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  Topic Review (Newest First)
08-08-2019 11:50 AM
Originally Posted by Heikkif View Post
Sounds like a problem with the valve body. It should not require total rebuilt of the transmission. In best case it could be repaired without removing the transmission. There are some threads on transmissions elsewhere on benzworld.
Agreed. Initially I just wanted to get the car driving, especially since I only paid $400 for it. Now that I've driven it a while, I'm really enjoying it, and I've fixed a few other things, I won't mind putting time into the transmission. I won't mind working on the valve body. That governor though... I understand that's a PITA.

...Looks like I found how I'm going to spend my time at this continued education seminar this weekend: Researching deeper into this transmission.
08-08-2019 06:54 AM
Heikkif This should be red if someone has problems with transmission:
08-07-2019 11:26 AM
Heikkif Sounds like a problem with the valve body. It should not require total rebuilt of the transmission. In best case it could be repaired without removing the transmission. There are some threads on transmissions elsewhere on benzworld.
08-07-2019 10:16 AM
isthenew Adding another follow up. I'm about 900 miles since I added the Trans-X and my transmission was perfect. Until this morning. I took the car on the interstate (for the second time ever). This morning, while doing 70 mph, the car kicked back down to 3rd gear. I drove a few miles on the interstate at 50 mph in 3rd. After getting off the interstate, the car shifted up into 4th, and kicked back down about 18 seconds later. ...I'll check my ATF and its level at some point after this weekend. Fingers crossed its just a little low.
06-16-2019 06:04 PM
isthenew I want to follow up here. I added trans-x to my ATF and that seems to have done it. It's been shifting perfectly for a bit. Here's a link to a more recent thread if anyone wants to know how I went from this to Trans-X.
05-22-2019 03:50 AM
ianrandom You'll get there. Seems like you definitely have the skills this car needs. Kickdown solenoid does sound a strong possibility.
05-20-2019 10:41 PM
isthenew Took the car out for a bit, figuring at 1am, I won't run into much traffic for me to slow down. In my 20 minute drive, it upshifted from 2nd to 3rd gear 2 X's. Both times it almost immediately tried to downshift into 2nd. It never tried to shift up into 4th, even though I was at 50 mph when in 3rd gear.

Here's where it gets interesting. My transmission gearbox is the PRD32, where 2 starts in 1st gear and automatically upshifts into 2nd and stays there. Given there was no other traffic (because i was concerned it may never shift out of first again if I did this), I started by selecting 2. Which put me in 1st gear. And the car was glorious! Except it never tried to upshift. It stayed in 1st gear. Until I moved the selector to 3. At which point it immediately slammed into 2nd gear. And stayed there. Didn't try to go up or down. So it seems the car is trying to stay in the lowest possible gear for my selection.

After that, I'm really thinking kickdown solenoid. Especially since I found the kickdown switch tucked up under the center console. Who knows how long it was there. And if it being there meant it was on for who knows how long. Potentially causing trouble w/the solenoid.

Finger crossed.
05-20-2019 04:24 PM
christuna you will mostly find w124 300E or TE (make sure its 3.0) on the junkyards.

just checked the part numbers and these cars had only 2 models of those transmissions and the breakpoint was somewhere around 89 or 90:

older 300SE had 722.319 and it has the same valvebody as 722.320 in 300E (same years)

newer 300SE had 722.351 and it has the same valvebody as 722.358 in 300E (same years)

I dont know if the older ones are interchangeable with newer ones. maybe some tranny expert can chime in.

your maintenance booklet should have your transmission number and other data on the last page

as far as compatibility with other 722.3 models made from 1979 to 1996 who knows if they would work.
05-20-2019 03:22 PM
Originally Posted by christuna View Post
in my opinion your problem is caused by either worn/plugged valvebody or worn/plugged governor. maybe a bad kickdown solenoid

If you have a pick and pull junkyard nearby you can pull a valvebody and put it in your car. you can also rebuild the one you have but thats advanced diy.

and yes green marks are where you check the level
I was watching a video on a valve body rebuild last week. I'll finish it. It looked like it's in my skill set. Though I have a couple U-pull salvage years here. And no patients tomorrow. I think I'll pull one. ...I was thinking bad kick down solenoid, myself. Because it's just all over the place. Tries to downshift, goes back, tries to downshift, reacts to hitting the kick down switch...

Appreciate the verification on where to check the level.

Originally Posted by christuna View Post
and also your car has 3.46 rear: 3K rpm at 60mph in 4th gear is normal
This is good to know. When it was using all the gears, I was about there in 4th gear. Coming from the 722.5 and 722.6 in the '96 and '97 SL320's, it was a little unsettling. Today, it was somewhere between 3k - 3.5k RPM at 45 mph, so 3rd gear. One of the other things I found today was the right front tire doesn't match the others. And I think it threw a belt since yesterday. The car shakes terribly at 55mph. So right now I can't even push the car to 60mph to see if it will upshift into 4th. ...Adding tires to my replace list.

Good thing is the car can sit while I slowly rebuild it. ...For those of interest, I only paid a few hundred dollars for the car. The woman wanted substantially more. But she also wanted to see the car restored. That's why she sold it to me. So I don't mind putting time and money into repairing it. All in all, it's super solid. Just been totally neglected for about 3 years. And I have no history of repairs or problems or changes.

I appreciate everyone's help.
05-20-2019 01:43 PM
christuna and also your car has 3.46 rear: 3K rpm at 60mph in 4th gear is normal
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