Gear change

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Sunfly
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Gear change

Post by Sunfly » Fri Mar 15, 2024 10:36 pm

The Flying machine is in first class running order apart from one thing! Stiff gear changing - and occasionally gear crunching! My reccolection of my 16v was that you could change gear with the lightest push on the gearstick but with the FM its a very firm tug. Oil has been renewed and linkage has been lubricated so I guess its the synchro as the clutch is also new and working ok. Its spoiling the drive for me, so though its quiet running, I think it will have to have the synchro serviced.

I just wondered if anyone can confirm that a box in good order is smooth and light to change gear and that youd agree I've got worn synchro rings (all gears but 1 & 2 are worst. Any idea of cost to get it sorted as my days of crawling under acar are happily over.

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Re: Gear change

Post by andy p » Sat Mar 16, 2024 6:20 am

Are you absolutely sure the clutch is completely releasing? As it sounds more like clutch drag if it's happening in all gears. Very unusual for all the synchro's to go at the same time.

mojo98
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Re: Gear change

Post by mojo98 » Sat Mar 16, 2024 9:18 am

Sounds like a big job if you go down that route of stripping a gear box,
Yes gear change should be smooth and easy to change gears, apart from my
daily runner had a issue with changing gears, over the years I've changed to gearbox oil, added moly slip even after changing the clutch, I ended up changing the master and the salve cylinders,
But still struggled to get it in to gear, ended up adjusting the clutch pedal, and guest what it's seems to having done the trick. I would do the small stuff first, before going down the route of stripping the gearbox

Sunfly
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Re: Gear change

Post by Sunfly » Mon Mar 18, 2024 1:46 pm

Hi Andy and Malcolm.

Tempting to think of the clutch but its new in mileage terms. I renewed it at about 82k and its now on 101k. New flywheel too (thanks Duncan) so new to all intent and purpose. Plus which, it disengages almost immediately and reengages high. With it in gear with the clutch in, theres no drag at all and it rolls on the very slightest slope so I'm fairly sure its not the clutch. However, its off for an MOT on Wednesday so I will ask my trusted mechanic who fitted it, for his opinion.
However, now Malcolm has reassured me it should be light - if as suspected its the synchromesh, I have a nephew by mariage (Geartech in Carterton) who as his name suggests, does gearbox repairs. I think it will be a simple job by his standards, so you never know, I might get a concession. Even if it does cost me a few quid, I think I'd like to have it sorted as it spoils the fun of driving the car and I dont keep it for any other purpose. Plus I dont have any other vices to spend money on - mores the pity.

Spoken to Stuart. Just off to Carterton for him to give it a coat of looking at. Stuart is checking the price / availability of the synchro rings.

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Re: Gear change

Post by Sunfly » Tue Mar 19, 2024 8:35 am

I went to see Stuart McCrudden yesterday who took the car out for a rigorous test drive (a little faster than I liked) and he seems to think the problem lies with the front UJ and not the synchro. Also suggested a lighter gear oil may help. Has anyone had experience of the gearbox end universal joint (which does look dry in fairness) causing a stiff gear change. It doesnt flex much in service from what I can see and only has to cope with the engine flexing on its mounts in reality.

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Re: Gear change

Post by mojo98 » Tue Mar 19, 2024 9:01 am

That's a new one for me Bob,
As for gearbox oil, I alway use synthetic GL4
This from the Oracle :-
Synthetic gearbox oil is found to work the best, improving the 1st to 2nd gear changes especially when the gearbox oil is cold. In practice Redline MT90 GL-4 75w90, Valvoline Synpower 75/90 Synthetic

If a GL-5 oil is used it must be compatible with brass/bronze synchros i.e. sulphur free ? many are not. Use of the wrong oil will halve the life of synchros & bearings.

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Re: Gear change

Post by Sunfly » Tue Mar 19, 2024 9:44 pm

mojo98 wrote:
Tue Mar 19, 2024 9:01 am
That's a new one for me Bob,
As for gearbox oil, I alway use synthetic GL4
This from the Oracle :-
Synthetic gearbox oil is found to work the best, improving the 1st to 2nd gear changes especially when the gearbox oil is cold. In practice Redline MT90 GL-4 75w90, Valvoline Synpower 75/90 Synthetic

If a GL-5 oil is used it must be compatible with brass/bronze synchros i.e. sulphur free ? many are not. Use of the wrong oil will halve the life of synchros & bearings.
I was a little sceptical as it feels like stiff engagement but Stuarts not in the buiness of making poor judgement or turning down work so the UJ has to be checked. (It will do it no harm after 27 years) That will happen tomorrow after its MOT. Fingers crossed for that!
Thanks for the oil tip Malcolm. Interesting they mention 1st and 2nd.

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Re: Gear change

Post by Sunfly » Tue Mar 19, 2024 10:05 pm

Sunfly wrote:
Tue Mar 19, 2024 9:44 pm
mojo98 wrote:
Tue Mar 19, 2024 9:01 am
That's a new one for me Bob,
As for gearbox oil, I alway use synthetic GL4
This from the Oracle :-
Synthetic gearbox oil is found to work the best, improving the 1st to 2nd gear changes especially when the gearbox oil is cold. In practice Redline MT90 GL-4 75w90, Valvoline Synpower 75/90 Synthetic

If a GL-5 oil is used it must be compatible with brass/bronze synchros i.e. sulphur free ? many are not. Use of the wrong oil will halve the life of synchros & bearings.
I was a little sceptical as it feels like stiff engagement but Stuarts not in the buiness of making poor judgement or turning down work so the UJ has to be checked. (It will do it no harm after 27 years) That will happen tomorrow after its MOT. Fingers crossed for that!
Thanks for the oil tip Malcolm. Interesting they mention 1st and 2nd.
Just ordered the RedlineMT85 GL-4 75W85 (a little thinner at high temp) as they claim it makes shifting easier and compatable with sintered bronze sycs.
I shall report in due course.

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Re: Gear change

Post by cpt black » Wed Mar 20, 2024 1:08 pm

Hope al goes well Bob,got short shifters in mine

Sunfly
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Re: Gear change

Post by Sunfly » Fri Mar 22, 2024 10:23 am

cpt black wrote:
Wed Mar 20, 2024 1:08 pm
Hope al goes well Bob,got short shifters in mine
Hi Kev.

What are short shifters? How do they affect the gear change?

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