The pressure modulator does indeed control shift firmness. On my 928, I had a soft change with an annoying “flare” between changes. Winding up modulator fixed this, to the point I get a tyre squeal between gear changes when my foot hits the pedal hard. Cheers from Sydney.

@MrToddgibbs

29 күн бұрын

Hi Anthony, oh nice work :) not sure mine has the ooomph to squeak in gear change. I’ve wound mine another 1/2 turn clockwise and it definitely firmer.

I bet that housing estate really looks forwards to you using them for a sound test 🤣 More great diagnosis work. You'll get there in the end!

@MrToddgibbs

19 күн бұрын

Lol yes, I can almost hear them cheer… Slowly getting there, not happy with Bowden cable yet….. tune in next week!

Firstly, I have the later 4 speed but I think the idea is the same. The bowden cable is critical for the shift point and a small adjustment makes all the difference. The kick down is entirely electrical - there's a switch under the gas pedal and an electrical servo on the gearbox. On mine, the adjustment for the bowden is under the inlet manifold. Tricky to get at but possible. The factory setting requires removing the ball joint (which you did) and adjusting it so that it just reconnects without any pushing or pulling. You have to remove it as the return spring is not that strong. This depends, of course, on your throttle being correctly adjusted first.

@MrToddgibbs

Ай бұрын

Hi Howard, I think its different on the 3speed. Going to read some merc docs on the gearbox... will keep you posted

As always, impressed with your approach to repairing your car. Did you make a video outlining your goals and approach for the build?

@MrToddgibbs

Ай бұрын

Hi! Thanks :) no I never made that video - my goal is just to finish the car to the best quality I can

Hi Todd, I have the 3 speed AT and setting the shifting later or earlier is done at the back on the AT itself. There is a clamp that you can change. The more tight you set the cable, the quicker it shifts. I have the impression that your kickdown is not working properly. Kickdown is done via a switch under your gaspedal. If operate the kickdown at around 30Mph, it should raise rpm from 2000 till 4000

@MrToddgibbs

Ай бұрын

Thanks for your reply! Yes I think you are right. Towards the end of my video (right at the end I think) I flash up a photo and circle the bit you are talking about - is that right ?

@MrToddgibbs

Ай бұрын

And yes, it’s possible kickdown wasn’t working

@user-wk9cn1rn6r

Ай бұрын

@@MrToddgibbs yes you can change the tension of the cable via the clamp on the photo at the end of your video

@MrToddgibbs

Ай бұрын

great, thanks!

@user-wk9cn1rn6r

Ай бұрын

regarding your speedo problem : I have put an item on rennlist porsche 928 forum: for those who have issues with their speedometer ( no speed, nor odometer indication), it could be that the sinus-signal ,coming from the speedsensor , is too weak. The magnetic field of the magnetic disc could be weakened through the years by aging. the solution : boost up the signal by shunting the 12V to the Sinus-signal via a resistance of 1kOhm. this is done by soldering this resistance at the back of flex foil and this between the lowest rivet (12V @speedometer ) and the rivet just above (signal from speedsensor) I can send you a photo of this because any links put on youtube are being removed….

Good to see you back Mr Gibbs! When is the nitro boost going in? I’m expecting at least 1000bhp out of this baby.

@MrToddgibbs

23 күн бұрын

Loving the enthusiasm:)

There's a possibility that the Bowden cable is stretched almost to the limit of adjustment. Worth bearing mind, if nothing else. Keep up the good work Todd, looking forward to the next vid. 👍

@MrToddgibbs

Ай бұрын

Thanks John :)

I bow do(w)n to your perserveance wiith fault finding I can give my 3 speed 4.5 a blat tomorrow and see where things change up and down if you like Weather might be alright, winter is knocking on door But another great video for us to referernce to

@MrToddgibbs

Ай бұрын

Thanks Pieter, that would be useful. And compare your engine up in higher rpm…. Does it sound like mine ?

@pieterschaar5613

Ай бұрын

@@MrToddgibbs Hope to get this done tomorrow, weather today very unfriendly I'll see if I can video it, only have my phone

Maybe something with the magnets inside the diff?

@MrToddgibbs

Ай бұрын

Hey :) I dont think so... my huge magnet should have worked. I'll take it away from the car and test on the bench.

Hi Todd, our first 928 S1 '82 3spd auto did kickdown to first till aprox 55mph or so. Can't Mercedes bring more info about when to shift as this box came from them? Good luck!

@MrToddgibbs

Ай бұрын

Yes good point! Will check merc videos. Interesting about kickdown…

Modulator is for shift firmness...it should be relatively firm. Bowden is your kick down. The shift point on a 3sp is not something I'm super familiar with. Have you gone to Rennlist to research?

@Dundertaker1

Ай бұрын

This is for the later 722...but he shows how the Bowden cable works. Lots of videos to look through and great leak detection and solutions here on the channel: kzread.info/dash/bejne/k32dspKSmJWXeM4.htmlsi=Bzsv7gdzIWUcbnKk

@Dundertaker1

Ай бұрын

There also should be a test port and a "bar" range (if it's like the 4sp) to set the shift modulator "perfectly". Again...Mercedes source has a video and sells the tool. I'm sure you could source one locally. They sell theirs with an 8' hose to run it through the window when testing.

@MrToddgibbs

Ай бұрын

Ah great idea… I never thought of searching Mercedes! Thanks :)

My car is an S and has the 4 speed auto, so that is different, however certainly the "engine end" of the bowden cable is adjustable and it greatly changes the change up point. The 4 speed also has the vac pod, my understanding is that changes the "firmness" of the shift rather than the shift point. BTW are you sure your rev counter is accurate? I might be totally wrong but the engine sounds higher than just 4K revs. Maybe the bowden cable is the wrong type, if I look at the 3 speed cable on the rosepassion website, it does look adjustable to me? does yours look like that?

@MrToddgibbs

Ай бұрын

Hmm good question about the rpm. Although at the start I included a clip of it revving to 6000, did that sound higher? I don’t think these engines would rev much higher? I’ll check the Bowden cable but I think it’s right - thanks for the reply

@G928...

Ай бұрын

@@MrToddgibbs Ah yes I had missed the first few seconds of the vid when you revved it out to 6K, so yes agreed that is clearly higher than later when it changes just over 4K. I think you have found the answer to the adjustment in other replies. My confusion comes from only knowing the 4 speed, it's very different for the operating cables on the box.

@MrToddgibbs

Ай бұрын

Yeah it seems differently adjusted. I think the rpm when shown at 6000 is about 6000 in reality.

Can you do a video on AC / alternator / power steering belt replacements

@MrToddgibbs

20 күн бұрын

Hi realdata6116, if you go back through my videos I cover all of those belts. Just after fitting the engine. Hope that helps!

Sort of, the engine vacuum determines the type of shift from soft to hard (with no vacuum). The bowden cable determines the shift point and there's a switch under the throttle pedal that causes kickdown. When your gently driving it should shift up at under 2k not 4k. I'm not sure your rev counter is right, it looks low compared to the sound of the engine

@MrToddgibbs

Ай бұрын

Hi Gaz, when it shifts at 4k the pedal is in the floor. Normal driving shifts down at 2000 or so. I think the rpm is correct, but I’ll get a digital meter to check….

I have a 78 manual myself, so I don't know enough about the automatic transmission. However, I am interested in whether the speedo is working after the speed sensor replacement. Super interesting videos, I'll keep watching.

@MrToddgibbs

Ай бұрын

Thanks Eugene. Mine is unlikely to work since I believe the cluster’s flexible circuit board is broken (it’s the one stuck to the back of the instrument cluster). Video coming soon on that …

@keithhoughton4308

16 күн бұрын

​@@MrToddgibbsI have had mine sine 87. The cluster has been off a few times. The clips on to the edge of the board are awful. I have heard of people soldering to the board and using multiple connectors. A job I have been putting off for 30 years or so.

@keithhoughton4308

16 күн бұрын

Multipin connectors.

@MrToddgibbs

16 күн бұрын

@keithhoughton4308 hi Keith, I have a solution coming up in a few weeks… stay tuned :)