Howdy folks, I have been slowly converting my 85 300d from auto to manual and also doing some other needed fixes while I am at it. I have the trans in, shift linkage and everything else pretty much tied up and ready to go(yes I got the flywheel balanced). Now Is time for the driveshaft work.

I have the original dampened shaft from the 300d, and also a used 240d shaft I acquired while getting parts for the swap. My plan was to use the dampened portion of the 300d shaft, and the longer rear section from the 240d shaft. That way I have a dampened shaft and I just have to get the 240d portion cut to the correct length and the whole assembly balanced. I started calling driveshaft shops and here's what I found. I am in Olympia, Wa. btw.

*Drivelines NW- a local place that told me they would just be sending it to Powertrain Industries in Ca., also said to call Driveline Services of Portland.

*Driveline Services of Portland Or.- Said they could just build a whole new driveshaft to spec. if I could get the measurements, couldn't alter the shaft I have. $600-$800

*Powertrain Industries- Said they could do they work for $460+ frieght, I would have to send my shaft to Ca.

I searched a lot and couldn't find a whole lot of recent threads where people had this done. These prices seem a little high to me, I was hoping to get the job done for more around $300. If those are my only option I guess I will just have to save a bit more and bite the bullet but I seemed to remember reading where others had got this done a lot cheaper than what I am being quoted.

Just looking for more feedback from others. Thanks!

Bm:

Since you are in the fortunate position of shortening the aft section of the front shaft, it may be done by you thus:

1) Remove a portion of the aft section to create a new section of the correct length, making sure that the cut ends are square.
2) Have a machine shop turn a piece of tubing ~3" long so that the tubing is a light press fit into the cut pieces of the shaft. The splice tubing should have a finished wall thickness of ~.080-.090".
3) Drill two holes of 7/16-1/2" in each piece of the shaft about 1" from the cut ends. These holes are for plug welds.
4) Press the splice tube into one of the shaft sections 1 1/2" and tack weld one of the plugs. Press the splice into the second shaft section, and finish weld all the plugs & the butt weld between sections.
5) Send the whole driveline to Portland for balancing, and, if necessary, replacement of the u-joint.

Frank, thanks for your reply. I actually have a machine shop at home and I do tig welding. The thought of trying to do it myself had crossed my mind, I just hadn't read about anybody doing driveshaft work on their own so I just had it in my mind to take it to a shop. I can handle the cutting and welding.

We cut&welded the stock driveshaft for my brother's RB25DET->240SX swap using a 50yr old lathe (with leather belts) and an arc welder. We marked the flange alignment when cutting so the balance remained the same. He never had any complaints (as if anyone would with that monster engine )

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$60 OM617 Blank Exhaust Flanges
$110 OM606 Blank Exhaust Flanges
No merc at the moment

If all else fails I can get you a shop here to do it and ship back and forth.

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[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.

Blazemaster: I'm curious how you handled the pilot bearing. It's my understanding that 85 and some 84 OM617A engines have a 34mm pilot bore instead of the standard 35mm.

I have an 85 300D I'd like to convert but I want to have a handle on solving this first.

On the driveshaft - I bought some rebuilt units from Powertrain Industries with good results. I also had one custom made a few years ago. For the custom shaft I returned a shorter core with their approval.

When I looked at the combination of balancing, new center bearing, U joint and centering sleeves plus the ability to return my shorter auto driveshaft for core credit it just made sense for me. Plus my application used a 3.92 which made balance critical.

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1969 220D 5 Speed (OM616)
1983 240D 4 Speed
1985 300D Auto 376K
1985 300D Auto 275K

The 85 I have is a grey market car from canada. It has 687,000 km on it but the previous owner took very nice care of it. I would not be surprised if the engine has been replaced, because the pilot bearing was a standard 35mm.

After doing some measurements, I came up that the half shaft I have from a 240d only has to be shortened by about 1-7/8", not the 4" that I have read in so many places. Since I have the original 300d half shaft as well, and I plan to try the shorten job myself I technically have 2 chances. If I screw up the first one, I'll probably take/send it somewhere for the second.

The shift linkage is also kinda a mystery. All the threads I read said you had to cut, shorten and weld the shift linkages to get them to fit. All I had to do was add more threads to the existing ones with a die, and cut about .500" off the end of the threads. Fit like a glove.

Was the 240D you got the transmission and linkage from a W115? If so that would explain the length differences. The W123 240D and 300D definitely have an approximately 4" difference between them.

When I put a 5 speed from a W123 300D in a W115 220D the linkage fit with only slight adjustment (lengthen). Sounds like you just did the reverse.

If I had put the 300D 5 speed in a W123 240D it would have required lengthening the shift linkage and driveshaft by 4" because engines in the W123 are mounted so that any extra length moves toward the firewall. That's why the radiator hoses for the W123 240D (OM616) and 300D (OM617/A) are the same. So are the oil cooler hoses (for coolers of the same type) because the extra cylinder is added to the rear of the block behind the oil filter stand. As compared with the OM616, the added length of an OM617 pushes the transmission back 4" requiring a shorter driveshaft front section and longer rods.

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1969 220D 5 Speed (OM616)
1983 240D 4 Speed
1985 300D Auto 376K
1985 300D Auto 275K

I guess that would explain it. I know the trans has a 115 part number on it, and the shift linkage/driveshaft probably are too since they came from the same person. He just said 240d. Made less work for me.

a 115 part number can easily be used correctly in a 123 body car. If it was not changed it would stay the same. I took steering gears from 123 cars which had 116 numbers on them.

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[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.

Something to remember on some driveshafts, the ends are friction welded on rather than a pilot and arc weld. Friction welds have a curl front to back and a line in the middle.

With friction welding, a pilot on the flange does not exist making the sleeve in a tube the only option short of friction welding again. Friction welding is a very fast process but the equipment is $$$ so short runs are expensive.

Some people are more confortable with a welder & saw than a threading die

__________________
$60 OM617 Blank Exhaust Flanges
$110 OM606 Blank Exhaust Flanges
No merc at the moment