Well, without taking into account any slippage in my torque converter, going from a 3.69 rear end to a 3.46, I calculated a reduction of around 200 rpm at 65 mph. If the conversion parts are free, is it worth it?
A 3.07 ratio would net about a 600 rpm reduction, but my little diesel might not have enough power to maintain 65 mph!

Like some of my other ideas, this may remain a daydream. Back in the '70s, I thought about transplanting a 190SL engine into my Ponton 180b. Well, that never happened!

Happy Motoring, Mark

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DrDKW

Mark-

Changing to that ratio is a 6% difference. I doubt that will make enough difference to be worth the trouble (even free). I would just switch to taller tires next time you buy some.

Rick

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80 300SD (129k mi) 82 240D stick (193k mi)77 240D auto - stick to be (153k mi) 85 380SL (145k mi) 89 BMW 535i 82 Diesel Rabbit Pickup (374k mi) 91 Jetta IDI Diesel (155k mi) 81 VW Rabbit Convertible Diesel 70 Triumph Spitfire Mk III (63kmi)66 Triumph TR4a IRS (90k mi)67 Ford F-100 (??)

Changing from a 3.69 rear end to a 3.46 to get 200 rpm sounds like a lot of work, but if you have the time/energy have fun. I don't think I would put 3.07 gears in a 240D, it just doesn't have that much power for acceleration/hills.

i called NAPA. they just have standard circular hour meter guages, one for $59 and another for $64. TinyTach = $65 (compact, digital, tach, hourmeter).

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Current Vehicles: 2001 Mercedes E320 Wagon | 1979 Mercedes 220D | 1995 Volvo 850 Turbo Wagon | 1993 Volvo 240 Wagon

Well, I mainly wanted to make the engine roar a bit less obtrusive at highway speeds. Up to about 50 - 55 mph it's tolerable, but over 55 it gets pretty loud!
I had hoped that a 3,69 to 3.46 ratio change would make more than a 200 rpm difference, but at 65 mph that would only reduce the revs/noise to what it is now at about 60. Alternately, I'm willing to explore some added soundproofing and maybe a better audio system. I'm getting pretty used to the lack of power. It's really not quite as bad as I feared. It kind of reminds me of my first $200 Benz, a Ponton 180b.
Meanwhile, I had her up to about 60 today and she didn't sound so bad. Maybe I'm starting to get used to the racket! For me, this diesel thing is going to be a learning experience for awhile.

Happy Motoring, Mark

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DrDKW

Well, reconnecting the 4 radio speakers did help drown out the engine racket a bit. (Or at least I can now hear the radio at 65 mph!)
Speaking of time/energy, if I did get that free 300D, I could transplant the whole engine/diff/speedometer. Then I'd have sort of a Euro model 240D 3.0, with big bumpers. But I'm getting tired just thinking about it.

Happy Motoring, Mark

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DrDKW

If you do a lot of highway driving, you may be better off just buying a 300D. My 240D is mostly used locally, it's reasonably quiet up to about 65-70 mph, but it does get noisy at highway speeds.

Aside from the $225 price, one of my reasons for getting this particular diesel over a 300D was to avoid the dreaded ACC. The engine roar seems to get severe around 60 mph, but doesn't seem to get that much worse above that speed. Actually, if I'm not paying attention, this 240D seems to want to creep up to around 70 mph on the highway. If I had a working magic wand, I'd have a 300D with manual climate control and a 5-speed.

Happy Motoring, Mark

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DrDKW

All the concern about the "dreaded ACC" is a little overrated, you can replace the (newer horizontal button) unit for a few $100 if/when it fails. I have one of each and I definitely prefer the ACC system on the 300D, it's nice to just leave it set and not have to keep adjusting it. However, I would also avoid the old style ACC system.

My 240D also likes to run at about 70 mph (around 3500 rpm, I think), but it feels like it's straining at 75+. It's definitely loader than the 300D, but the noise isn't excessive. Good luck finding a 5-speed.

Well, if those people had had a $225 300D instead of a 240D, I probably would have bought it.
A guy down the end of my street wants to give me his 300D, just to get it out of his driveway. From 50 feet away, the paint & body looks great, except for the left front fender, which the owner replaced and is still in grey primer. (now grey & mildew!) Unfortuately, it's been sitting 5 years since the automatic died and, close-up, the body appears to be rusted even worse than my 240D was. It has the early Chrysler type ACC system which looks like it's been partly bypassed, and I'm certain, many other problems with a car that's been sitting too long. As for parts, this 300D's sagging seats aren't any better than mine were, with lots of crumbling 'horsehair' spilling out. I could use the AC condenser and some other bits but I'm reluctant to park another junker in my backyard, as I've been starting to try and organize my clutter, and get rid of excess cars & junk. We'll see If I break down and decide to 'rescue' this one.

Happy Motoring, Mark

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DrDKW

I am digging up this old thread. Just curious, have you finished this project? I have an 83 240D and the magnetic pickup (I think it's for the EGR?) measures 80 ohms, same as the one on the 83 300D turbo. I am quite certain it will work for the tach. I plan to borrow the tach amp and tach/clock from the 300D and transplant it into the 240D and see how that works out.

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85 300D turbo pristine w 157k when purchased 161K now
83 300 D turbo 297K runs great. SOLD!
83 240D 4 spd manual- parted out then junked

I've decided to deal with more urgent repairs (A working AC would be nice) on my 'project', as I don't have a tach-equipped cluster, or the electronic module I believe will be needed to make one function in my 240D.

Happy Motoring, Mark

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DrDKW

Funola,

I don't know if this will be applicable to the 240D, but this is the thread that helped me attach a tach to my 84 euro 300TD.

Adding a tach to a 300TD

Basically, there was a factory mounted pickup on the engine with wires leading to pins 2 and 6 on the fender well. I added a wire to pin 3 on the fender well (green/black), plugged in the donor tach amp, and ran the new wire and a power source (spliced into fuse 12) to the tachometer. Ground the tachometer (if you haven't installed it in the instrument cluster yet), and voila!

I still haven't installed mine yet, since I've been dragging my feet on the dash swap, but it works hooked up as described.

I used the EGR controler to drive the tach in the car Im putting back together very simple install just add 1 wire from the egr conrtoler box up to the tach and a power wire and your good to go

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82 240D (82 300D drive train)

Thanks Doug, I'll check it out. Did you get my pm?

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85 300D turbo pristine w 157k when purchased 161K now
83 300 D turbo 297K runs great. SOLD!
83 240D 4 spd manual- parted out then junked