1985 300SD shop "truck" daily driver 5 speed project - Page 6 - PeachParts Mercedes-Benz Forum

rwd4evr · #76 02-21-2021, 05:52 AM

All done. Turned the bump stops from nylon block I had. Up travel stop is adjustable to be sure it sits right and releases the master all the way. It won't bleed or work correctly if it doesn't. Almost bought pedals then though about it and made my own. Why stop at just the pedal arm? Counter sunk the holes and curved the pedal surface. Turned out nice. Just needs some paint.

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rwd4evr · #77 02-23-2021, 12:34 PM

Been tied up with other stuff but got this done last night. Turbo 617 with a clutch. Been dreaming about this for a very long time.

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HughO · #78 02-25-2021, 01:41 PM

Quote:

Originally Posted by rwd4evr

I am tired of 12-18 mpg in my v8 mountaineer. It rides ****ty and handles bad. I need a wagon or pickup and wont deal with a w124 gas car though. So I picked up a prettty decent 300sd dirt cheap and have some plans. I have most of the info I need but I need some opinions and real world experience if possible.
The plan is to swap in an AX15 5 speed from a dodge Dakota. I have the adapter kit intended to put a om617 in a jeep. The gear ratios are almost identical in the transmissions plus a .79 OD in the ax15. I will be doing some towing with the car as much as a car in flat tow or a dolly, probably not a car on a trailer. It weighs almost as much as my mountaineer and has better brakes and suspension so I'm not concerned with that. It's not hard to build a class 3 hitch into the rear structure. I will also probably down the road a bit be chopping the back roof off and welding the rear doors shut to make it a pickup. A early s10 cap will fit pretty well.
So my questions are about power and gearing. Has anyone done any towing (or driving for that matter)with a turbo 617 with the 2.88 factory rear axle ratio changed? I have 3.07, 3.23, and 3.69 differentials available. 3.69 is dumb since it would actually end up as a 2.91 final with od. All the gear change threads I've found are NA cars and have power issues. I had s 85 300TDt which felt like it had plenty of power to pull more gear on the highway. So I could go with a 3.07 to get a little more off the line and considerable reduction in highway rpm or 3.23 which has a lsd(really makes me lean this way) and would really help with off the line towing my drift car or parts cars and would still reduce higway rpm with a 2.55 final drive in 5th. The only problem I'm worried about is if it can't pull od on the higway with a load in 5th I'll be increasing cruise rpm havling to run 4 th. So at that point should I just leave the stock gearing and get awesome everyday mileage and probably have to run 4th on the highway?
On top of that how about practical power increase in a om 617? I remember years ago hearing about larger elements being installed in a NA300d om617(which I have). Any input would be great. I miss driving a Mercedes everyday so it's time.

Economically and practically, projects like this never make sense. We do projects like this for the interest and challenge. If you rarely tow you buy a used 20 or 30 yr old chev or F150 for a grand or two. You drive the MB the rest of the time. Both were designed for a specific purpose and repurposing rarely is worth the time or money and resale will be near zero. Just my two bits.

rwd4evr · #79 02-25-2021, 08:02 PM

Quote:

Originally Posted by HughO

Economically and practically, projects like this never make sense. We do projects like this for the interest and challenge. If you rarely tow you buy a used 20 or 30 yr old chev or F150 for a grand or two. You drive the MB the rest of the time. Both were designed for a specific purpose and repurposing rarely is worth the time or money and resale will be near zero. Just my two bits.

I tow on a fairly regular basis and I have a Mercedes salvage yard and parts sales business. When I'm not towing there's a good chance I need room for large parts. I can drive my mountaineer and use it for both if I need to but like I said at the very beginning of this thread, it rides ****y and gets less than great mileage. I don't really pay for diesel most of the time and a great handling fun to drive car that does the same thing as my truck absolutely makes sense. So I have about $1600 total in the 4 speed swap from a beautifully restored but tragically wrecked 240d, the car, the fresh motor and the flywheel work. I'll be putting it together so I'm not worried about reliability. It runs on free(ish) fuel I make. How do you figure it's not economical? If it tows my drift car or my utility trailer it does the same thing my truck does so how's it not practical? My 300sdl did this job perfectly but had a clutch fan fail and it hurt the motor. If it wasn't a rusty mess I would've swapped that for the extra wheelbase and bigger rear doors.
Would it be practical for someone paying for work on thier car or having it built? No. My mechanical and fabrication skills are quite a bit higher than most tinkerers so I really can do just about anything myself with enough time. Plus learning to do anything just adds onto my skills list for the future.
Resale? Have you seen how worthless a w126 is lately? My 4 speed car will be worth way more than a stock beater level 300sd if I ever decided to sell it.
I have 10 different Mercedes I can get in and drive if I want to but one that can tow and rip down a twisty road or get a couple hundred pounds of crap throw in the back is what I want to drive every day. At least until my 300+hp 6 speed wagon is done.

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rwd4evr · #80 03-11-2021, 04:20 AM

Big progress in the last two days. Motor and trans are in the car mounted up. Found a 280se manual trans crossmember I forgot I had. Perfect fit. Mocked up the DS and the length is perfectly acceptable. It's got about 3/4 inch of splines exposed at the center jont but that leaves 1.5 engaged. Went to mount the shifter and that stupid white plastic always fail end cap/bushing/spring retainer was missing from the 240d shifter when I got it. Didn't have one and wasn't about to wait to order a piece of garbage that will fail after 5 years anyway so I turned one on the lathe from aluminum and inserted a uhmw liner in it. So this was Tuesday, got the shifter installed after massacring the console for every part basically to be able to wiggle it around enough to squeeze the old Auto shifter out and drop the new manual shifter in. Phone was dead unfortunately.
So today I got started a little late and replaced the center bearing on the 280 SLC drive shaft rear half that I'm using which I then used to figure out a mounting set up for the center bearing which was now like 6 in or so further forward. I had planned on welding in new mounts or possibly picking the spot welds from the old mount and relocating it, I then realize that I would probably end up with an inferno in my car up on the lift after welding on the transmission tunnel, and I wasn't about to pull the carpet out of this thing. So I made a couple of brackets out of angle iron that bolt to the stock brackets and run up the transmission tunnel and a bolt in ahead of its new location with nutserts. They worked out very nicely and it's fully reversible(never gonna happen). The last bit of fabrication for tomorrow will be extending the shift rods 48mm. Should be ready to or close at least to running tomorrow night. I want to shake it all down Friday night delivering some pizza. It's my favorite way to fish out problems that are easy to deal with around town. Worst case I call a friend to tow me.

rwd4evr · #81 03-12-2021, 04:17 AM

Well, it's not gonna be ready for driving tomorrow night(Friday). I got wrapped up in life. Had to get a new phone after work and a bunch of other crap. Then fixed my friend's car so she didn't blow it up driving Saturday. Didn't really get to work on it till like 10:30-11:00. Probably took 2.5 hrs to get all the shift rods extended, smoothed and test fit. Had to extend them 48 mm and they all line up perfect. Probably could have thrashed for 3+4 hours and gotten it all together but it's not happening. Gotta work at 10-3.Then at 4- ? . Decided to throw some paint on them and mess with my new phone for awhile instead. I'll have it going this weekend at some point. Only fab left is trimming the brake pedal and extending the side to make it match the factory manual pedal, Then routing the master cylinder line.

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rwd4evr · #82 03-13-2021, 06:39 PM

Got some more done last night after work. Pedals are complete and ready. Master cylinder had to come apart to be cleaned out. Pedals out of the car. Shifter installed with rods connected. Sat in the car and made vroom vroom noises and it goes through all the gears beautifully. Almost there.

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rwd4evr · #83 03-14-2021, 08:54 PM

Final push tonight. I just bled the clutch and all seems to be operating correctly. Now to reasemble all the engine swap related items. Hope to be on the ground outside my shop tonight !

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rwd4evr · #84 03-17-2021, 04:16 AM

Woo hoo!! It's done(ish)! Took it out for a maiden voyage today. First impression is exactly what I was hoping for. No 1stgear lag while the turbo tries to spool. Just rev it up a bit and off you go. The car is faster now than it was before. And I'm running stock wastegste only showing 10psi and no propane yet. Fell like it pulls hard up to 4600 where I was shifting. The engine runs fantastic. After first shakedown I have a strange noise if I accelerate hard in first and sometimes in second when I dump the clutch. Like a squeak sorta but kinda squeal. I keep going back and forth thinking maybe it's the throw out bearing touching the clutch fork, but then it seems like it's not it the more I screw with it. I'll have to get some one to listen outside while I launch it. Showed 80mph at just over 3000 rpm. Gotta get the speedo working for sure. It carries spped you don't even notice. No driveshaft vibration at 90mph so I think I'm good there. Got the pyrometer hooked up after the first run and went for another little drive. Never saw over 470c° or so. Can't wait to get the propane bottle exchanged and see if it does in fact reduce egt. Only think I wish was it was a 5 speed so I could run a higher numerical gear and bring final back down to where it is now for a little more 1st gear pull without having to slip the clutch. But ****in a it's manual and turbo diesel so I'm good for now. Have to see if it's happy with towing the drift car or not in the next day or two.

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rwd4evr · #85 03-18-2021, 05:12 AM

Drove the car all day today. I really like it but it's making this sound. If I rev it to 2000rpm or so where it starts really making some power and accelerate from a stop somewhat agresively it kinda squeal/squeaks for a moment. I'm thinking it's the clutch chattering maybe? First was thinking throw out bearing shuddering on the trans snout right as it releases pressure but after listening and thinking about when it happens I'm not sure now. Driving normally it's got no real issues. A driveline vibration (not out of balance though)when at certain throttle points happens while at lower rpms. Like if cruising like 50mph in 4th putting along it will vibrate a bit and giving it a little more or less throttle will stop it. The flex disc are pretty crappy so that's not helping. I'm gonna put some miles on it and see if the clutch noise smooths out and If not it will bei mir getting a new 300d clutch. It doesn't slip under power but it may just be on the border of too weak. I have a few interior panels to reasemble as well. Rear brakes are squealing and the delivery valve is leaking. It's a blast to drive though. It may need a deeper gear for towing and some around town quickness. It's much better than the auto but you do have to rev and dump the clutch to get a good start off and thats when it squeals so I've been avoiding it. I have the 3.27 lsd still do that may go even without the overdrive for the time being. Some fine tuning to do but it's all going to be worth it. Already is.

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t walgamuth · #86 03-18-2021, 06:33 PM

You running a straight pipe? .....turbo will whine on build up.

rwd4evr · #87 03-19-2021, 03:23 AM

Yes it sounds like a little big rig.i love it. Turbos make great mufflers. I hope it quiets down in the cabin slightly when I finish the full 2.5 inch system to the rear. It's just the down pipe to the bottom where it is clamped to the mount off the bellhousing right now. I may make a small fully pass through glass pack muffler if not, It's got a bit of a eardrum rattler at wide open at certain rpm. Any restrictions will increase EGT and engine temps though. I do have a big sidepipe that some crazy guy put on an slc I bought. That would be kinda cool inna ridiculous way.

All that after I replace the bent control arm from drilling a curb tonight. Pulling into a parking lot I go to play around in, in the rain.its sealed pavement and it just 4 wheel slid like I was on black ice and kablam!! Right rear wheel, destroyed. Control arm definitely bent. Shocked the tire survived. Subframe looks ok and im praying it is. So ****ty it wasnt even while getting wild. I was sliding it around all night and this stupid turn gets me off guard. Oh well **** happens. I built it to be used for my enjoyment and it will. It drive home just fine but I could see the toe was off. Gotta give the kumho solus props for tough ass sidewalls pretty sure it's unscathed.

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rwd4evr · #88 03-19-2021, 03:26 AM

Quote:

Originally Posted by t walgamuth

You running a straight pipe? .....turbo will whine on build up.

Oh! if you are referring to "the sound" its not the turbo. I'm about 90% sure it's the throw out warbling on the input sleeve. ****ty.

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t walgamuth · #89 03-19-2021, 06:36 AM

My #2 daughter curbed one of my 240s sideways about 20 years ago. ... bent the control arm. It was still drivable but dog ran when going straight.

fonzi · #90 03-19-2021, 08:36 AM

Its a hell of a lot quieter than my neighbor’s truck.

I described the sound initially like the sound I think you’d hear if the inner race of a bearing was slipping scooting along the metal shaft of which it should fit snugly. So maybe throw out bearing on the trans snout does make sense, and there’s some concern for the aluminum housing wearing.

But why does it only do it on faster launch and not the softer launch when the clutch is more slowly engaged?

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