Transmission shifting erratically

[landspeed]

1993 400E 196k miles.

Owned the car for almost 2 years, bought at 187k. It always had a 3-4 shift flare, even after a trans service with all OE parts and fluid. At 194k miles, I changed to Type F fluid at the recommendation of several on this forum. No change to shift quality with Type F. About 1500 miles later, it started shifting erratically only when warm. when cold, it shifts fine(except the 3-4 flare), but as it warms up, the shift quality degrades. When fully warm, it SLAMS 2nd gear, then immediately shifts again and flares the 2-3 shift, and then immediately shifts again, and flares the 3-4 shift. I have the lift off the gas for either flaring shift When this happens, I'll be in 4th gear at 20-25mph, good thing it has lots of torque. The transmission has always felt kinda clunky with downshifts, and feels worn overall, but even when warm, doesn't slip when in the gear, only when shifting. The modulator is not leaking, and adjusting it seems to be making a difference, but does not affect warm shift quality. I went back to OE fluid, but no change.

I am planning on a rebuild, or rebuilt exchange trans at some point, hopefully later than sooner.

I'm also an MB dealer tech, if that help with technical questions.

Thanks guys.
Ian R.

 

[gsxr]

Most likely needs a rebuild. However, you could check the B1, K1, and K2 spring trains for damage.

Welcome to the forum!

 

[landspeed]

I forgot to add that I did replace the K2 spring and damper(valve?) with OE parts after it started acting up, with no change.

To me, it seems kind of odd, that a worn transmission would act up so suddenly, not gradually. So, I was anticipating a component failure, that I could repair and buy some time. I work with some old timers, and they seemed to think "rebuild time" as well.

 

[gsxr]

K2 only affects the 2-3 3-4 upshift. If rebuilt, the trans needs to have ALL the springs checked inside the VB. A bad VB can make an otherwise good transmission shift terrible. Still, with 200kmi on the original box, it seems a rebuild is inevitable...

 

[landspeed]

K2 only affects the 2-3 upshift. If rebuilt, the trans needs to have ALL the springs checked inside the VB. A bad VB can make an otherwise good transmission shift terrible. Still, with 200kmi on the original box, it seems a rebuild is inevitable...

I was under the impression that K2 is for 3-4, and K1 was 2-3. Everything I have read(here and other places) have stated that, but I trust your knowledge too. I was planning on replacing the K1 anyway, parts are cheap.

 

[Kridre]

Here is what band or clutch is engaged on what gear, for me, it looks like K2 is for 3-4 shift and K1 2-3.


From my personal experience I also can say that at this mileage when the shift flare starts to happen it means that full rebuild is coming. Still, I was driving like this for 7 years and made more than 50kkm, but I recommend don't drag this out. New reverse piston is expensive.

 

[gsxr]

I was under the impression that K2 is for 3-4, and K1 was 2-3. Everything I have read(here and other places) have stated that, but I trust your knowledge too. I was planning on replacing the K1 anyway, parts are cheap.

SORRY! Typo... you are correct. K1 is for 2-3, and K2 is for 3-4. Previous post edited. If all shifts were ok but 3-4 upshift flared, a new K2 train should have helped (126-270-04-35).

Still, the same applies... need to check all the VB springs. It's not uncommon to find one or more broken springs, although at 200k this may be chasing ghosts.

 

[landspeed]

Yes, that is the P/N I installed. I may pull down the VB and pull it apart and check for broken springs and blockages. In the mean time, I added a bottle of Lucas Trans Fix(hail mary), and so far I'm liking the results. It's not 100% fixed, but after 30 miles, it definitely takes longer to act up. I'm just trying to buy time, with trying to buy a house, and a baby due in June, my budget is approx. zero.

 

[gerryvz]