the shorter tires so it doesn't have that open look. Close as I can figure there is a 16% difference in gearing with stock tires and 9% with 60's. What's another $300 in Mercedes world.

Happy Benzing
Darryl, Hill
350 SL4.5 #60
1967 250sl "California"

[gugel]

quote:Originally posted by rob walker

Dan and group. On a European version 280SL build date early 1968 which axle ratio would have been fitted?
Mine runs around 4000 rpm at 70 mph, which I still find a little high and would love to get this down by 500 rpm.
...
Rather than changing the axle route, the 15 inch Bundt alloys would offer some relief and also make it easier to obtain new tyres, any idea what this would bring the revs down by?

Sounds like a 4.08, although the rpm is probably 3875 to 3900, depending on your brand of tires.  Changing to a 15" wheel (or to a 3.92 rear axle) would bring that down by no more than 150 rpm.  Changing to a 3.69 rear axle would bring it down by about 370 rpm.  To bring it down by 500 rpm you'd need a 3.55 rear axle.

Chris