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MG Midget and Sprite Technical - Crunchy first and reverse

Hi all
Just got the car running for the first time and have uncovered a slight issue.
When at a standstill if I press in the clutch the engine revs drop about 100 rpm. If I then try and engage 1st or reverse it goes in with a crunch. All other gears seem fine.
Gear box and clutch are new as are the hydraulics.
Is it just a case of air in the hydraulics?
(Although this doesn't explain the revs dropping, is this just the carbon thrust bearing bedding in?)
Tim
T Dafforn

Tim,
for the crunching have you checked the hydraulics (air, slave pin, pedal, ect.)

as the g/box has fresh oil at the correct level then it leaves the g/box itself if it's not the clutch (any problems with installation of clutch)

does your clutch engage at top or bottom of pedal travel

for the drop in revs it's usually worn release bearing or worn crankshaft thrust bearings
Nigel Atkins

Thanks Nigel.
Thrusts, throw out, gearbox and clutch all new.
gut feeling a hydraulic issue but why would 2,3,4 all be ok?

Cheers
Tim
T Dafforn

if there only a bit of drag perhaps because they have syncho and you're not testing under load on the road(?)
Nigel Atkins

The only thing I will add is that all pre 1975 cars had straight cut first and reverse gears, therefore no syncromesh to match the revs between gears
R Williams

Sounds to me like there is a little drag on the clutch or the spigot bearing - both likely to resolve once they are run in.

In the meantime simply push down the clutch and pull the gearlever towards 2nd so the synchro slows and stops the spinning input shaft and laygear before engaging 1st or reverse.
Chris at Octarine Services

Chris,
Could be possible that the spigot bush is dragging. It is new and a needle bearing type, and it did strike me that the oil seal at the outer end of the bearing gripped a little on the input shaft. I guess that will soon wear in once it has been run for a little while.
May still blead the hydraulics just in case
Tim
T Dafforn

If the bite point of the clutch is a couple of inches off the floor then there it is not the problem!
Chris at Octarine Services

This thread was discussed on 26/08/2013

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