Author Topic: 3/25 gear ratio experience?  (Read 6928 times)

star63

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3/25 gear ratio experience?
« on: September 08, 2015, 19:34:41 »
Has anyone installed one of these?



Is it as quiet as original when correctly set up (with gear-marking compound)?
Petri
'67 250 SL (early)
'66 230 SL (long project)
Finland

tel76

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Re: 3/25 gear ratio experience?
« Reply #1 on: September 09, 2015, 08:45:32 »
Fitting a new crown wheel and pinion requires several tools specific to the job, if you have not got these then your best plan would be to purchase a complete axle, change all the seals and half shaft bearings.
Eric

stickandrudderman

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Re: 3/25 gear ratio experience?
« Reply #2 on: September 09, 2015, 10:01:50 »
Or fit a 5 speed box with o/drive.

star63

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Re: 3/25 gear ratio experience?
« Reply #3 on: September 09, 2015, 18:01:48 »
Thanks!

The problem is that a rear axle with 3,27 gear ratio or a getrag 265 with the parts needed for installation would double my budget...
Petri
'67 250 SL (early)
'66 230 SL (long project)
Finland

stickandrudderman

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Re: 3/25 gear ratio experience?
« Reply #4 on: September 09, 2015, 18:55:44 »
Installing a new crown wheel and pinion is not going to be cheap, but I guess it will be cheaper than the 5 speed. Not sure about cheaper than an axle swap though by the time you take the specialist labour required to install the crown wheel & pinion into account.

Cees Klumper

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Re: 3/25 gear ratio experience?
« Reply #5 on: September 09, 2015, 19:11:02 »
I had a complete axle swap done, 4.08 to 3.69, for $900 some years ago. Can highly recommend the 3.69, I would not go further down to 3.25 personally.
Cees Klumper
1969 Mercedes 280 SL automatic
1968 Ford Mustang 302 V8
1961 Alfa Romeo Giulietta Sprint Coupe 1600
1962 FIAT 1500S OSCA convertible
1972 Lancia Fulvia Coupe 1.3
1983 Porsche 944 2.5
1990 Ford Bronco II

nirmal

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Re: 3/25 gear ratio experience?
« Reply #6 on: September 15, 2015, 16:46:04 »
I bought a 3.27 crown and pinion from Gael for $ 500 and spent another $500 to change from the 4.08. The result is a much quieter ride and better fuel economy. As I have a automatic and now start in a lower gear and manually shift it. Works well.

Nirmal
Dubai

Raymond

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Re: 3/25 gear ratio experience?
« Reply #7 on: September 15, 2015, 18:16:30 »
Petri, At the PUB this weekend, several of us discussed differentials.  Although Nirmal seems happy with his result, the consensus was that the 3.27 in an automatic would be a dog.  Most agree with Cees that going below 3.69 causes the engine stress to lug it off the starting line.   The exceedingly low ratio of 1st gear in the manual would make it livable but, as the automatic requires a 'kick down" to get into first, that would be a different story.  Now, these are garage-talk opinions but many are born from experience.
Ray
'68 280SL 5-spd "California" Coupe

star63

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Re: 3/25 gear ratio experience?
« Reply #8 on: September 15, 2015, 19:18:32 »
Thank you all for the valuable comments!

My car has a manual transmission and based on your experiences I'm beginning to lean towards Getrag conversion.
Petri
'67 250 SL (early)
'66 230 SL (long project)
Finland

ctaylor738

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Re: 3/25 gear ratio experience?
« Reply #9 on: September 16, 2015, 00:38:49 »
My .02 $ or euros is that a 3.27 with a 4 speed is an excellent driver, having driven a couple. 

My automatic 280SL with a 3.27 has a "magic button" in the front of the tray that allows a downshift without flooring the accelerator, and this works well when you need a first gear start or a little kick. 
Chuck Taylor
1963 230SL #00133
1970 280SL #13027 (restored and sold)
1966 230SL #15274 (sold)
1970 280SL #14076 (sold)
Falls Church VA

66andBlue

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Re: 3/25 gear ratio experience?
« Reply #10 on: September 18, 2015, 05:21:52 »
.....Although Nirmal seems happy with his result, the consensus was that the 3.27 in an automatic would be a dog.  ....
Not sure whom our esteemed president polled but certainly there wasn't a consensus.  ???
I and at least three other members prefer the 3.27 axle in an automatic 280SL compared to the original 4.08. Nothing better for cruising on the freeways of southern California.
Quote
...  The exceedingly low ratio of 1st gear in the manual would make it livable but, as the automatic requires a 'kick down" to get into first,  ...
Just put the gear selector in "2" and it starts off in first gear - no kick down required!
Alfred
1964 230SL manual 4-speed 568H signal red
1966 230SL automatic 334G light blue (sold)
1968 280SL automatic (now 904G midnight blue)

Raymond

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Re: 3/25 gear ratio experience?
« Reply #11 on: September 19, 2015, 21:40:34 »
I guess should have said the consensus of the fellows in our discussion who believe that 0-60 is an important measure when pulling onto a freeway.  I'll put my 5-speed manual 4.08 against an automatic Pagoda with a 3.27 any day.  If you never drive in traffic or don't climb curvy mountain roads, I'm sure it will be fine.  I actually suggested to Paul who has a 3.27 on a shelf to put it in the car and see how he likes it.  I just hate to lug an engine that is designed for higher winding. 

One nice feature of our forums is you get various opinions from many people and get to decide which aligns with your philosophy.  Good luck.  Let us know how it turns out.
Ray
'68 280SL 5-spd "California" Coupe

66andBlue

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Re: 3/25 gear ratio experience?
« Reply #12 on: September 20, 2015, 00:52:01 »
.... or don't climb curvy mountain roads, ...
But I do, that's what the 230SL is for!   ;D
Alfred
1964 230SL manual 4-speed 568H signal red
1966 230SL automatic 334G light blue (sold)
1968 280SL automatic (now 904G midnight blue)

nirmal

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Re: 3/25 gear ratio experience?
« Reply #13 on: September 20, 2015, 13:35:52 »
I start my automatic in the 2nd like Alfred and the car cruises like a dream.

Nirmal
Dubai