Transmission delay
 

Just wanted to run a transmission problem by you. My 500SEL has a delay going into gear at first start of the day. After this 3 to 5 sec delay, the problem is gone until the next day. At first I thought it was just reverse because I always back up out of the car port. Today, just to see, I put it in drive first and had the same delay. I talked to a friend of mine that rebuilds transmissions. He ask if the trans worked good after the delay with no slipping and in forward or reverse gears. I said yes. He said "Check valve in the valve body was leaking and allowing the torque converter to drain back into the transmission." He then instructed me to check the level of the fluid just after shutting down the engine. Then check again before starting the next morning. If the level was a lot higher in the morning then that had to be the problem. I ask a lot of questions including How Much? He said about $20 or so. The fix is to install an external check valve in the return cooler line. Chrysler has the parts. I will check the level tonight, and in the morning and see how much difference there is. If this does show a problem, he will get the parts from Chrysler next week. He also said that It didn't hurt anything and I could just leave it the way it is, just wait 5+ seconds in the morning before shifting out of park. I usually am one to go as soon as oil pressure is up and drive easy for the first few minuets. This could be hard to do as I also have the 300D. Lets see, 500-start and wait 10 seconds -300D wait 10 seconds and start. I already have the problem of switching the 500 on and waiting to start or getting in the 300D and hit the key to start. Life is hard on old people.
Anyone heard of a problem like this? My transmission man said Chrysler/Jeep had a lot of trouble, that is why they have the parts to fix it. He also said some Jeeps have basically the same transmission as the 722.X. That is where he learned about this problem. He was a Chrysler transmission tech, but now independent.

Sorry for the long post

Paul

Chrysler's shared the 722.6's and 722.9' transmissions during the illfated Daimler/Chrysler era.
The W126 500SEL had an old 722.3. Some Porsches shared that transmission.

I see from your sig that you have 265,000 miles up on your 500SEL. That's getting up to the amount of miles your tranny might need a rebuild. I.M.H.O. I suspect the front pump.

I would change the fluid first.

The valve bodies in these transmissions do get some sludge in them over time. When they gunk up to the point of faulty operation that generally means that wear in the clutches etc has got to the point requiring replacement/rebuild.

Later version transmissions would delay the shifts when first starting out from cold to warm the fluid up quickly.

In a completely normal working transmission the fluid level will rise as soon as you shut off the engine - this is due to the top half the torque converter draining out in the transmission.

How would this valve prevent that?

It sounds to me like the engine is a bit down on power when really cold - may be a service and check of the idle speed on a cold start up would show a problem / provide a solution? Are the engine revs noticeably different when warm and at idle?

Within a second or two the engine is idling about 1100rpm. If I put the trans in R or D the transmission doesn't engage. After about 5 or 6 seconds you can feel the trans engage and everything is fine. If I leave the trans in Park for 5 to 6 seconds and then put the trans in D or R it will engage in about 1 sec which is normal for this trans and a lot of others I have driven.
If everything is working as it should, the torque converter will not drain back. There are check valves in the valve body and front pump to prevent this from happening. It can also be caused by bad seals. The check valve in the transmission cooler line will help if one of the other check valves is leaking. It is worth a try because the next thing is to remove and repair/rebuild the unit. The man recommending this has been a transmission specialist for 30+ years. He has worked on a lot of these transmissions. He recommends doing the check valve first, then go to plan B if it doesn't help. Sounds like a good plan to me. I'll let you know if it works or not.

Paul

please report back with your result.

I haven't done the check valve yet but now don't think I need to. The problem is getting worse. I have checked the cold level before start and it is the same. I have also checked my 300D level before start and it is the same as the 500. I have a trans from an 85 500 that looks like it was just put in before it was parked. I bought it not running so don't know anything about the trans but it is really clean compared to the rest of the car. If I put it in and it doesn't work, then plan C goes into effect. That will probably be to rebuild the trans that is in the car now. Any one know the BOOK TIME to R&R the transmission?

Paul

Remove and install 7h overhaul 12h.

Thanks spit64

Paul

Well, it is not a drain back problem. Now there is NO reverse when trans is hot. This problem went from a delayed engage when cold to no engage in reverse in 5 or 6 short trips and one 5 mile trip. All forward gears still fine after 5 seconds after cold start. Right now it looks like plan C (rebuild) is the plan. Will decide first of the week.
Paul

your reverse missing more sounds like the clutch drum behind the front pump - I think its called the K3. It also plays a role in 1st gear I believe.

Stretch has a nice chart for this.

All is good now. Transmission rebuilt. The main problem was the B3 clutch seal was actually coming apart. All of the clutches and bands looked good including the reverse clutches. Other seals were hard as a rock. Went ahead and did a complete rebuild. It is like it is an entirely different car. It is so smooth and responsive. The transmission must have been doing things I didn't know about. Final cost with all clutches, bands, seals, converter, modulator valve, etc and labor and tax was $1637. I felt this was fair. I am so happy.
Paul

Very good price. It would have cost at least twice as much for a good job here.