190D turbo won't go into 4th (722.4 trans) - PeachParts Mercedes-Benz Forum

Turbo190D · #1 06-11-2017, 07:14 PM

I've got a 1987.5 190D 2.5 Turbo with automatic transmission. I've fiddled around with the transmission linkage deal near the throttle and got the transmission shifting at the proper point. 4th gear does that "flaring" jazz though. It almost never actually works. It'll try to shift into 4th and instead it's like its sitting in neutral. I changed the transmission fluid and filter (the fluid was brown as flip). Problem is I can't tell if its got enough in it or not. I put in 5 quarts. The dipstick seems pretty useless. Every time I pull it out its got fluid about a foot up the dipstick. The manual says its supposed to be useful but it sure doesn't seem to be.

Anyone got any advice on how to get the proper amount of fluid into this guy?

Advice for how to fix the 4th gear flaring?

Mxfrank · #2 06-11-2017, 09:00 PM

Did you drain the torque converter? A lot of these cars don't have a TC drain. The pan holds just about exactly 2 qts.

I use a dip tube to check the level...just a 3' length of small diameter nylon tube. Push it down as you would a dipstick, then put your thumb over the end and draw it out. Air pressure will hold the level in the tube, and you'll be able to get an accurate reading. That doesn't help much without a reference, but the pan is about 1.5" deep, and the level should be just below the gasket. You can get a more accurate estimate by measuring the height of the pan.

The only cheap possibility is a broken K2 accumulator spring, although that would more likely give you a flare followed by a harsh engagement. Do a search, there should be a photo guide somewhere here. You may get some temporary relief by using a viscosity modifier additive, but this condition is usually progressive no matter what you do. I know you don't like the answer, but this transmission likely has a worn out K2 pack or K2 seal. It's going to need a rebuild.

compress ignite · #3 06-11-2017, 11:36 PM

x2 1 st reply

BUT...

722.4 has Torque Converter Drain (SO YOU may Have overfilled)
( I won't BET you BUT I know you did) Dipsticks don't lie.

Proper ATF check is performed with ATF @ Operating temperature
(Minimum 20 minute drive) On Uber LEVEL platform.

WELL ... O.K.
I gots No problem admitting I was wrong about the Fluid Quantity.
My Apologies.

Turbo190D · #4 06-12-2017, 12:55 AM

I did drain the torque converter. I'll drive the car to work in the morning (takes about 15 minutes). The parking lot is very level, so I'll check the fluid then. Maybe it'll settle down in there and stop being all over the dipstick. I drained a hair under 5 quarts out and put 5 quarts in, so it shouldn't be overfull.

MXfrank, that's a good idea regarding the tube. The stick is so hard to shove down in there maybe i'm just being too violent with it.

Mxfrank · #5 06-12-2017, 07:29 AM

Quote:

Originally Posted by Turbo190D

\
MXfrank, that's a good idea regarding the tube. The stick is so hard to shove down in there maybe i'm just being too violent with it.

Just be patient. The stick has to rotate as it descends. If you force it, you'll break it and they the problem will be worse. The convoluted path is the problem...I've never been able to get a satisfactory reading on this car.

Turbo190D · #6 06-12-2017, 10:13 AM

I thought I'd read that the K2 spring stuff was mostly for problems with 2-3? I've found a ton of information on flaring from 2nd to 3rd, but not much on flaring from 3rd to 4th.

Forgot I had a ton of stuff to haul to work today, so I had to drive the pickup. I'll see if I can fiddle with the car some tonight.

Diseasel300 · #7 06-12-2017, 10:18 AM

K1 accumulator spring is for 2-3 shift. K2 accumulator spring is for 3-4 shift. Even with a broken spring, it should still shift, you may just get a flare or a violent shift. Considering the condition of your fluid when you changed it, the damage may already be done.

Mxfrank · #8 06-12-2017, 11:58 AM

The accumulators work like clutch pedals on a manual car, there's one for each of the two clutches. They feather engagement, so that it's smooth. If you've driven a manual car, you know that too fast off the clutch gives you a rough engagement. Too slow and you flare the shift. So the usual symptoms of a bad accumulator are either lengthy flares or crashing engagement. Since the spring or piston is a $50 job with the transmission in place, it's probably worth doing before you throw in the towel.

To anticipate the next couple of questions, usually a used transmission is a cheap way out. But unfortunately the 190DT transmission is unique. It's a 722.4 with extra disks in each pack to handle the extra torque, as well as a larger output flange. If you can't find an original 722.413, the closest match would be a 722.418 from a 300D 2.5 turbo. A long shot would be a 722.409 from a 2.6 190E, but you'd probably have to swap a bunch of parts. Otherwise, you can get yours rebuilt for around $2K. If you live anywhere near Van Nuys, CA, Sun Valley is the place to go. If you live elsewhere, we can maybe recommend a local shop.

Turbo190D · #9 06-12-2017, 05:07 PM

Ah, that makes sense. My pickup is a manual, so I'm more familiar with those. I've never messed with an automatic until this one. For $50 I might as well try it. Don't look forward to getting back under there, lol. I'm flipping sore as all get out from doing the fluid yesterday. Working on a lifted pickup is so much easier

I'm in north Alabama, so I'm almost as far from CA as you can get

Thanks for letting me know about the unique 190DT trans though. I was in Huntsville earlier today and was looking at a 85 190E that was up on craigslist for 500 bucks as a parts car. Was thinking about getting it for the trans, figuring only the bellhousing would really be much different. Alas, you've informed me that my assumption was incorrect.

Worst case I'm not against spending 2k to get the trans working, but it'll probably be a while. For most of my driving 3rd gear is fine. I'll just stick to the yaris for road trips until I can get this sorted out.

I do need to adjust that vacuum modulator deal though. With the new fluid in there the car shifts hard as frick. The 1-2 shift has been hard since I picked it up, but the rest of them are a fair bit harder now as well.

Mxfrank · #10 06-12-2017, 08:55 PM

I posted the 722.4 modulator specs last night. Here's the link:

http://www.peachparts.com/shopforum/attachments/tech-help/135627d1459387599-190e-300e-4-speed-trany-vac-modulator-difference-modulators.pdf

Turbo190D · #11 06-13-2017, 02:35 PM

Thank you sir.

Didn't get to drive the car today either, because the brakes are being a bit weird. I bought one of those little suction bleeder things (the girlfriend aka brake bleeding assistant is TDY for another few weeks). It should be here Thursday. I'll get the brakes bled (the fluid is disgusting, so I'll probably just suck all the old fluid out of the system and keep adding fresh) then diddle with the transmission some more.

Mxfrank · #12 06-13-2017, 03:23 PM

One tip on the brakes: You have one reservoir, but it's divided up into two compartments. The rear compartment doesn't fill until the front one does. So when you go to bleed the rear brakes and you're sucking air, that's why. I fill the reservoir to the very brim until I'm done flushing the rears.

optimusprime · #13 06-14-2017, 05:44 AM

You must have the right amount of oil in the auto box .To much ATF fluid and you will damage the box .So first things first .Dont do anything else till you have the levels right .This is most important . Engine up to temp, brake on , and selector in park engine running . Pull the dip stick wipe it clean with a cotton lint free duster or old car wash leather ,so no particals will be inserted in to the dipstick tube ...Oil level should be in the middle of the 2 marks . If you have no dipstick get one, or end up with a gearbox replacment.

vstech · #14 06-14-2017, 07:33 AM

you mention difficulty pushing in the dipstick...

is the end flat, or rounded on the end?

you may have a broken dipstick... several of my cars have broken dipsticks...

you should have two notches about a centimeter apart, and about 3 cm space below that to a rounded section.

Turbo190D · #15 06-14-2017, 09:11 AM

Thanks for all the responses guys. The stick isn't broken, it just seems useless. When I pull it out there's almost always ATF well over a foot up the stick. It doesn't seem possible that it could be overfilled that much. It's not fully coating the stick up that far, generally there's a bunch of fluid on one side or some such. I dunno. I know reading dipsticks is usually a bit of an interpretative dance but I've never seen one that's as weird as this one is.