[Nobbc] Update on Tech Session

[Greg Tatarian]

Hi Mark,

Gear clashing is usually, but not always, the result of worn synchro 
rings, but other causes are incorrect oil level or type, worn or bent 
shift forks and/or rods, or banged up dog teeth on the gears or synchro 
sliders (hubs). Rarely, a worn shift lever mechanism can be at fault. 
Synchros are brass, soft, and meant to wear out. Sitting with old oil 
can also cause them to corrode (or erode, really), as will using an 
incorrect oil type with the wrong additives. Oils were pretty simple 
compared to today...

It's been awhile since I drove an MGA and others on the list can answer 
the question of how the shift should feel, but I have driven many MGBs, 
including early 'boxes with no first gear synchro (so pretty much the 
same as your "A" 'box). I never found a clashing gearbox that didn't 
have some problem, and good gearboxes always shifted well and rather 
precisely.

You can buy some time by either rev-matching when downshifting or double 
de-clutching, but it's tougher if you are clashing going up from 2nd to 
3rd. That usually demands a very slow shift and a throttle blip.

If no member in your area steps up to give your car a test drive I'll be 
happy to do it. I'm in Santa Rosa, and have done many vehicle 
inspections and test drives for prospective buyers.

Cheers,
Greg


Mark Darley wrote:
> Greg,
>
> Sounds interesting. If you can avoid the second saturday in the  
> month...........
>
> On the topic of gearboxes:
>
> I seem to be having trouble avoiding crunching when shifting down  
> from 3rd to 2nd (except when really low revs), and getting up through  
> the gate from 2nd to 3rd seems to be getting stiffer.  (Only driven  
> 500 miles or so since I got it on the road). I double de-clutch from  
> 1st to 2nd but rely on the synch between 2nd and 3rd, at least coming  
> down. Oil in gearbox is right and fresh.  The car was stored for 4  
> years before I got it.
> Car has about 52,000 miles on it and according the the original  
> owner, she cannot remember having the clutch or gearbox rebuilt.
>
> Any suggestions as to what the trouble might be?.....hoping it is  
> simpler than rebuilding the gearbox....
>
> As a new owner, part of the problem is I am not really sure how  
> smooth the gate should feel.  The MGA I had for 6 weeks in 1974 was a  
> beater and no guide!
>
> I think I need a volunteer to drive the car and give me feedback.   
> Any MGA owners up for a test drive in Mill Valley?
>
> Mark
>
> Mark Darley. 58 MGA
> markdarley at mac.com
> Mobile Phone 415 310 5252