Transmission part 1994 E420 - Page 2 - PeachParts Mercedes-Benz Forum

Gilly · #16 08-15-2006, 09:06 PM

It's sounding more and more like a bad upshift delay solenoid. You can tell because the upshifts are delayed (hence the name) but should only do this when the engine is cold. They can go bad and delay the upshifts all the time. The easy way out is to readjust the throttle valve to base line, but then you won't have the upshift delay at all. Yes the thing you are calling a pump is the upshift delay solenoid. The throttle valve cable for the transmission runs to it as well as the vacuum line from the upshift delay switchover valve. The problem could of course be the switchover valve or something related to that. The vacuum modulator only adjusts the hardness of the shift, not the timing of the shift, the throttle valve cable adjusts the timing of the shift. The throttle valve cable is simply adjusted like a brake cable on a bicycle, nothing fancy about it. The upshift delay solenoid just "tightens" the cable when the engine is cold to change the timing of the shift. By delaying the upshift the engine rpm will run a bit higher before the upshift (later shift) and helps warm up the catalytic converter. I think your delay solenoid has stuck in to the "delayed" position so you are always getting the late shifts, not just when cold. Most people don't even notice this delayed upshift when cold, it goes back to the regular position within a few minutes of driving.
Gilly
ps I'd put the vacuum modulator adjustment back where is was....

DRICHFL · #17 08-18-2006, 01:11 PM

Gilly, I feel that you are right about the bad upshift delay solenoid. It must be stuck!!! While driving the car I get on the gas pedal hard in order to make it switch gears. It still will not shift until it revs to 4500 RPM or redline. I plan to drop the transmission so that I can pull the upshift delay solenoid. Before I start is there any suggestion. I have no desires to break down the entire transmission at this time. In addition, do I need any special tools to get the solenoid off so that I may order a new one. Thanks

Gilly · #18 08-18-2006, 03:49 PM

I'd try unplugging the vacuum line up at the switchover valve first. I don't believe the trans has to be removed or lowered to do this job.

Gilly

DRICHFL · #19 09-13-2006, 05:13 PM

Here are some photos of the valve body pulled of my e420 722.366 transmission.

There is also another post I have post about transmission service manual for overhaul. WTB e420 transmission diagnosis manual

I recently change the fuild and discovered that the fuild was dark and metallic. I changed the filter and put fresh fuild in tranny. The transmission did improve a little but it did not shift as normal.

Yesterday, the transmission begin to shudder while in reverse. Later that day the reverse would not engage unless I rev the RPM extremely high towards red line. I decide to overhaul the tranny. Before I overhaul I would like a service manual, so I at least decided to drop the pan and check the valve body. I drain the fuild and it was again dark with metallic and the filter was shot. This is what I seen once I got the pan off.

Photo 4 is the top of valve body.
Photo 5 is the bottom of the intermediate plate

DRICHFL · #20 09-13-2006, 05:26 PM

Here are photos of the intermediate plate and valve body. The photo display how dirty the valve body is once open and you can see the springs and balls stuck in place. The fluid could not travel freely throw the valve body.

Absolutely dirty. Last transmission fluid change was in 2004 by independent MB shop. They claim to have change the fluid when they replace the B1 piston. I find it hard to believe after seeing this. Another reason why you have to follow up on these shops. I checked the fluid ever so often but I never notice it being that dark, the fluid would leave a deep redish color on the cloth. I did not suspect this, so I take the blame for being lazy and not changing my own fluid.

DRICHFL · #21 09-14-2006, 12:23 PM

Okay I clean the Valve body and intermediate plate then I reinstalled both items. New filter and fluid hoping to get positive result.

Well the transmission did improve, 1-2, 2-3, little flare 3-4. Far as the reverse it would engage slowly. I now feel overhaul is the only way to fix problem

. B-3 was slightly visible from the bottom of transmission with valve body and plate was remove. It looked fine but I would need to pulled it out to inspect it more clearly. K-2 clutch pack may be the problem due to worn friction disc. From what I have read B-3 and K-2 go hand in hand when it come to reverse and 4th gear.

Any pitfall I need to look out for while removing tranny?
Is new torque converter necessary?
Thanks for feedback.

david s poole · #22 09-14-2006, 01:19 PM

did you take the small valve body off the intermediate plate and clean out the two little screens that protect the govenor while you had it apart?the big clutches in the centre or the trans[very very common problem] sound as though worn out[reverse gear] it sounds as though this trans needs a rebuild.

DRICHFL · #23 09-15-2006, 06:23 AM

David, Yes I pulled all the springs and balls out of the valve body while cleaning. They were gunked up. I feel that I need to do a rebuild also.

david s poole · #24 09-15-2006, 09:52 AM

you missed my point.on the intermediate plate there is a small valve body held on by slothead screws.this handles govenor duty and also contains the emergency lockout pin [so that you can't move trans to reverse while going forward] this needs to be removed and turned upsidedown to get to the 2 little metal screens[shaped like tiny thimbals].the passage leading to one of them will be full of dirt and debris as will one of the filters.

DRICHFL · #25 09-19-2006, 04:31 AM

David, I am aware of the filter; however, I did clean the valve body pretty well. Waiting on parts so that I can do rebuild.

DRICHFL · #26 09-29-2006, 06:20 PM

I finally remove the transmission today. I was able to find a 722.366 transmission from a wrecked 95 e420 with a little over a 100,000 miles on the dash. The rear of the car was damage but from the rear doors to the front of the vehicle everything was intact. I paid $500 and $125 shipping for the transmission with a 30 day warranty.

Anyway, I decided to swap trannies so that I can get back onto the road ASAP. In the meantime I plan to rebuild my orginal transmission and keep as a backup.

Can anyone give me advice on a easier way to install the two bolts located on the top of the bell housing. It was a pain and took me a few hours to remove the bolts due to tight limited space. The thottle linkage and the firewall does not give you much room. Is there any tool that would make this task a little easier.

FYI: If anyone decide to do this job expect to fight with the starter bolts. Those two 10mm hex bolts felts as if they were welded onto the transmission. In order to remove those bolts I suggest getting a stub rachet and use a pipe on the end to break lose bolts. There is just no room and you will not get any click from the rachet.

Gilly · #27 09-29-2006, 08:04 PM

On the top bolts, when removing the trans, do the top ones first. Take out the driveshaft bolts and get exhaust out of the way if needed (on the V8's I thought the exhust needs to come off), the support the tranny and take off the rear trans mount, lower the tranny to allow it to angle down a bit, then use a long 1/2 inch extension (or several short ones, you want 4 feet of extension or so), then use either a long breaker bar or ratchet, you'll also want some sort of flex end for the socket, either a universal joint or a wobble socket.
Gilly

DRICHFL · #28 09-30-2006, 02:04 PM

Is it alot of trouble to change the seal located behind the torque converter? Is there a special tool needed in order to remove the torque converter and seal? I have not remove the torque converter because I am not sure if I need to fool around with the seal. I am about to install the used tranny but I started thinking about the front and rear seals. After all, the transmission came out of a wreck vehicle that was fully operation. Do these seals need to be change or should I just install the transmission and replace the filter and fluid and call it a day. I still plan to take my time and rebuild my old transmission for backup. Any feedback welcomed.

Gilly · #29 09-30-2006, 02:30 PM

About the only tool I can think of is used to compress a spring plate behind the pump. Might be hard to do it without this tool, might not be impossible to design your own tool to compress the plate.
Gilly

DRICHFL · #30 10-05-2006, 01:25 PM

Finally got around to replacing the transmission with the used one yesterday. The transmission shift gears smoothly. No problems at all with shifting; however, I did notice a small leak of trans fluid this morning. I drove the car again and notice the leak in the parking lot at the store. I got home, got under the car and saw that the leak was coming from the B-2 pistion. I decided to push in the piston, remove the retainer clip on my old transmisson. After viewing my old transmission B-2 piston and seals I decided to change the seals on the transmission in my car.

In reguards to the B-2 piston seals is the larger seal or first seal you see as soon as you open the chamber a common failure? Is that the seal, the only seal, I need to change in order to solve my leaking problem?

Before installing the used tranny I did notice that there was a small amount of fluid around that retainer clip. I did not pay much attention to the fluid because I though it was most likely due to fluid that was spilled onto the transmission. I also notice that the B-2 piston housing look like it was probably bump when it was being removed from the other car.