Second gear starts when cold

[kiteoregon]

Since winter started my 300d auto has decided that when it sits for 4 or more hours to not shift into first from a stop. Even when manually shifted i can't get it to go below second. After 5 minutes idle or driving it's shifts fine.

It has been this way almost all winter, but 1/2 way through for about 10 days it shifted perfect again. wtf?

Fluid is correct level, filter was new end of summer, modulator correct, bowden adjusted correctly. Vacuum is 15 at idle and drops to 0 under full acceleration.

Again, after 5 minutes or warming up car shifts great.

any ideas?

thanks.
ko.

[babymog]

Most cold-start transmission problems are a result of the internal seals hardening and shrinking, when first running the operating pressures will be low due to fluid leaking by these seals, different transmissions show different symptoms (slipping is common).

Once the transmission warms up, the seals grow and soften sealing the leaks, and the operating pressure returns to adequate levels.

If this is your problem, it is sometimes (temporarily) resolved by pouring a solvent into the transmission to soften seals, sold under many names EX: Trans-X.

I'm not recommending it, but if the transmission is failing, this could help nurse it along until a replacement is found.

[kiteoregon]

Are these seals in the valve body, or inside the transmission it's self?

[babymog]

Both. The pistons that move clutches/bands can leak, lowering working pressure. Sometimes, if caught in time, these transmissions can be "re-sealed" by tearing down the transmissions and all of the hard parts are re-useable including friction parts.

If it starts to slip, then it becomes critical.

[Diesel911]

When my Trans started to do that later the B2 Piston broke and I had no First Gear at all.
Pic one is the Broken Piston. All the stuff in the pic should be one assembly.

Pic 2 is the Seal and behind it the Bushing. Both, get replaced.

B2 Piston, Seal and parts
B2 piston number 107 270 04 32 (1702700432) {number cast into the piston 126 277 11 38}
{Outer O-ring 005 997 70 48} For the Outer Cover
{plastic bushing 126 277 08 50} Replaces the Metal one
{Lip Seal 006 997 73 47} Holds the Plastic Bushing in and the Lip faces out.

[tangofox007]

Originally Posted by kiteoregon

Are these seals in the valve body, or inside the transmission it's self?

Originally Posted by babymog

Both.

How about a picture or part number for a valve body seal. I would like to see one.

[babymog]

I guess I would start with the accumulator pistons, ...

[kiteoregon]

It's interesting, i had the transmission out this summer and replaced almost every seal except the B2. Once i had it installed i noticed a very small leak from the B2, i was thinking i would go here first, i guess it's easy enough to check and replace.