[928uk] 3 speed gear change rpm

[James Musson]

I've just been adjusting the cables on my 4 spd (hence how I lost my clip), but some of the same principles might apply to yours. I adjusted the cable to the throttle body until I could just hear the idle switch clicking open and closed with a small amount of movement (and always closing when the pedal is released). If you are in a quiet place, the micro switch is actually quite loud (assuming you are checking by moving the quadrant by hand, so head close to the inlet). You also need to make sure that the WOT switch closes at full throttle; I can use the diagnostic tool for this but for older cars I think that there is another procedure involving a multimeter that you can find on the web.

The tension on the cable to the auto trans is a bit of personal preference, it seems. I now have adjusted mine to the point where the car is quite reluctant to upshift, so I need to back it off. It's interesting to play with the different settings, though.

I did get to a point where there wasn't enough cable movement to engage the kickdown switch but there is also some adjustment in the pedal (fore and aft, by using different sets of bolt holes at the floor mounting) and in the threaded rod that connects the pedal to the arm, and that helped me.

James

________________________________
From: 928uk <928uk-bounces at lists.928.org.uk> on behalf of Paul R Smith via 928uk <928uk at lists.928.org.uk>
Sent: 04 June 2024 9:15 AM
To: 928uk at lists.928.org.uk <928uk at lists.928.org.uk>
Subject: Re: [928uk] 3 speed gear change rpm

When you push the pedal the last few mm to the floor (engine/ignition
off), can you hear the kickdown switch click?

Smiffy

On 04/06/2024 07:25, toddgibbs111--- via 928uk wrote:
> Hi Llew,
>
> So, throttle is sharper, zero play. Perhaps a little too tight as I noticed the idle siting at 1100 (I think cable is keeping it open slightly).
>
> Anyway, gear changes at 4100 rpm still.... I'll get under the car today and see what I can find.
>
> Todd.
>
> -----Original Message-----
> From: Llewelyn Guildford<llew.guild at gmail.com>
> Sent: Monday, June 3, 2024 4:50 PM
> To: Todd Gibbs<todd at oxfordeye.co.uk>
> Cc: 928<928uk at lists.928.org.uk>
> Subject: Re: [928uk] 3 speed gear change rpm
>
> Hi Todd
>
> No worries, I’ve been there myself with a lot of what you’re doing so it’s quite relaxing viewing from the sidelines!
>
> Can you send a photo?
>
> Let me know what it is like with the throttle cable adjusted , you might find it sorts itself out because the throttle actuator is what pulls on the gearbox shift cable and if it’s too slack it won’t work properly! The gearbox cable is definitely adjustable though, sorry I can’t explain the exact steps.
>
> Llew
>
> Sent from my iPhone
>
>> On 3 Jun 2024, at 16:09, Todd Gibbs via 928uk<928uk at lists.928.org.uk>  wrote:
>>
>> Hi Llewelyn
>>
>> Thanks for watch the videos :)
>>
>> Ok I’ve had the airbox off again today and there is no adjustment there in mine. I know exactly where you are thinking (there is a hard tube rising from the bell housing that thur cable passes through). Mine just has a flexible cable “shield” that connects to the hard pipe.
>>
>> I’ve gone back and adjusted the throttle cable, it was slightly loose, and about to test it out….
>>
>> Thanks and will report back
>>
>> Todd
>>
>>> On 3 Jun 2024, at 09:42, Llewelyn Guildford<l.guildford at stemmer-imaging.com>  wrote:
>>>
>>> Hi Todd
>>>
>>> I follow your project on YT - Great progress 😊
>>>
>>> It's a while since I've done this (2017 I think!) so hopefully my memory serves me semi-well!
>>>
>>> The cable is adjustable - Although the adjuster doesn't look obviously so. It seems hard to find an image of it online. The adjuster isn't as an end of the cable, it is half way down. It is located slightly right of centre if you're looking from the front of the car, and is situated behind the airbox on or near the bell housing, so if you take off your airbox and look down behind the bulkhead, standing on the left hand side of the car you should be able to see it. I can't remember in detail exactly how to tension it but it is fairly obvious.
>>>
>>> Check list for correct shifting:
>>>
>>> Make sure the kickdown switch is working, is adjusted correctly and
>>> that the throttle pedal actuates it at WOT (all this can be done
>>> stationary) Make sure the gearbox has the right level of oil in it and that the oil is in reasonable condition I've personally never had to mess around with the vacuum modulator thing on the gearbox and I've had quite a few 3 speed 928s.
>>>
>>> Then move on to the cables
>>>
>>> Start with the throttle cable and get it tensioned so it's nice and tight but doesn't bind! Once you're happy with that adjust the elusive Bowden cable and you should be good to go.
>>>
>>> Gearbox side I would a) not mess with the vac modulator other than to
>>> make sure there are no vacuum leaks b) whatever you've altered on the
>>> cable mount bolt I'd put it back to the original position
>>>
>>> 9 times out of 10 gearboxes run perfectly after this.
>>>
>>> When you've got a baseline result you can then drive, make a small adjustment to the Bowden cable either way then compare - You'll find your own sweet spot with it!
>>>
>>> If you need a hand ever I do find myself in Oxford from time to time so could pop over and have a look with you...
>>>
>>> Hope this helps,
>>>
>>> Llewelyn
>>>
>>> -----Original Message-----
>>> From: 928uk<928uk-bounces at lists.928.org.uk>  On Behalf Of Ben Hodges
>>> via 928uk
>>> Sent: Sunday, June 2, 2024 7:12 PM
>>> To: Todd Gibbs<todd at oxfordeye.co.uk>
>>> Cc: 928 List<928uk at lists.928.org.uk>
>>> Subject: Re: [928uk] 3 speed gear change rpm
>>>
>>> Hi Todd
>>>
>>> I’ve sent you a couple of docs that may help - apologies if you
>>> already have them
>>>
>>> Cheers
>>> Ben
>>>
>>>> On Sun, 2 Jun 2024 at 16:43, Todd Gibbs via 928uk
>>>> <928uk at lists.928.org.uk>
>>>> wrote:
>>>>
>>>> Gents,
>>>>
>>>> Someone put me out of my misery - how do I adjust my 3 speed gearbox
>>>> change up rpm?
>>>>
>>>> Currently it changes at 4100rpm.
>>>>
>>>> My Bowden cable is not adjustable, it has press fittings both ends.
>>>> I’ve adjusted the pressure module and now my gear changes are
>>>> punchier (good), but same 4100rpm. I’ve adjust the bolt thing on the
>>>> side of the gearbox in the mechanism that the Bowden cable pulls on. 4100rpm still.
>>>>
>>>> So I’m at a loss. What else is there?
>>>>
>>>> Thanks for any help
>>>>
>>>> Todd