1981 Mercedes 300D will not shift into 3rd

[TDaub]

Just bought a 1981 Mercedes 300D (no-turbo).

Previous owner was non-mechanical. Oil looked like crude (still does after 3 changes), vacuum lines routed incorrectly, PS fluid looked like rootbeer, just to mention a few things.



When I picked her up she would only go into 2nd if you pumped the petal, or started in 2nd. 3rd gear was smooth, ran great at 65-70 MPH.



Changed oil (x3), PS/Fuel filters. Took her for a ride, shifts HARD at 20, then no 3rd gear. Checked vacuum lines to see if I pulled one, turns out some were routed wrong, one boot split. I fixed what I found still no third gear.



Any ideas

 

[BGlidewell]

I guess we're talking an automatic. best wishes. I just spent 4k on a 6k car that way.

 

[TDaub]

I guess I could have specified that it is an automatic.

 

[rscurtis]

Check that the kickdown switch under the accelerator is not stuck. Make sure the bowden cable is working freely. Failing this, sign up at Peach Parts as a member- plenty of people there will be able to help you. Remember, there's nothing more expensive than a cheap Mercedes.

 

[TDaub]

Will do. Thanks.
I'm finding its not that the parts are expensive, it's the postage, nobody has them in stock. ;-)

 

[HBarlow]

Check that the kickdown switch under the accelerator is not stuck. Make sure the bowden cable is working freely. Failing this, sign up at Peach Parts as a member- plenty of people there will be able to help you. Remember, there's nothing more expensive than a cheap Mercedes.

That's a good line. Probably provides an excellent warning to someone who is not very knowledgeable about MB cars considering the purchase of an older used one.

 

[leaky gasket]

Another good source for info and parts is diesel giant.com

 

[AHarris]

[/B][/U]That's a good line. Probably provides an excellent warning to someone who is not very knowledgeable about MB cars considering the purchase of an older used one.

More brilliant insight from Seaman Barlow.

 

[TDaub]

Got it into 3rd, just wasn't going fast enough. Have to be going at least 43MPH. Now I just need to get he shifts softened and change the shift points.

 

[rscurtis]

You should actually be in fourth gear, and a lot sooner than 43 MPH. That car has a 4-speed auto. When stopped and idling, the transmission is in second gear. This is done to reduce creep, as first gear is very low, sort like an Allison 540 or 545. As soon as you touch the throttle, the Bowden cable will downshift it to first before the engine is accelerated. When working properly, this shift is almost imperceptible.

 

[TDaub]

rscurtis, thanks. I read to Owners manual, but it didn't make sense.

GOT GOT it Fixed. Some jack wipe re-routed all the vacuum lines (could be why I got it so cheap). routed them according to the diagram under the hood, shifts like a dream.

Thanks everybody. Time for the WVO kit.

 

[rscurtis]

I wouldn't recommend WVO, even though the engine will run on it. Eventually, it will ruin the injection pump. Learn to make biodiesel, which you can use all year in Florida. Change some of the fuel lines to resist the solvent ability of the fuel, and you're good to go.

 

[TDaub]

I've been considering that as well, the set up cost is about the same from what I have read so far.
I have found instructions on how to build both, but I have not found step-by-step instructions on how to make the biodiesel.
Don't want to screw things up, especially if I put it in my truck.

 

[Gene Arnold]

Oil looked like crude (still does after 3 changes)

Way, way back in the day I had a '69 220D. Owned it for about seven years. The oil always looked really cruddy (never thick, just black). I tried running cleaner through it a few times with no change in appearance so I just lived with it. Seemed to be quite normal. Maybe so with yours as well.

Gene

 

[TDaub]

Thanks, I'm beginning to think the same thing. I finally got the oil pressure to drop to 1 Bar at idle, but still pegs when running.

 

[rscurtis]

Forget about clean oil in an old Mercedes, it's not going to happen, as it's not a smokeless engine. The oil pressure gauge should be pegged when running; when it's not, you have a problem. Normal idle pressure should be about 1. 5 bar. The engine also requires periodic valve adjustments.

 

[TDaub]

Ok, Thanks. 2 less things to worry about.

St. Thomas?, Boss lady is from Biglerville.

Thanks for every-bodies help.