My '85 seems to pull nicely up most hills. I would have thought wth the different gearing I would get better fuel economy because of the lower RPM's but I don't seem to get the better MPG's like the other years. I'm thinking it may be because I have a CA model with the OX CAT. Vwbuge converted his CA model 300SD to a fed model but according to him didn't get any improvement in MPG's.

I believe it was 175K miles. There is also a 76 300D there with the 3.96 that I'm taking for myself.

That's significantly less than mine :-). If you're still willing to pull & ship it, please tell me how much $ it'd be (add whatever you think is fair for handling, of course!) so I can see if I can afford cough it up or not...

Was the cat recall only for the 603's? I thought it might also affect '85 California models.
Thanks
David

It covered the 617's as well. My car was included in the recall.

DieselDieHard: Actually I was refering to the amount of speedometer error that would result. There is no doubt in my mind this would a good thing, if changing from 3.07 to 2.88 or something taller. The only thing that makes me hesitate to try this (other than $$$) would be my transmission. It shifts pretty hard and shudders in second. (some threads I've read here make me think it might be a B2B piston) Once I get the transmission sorted out I hope to do something, A drop-in 85 2.88 is probably easiest but I might try experimenting with something that would actually move third up to something like a passing gear. That may be overly ambitous but it sounds like the numbers the original post was refering to.

Pull & save wants $52 for rear ends but sometimes they have a $30 sale. Being almost solid metal, it will be one heavy SOB to ship so I have no clue what that would cost.

Kerry Edwards met me at the yard and was showing interest in getting it for himself. Seeing how much it might cost overall, I'll see if he wants it first.

LMK if you still want it and I'll keep an eye out for sales.

Pumpkin Shipping
 

Make a cheapo pallet from a piece of scrap plywood and a couple of scraps of 2x4. Drill some holes in the appropriate locations and band that punkin' onto the pallet.

Take the whole kit and kaboodle to FedEx freight (not the regular FedEx) and ship it their cheapest way. You can probably get it sent anywhere in the USA for under $125.

Lance,
Keep an eye open for a 2.88 rear end when they have a sale...I'd like to have one in inventory...just for grins.

Does anyone here know how much a differential weighs? If shipping is $100 or less it seems like a good deal to me, I'll take it if Kerry doesn't :-).

Cr@ppy news everybody.

I went to Pull&Save last saturday to find the 85, along with 8 other cars (including two good 280S 4.5's), had been already been crushed! :mad: Its a damn shame. The body, block, head, rear end, transmission (w/85 torque converter) and other '85 specific parts were still good. :mad:

I did manage to get the 3.96 rear end from the 76 300D and the EGR "computer" from the 85. I found how to get the four bolts at the top of the pumpkin. There are four rubber plugs in the trunk that give direct access to the 19mm nuts from the top. How to get to it in a TD, I have not the slightest clue.

I have been trying to get a good turbo for my (future) turbo-jet project. I have found a subaru and several crysler turbos. The sub dang near makes me want to cut it off to get it, and the cryslers.... the "engineer" who designed the engine placement needs to be shot. The egnine or the cylinder head must be pulled to remove it. :mad:

Just reviving this thread for a minute. I have an '81 300SD with the 1:3.07 rear end, and would like to put in the 1:2.47 rear end from a 420SEL I found. I have heard that they just drop in, but upon further inspection I see that the mount is different. What have you guys been doing to solve this? Can you swap the back-plate of the differential where the mount is? Looking for ideas, thanks!

Re: Well - I have found the MB diesel "easter egg"
 

My 1983 300D revs a little lower than that in stock form. I can go 70mph or a little over at 3k rpms, 65mph is about 2850rpms. My 84 had the normal rear end in it, the car itself was a bit faster but it could never touch the mileage the 83 got. Not many of us here can claim our turbo W123 got 33-34mpg several tanks in a row with a mix of 50/50 city and highway driving. At any speed under 10mph I'm in first, I have it set so under normal acceleration at about 43mph it shifts into 4th. If I want to keep it in third I just push the pedal down, I can hold it until redline if I want to.

What I don't understand is how does it now take off in first instead of second? It has no way of knowing the rear ratio and the trans has to start turning for at least a few times before it can figure out what gear it needs to be in.

Without rereading the thread I believe he changed to a more highway friendly rear end, this means when taking off from a stoplight you'll probably push the pedal down further. Since the pedal goes down further the tranny keeps it in gear longer or if possible in a lower gear.

Guess I'm just use to the 240D where even with the better low-end gears, you're still pushing the pedal all the way down :D

I don't have a 240, but I still drive wityh the pedal all the way down.:D
Thanks
David

Bump!
 

Here's the scene: I have a '85 SD, and a 82TD. The TD has low miles (135K) and plenty of power, and it's primary use is ultra flat highway runs to Grandma and Grandpa's house- 180 miles one way. Love to have the lower RPM of the the later model rear ends. The SD is a luxury (no pun intended- with three MB's and one driver in the household) so I can use it as I wish. The engine and mechanical systems in the SD are very good. The tranny is less than three years old. I'd like to change the rear end in it to the 2.46 of the 420-560 sel's, use it's 2.88 for the TD. I have the best yard resources in the country it seems- there were 7 W126's in the three WPB yards last weekend, so getting parts is no problem. Is this a DIY???


BTW, I'm now seeing quite a bit of ebay MB parts being pulled and sold by people in both WPB and South Florida- moparmom is one. Many people are PM'ing (and emailing) me to find out about these yards and asking me how they can get to them. Like a good surf spot, you want to tell only your best friends. I have and will continue to "share the wealth" with little reserve, but please do ask me for information of the yards if you are going to pull parts and ebay them. I was taught not to poo-poo where you eat, if you catch my drift. :mad:
I pull parts for members who ask with little profit to me. Enough to trim some fuel costs to the yards. This year's revenue over expenses (NOT including yard, shipping or packing time, tool costs or wear and tear to the '80 wagon ) will be less than $100. Keep asking, though, because I will find what you need, even if it takes bit of time. :sun_smile

William

MTU, it should be a fairly easy DIY to swap the rear diffs with the only real hard part of the job is needing some good muscle to do it. The diffs I can imagine are quite heavy because the axle shafts alone are like lifting some medium weight dumbells when working on your back with the rear of the car lifted. Since you'd be just swapping the diffs you wouldn't probably even need to remove the shafts completely, only from the wheels. There aren't that many bolts holding the diff to the chassis either. Just get a very good jack to secure the diff when lowering it from the car.

W126 diff to W123?
 

So what are we saying here? Can we post a table of "working diff swapout combinations" such as:

Source = W126, Destination=W123, ratio swap= 3.68 to 2.88, notes: difficulty / easy / things to watch out for?

blah blah.. PER success?!

So far, I am thouroghly confused as to WHAT source cars and ratios could (should) be used in my 230TE !.. I also suspect other members might be interested!

thanks!

>Joe

This is interesting.

What ratio does my 1992 300Sd 3.5L has ?

this thread has got me all twitterpated :D ...sounds like something i might like to try in my 85 SD...mine has the 2.88, as opposed to breckman's former 3.07...i have a few questions about this...say i switch from my current 2.88 to the 380's 2.47 diff...what kind of increase in top speed would i see? any? i assume i would almost always need to run it in 3rd gear for city driving to keep it in a decent powerband, for anything under 40-45mph i run in 3rd now....might there be any ill effects on my transmission by doing this? would i be sacrificing much on the low end? right now im pretty satisfied with the low end power, even with starting out in 2nd a lot of the time...first gear is quick, it never runs over 3500rpm before shifting, even with WOT...i dont know what thats about...its always done it though...all other gears shift at around 4500rpm....so what seems to be the general concensus on this swap? think its worth it? a new diff isnt all that pricey, esp. a used one....i think im gonna bite the bullet and try it out, right after i get the beast back on the road...should be interesting at the least

"Golden Egg"

It's staring us all in the face...............wake up...........

Why do we need to start in second gear? Because first is way too low!

Was first gear intended for an entirly different rear ratio, that we don't get here in the USA.........They do refer to us as STOOPID AMERICANS!!!

Is this why the dots on the speedometer set for gear changes seem to be foolishly high, I mean, wouldn't your engine red line before it got to the first dot (approx 35 mph) probably!

What would be the right ratios if 2000 rpm is the proper shifting point for 35 mph in first gear, and dots for second, third and fourth, respectively? :eek:

I just got 28 mpg. I drive like a jerk. The car is never sooted up. What's the point in a different differential? SDL with 2.88. Just weighed it today(fer kicks on a CAT scale) on a full tank of diesel. Car was completely empty otherwise(I wasn't in there), came out to be 3960 lbs. Not bad mileage for the weight and season, eh?

Even my 300SE seems perfectly suited to it's 3.46. Plenty of balls, and a wonderful German gutteral I6 sound at 80 - 90 mph.

Most Mercedes are geared optimally straight out of the box. The diesel and the gas six cylinder run top speed at their peak hp levels.

I actually agree with the general personally conflicting philosophy: "keep it stock, stupid!" :P

In this case, at least.

First is not at all too low. I always start in 1st, likely due to a bad kickdown solonoid. :rolleyes: I can't imagine how slow and painful it would be to start from second anytime I'm not in L. With my 3K turbo on, I'll hit 9psi by the 1-2 shift at 3K. BTW, 722 tranny won't go past 3800 rpm in 1st. It will shift to 2nd by 4K.

I was just trying to make an observation! First gear in my 190E, 87 300D, and my prior 83 300D, all seemed to have extremely low first gears, lower than any car I've ever driven, however my 80 450SL is only a 3 speed and first is not quite as low.

Do you think the dots on the speedo are practicle points to shift gears?

Is it possible that a lower ratio differential might have been intended, but not introduced to the US market?

The dots are not shift points, but maximum speed for the gear indicated (by the number of dots).

Relax, I was not trying to be a jerk. :)

phantoms is right, they are the max speed for that gear. This way, the 240D's with manny's wont shift too late and the slushboxes won't downshift (Via manual selection) and over-rev the engine. I'd not really be worried about over-revving the engine, more about more about balooning slushbox the torqueconverter! :eek:

One thing I believe here is that no one is absolutly sure what the dots were intended to represent since I, me, myself, have heard now, two completely different reasons for the DOTs!

I will make an attempt to reveal Mercedes Benz's purpose for the dots and will report back my findings because I want to know too the real reason. Give me a few days, and I'll report back.

In some of my cars I have "beaten" them.

My SDL can shift 10% higher than the dotted speed for the corresponding gear.
My 300SE can shift past 60 mph and zoom past it's redline to 6500 rpm. ;)

Issues w/ the 55 mph speed limit/gear ratio theory.
 

I've got the grey market 1980 300D w/ 4 speed manual and 3.46 rear end. It was brought to this country in 1988.

I have to believe that MB was selling their domestic vehicles w/ the best ratio for the engine. Not based on some stoopid foreign gov'ts twitterpations.

Either way, I cannot wait to drop a 3.07 rear end in there!!!



Cheers,
Robert

Read the owners manual. They are maximum speed for that gear. I made a refrence to them in another thread in which someone was commenting about not having a tach. I mentioned them, but did not clarify that they where "maximum" speed in their indicated (by number of dots) gear. sorry about that.

1984-380se
 

The differential came from a 1984-380SE that I bought up west of Chicago and it was motorless. i have the same rear end from a 1985-500SEL. About 130K. My email address is jim16671836@yahoo.com Boonville, Indiana ..Jim

tony,
could you tell me what to search for to find this thread? thanks...

I'm not sure where I misunderstood, or read the mail up side down, I've never considered the dots to represent anything other than highest shift point, but confused the issue while trying to convey a suspision about lower differential ratios and how they relate to the dots on the speedo. :confused: BB

If you change the differential to a different ratio, naturally, you will need a new set of "dots". They will change directly proportional to the differential change.

My point precisely!

Now, if US MB's have different rear ratios than Euros, and the dots are in the same place on both US and European what would that suggest????

There seem to be a few memebers here who believe in the "Golden Egg" that maybe US models got short changed and our MB's are not geared as well as they might be.

It is an interesting prospect if there's any merit to it! It has just seemed odd to me that the dots are eceedingly high, in fact I don't think I could get first gear up to the first dot before the governor limited engine RPM, haven't tried it, and don't want! But if the rear ratio was higher, I think my engine might get there in first without achieving governor limits, probably several hundred RPMs less. :confused: BB

The dots no longer apply on my speedo. I need to move them on my next gaugeset. The V8 winds up higher than the diesel, I would never ever take my engine near the dots as they sit now!

Well I did the swap yesterday to the 2.47 differential from the 3.07 that was in my 300SD. This is not a job for the faint of heart. It requires some special tools to get at the nuts to change the yokes. The bolts on top of my old differential were seized and there's not much room to work up there.. The back cover of the housings must be removed to get at the clips that hold the axles in. It's messy...
I also did the flex discs while I was at it.. The results? Well, it certainly feels strange and different, but I guess that is to be expected.. My engine now turns 3k rpm straight up at 80mph, about 2500 at 65mph. My engine never started to howl until 3k rpm so now below 80 I can't even hear the engine anymore, it's a little creepy... On a not so happy note, the is a slight whine at slower speeds, that is there only through a narrow range.. I'll replace the drive shaft center bearing and hope that's the problem and not that I got a shot differential. Mileage is definitely better, though until I calibrate the speedo, I won't have numbers. After the swap I took it on a 600 mile trip over two mountain ranges and now 3rd gear is only slightly lower than 4th used to be. I dropped down a couple of times to pass people and thought wow, it's really revving, oh wait, 3500 is nothing compared to how I used to drive it..
Oh yeah, was that a forum member I saw staring from a 116 as we passed crossing Glen Canyon dam?

Thank you for an excellent post! It really makes me feel like I want (no... need!) to change my ratio from 3.69 to something taller... nice one!

I'm now active in my hunt for a decent 2.88...

I know setting the odometer back is a no-no, but how hard is it to set one forward?

I'd like to do the 2.47:1 swap and use the 160MPH speedo, but I'm proud of the mileage on the car (323,000 when the odo quit last year) and I'd like the new speedo to reflect it.

Does anyone happen to know if the 2.65 pumpkin out of a W124 300D will fit the W123 subframe?

The same either way. ;)

Hmm... what if I take the odo wheels out of the old 85MPH speedo and transplant them into the 160MPH unit? :)

Probably be easier to just set the 160's odo to the old 85's reading. You'll probably end up in the same mess trying to do either.

Interesting thread!!!...Bert

Inspired by Breckman
 

Just bought a 2.47 diff from a MB 560 after studying Breckman's 'easter egg' post. Now the adventure continues as I pair it up with my 84tdt... :eek:

A 560 has a non-slip you know. Just a little FYI, but I'm sure you already know that.

Thanks
David

Larger 2:47 HELP
 

I have a 2:47 from a 1985-380SL and I have a 2:47 from a 1985-380SE....Both of these diffs are larger than the 3:07 from the 240-123's. The Yoke is also larger and the 4 studs have larger dimensions.. What are people using as the source of a 2:47 diff that they want to use in a 240D or a 300D????????Is the larger diff the same as the 300D Turbo and the 300SD Turbo???????? Or are all the 123 diff's the smaller one????? Jim

Great Post!!!!!!