STD Tuning Drivetrain 1985 300SD Transmission issues. Help please??

1985 300SD Transmission issues. Help please??

1985 300SD Transmission issues. Help please??

 
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dieselsmoke300d
To many things I say: Bah Humbug!

65
05-12-2013, 07:31 PM #1
Well I found a really nice 300SD on craigslist for the right price but it's an hour away and the trany doesn't shift above 2nd gear... The redeeming factor is that it comes with a spare transmission that was with it when the seller bought it.

The problem is getting it home to fix it. I'd have to either get a tow dolly and beg a friend to tow it for me (not preferred), or I drive through the longggg way in second gear, or it somehow miraculously happens to be something stupid like a loose vacuum line, or I find a lot to jack it up in and swap the transmission right there in like a day (assuming the transmission really is bad).

The facts:
The car was beautifully maintained. 101,000-ish miles on it. Near squeaky clean everywhere. The fluids all look good. The seller said the main booster hose was off when he got it so therefore someone messed with the vacuum lines. And the central locking system doesn't work. And yes I did check the kick-down switch.

When I test drove it, it seemed to shift seamlessly from 1st to 2nd but anything after it would slip like crazy. I don't think it even got to 3rd. So this leads me to believe that it's a vacuum issue.

What I need from you amazingly knowledgeable people is ideas as to what could be wrong with it besides the actual trany being bad. Like who knows it could be a single line that popped off. If that's it, then I'll bypass everything non essential.

Is there any common problems or things I should check for? So please let me know what you guys are thinking. Thanks!

Matt.

'85 300SD Turbo
'92 Subaru SVX
'83 Pontiac Firebird S/E
'88 Pontiac Firebird
dieselsmoke300d
05-12-2013, 07:31 PM #1

Well I found a really nice 300SD on craigslist for the right price but it's an hour away and the trany doesn't shift above 2nd gear... The redeeming factor is that it comes with a spare transmission that was with it when the seller bought it.

The problem is getting it home to fix it. I'd have to either get a tow dolly and beg a friend to tow it for me (not preferred), or I drive through the longggg way in second gear, or it somehow miraculously happens to be something stupid like a loose vacuum line, or I find a lot to jack it up in and swap the transmission right there in like a day (assuming the transmission really is bad).

The facts:
The car was beautifully maintained. 101,000-ish miles on it. Near squeaky clean everywhere. The fluids all look good. The seller said the main booster hose was off when he got it so therefore someone messed with the vacuum lines. And the central locking system doesn't work. And yes I did check the kick-down switch.

When I test drove it, it seemed to shift seamlessly from 1st to 2nd but anything after it would slip like crazy. I don't think it even got to 3rd. So this leads me to believe that it's a vacuum issue.

What I need from you amazingly knowledgeable people is ideas as to what could be wrong with it besides the actual trany being bad. Like who knows it could be a single line that popped off. If that's it, then I'll bypass everything non essential.

Is there any common problems or things I should check for? So please let me know what you guys are thinking. Thanks!


Matt.

'85 300SD Turbo
'92 Subaru SVX
'83 Pontiac Firebird S/E
'88 Pontiac Firebird

aaa
GT2256V

913
05-12-2013, 10:27 PM #2
You mentioned the common problem, the kickdown switch. Be ready to swap in the spare.
aaa
05-12-2013, 10:27 PM #2

You mentioned the common problem, the kickdown switch. Be ready to swap in the spare.

SurfRodder
Jackass Extraordinaire

611
05-13-2013, 11:29 AM #3
I would see if the seller is adverse to you bringing some tools, a jack and a jackstand to swap it in their driveway after the purchase... Even if you havent done it before it should only take 5 or 6 hours to swap out... worst case you start on a sat morning and have to come back on sunday...

W123 Mods: 4 speed ** manual climate control ** '85 Kalitucky intake ** manual windows & full tint ** Euro headlights retrofit w/bixenon projectors ** 4 brake light mod ** Vogtland 50mm drop front & Lesjofors S600 drop rear springs ** 16" rims ** late w126 brake spindles, rotors & calipers ** full suspension rehab ** Bilstein HDs ** AL129X alternator & 1/0 starter and charging cables ** 300GD clutch/flywheel ** AFCO 80103N radiator & Earl's 41610 oil cooler ** custom block-off plate, remote oil filter & t-stat ** MW IP w/ tomnik's 6.5mm 'Holly' elements **

S124 Mods: 400E Rear subframe ** SL600 Brakes ** Late 300E 210mm diff ** SLK230 6 speed ** 17" CLK rims ** Vented RF Fender ** Facelift Hood, Headlights, and Lower Cladding **

OBK# 62
SurfRodder
05-13-2013, 11:29 AM #3

I would see if the seller is adverse to you bringing some tools, a jack and a jackstand to swap it in their driveway after the purchase... Even if you havent done it before it should only take 5 or 6 hours to swap out... worst case you start on a sat morning and have to come back on sunday...


W123 Mods: 4 speed ** manual climate control ** '85 Kalitucky intake ** manual windows & full tint ** Euro headlights retrofit w/bixenon projectors ** 4 brake light mod ** Vogtland 50mm drop front & Lesjofors S600 drop rear springs ** 16" rims ** late w126 brake spindles, rotors & calipers ** full suspension rehab ** Bilstein HDs ** AL129X alternator & 1/0 starter and charging cables ** 300GD clutch/flywheel ** AFCO 80103N radiator & Earl's 41610 oil cooler ** custom block-off plate, remote oil filter & t-stat ** MW IP w/ tomnik's 6.5mm 'Holly' elements **

S124 Mods: 400E Rear subframe ** SL600 Brakes ** Late 300E 210mm diff ** SLK230 6 speed ** 17" CLK rims ** Vented RF Fender ** Facelift Hood, Headlights, and Lower Cladding **

OBK# 62

dieselsmoke300d
To many things I say: Bah Humbug!

65
05-13-2013, 03:15 PM #4
Ok thanks. I doubt he'd care. He's probly one of the friendliest pot-heads I've met. lol I should be able to do it with the tools I have idk. I'll have to check On-Demand for the actual process too. I never cease to be impressed by MB engineering. I looked at the transmission and it's barely bigger than a GM T5 manual, and yet it's tough little auto. I'm also impressed by the tow-start feature. Pretty sweet!

Anyway after I get it I'll probly start a build/restoration thread so keep on the lookout.

Matt.

'85 300SD Turbo
'92 Subaru SVX
'83 Pontiac Firebird S/E
'88 Pontiac Firebird
dieselsmoke300d
05-13-2013, 03:15 PM #4

Ok thanks. I doubt he'd care. He's probly one of the friendliest pot-heads I've met. lol I should be able to do it with the tools I have idk. I'll have to check On-Demand for the actual process too. I never cease to be impressed by MB engineering. I looked at the transmission and it's barely bigger than a GM T5 manual, and yet it's tough little auto. I'm also impressed by the tow-start feature. Pretty sweet!

Anyway after I get it I'll probly start a build/restoration thread so keep on the lookout.


Matt.

'85 300SD Turbo
'92 Subaru SVX
'83 Pontiac Firebird S/E
'88 Pontiac Firebird

SurfRodder
Jackass Extraordinaire

611
05-15-2013, 11:39 AM #5
Cool, man I look forward to it.

The R/R is pretty straightforward... only "weird" tool is a 10mm (IIRC) allen socket bit for the starter attachment bolts. Youll need plenty of extensions to get at those as well as to get at the top bellhousing bolts... althought thats on a w123, so with the slightly larger w125, it should be a little easier to get to...

I have used about 36" or so total extension and a universal drive to get at those... if you have good quality extensions, you wont have excessive twist on the extensions... If you have HF extensions, I would use the 1/2" extensions/universal and an adapter to step down to whatever socket youre using (or use a larger socket as well)...
This post was last modified: 05-15-2013, 11:41 AM by SurfRodder.

W123 Mods: 4 speed ** manual climate control ** '85 Kalitucky intake ** manual windows & full tint ** Euro headlights retrofit w/bixenon projectors ** 4 brake light mod ** Vogtland 50mm drop front & Lesjofors S600 drop rear springs ** 16" rims ** late w126 brake spindles, rotors & calipers ** full suspension rehab ** Bilstein HDs ** AL129X alternator & 1/0 starter and charging cables ** 300GD clutch/flywheel ** AFCO 80103N radiator & Earl's 41610 oil cooler ** custom block-off plate, remote oil filter & t-stat ** MW IP w/ tomnik's 6.5mm 'Holly' elements **

S124 Mods: 400E Rear subframe ** SL600 Brakes ** Late 300E 210mm diff ** SLK230 6 speed ** 17" CLK rims ** Vented RF Fender ** Facelift Hood, Headlights, and Lower Cladding **

OBK# 62
SurfRodder
05-15-2013, 11:39 AM #5

Cool, man I look forward to it.

The R/R is pretty straightforward... only "weird" tool is a 10mm (IIRC) allen socket bit for the starter attachment bolts. Youll need plenty of extensions to get at those as well as to get at the top bellhousing bolts... althought thats on a w123, so with the slightly larger w125, it should be a little easier to get to...

I have used about 36" or so total extension and a universal drive to get at those... if you have good quality extensions, you wont have excessive twist on the extensions... If you have HF extensions, I would use the 1/2" extensions/universal and an adapter to step down to whatever socket youre using (or use a larger socket as well)...


W123 Mods: 4 speed ** manual climate control ** '85 Kalitucky intake ** manual windows & full tint ** Euro headlights retrofit w/bixenon projectors ** 4 brake light mod ** Vogtland 50mm drop front & Lesjofors S600 drop rear springs ** 16" rims ** late w126 brake spindles, rotors & calipers ** full suspension rehab ** Bilstein HDs ** AL129X alternator & 1/0 starter and charging cables ** 300GD clutch/flywheel ** AFCO 80103N radiator & Earl's 41610 oil cooler ** custom block-off plate, remote oil filter & t-stat ** MW IP w/ tomnik's 6.5mm 'Holly' elements **

S124 Mods: 400E Rear subframe ** SL600 Brakes ** Late 300E 210mm diff ** SLK230 6 speed ** 17" CLK rims ** Vented RF Fender ** Facelift Hood, Headlights, and Lower Cladding **

OBK# 62

willbhere4u
Six in a row make her go!

2,507
05-15-2013, 04:43 PM #6
w126 not w125

1987 300SDL 6spd manual om606.962 swap project
1985 300td euro 5spd wagon running
willbhere4u
05-15-2013, 04:43 PM #6

w126 not w125


1987 300SDL 6spd manual om606.962 swap project
1985 300td euro 5spd wagon running

SurfRodder
Jackass Extraordinaire

611
05-20-2013, 02:16 PM #7
(05-15-2013, 04:43 PM)willbhere4u w126 not w125

yeah, typo...nice catch!

(I had to do a Ctrl+F to see it...or actually was too lazy to find it w/o)
This post was last modified: 05-20-2013, 02:17 PM by SurfRodder.

W123 Mods: 4 speed ** manual climate control ** '85 Kalitucky intake ** manual windows & full tint ** Euro headlights retrofit w/bixenon projectors ** 4 brake light mod ** Vogtland 50mm drop front & Lesjofors S600 drop rear springs ** 16" rims ** late w126 brake spindles, rotors & calipers ** full suspension rehab ** Bilstein HDs ** AL129X alternator & 1/0 starter and charging cables ** 300GD clutch/flywheel ** AFCO 80103N radiator & Earl's 41610 oil cooler ** custom block-off plate, remote oil filter & t-stat ** MW IP w/ tomnik's 6.5mm 'Holly' elements **

S124 Mods: 400E Rear subframe ** SL600 Brakes ** Late 300E 210mm diff ** SLK230 6 speed ** 17" CLK rims ** Vented RF Fender ** Facelift Hood, Headlights, and Lower Cladding **

OBK# 62
SurfRodder
05-20-2013, 02:16 PM #7

(05-15-2013, 04:43 PM)willbhere4u w126 not w125

yeah, typo...nice catch!

(I had to do a Ctrl+F to see it...or actually was too lazy to find it w/o)


W123 Mods: 4 speed ** manual climate control ** '85 Kalitucky intake ** manual windows & full tint ** Euro headlights retrofit w/bixenon projectors ** 4 brake light mod ** Vogtland 50mm drop front & Lesjofors S600 drop rear springs ** 16" rims ** late w126 brake spindles, rotors & calipers ** full suspension rehab ** Bilstein HDs ** AL129X alternator & 1/0 starter and charging cables ** 300GD clutch/flywheel ** AFCO 80103N radiator & Earl's 41610 oil cooler ** custom block-off plate, remote oil filter & t-stat ** MW IP w/ tomnik's 6.5mm 'Holly' elements **

S124 Mods: 400E Rear subframe ** SL600 Brakes ** Late 300E 210mm diff ** SLK230 6 speed ** 17" CLK rims ** Vented RF Fender ** Facelift Hood, Headlights, and Lower Cladding **

OBK# 62

dieselsmoke300d
To many things I say: Bah Humbug!

65
11-13-2013, 05:12 PM #8
Well guys this is an old thread by now but I figured I'd just not make clutter by making a new one. I ended up buying this thing and a friend of mine with a beastly V6 Dodge van with a bad valve offered his services and we got it home just fine on a tow dolly with it facing backwards. Didn't help that the idiot I bought it from wasted like $120 moving it an hour north from where it already was... Took at least 3 hours to get it home... On top of that we didn't have a key to steer it onto the tow dolly. That was a nightmare... I got a new key for it so it's all good.

So I got to play around with it recently. I fixed a vacuum leak or two that were obvious. Can't test it further unless I cap off the body lines. No change. I've been doing research and according to all that info the most likely issues could be a stuck kick-down switch, stuck shift switch (next to L on the shifter), stuck solenoid, or maybe a bad governor. Not sure if a tranny this old had the plastic helical drive gears for the governor (if it's even the same type) or not. Those were prone to breaking.

I have the spare tranny in the trunk but it's mad cold in the state of NY as of the last week so I'd like to avoid that swap... I'm about to go outside and mess around with the kick-down switch etc and look for issues with that. I did notice something odd yesterday. I was underneath the car inspecting everything and I saw that the solenoid wire was kinda hangin out and was weaved through those mounting ear things on the back-bottom of the tranny and in to the solenoid. And there's a wire-nut splice in the middle of the wire. Odd to say the least. Hopefully gonna do some extensive tweakage on it tomorrow. I'm really hoping to get it on the road on Friday.

Any thoughts?

Matt.

'85 300SD Turbo
'92 Subaru SVX
'83 Pontiac Firebird S/E
'88 Pontiac Firebird
dieselsmoke300d
11-13-2013, 05:12 PM #8

Well guys this is an old thread by now but I figured I'd just not make clutter by making a new one. I ended up buying this thing and a friend of mine with a beastly V6 Dodge van with a bad valve offered his services and we got it home just fine on a tow dolly with it facing backwards. Didn't help that the idiot I bought it from wasted like $120 moving it an hour north from where it already was... Took at least 3 hours to get it home... On top of that we didn't have a key to steer it onto the tow dolly. That was a nightmare... I got a new key for it so it's all good.

So I got to play around with it recently. I fixed a vacuum leak or two that were obvious. Can't test it further unless I cap off the body lines. No change. I've been doing research and according to all that info the most likely issues could be a stuck kick-down switch, stuck shift switch (next to L on the shifter), stuck solenoid, or maybe a bad governor. Not sure if a tranny this old had the plastic helical drive gears for the governor (if it's even the same type) or not. Those were prone to breaking.

I have the spare tranny in the trunk but it's mad cold in the state of NY as of the last week so I'd like to avoid that swap... I'm about to go outside and mess around with the kick-down switch etc and look for issues with that. I did notice something odd yesterday. I was underneath the car inspecting everything and I saw that the solenoid wire was kinda hangin out and was weaved through those mounting ear things on the back-bottom of the tranny and in to the solenoid. And there's a wire-nut splice in the middle of the wire. Odd to say the least. Hopefully gonna do some extensive tweakage on it tomorrow. I'm really hoping to get it on the road on Friday.

Any thoughts?


Matt.

'85 300SD Turbo
'92 Subaru SVX
'83 Pontiac Firebird S/E
'88 Pontiac Firebird

larsalan
Superturbo

1,272
11-13-2013, 06:51 PM #9
I had one trans cooler line bust a hole. Once they get too low on fluid they stay in 1st and 2nd. And the fluid pump starts to suck air and froth up the mix. Pretty amateur problem, low fluid. But maybe that's it. No matter what it's going to be too cold to work outdoors much now.

Rusted out beat down 300d turbo 82' -- RIP
Nice body, tons of ridiculous mechanical issues - 300d turbo 82' /motor 85'
larsalan
11-13-2013, 06:51 PM #9

I had one trans cooler line bust a hole. Once they get too low on fluid they stay in 1st and 2nd. And the fluid pump starts to suck air and froth up the mix. Pretty amateur problem, low fluid. But maybe that's it. No matter what it's going to be too cold to work outdoors much now.


Rusted out beat down 300d turbo 82' -- RIP
Nice body, tons of ridiculous mechanical issues - 300d turbo 82' /motor 85'

Jooseppi Luna
Certified Nut

114
11-14-2013, 10:10 AM #10
The governor gears are metal.

-Jooseppi

1982 300SD -- 211k, Texas car, tranny issues

1979 240D 4-speed 234k -- turbo and tuned IP, third world taxi hot rod Big Grin .  Given to me by JB3, who got it from purplecomputer.

Some blasphemous vehicles in the fleet as well -- 2004 Corolla 5-speed and 1994 Buick Century

2 Samuel 12:13: "David said to Nathan, “I have sinned against the Lord.” And Nathan said to David, “The Lord also has put away your sin; you shall not die."
Jooseppi Luna
11-14-2013, 10:10 AM #10

The governor gears are metal.


-Jooseppi

1982 300SD -- 211k, Texas car, tranny issues

1979 240D 4-speed 234k -- turbo and tuned IP, third world taxi hot rod Big Grin .  Given to me by JB3, who got it from purplecomputer.

Some blasphemous vehicles in the fleet as well -- 2004 Corolla 5-speed and 1994 Buick Century

2 Samuel 12:13: "David said to Nathan, “I have sinned against the Lord.” And Nathan said to David, “The Lord also has put away your sin; you shall not die."

willbhere4u
Six in a row make her go!

2,507
11-14-2013, 10:15 AM #11
The kick down switch is under the gas pedal

1987 300SDL 6spd manual om606.962 swap project
1985 300td euro 5spd wagon running
willbhere4u
11-14-2013, 10:15 AM #11

The kick down switch is under the gas pedal


1987 300SDL 6spd manual om606.962 swap project
1985 300td euro 5spd wagon running

dieselsmoke300d
To many things I say: Bah Humbug!

65
01-01-2014, 04:46 PM #12
The governor gears on this one may be metal. But later on they were made of plastic. I'm just saying screw it, I'm taking it to the transmission shop tomorrow to be diagnosed. I can't do anything myself in this cold.

Matt.

'85 300SD Turbo
'92 Subaru SVX
'83 Pontiac Firebird S/E
'88 Pontiac Firebird
dieselsmoke300d
01-01-2014, 04:46 PM #12

The governor gears on this one may be metal. But later on they were made of plastic. I'm just saying screw it, I'm taking it to the transmission shop tomorrow to be diagnosed. I can't do anything myself in this cold.


Matt.

'85 300SD Turbo
'92 Subaru SVX
'83 Pontiac Firebird S/E
'88 Pontiac Firebird

dieselsmoke300d
To many things I say: Bah Humbug!

65
12-15-2014, 04:21 PM #13
Well I thought I'd just finish this thread up, after many hours of tweaking, fiddling with modulator pressures, and adjusting random things, I've pretty much determined that the transmission was badly abused and the bands are probly burnt up. So a buddy of mine came over and replaced the 722.315 that was in the car with the spare 722.303 that came with the car. Seems to be shifting perfectly. So I'm happy. But now I'm having a couple minor electrical issues... Reverse lights aren't working. I checked the switch, all good there. Checked the harness, all good. Checked the bulbs and fuses, they seem to be all good... So Idk, I'll figure it out.

Matt.

'85 300SD Turbo
'92 Subaru SVX
'83 Pontiac Firebird S/E
'88 Pontiac Firebird
dieselsmoke300d
12-15-2014, 04:21 PM #13

Well I thought I'd just finish this thread up, after many hours of tweaking, fiddling with modulator pressures, and adjusting random things, I've pretty much determined that the transmission was badly abused and the bands are probly burnt up. So a buddy of mine came over and replaced the 722.315 that was in the car with the spare 722.303 that came with the car. Seems to be shifting perfectly. So I'm happy. But now I'm having a couple minor electrical issues... Reverse lights aren't working. I checked the switch, all good there. Checked the harness, all good. Checked the bulbs and fuses, they seem to be all good... So Idk, I'll figure it out.


Matt.

'85 300SD Turbo
'92 Subaru SVX
'83 Pontiac Firebird S/E
'88 Pontiac Firebird

sassparilla_kid
diesel > all other fuels

1,618
12-15-2014, 04:25 PM #14
If nothing else you could do like me and put in a toggle switch to control the reverse lights, just don't achievable l accidentally leave them on lol

-1982 300D Turbo, 280k miles, ALDA apparently maxxed, fram 8038, 12 lbs boost, non-egr manifolds, W/M injection, 4 brake light mod, Gen II w126 front rotors/calipers, 4-speed swap
In the works: A/W IC, adjust pump, turbo rebuild (w/60 trim comp wheel)
-1980 300SD, 110k, project car. Goal is to get it lookin' like it did on the showroom floor (body and interior wise, not necessarily under the hood )
-1974 240D, FRESH PAINT!!!!!!
sassparilla_kid
12-15-2014, 04:25 PM #14

If nothing else you could do like me and put in a toggle switch to control the reverse lights, just don't achievable l accidentally leave them on lol


-1982 300D Turbo, 280k miles, ALDA apparently maxxed, fram 8038, 12 lbs boost, non-egr manifolds, W/M injection, 4 brake light mod, Gen II w126 front rotors/calipers, 4-speed swap
In the works: A/W IC, adjust pump, turbo rebuild (w/60 trim comp wheel)
-1980 300SD, 110k, project car. Goal is to get it lookin' like it did on the showroom floor (body and interior wise, not necessarily under the hood )
-1974 240D, FRESH PAINT!!!!!!

dieselsmoke300d
To many things I say: Bah Humbug!

65
12-15-2014, 04:52 PM #15
I may have to do that. I'm gonna look and make sure the connectors are all good in the trunk.

Matt.

'85 300SD Turbo
'92 Subaru SVX
'83 Pontiac Firebird S/E
'88 Pontiac Firebird
dieselsmoke300d
12-15-2014, 04:52 PM #15

I may have to do that. I'm gonna look and make sure the connectors are all good in the trunk.


Matt.

'85 300SD Turbo
'92 Subaru SVX
'83 Pontiac Firebird S/E
'88 Pontiac Firebird

dieselsmoke300d
To many things I say: Bah Humbug!

65
12-19-2014, 01:49 AM #16
Turns out someone went and disconnected the lead to the reverse lights in the fusebox. It was supposed to be connected to fuse 10 with another lead that goes to a bunch of things. AND, the one lead that was disconnected also goes to the kickdown solenoid... I think we found out what killed the original transmission...

Matt.

'85 300SD Turbo
'92 Subaru SVX
'83 Pontiac Firebird S/E
'88 Pontiac Firebird
dieselsmoke300d
12-19-2014, 01:49 AM #16

Turns out someone went and disconnected the lead to the reverse lights in the fusebox. It was supposed to be connected to fuse 10 with another lead that goes to a bunch of things. AND, the one lead that was disconnected also goes to the kickdown solenoid... I think we found out what killed the original transmission...


Matt.

'85 300SD Turbo
'92 Subaru SVX
'83 Pontiac Firebird S/E
'88 Pontiac Firebird

 
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