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-   -   85 300D Automatic transmission hits first shift at 4200rpm (http://www.peachparts.com/shopforum/tech-help/23600-85-300d-automatic-transmission-hits-first-shift-4200rpm.html)

Carrameow 09-18-2001 08:45 PM

85 300D Automatic transmission hits first shift at 4200rpm
 
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I recently rebuilt the top half of my 85 300D. The car has an automatic transmission which doesn't hit its first shift until 4300 rpm. (1) Isn't this kind of high? and (2) (assuming the fuel pump and engine are working fine) What do I adjust to make the transmission shift properly?
Does anyone have a procedure? I can't find one on the service CD?

engatwork 09-19-2001 06:32 AM

Car - It is high - try loosening the "bowden" cable. Sounds like it is way too tight. As you look at the picture it is the cable that is shown at the very top of the picture, center of right, with the black rubber accordian type of cover on it. Disconnect the "ball" end and adjust the cable till the "ball" is right over where it is supposed to be connected without having to pull on it. Also, take another pic from the top showing all the linkage and I will compare it to mine to make sure everything looks like it should. Good job on getting it back together, sounds like you had quite a struggle.
Thanks :)for helping me out too.

stevebfl 09-19-2001 08:14 PM

The adjustment as Jim points out is around #6. It will take a major misadjustment so be sure the cable pulls and springs back easily and completely when you have the cable end loose.

Also be sure that the electric kick down isn't energized. I usually do this very simply by disconnecting the kick down solenoid (at right rear of trans). The wire should just pull out of the solenoid.

Carrameow 09-19-2001 08:38 PM

Cable position
 
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Dear Mr. Brotherton /Mr. Ellington
Wouldn't a slack cable contribute to a higher shift RPM?
The slackness in the cable would force the throttle reach a higher swing postion and therefore a higher RPM before the transmission would detect a tug on the cable by the throttle mechanism at Rod (4)?
My impression is that the more taut the cable, the faster the transmission will detect a change in throttle position by a quicker cable movement and will therefore shift faster, at a lower RPM.
My final idea is that I was reading all the newsgroups today on the 1985 300D Automatic, and hypothetically, the transmission should be dead now because the car has 232000 miles on it. I saw almost 20 messages on the Google Website. However when I bought the car at a junkyard, there was an AOPA (Aircraft Owners Pilots Association) sticker on it which convinces me it was well maintained and well driven. The car had new brakes, calipers and fresh oil.
Respectfully, Richard Chang

stevebfl 09-19-2001 09:12 PM

No, you have it backwards. The slack cable tells the transmission that the rpms are being developed without throttle movement so it shifts since there is no load.

The idea is to put the trans in the appropriate gear for the load being delivered. If ones throttle is heavy then the trans stays in the lower gear longer to gain torque advantage and develop horsepower.

Steve

PS if you have a slack cable and are shifting late, the cable is probably frayed and stuck out. This will definitely cause late shifts.


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