300SDL Valve Body

[BenzB0y]

1. What causes the reverse gear to lag before catching. Is this a MB feature?

2.Where are the screens in the body itself that will build up gunk and cause poor shifting?

3.What are some things to do to extend the life of a transmission?

Thank you for ALL replys, comments, and opinions!

[BenzB0y]

ANYONE who at least might have an idea, would be greatly appreciated!

I really don't drive this car a distance, because I'm worried the transmission is about to go. The RPM's start getting higher the faster I go. The RPM's normally stay at about 2000-2500 at 65-70 mph. I'm worried its stuck in 3rd gear or something. ANY replys' to my questions are greatly appreciated!

THANK YOU!

[TX76513]

1. My SDL does not lag when placed in reverse
2. The screens are in the valve body and can be cleaned when you service the transmission. If a transmission is serviced regularly you won't have anything to clean.
3. Regular Service will allow you to get the most life possible out of your transmission, but you must plan for the future as nothing is forever.

[latitude500]

I have that same problem, I put the car in reverse and it lags and then shifts. What causes that? I'm hoping to replace the tranny fluid with amsoil to see if that fixes anything. But I'm not wanting to replace the fluid if If I have to repair something in it.

Did you ever fix your problem?

[brandlj]

I Have a 86 300sdl and at 55mph my rpm is 2100, at 60 it is 2400rpm
at 65 2700 rpm and at 70 mph it sits right at 3000rpm. This is totally normal. This car was designed when the national speed limit was 55 mph. Now that it is 70 or 75 in places, you will notice 3000 to 3300 rpm at those speeds.

I have no lag when I place my car in reverse. My car has 104,000 miles and I change transmission fluid and filter every two years religiously.

John

[Hit Man X]

Reverse delay means the trans is getting tired. My 300sel takes a while to get into reverse. But with 255k hey, it's been around for a long time.

Service it on a regular basis, this includes draining the converter. Keep the shifts tight/firm. Drive in the city in 3rd gear to limit 3-4 and 4-3 shifting.

[BenzB0y]

would that cause damage to drive around, stop and go traffic in just 3rd gear? seems like it would...

[Hit Man X]

Originally Posted by BenzB0y

would that cause damage to drive around, stop and go traffic in just 3rd gear? seems like it would...

Think about it. What damage could possibly be incurred?

If you still don't believe me, I have some ocean front property in AZ you may be interested in also.

[redassag00]

A one speed transmission would be better in your case, that way it does no damage....

[Hatterasguy]

If you read the owners manual it will tell you that trans breaking is fine. In slow traffic I keep it in 2nd to save the breaks and keep it from hunting gears. Its okay if the engine gets up to 3k or 4k, they are built for that and perfectly happy with it.


Usualy shifting problems are vacuum related, I forget the troubleshooting process but its in the FSM. You can adjust the firmness by the modulator on the side of the IP, but it sounds like you have a leak.

Change the fluid if you are getting a delay going from F-R, their should be none.

[probear]

besides changing the fluid, using synthetic fluids, the biggest thing for transmission life is to keep it cool.
Most people do not realize the most damage to truck transmissions is during backing up, when air is not forced through the radiator/transmission cooler. Transmission temperatures will soar !!!

[Hit Man X]

Originally Posted by probear

besides changing the fluid, using synthetic fluids, the biggest thing for transmission life is to keep it cool.
Most people do not realize the most damage to truck transmissions is during backing up, when air is not forced through the radiator/transmission cooler. Transmission temperatures will soar !!!

You don't have a fan clutch pulling air thru at all times?

[probear]

Originally Posted by Hit Man X

You don't have a fan clutch pulling air thru at all times?

Sure, but in reverse, you generate a lot more heat since the torque converter is not locked up. The bottom line is lots of heat generated and very little airflow. As with the heat, the hotter the transmission fluid, the shorter it's life. I personally do not generally like running the transmission fluid through the radiator core either. There is no reason that the transmission should be at engine temperature. However, in doing so, it's a trade off for the few times that the transmission gets really hot even though that is usually stop and go traffic, when the greatest load is on the cooling system.

[1983/300CD]

Anybody remember seeing that picture of the groove the pin in the differential wore after years of throwing it between drive and reverse? The peg is supposed to be poking through a hole, but this guy had a 3" long slot worn out. Anybody have that pic handy?

[BenzB0y]

Had it diagnosed by a MBH owner that took it for a test drive with me in it after looking at the engine. He said it seems that the clutch for second or whatever is gone and it jumps from 1st-3rd gear. Not sure if that means it's time for a rebuild or if its possible?

Thanks for any input...