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MG MGB Technical - problem getting reverse

Advice needed, I have a 79 Roadster, no problems engaging all forward gears, but will not engage reverse. any advice greatfully received.
Cheers John
john hall

What exactly is the problem?

Does the gearlever not move to the reverse position, or does it just not engage?

Has this just happened out of the blue, or were there any symptoms leading up to it?
Dave O'Neill 2

Does it grind when you try to put it in reverse? If so, the bushing inside the crankshaft which bears on the input shaft may be damaged, or the input shaft worn or bent. This would keep the input shaft spinning thereby making it grind in reverse, however the forward gears may not grind due to the syncros. I had this very problem for awhile before my rebuild, although it would engage after a short "grind" I stopped the reverse grinding by putting the gearlever into first, then quickly running it back into reverse before the input shaft had time to spin up. A new bushing solved the problem.

Unfortunately I can't advise you if the lever won't even move into reverse, but many others on this board are knowledgeable in this area.

Erick Vesterback

I had exactly the same problem on a '71 B. The problem was the push rod on the master cylinder. Over time, the hole had worn into an oval shape meaning that the clutch would not fully disengage.

Remove the pedal box cover and have a look at the pushrod. A new one will cost £10 from Moss and is very easy to fit.
James Stewart

Also look at the slave cyllander --- perhaps a new clevis pin will do the job.
Dan Robinson

Has got gradually worse, now it feels like the lever is hitting something and will not engage, even with engine not running.
Cheers John
JOHN HALL & JULIE ROBERTS

Grinding in reverse can also be a dragging clutch. Quite often baulking is 'normal' for every BL gearbox I have ever had (and occasionally so in every other gearbox I have had), also in first, but yours sounds like selector wear.

For pedal clevis wear the pedal, push-rod and clevis pin all wear and you have to deal with all three, doing just the push-rod will only remove 1/3rd of the lost travel. I welded up the worn side of the hole in my pedal and filed it back out to shape as being easier to get accurate positioning than completely welding and redrilling. I happened to have a spare but unworn push-rod, but I'd have done the same to that as well. That together with a new clevis pin got rid of about an inch of lost travel. Make sure you get the correct size, an under-size pin will also cause lost travel. Note that this is not required at the slave end of the hydraulics as the system is designed to compensate for wear at that end anywhere in the linkages, driven plate, friction plate or flywheel.
Paul Hunt 2

This thread was discussed between 20/10/2007 and 22/10/2007

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