Pagoda SL Group

W113 Pagoda SL Group => Drive train, fuel, suspension, steering & brakes => Topic started by: WRe on June 21, 2025, 14:02:46

Title: Auto Transmission: Strong shift shock when engaging reverse gear
Post by: WRe on June 21, 2025, 14:02:46
Hi,
My automatic transmission shifts very nicely, no big backshift, precise up and down.
What bothers me a little is a strong shift shock when engaging reverse gear. You get the impression that the car wants to reverse with all its might. It actually happens in every situation, regardless of whether the gearbox is warm or cold. It doesn't get particularly hot either, oil level is correct, just changed, including filter.
Does anyone have any ideas on how to correct this or is it just normal?

The same thing happened when the car came to a standstill and shifted down to 2nd gear. I solved this by increasing the speed switching range on the throttle switch to 1400-1500 rpm (usually 1200rpm).
...WRe
Title: Re: Auto Transmission: Strong shift shock when engaging reverse gear
Post by: MartinK on June 22, 2025, 15:52:35
Servus Wolfgang,
 I think you should try to adjust the reverse band. If it has too much freeway it could cause your mentioned problems. Loosen the counternut right hand side (SW27 or 24) tighten the threaded Bolt (SW10) cw up to 5 Nm and then turn back ccw 1 or 1 1/2  complete turn to free it. Good luck. Martin
Title: Re: Auto Transmission: Strong shift shock when engaging reverse gear
Post by: WRe on June 22, 2025, 18:02:32
Hi Martin,
Thanks for the tip, I'll have a look.
I also found this: https://www.sl113.org/forums/index.php?topic=819.0
...Wolfgang
Title: Re: Auto Transmission: Strong shift shock when engaging reverse gear
Post by: WRe on August 16, 2025, 07:08:22
Hi,
I checked the reverse band but everything is fine.
The problem was that the idling speed was too high, especially when shifting into gear (automatic).
...WRe
Title: Re: Auto Transmission: Strong shift shock when engaging reverse gear
Post by: BobH on August 16, 2025, 08:17:49
i used to experience that, particularly when stopping, and then selecting reverse.  Sometimes the revs didn't drop very quickly, and there was a hell of a shock, i think maybe the linkage was sticking somewhere.  If it happens now i just tap the accelerator until the revs drop before selecting reverse.  The more i drive the car, the less it happens, so i guess it loosens up through use
Title: Re: Auto Transmission: Strong shift shock when engaging reverse gear
Post by: Pawel66 on August 16, 2025, 09:38:21
From my struggles when I was tuning the car:
1. Overall modulator pressure adjustment to book values (needed lift, pressure gauge and banjo connector), described on the forum
2. Idle. Too high idle will cause the jerk of the car when engaging gear, particularly reverse.
3. Reverse band adjustment (described)

I think even when you do all of the above, reverse engagement may cause some jerk. I, when I can, do not press brake when engaging reverse - to preserve the rubber disc on the shaft.
Title: Re: Auto Transmission: Strong shift shock when engaging reverse gear
Post by: Peter h on August 16, 2025, 12:15:27
I also experimented for a long time. First, the solenoid should be working correctly. Often, it gets stuck in a faulty state and only comes free with a tap on the pedal, or it doesn't work at all. So, it needs to be repaired. Then, the idle rpm of the automatic transmission should be around 800 and only drop by a little (100) when the car is engaged. For this to happen, however, all engine settings must be correct so that the engine doesn't become too lean or stall at a CO of 4%. This all depends on whether the engine is completely cold, almost warmed up, or completely warm. It's all a complicated matter, which workshops often bypass and simply feed more fuel to the engine via the throttle linkage and manipulate it.
Peter
Title: Re: Auto Transmission: Strong shift shock when engaging reverse gear
Post by: ja17 on August 26, 2025, 05:51:10
Sounds like you need to go through "The Linkage Tour"'.