No first gear in 722.3

[Jeeze]

Tranny seems fine.. start in 2, give some gas and it goes into 1st. It won’t go into 1st after pushing it into b mode anymore.
I have replaced the kick down solenoid, confirmed voltage, can here the click of the solenoid, but will not start in first gear!
My fgs module depends on this working so it can do it’s job.
Any ideas??

Chris
Btw 1991 500sl

 

[nocfn]

So to be clear, at a stop light you physically move the shifter to 1, but it still starts in 2nd?

 

[Jeeze]

So to be clear, at a stop light you physically move the shifter to 1, but it still starts in 2nd?

Yes

 

[nocfn]

That is odd. Original trans, last drain and fill? Anything in the pan when you changed filter?

 

[gsxr]

Might need to take the valve body apart for a good cleaning...

 

[Jeeze]

Might need to take the valve body apart for a good cleaning...

I was afraid of that

 

[Jeeze]

I was afraid of that

Anything else I should be doing while I’m in there

 

[gsxr]

Anything else I should be doing while I’m in there

New K1/K2 valve & spring kit wouldn't hurt, if not NLA. Not much else to do but clean & inspect. Guess you could replace the Teflon seals on any other valves/pistons (i.e., B1) but those are spendy.

 

[Jeeze]

That is odd. Original trans, last drain and fill? Anything in the pan when you changed filter?

I sold the car to my nephew 3 years ago and have bought it back again. Previously I had it for 12 years. Have tranny receipt from him at home so I will see what they did and what fluid they put in. Will report later.

 

[nocfn]

Just back from a deal I had - As Dave suggested, remove the fluid on a hot drain, do the TC as well with appropriate gasket and filter. If you don't do the work, there could be pan sealant, sludge, broken bits of friction stuck in the VB etc. Sometimes you have to open up the patient and cleaning the VB may be just inspecting it off the car and there may be obvious detritus gomming up the works.

 

[Jeeze]

Just back from a deal I had - As Dave suggested, remove the fluid on a hot drain, do the TC as well with appropriate gasket and filter. If you don't do the work, there could be pan sealant, sludge, broken bits of friction stuck in the VB etc. Sometimes you have to open up the patient and cleaning the VB may be just inspecting it off the car and there may be obvious detritus gomming up the works.

The filter and oil was replaced a year ago. No other choice but to get it serviced again with the issue in mind. Very annoying starting from 2nd gear again.

 

[dionphaneuf]

Following along. I think my 86 SEC has this exact issue: Seems to go into 1st fine on its own, but if I engage B on a long downhill (as one does in SF) I get nothing. Car had 90k mi when I bought and trans was slipping like crazy. New fluid and filter (including TC) and it's wayyyyy better. Not as good as my 500E but close. Might try and clean the valve body as suggested by Dave and shown in these videos, looks like a fun project

 

[maw1124]

Following along. I think my 86 SEC has this exact issue: Seems to go into 1st fine on its own, but if I engage B on a long downhill (as one does in SF) I get nothing. Car had 90k mi when I bought and trans was slipping like crazy. New fluid and filter (including TC) and it's wayyyyy better. Not as good as my 500E but close. Might try and clean the valve body as suggested by Dave and shown in these videos, looks like a fun project

Maybe call Marc at Sun Valley and spend 10 mins on the phone first. One suggestion you may hear is to run another transmission flush about 500 miles after the first, because ... cleaning agents. That might clear both the trans and the VB. Just a thought, but he's a better resource than me. He's warned me before to stay away from the off the shelf transmission cleaning agents (e.g., BG, etc), because it's not the chemicals that go in that are of concern -- it's what stays in and ruins the seals over time, etc. He didn't trust them, and he LIVES Mercedes transmissions and has for some time.

maw

 

[Jeeze]

Maybe call Marc at Sun Valley and spend 10 mins on the phone first. One suggestion you may here is to run another transmission flush about 500 miles after the first, because ... cleaning agents. That might clear both the trans and the VB. Just a thought, but he's a better resource than me. He's warned me before to stay away from the off the shelf transmission cleaning agents (e.g., BG, etc), because it's not the chemicals that go in that are of concern -- it's what stays in and ruins the seals over time, etc. He didn't trust them, and he LIVES Mercedes transmissions and has for some time.

maw

Thank you everybody for the advice and resources you have given me. I will keep you posted for the result.