No drive!

[Chipper]

I've been having problems with my Traveller's hydraulic clutch this week, which leaked its fluid, so for a couple of days this week, I had to drive it relatively short distances with effectively little/no clutch.

On Wednesday, I went to pull away and had real difficulty selecting 1st/2nd, so decided to drop it into a garage to have the clutch hydraulics fixed. All seemed well driving it yesterday, apart from some difficulty selecting and holding onto 1st and reverse gears - 2nd, 3rd and 4th all worked fine, so I mostly stuck to those.

However, this morning, I started off and got about 1/4 mile down the road when it suddenly lost all drive! :shock: I tried all gears, but it wouldn't budge; just a whirring noise in 3rd and 4th. :?

I took a quick look underneath but couldn't see anything obviously amiss.

Have I completely mullered the gearbox (an MG Midget 1275cc one), or is it something else that's let go do you reckon?

Any advice gratefully received...

[IslipMinor]

With the car stationary, and running in gear, does the propshaft rotate? If so it is very likely a halfshaft that has broken. If the propshaft is also stationary, then the gearbox internals (less likely?).

[bmcecosse]

The easy clue - is the speedo reading?? If so - broken halfshaft (or much less likely - the final drive). I suspect though it will be a clutch problem - since the 'garage' have been fiddling in that area. Does it feel 'normal' - or is it maybe stuck down ? Why a hydraulic clutch anyway ??

[Chipper]

Thanks for the replies - some useful things to check out there...

I fitted a hydraulic clutch conversion after fitting the MG Midget engine & box, and discovering the clutch action to be rather sharp and heavy - it eventually wore out the original Minor bell-crank linkages, so I thought fitting a hydraulic kit as used on the Midget might be a good idea, which it is, when it's working properly!

[mike.perry]

Much easier once you have sorted out the problem, which sounds like a broken halfshaft, to fit the ordinary 1098 manual clutch linkage modified as stated in other posts.

[Chipper]

Sure enough, the propshaft is indeed turning with the car running and in gear - which is good, I suppose! The rear axle is making a grinding noise, which seems slightly louder on the nearside, so I suspect that the halfshaft has broken on that side.

Thanks for the replies.

[bmcecosse]

Oh dear - you'll need to take the final drive out to make sure you get rid of every little bit of shrapnel in there....

[Chipper]

OK. May be a good time to update to the 3.9:1 Midget diff I have had stored in the garage for yonks now...

[bmcecosse]

Absolutely.

[Chipper]

Finally got around to jacking up the back and whipping out the halfshafts for a look-see today, and sure enough, the nearside one has twisted and snapped its splines going into the diff.

So, had to remove both halfshafts in order to get the diff out to be able to remove the broken bit, which was well jammed in and took a bit of beating with a hammer and long screwdriver to extract it. Good news is, the diff seems to be in good order despite a bit of metallic stuff in the oil, so a replacement halfshaft, seals and diff oil and the car should be good to go again...

[bmcecosse]

Fit the 3.9 !!

[Chipper]

Well, thanks to King Street Motor Services of West Malling, who supplied a replacement halfshaft, diff & halfshaft gaskets and O-rings, I was finally able to rebuild the back axle this afternoon, along with the 3.9:1 Midget diff I've been meaning to fit for yonks, so all back together again now.

[bmcecosse]

Well done. Just need to calibrate the speedo now...

[IslipMinor]

The side benefit of using a 3.9 ratio is that it transmits less torque to the halfshafts, so they will get a slightly easier time.

[Chipper]

Yes, I was thinking that may be the case. Any idea how much the speedo might be out, and will it under- or over-read?

[MarkyB]

Check it againsy a GPS.
If you have a smart phone there are plenty of free ones you can install .

[IslipMinor]

Maurice,

Assuming that the original ratio was 4.22, then with a 3.9 the speedo SHOULD under-read by ~8%, but since Minor speedos typically read 'fast' by quite a bit, the end result could well be a reasonably accurate reading! As suggested check it with a GPS or smartphone app.

[bmcecosse]

Absolutely - especially if it is a 1378 speedo, rather than the 1408. It may well read a couple of miles slow - so don't push the speed limits !

[Declan_Burns]

Mine reads perfectly accurate with the 3.9 diff-could be the same in your case.
Regards
Declan

[mike.perry]

The 1408 speedo over reads by so much with the 4.22 diff that it is almost spot on with the 3.9