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 Posted: Aug 14, 2017 03:20PM
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Good analysis Mur, even a specialist would understand that.

If in doubt, flat out. Colin Mc Rae MBE 1968-2007.

Give a car more power and it goes faster on the straights,
make a car lighter and it's faster everywhere. Colin Chapman.

 Posted: Aug 14, 2017 10:29AM
mur
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It is too bad that things were allowed to progress that far before any action was taken.

For others reading this thread, it is first important to know that properly set up drop gears will have an excellent service life. Really hard wheelspin can reduce life of these components down to around 15,000 miles so if a person does this sort of thing they can expect to pay.

One should take the time now and then to listen for noise in the geartrain. With the car idling in neutral most of the gearbox will be turning. This means the primary-idler-input gear set, and then the first motion-layshaft and then the layshaft will be turning the 1st, 2nd and 3rd gears. The synchro hubs, third motion and final drive will be stationary. Listening for noise like this is a good start. Then push the clutch pedal down, disengaging the clutch. Most drivetrain will still be turning these gears for at least a moment, but once the shifter begins to move to select a gear the synchro will grab and stop any motion. Fully select a gear and everything will be stopped all the way back up to the clutch. A substantial change in sound at this point suggests worn components. In the case of Mark's Cooper S it would have sounded like a rock polisher being shut off.

When I was young I destroyed a few gearbox/drop gear housings so my perspective on wrecking these items comes from fairly genuine experience. I light the tires up less often now.

 Posted: Aug 14, 2017 04:08AM
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US
I would have to agree Mur, I have ask for pics of the damaged parts primary, idler, tranny case and clutch housing. I'm not sure ( as you say ) there is anything there to save. I would not have it shipped to my shop without some hope it can be repaired. I'm also finding I have to price every job based on parts and labor up front. Once additional issues are found the owner needs pictures and a revised cost. I have three rod change A+ gear sets complete with all new bearing, shafts, forks, synchros cleaned inspected corn cob blasted boxed for assembly. DAM 5626 tranny cases are getting harder to find due to first and third ball bearing failure. Currently prepping pre A+ gear sets and matching with new parts to complete as many as possible. Already have two sets of 4 synchro pre A+ SC/CR gears boxed up. I also have a new set of Swift rolling start dog gears and a new set of standing start JKD dog gears. No idea how many sets of CWP std and posi in different ratios. I know I have some 333 trannys but rarely look at them. 

I also have fine collection of tranny cases which have suffered idler failures. Hate to throw them away so I clean them and use them to set engine blocks on for painting. 

My concern with this tranny issue is having followed Marks efforts with this car. I would think he has a nice little car that deserved a full and complete going over. In stead Mark has patched at it with used and discarded parts for years now. BC likes to call me Mr Anal and that's fine with me. I set very high standards for my trannys. With careful selection of new parts, Rockwell testing and careful assembly there is no reason a tranny can't be as good or even better than when they left the factory.  Steve (CTR)

 Posted: Aug 13, 2017 07:36PM
mur
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Sorry about your luck.

First, I can't imagine your gearbox idler thrust face and the transfer case idler thrust face are even salvageable if that much damage has been done. 

Second, if the idler gear got that bad the, well, let's just call it EVERY other part in the gearbox is probably wrecked. 

Third, what gearbox was it? 

 Posted: Aug 13, 2017 02:02PM
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US
Mark how many teeth are on the idler gear?  But then looking at the parts catalog you are looking for a 22G 943 (idler gear, all models to 1976).  So it not like the Cooper 'S has a different tooth count on the idler gear.
As for the primary gear assembly there is no differentiation between the S, GT, 1300, or Austin America they are saying 22A 543 NLA-USE 22G 1053
I have heard of using the small bore primary gear and having it machined out to the 1275 size.

You are referring to the 3-sync transmission for the idler gear - correct?
In a quick look I only found two for the 4-sync - still looking

 Posted: Aug 12, 2017 09:46AM
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GB
I have 1275 'S' primaries good used if you're stuck but i'm in the UK. Shipping not a problem for me. 

 Posted: Aug 12, 2017 03:40AM
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I recently pulled my engine after some serious whining started. I found my idler bearings on the transmission side had vanished! The idler gear shafts are both worn and I've lost several teeth on my primary gear.

Does anybody have a primary gear and idler gear for a 1275 S pre-verto engine/trans?

I'd love to get it back together by the 23rd for an event but can't seem to track down a used set.

email me at [email protected]

Mark Looman, Ada Michigan 1967 Austin Cooper S