I am in the throws of rebuilding my gearbox. I've bought new synchro hub springs.
When I took apart the hubs I noticed that the old springs were different lengths, I assumed this was because one set were cactus so I checked another set of synchro hubs and they were the same!
1st/2nd hub long springs
3rd/4th hub short springs
In both sets of hubs!
Does anyone know if the 3rd/4th hub springs tend to go sooner than the 1st/2nd hub springs?

I compared them to the new springs and the new springs are shorter again!!!

The figures are as follows

1st/2nd hub spring height; 17.6mm wire diameter 0.68mm
3rd/4th hub spring height; 14.8mm wire diameter 0.68mm
New spring height; 13.3mm wire diameter 0.74mm

Any ideas?

From a bit of a search these springs have the same part number (22G2262) so should be the same, or at least would have been the same when new.

Steve

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1964 998cc Cooper
1971 Mini K x 2
1972 Clubman GT

New hub springs from UK are softer than originals, I knocked back buying a set last year and scrounged good s/h ones out of my stash instead.
Minisport SA sells stronger/longer ones. http://minisport.com.au/prod1437.htm

I think 3 synchro boxes had stronger springs in them than the 4 synchro did, from memory.

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DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.

Haha, last time I asked about hub springs on this forum, I looked at the Minisport SA ones, and you recommended me some UK made ones instead!

True back then but UK supplied springs have gone downhill since. I wonder where they might be getting made now..

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DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.

Bummer! I just picked up an order from minisport today.

I did a bit of a test where I drilled a small hole in some rhs and using a small machine screw through the spring I put the same weight on each spring. The long ones came out best, closely followed by the new ones. the short ones obviously came last.

I am thinking that the long ones are still ok to use?

Longer spring is better, 3 the same should be OK.
Put the strongest ones in the 1st/2nd hub it takes more of a hiding on downshifts.

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DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.

Cheers Doc,


That is what I thought yet in both the gearboxes I have the 3rd/4th hub springs were the worst. Bizarre!

3rd & 4th get more use, but to engage 2nd>1st & 3rd>2nd there is more force needed to let the baulk ringsynchronize the gear rotation speed. If the hub springs are weak they will not give enough initial thrust on the baulk ring to make it rotate in the synchro sleeve & `baulk', and the gears can then crunch similar when you have a worn out baulk ring.

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DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.