New Owner of a 240d , swap dilemna

[adphil]

Hi everyone , just got this 1983 240d manual... Was bought in Cali by the guy I bought it from . Not a lot of rust , very straight body . Some mechanical problems , brakes and exhaust are all in need of some attentions ... Nothing big for me , I work in a specialized German scrapyard . Here's the beast ( in winter storage now )


Here's my dilemma . A friend /customer with a 84 300d just replaced his car with a newer 190 e .the old girl being way too rusty in the rear suspension area to be safe or roadworthy. Everything is about to collapse.But the rest of the car engine , brakes and all are in very good condition. Before I buy it , I need advice ....Here's the monster

My question is , how feasible is it to swap the 300 turbo Diesel engine and mate it to the 4 speed manual of the 240d ? Is it a stupid idea ? Am I going to ruin a rare car ? Any advices ? Im more of a Vw/Audi specialist and did numerous diesels conversions and swaps ... This is my first Mercedes and I would like some expert advices before doing something completely stupid .

I could use some body parts from the 300( driver door , front bumper, rear tailights ) interior parts ( knobs, trims , etc ) and mechanical parts ( brake system and engine ) . I find the 240 a little short on power ... Anyway thanks in advance , any help will be really appreciated ! ( sorry for my English , I'm a French Canadian )
I already ordered the only exterior modification I will do ( for now ) euro headlights!

[charmalu]

First of all, welcome to the Forum.

This swap has been done many times.

You will need the 300D radiator.
The Manual trans will bolt right up to your 617.95 engine.
The 240D Clutch Disk, pressure plate and Pilot bearing will bolt right in.
You can use the 240D Flywheel, but if you can locate a FW from a 300D NA. It would be a euro car, one not sold in the NA market.
The 240 FW is 28 lbs and the 300D Fw is 30lbs.
You can use the 240D DL, just will have to cut the front section 4 inches, and have it welded and rebalanced.
You will need to use a 240D with an auto trans cross mount for the transmission. A 280E is the same mount.

Before you remove the auto FW from the 617 engine, be sure to look for a witness mark on the FW and Crank or use a chisel to mark both.
Then have the auto trans and manual trans matched balanced.
Be sure the machinist marks the manual FW to get it the right spot on the Crank.

The FW bolts are a torque to yield. Either check them for stretch (info in the FSM) or buy new ones. you will need 12.

The engine will mount to the same location as the 240D engine.

Something Iam probably forgetting here.

I swapped in a 240D Manual trans in our 300D, and the front end came up 3 inches or so.
The manual trans weigh less.
So I swapped in 240D springs and it dropped the front end down and sits good.
Only problem I noticed, it is a little soft in some cornering on a windy mountain road.

I swapped in a front Sway Bar from a 300TD (wagon) TD bar is 2mm thicker than a 300D bar.
You will need to use the TD Bushings where it bolts to the body.

Before you scrap the 300D, save every thing from it you can, there is less and less of these W123 cars around.

I could use a good 240D engine. Guess you are in Canada some where?

Charlie

[adphil]

Wow thanks for all the Infos !!! I won't get rid of the 300 , I'm a manager in a scrapyard and I have something like 650 cars here , maybe 3-4 w123 . I already got two front blue reclining seats from a 2 door 280ce mine were a bit ripped. I understand the value of a part car , especially when you invest in an older model. So , I have to use the front suspension from the 300 or can I just leave the 240 hardware ?

[pj67coll]

My suggestion. You can certainly do this swap. But given your situation my suggestion would be to keep the 240 D as is. In time you should be able to find another good 300D body to swap the 300D engine and drive line into and you would have two of the most iconic W123's ever made. The 240D is slow but there is something classic about it's simplicity that cannot be duplicated. Possibly the only better car might be a 300D non turbo, manual transmission which gives almost the same simplicity as a 240D with the extra cylinder and so a bit more power.

- Peter.

[adphil]

I could certainly use a nice wagon .... I fell in love with this one when visiting Berlin ... The thing is I can only justify one Mercedes for now , I already have a couple of other vehicles . The 240d will be my "picnic " car , I only have use for one of them ( for now )

[charmalu]

One thing I forgot, the 240D has a 3:69 Differential and the 82 - 84 300D uses a 3:07 Diff.
You would need to swap the Diff as long as the speedometer. The spedo is calibrated to the diff.

A 300D NA uses the evil servo climate control, 77 - 80. I has the verticle push button unit.
I agree the 300D would be a good set up if it had the manual CC.
The other none desireable thing they have the York AC compressor.
The 80 - 85 has the mono valve to control the water flow. and the horizontal push button unit.

The 240D`s all have the simple manual climate controls. The best set up would be a 240D with the 617.95 engine and a 4 or 5 spd trans.

The 77 - 79 240D`s also have the York compressors.

80 - 83 240D use the GM R-4 compressor, but can be improved using ROLLGUYS Sanden up grade.
They also have the improved pencil GP`s and a few more HP.

When you do the swap, just see if the front end comes up a little. If so then you will have to swap the springs.
Some people might cut a coil to lower it.

The 240 and 300 use the same suspension. The springs will vary from the various 123 models depending on what engine, transmission, sun roof or not etc....
I mentioned the 300TD front Sway Bar or Torsion bar, it is thicker than the 240D or 300D.

Charlie

[Junkman]

What Calibrates the speedo? We could simply swap the correct speedometer drives on other vehicles I've owned. That let us run whatever rear end with whatever trans we wanted. I haven't noticed similar documentation on these vehicles.

An easy method of determining rear end ratio would be helpful. We used to block 1 wheel and lift the other. Have 1 person rotate the lifted wheel through 1, 5, or 10 revolutions while counting the drive shaft revolutions. Divide larger by smaller and you have the ratio.

The number of revolutions depended on how many you needed for accuracy. Putting a reference mark on the driveshaft helped with the count.

Bottom line, where is the pickup for manual and electric speedo? Does anyone have documented what rear ends came with what cars?

[t walgamuth]

I'm not aware of any way to recalibrate the mb speedos to account for changing the diff.

[sixto]

Consider the cluster with tach and tach amp from the '84 as well if you're swapping diffs.

And x2 the comment about finding another project car. A 240D MT in good running order can be worth more than a 300D turbo in comparable condition along the west coast. A more worthwhile project might be learning to enjoy the 240D as is. Apologies if you're not as young as I figure you are

Sixto
83 300SD

[sixto]

Originally Posted by Junkman

An easy method of determining rear end ratio would be helpful. We used to block 1 wheel and lift the other. Have 1 person rotate the lifted wheel through 1, 5, or 10 revolutions while counting the drive shaft revolutions. Divide larger by smaller and you have the ratio.

I believe the ratio is stamped on the case.

Originally Posted by Junkman

Bottom line, where is the pickup for manual and electric speedo? Does anyone have documented what rear ends came with what cars?

Mechanical speedo cable attaches to the port side of the transmission at the tail housing. Electric speedo? No such thing on US spec 123s except maybe for the 81 TD. This book - Mercedes Benz Production Models Book 1946-95: R. Nitske: 9780760302453: Amazon.com: Books - has its share of tech spec errors but the diff ratios are accurate and distinguish between US and rest of world versions.

Sixto
83 300SD

[adphil]

Thanks a lot again for all the advices . I don't build my cars for resale value but for my enjoyment . I might be considered young ( turning 40 next year) but I learned to have a car for each occasion. This one will be used for Sunday drives . I just don't want to scavenge a classic , even if I will keep all the parts if I do the swap . I was not really looking to upgrade but I have the occasion to buy that 300 for dirt cheap. we redid all the brake system less than 600 km ago . I will buy it anyway because I need some body and interior parts ( mine has cracked trims ) . I have all the winter to think about it ...

[Mölyapina]

Originally Posted by Junkman

What Calibrates the speedo? We could simply swap the correct speedometer drives on other vehicles I've owned. That let us run whatever rear end with whatever trans we wanted. I haven't noticed similar documentation on these vehicles.

An easy method of determining rear end ratio would be helpful. We used to block 1 wheel and lift the other. Have 1 person rotate the lifted wheel through 1, 5, or 10 revolutions while counting the drive shaft revolutions. Divide larger by smaller and you have the ratio.

The number of revolutions depended on how many you needed for accuracy. Putting a reference mark on the driveshaft helped with the count.

Bottom line, where is the pickup for manual and electric speedo? Does anyone have documented what rear ends came with what cars?

Originally Posted by t walgamuth

I'm not aware of any way to recalibrate the mb speedos to account for changing the diff.

The mechanical speedos can be recalibrated by adjusting the spring in the speedometer.

Backyard speedometer adjustment

[adphil]

Went To pick up the donor car , really loved the torque of the 3.0 td ... Pretty sure with a manual trans iT will be perfect

[clacker]

Leave the 240 alone, it is great as is! Yes slow, but some tuning and adjustments can make a big difference as most if not all were neglected that way, very few were maintained with regular adjustments and servicing (valves, injectors, carbon cleaning, timing), especially in Canada very few mechanics knew what these cars were and what they required, rust claimed most of them in the first ten years. A good injection pump recalibration fixes most of the power issues and shakes.
I have a few myself, a VW sickness as well...
Grab the 300D and keep it complete, then search around for a project out of the states (rust free body that is not running or in poor mechanical shape) they show up often enough if you are patient, even in Ontario/Quebec -ebay gone wrong).
The cars really have no value unfortunately, even clean ones are very hard to sell for much ($5000 would be very high and hard to sell). We just don't have a market around here and the same ones sit for sale for a long time.
I grew up in these cars and collect as many as possible, have a garage packed full of them (several engines, manual transmissions, body, trim etc), love them and drive them on special occasions only to preserve them. When time allows I work on projects (have a few) so some day will drive them everyday. Parts cars are getting harder and harder to find, they should be grabbed and stored away complete indoors to preserve the interiors (our best parts vs USA cars which are heat soaked), they are all disappearing. It isn't a huge market for parts but when you have a car yourself it is nice to able to fix it on your own time without the need to order something or search around for it!

[clacker]

Aussi je parle francais mais pas ecrit bien