240D Differential swap - Page 2 - PeachParts Mercedes-Benz Forum

t walgamuth · #16 12-03-2015, 03:33 PM

I think with a 307 you might have trouble holding it steady at highway speeds without downshifting to fourth.....and forget taking off on a hill.

rotorbudd · #17 12-03-2015, 03:48 PM

Quote:

Originally Posted by t walgamuth

I think with a 307 you might have trouble holding it steady at highway speeds without downshifting to fourth.....and forget taking off on a hill.

Hell, if I had a 5th gear to downshift from I'd be in heaven!

barry12345 · #18 12-03-2015, 05:29 PM

Quote:

Originally Posted by rotorbudd

I've got a 83 240D that spends 75% of its time on the interstate. (back and forth to work every weekday)
I've got a 3.07 diff I'm thinking about dropping in, along with rebuilt driveshafts.
Around ATL if you can't do at least 75mph on the interstates you get eaten up by everybody including the big rigs.
Anybody think this wouldn't be a good mod, and if not, why not?

Better still to locate a five speed transmission perhaps.

Hit Man X · #19 12-03-2015, 05:40 PM

Quote:

Originally Posted by resto108

Could swear the 85 SD's had the 2.88 also. Another one year only, because 85 was the last year of the Gen I

You are correct, my 1985 SD has the 2.88:1 from the factory also. The OP is incorrect.

t walgamuth · #20 12-03-2015, 07:31 PM

The hit man! Haven't seen you around here for a while!

Hit Man X · #21 12-03-2015, 08:05 PM

Quote:

Originally Posted by t walgamuth

The hit man! Haven't seen you around here for a while!

I lurk often, most of the W126s are still full steam ahead and recently added a W124. SDL is down for a top end, SD is just about to receive a new front end (that Klimakit Sanden swap is still best thing I have ever done to it). 300SEL is a dog but rolled 308k recently, 560 needs front springs.

Glad to see you are doing well!

t walgamuth · #22 12-03-2015, 10:54 PM

Your flock of benzos sounds very impressive! Clearly you are doing well.

pj67coll · #23 12-04-2015, 12:04 AM

Quote:

Originally Posted by Grzpdlr

Mercedes just had it geared way too low.

I don't agree that Mercedes had it geared way to low. I think it probably just needed the the 5th gear that you could get in Europe.

I'm also having a hard time wrapping my head around crawling around at 25 in 4th. With mine I'm flat to the floor in 3rd before I get around to shifting up to 4th at around 40 to 45 depending on traffic conditions.

- Peter.

mannys9130 · #24 12-04-2015, 12:11 AM

Quote:

Originally Posted by pj67coll

I don't agree that Mercedes had it geared way to low. I think it probably just needed the the 5th gear that you could get in Europe.

I'm also having a hard time wrapping my head around crawling around at 25 in 4th. With mine I'm flat to the floor in 3rd before I get around to shifting up to 4th at around 40 to 45 depending on traffic conditions.

- Peter.

Exactly. 4th is of no use below 40mph in a 240D. At 25 in 4th some SERIOUS lugging would be going on and that's very bad for the engine.

swampmonkey · #25 12-04-2015, 06:20 AM

i have the same setup.. in w115 thou, both with the newer w123 240d engines.

car nr1.
a 240d 72hp with a 3.07 differential.
http://mbturbo.com/car/w115-om616-240d/

carnr2
a 240d 72hp with a 2.88 differential.

the 2.88 is much much faster, both engines are bad, much blowby, and overal nasty.
the 2.88 is healthier, and with a better tuned injectionpump. better timing, etc.
the 3.07 smokes nothing at al, so thinking about dialing it up a tad.

https://www.youtube.com/watch?v=ab27eba8TKY
thats the 3.07 equiped car.
do know that the speedometer is way of, at that moment shows about 10-15km/h to little vs real speed. and starting in a slight uphill.

ps sorry about the nasty upshift.

ontopic.
i would not say they are peppier than stock, but much less noise,
the differense probably feels larger than it is to, longer pulls on each gear, and the longer pulls makes it feel marginaly slower, but you also gain much more speed.

i run 195/65r15 on my cars.

i have no problem reaching 75mph, even with the torn engine.
and hills etc is somewhat easy.
below 45mph in fourth it will loose momentum at steep hills, but above 60mph, its almost "unstoppable" althou, it do loose some speed, but not much.

ps, i swap to fourth gear in about 40mph with the 3.07 in place, imo the gearing is way of stock. when joining a highway etc, i switch to fourth at about 50mph
with the stock 3.69 the first gear was more or less useless, and fourth came on from 25-30mph. (after i swapped to good enginemounts etc)

swampmonkey · #26 12-04-2015, 06:39 AM

on normal diesel ive done 38mpg, on the older "real" diesel 41mpg.
that is at about 60mph and long drives.

mixed aggresive driving they do about 33mpg

yes, al om617a (turbo) from 1985 had the 2.88 (in US), not in sweden thou/europe, so information might differ depending on what website you visit.
we never had the turbo in the coupe nor sedan w123 either, nor the w116 or w126 with dieselturbo

ps. Sweden diesel. might have more energy than the US, and the old "real diesel" is better than the one bought at pumps.

Stretch · #27 12-04-2015, 07:14 AM

Quote:

Originally Posted by pj67coll

I don't agree that Mercedes had it geared way to low. I think it probably just needed the the 5th gear that you could get in Europe.

I'm also having a hard time wrapping my head around crawling around at 25 in 4th. With mine I'm flat to the floor in 3rd before I get around to shifting up to 4th at around 40 to 45 depending on traffic conditions.

- Peter.

Most of the "5th geared" vehicles have a lower geared differential to remove the benefit!

I think on the whole the W123 was built for a different time where road speeds were slower.

If in the US of A the old fashioned 55mph maximum was forcibly regulated the gearing wouldn't seem too slow!

pj67coll · #28 12-04-2015, 08:25 AM

Quote:

i have no problem reaching 75mph, even with the torn engine.
and hills etc is somewhat easy.

That's an interesting video clip but the speedometer is in KPH not MPH.

- Peter.

ollo · #29 12-04-2015, 08:45 AM

"I think on the whole the W123 was built for a different time where road speeds were slower.

If in the US of A the old fashioned 55mph maximum was forcibly regulated the gearing wouldn't seem too slow!"

This is very true. The freeway I drive to Salem(Hwy 22) is posted 55 mph due to a history of bad accidents. Most traffic still cruises @ 60-65 mph but there are enough trucks and the occasional slow driving sedan for the 240D to be right at home with periodic opportunities to pass. Don

t walgamuth · #30 12-04-2015, 10:09 AM

Quote:

Originally Posted by swampmonkey

on normal diesel ive done 38mpg, on the older "real" diesel 41mpg.
that is at about 60mph and long drives.

mixed aggresive driving they do about 33mpg

yes, al om617a (turbo) from 1985 had the 2.88 (in US), not in sweden thou/europe, so information might differ depending on what website you visit.
we never had the turbo in the coupe nor sedan w123 either, nor the w116 or w126 with dieselturbo

ps. Sweden diesel. might have more energy than the US, and the old "real diesel" is better than the one bought at pumps.

Imperial gallons?