MG-Cars.info

Welcome to our Site for MG, Triumph and Austin-Healey Car Information.

Parts

MG parts spares and accessories are available for MG T Series (TA, MG TB, MG TC, MG TD, MG TF), Magnette, MGA, Twin cam, MGB, MGBGT, MGC, MGC GT, MG Midget, Sprite and other MG models from British car spares company LBCarCo.

MG MG Y Type - YB gearbox

Hi my yb jumps out of 1st gear under load
I've taken the top cover off and there doesn't appear to be any damage inside
Springs and ball bearings are intact that lock in the shafts
Should there be a ball bearing top and bottom of the springs. does anyone know what length the springs should be. Thanks
J R Dennis South Yorkshire
jr dennis

Hi JR,

There should be a ball under each of the three springs revealed on removal of the top plate. They push into recesses in the selector shafts to "click" them into place. The top of each spring locates in a recessed hole in the top plate ....... NO balls are fitted at the top of the springs.

Sorry, I don't know the length of the springs. (I had a look in the shed and there were none in my "Y / Morris 10" box. Any in my tins of bits could be TC, W/444 or ???) I know I might be a bit of a cowboy but I usually stretch the springs a SMALL amount ... perhaps 5mm? I doubt that the springs lose length but I don't see any harm in doing it. However, if your car is jumping out of gear I doubt that stretching springs will help much.

I rebuild my own gearboxes but I am NOT a gearbox expert. However, I once solved a "jumping out of 3rd/4th gear" problem on a race TC. The solution might apply to your car. The problem was that the (heavy handed) driver had used sufficient force to break the tip off the tiny bolt which locates the selector to the shaft. As a result, the selector had moved along the shaft. When third was selected, it did not fully engage and would jump out of third gear (while fourth engaged EXTRA well). A few gear-changes later, there would be "movement" and third gear would engage EXTRA well but it would jump out of fourth gear. If you have the gearbox top off, I suggest you (remove locking wire and) unscrew all locating screws (2?) on the first/second selector shaft. Check that they have NOT had their tip sheared off, and are indeed locating the selector fork or selector block to the shaft.

Cheers,
Bob Schapel
R L Schapel

Hi Bob
Thanks for your help I'll try stretching the springs
I've since spoke to Peter Edney who said some people drill the lid and screw a 8mm bolt in to give extra pressure. I think i'll try stretching the spring first

Cheers
John Dennis
jr dennis

I would never recommend Peter Edney's suggestion. Bodging is NOT the correct answer!

Given the similarity between our cars and the TD have you tried posting this on either the TD/TF BBS too? What about contacting Mike Green at NTG or Moss Motors technical support for the springs?

Paul
Paul Barrow

Hi Paul I didn't say Peter recommended only that some people did it

Cheers John
jr dennis

http://www.klassiktrans.co.uk/

They rebuilt my YB gearbox and it seemed to be good job.

Richard
R E Knight

John, are all the screws on the selector arms tight? Loose screws cause jumping out of second and third gear, but maybe it causes the same problem with the first gear?

Attached is a (before) picture of my gearbox with the springs clearly visible. maybe you can compare them with yours?

Willem van der Veer

My gearbox was reconditioned by Klassik Transmissions and I am very pleased with the result - I had a noisy first gear (tooth missing in transpired). Just foe info if also worth noting that if the small lug on the bottom lug on the gearbox (that accommodates the hold down pin) is broken (they often are being cast iron) it is possible to have it welded up quite cheaply by a competent welder who is used to cast iron. I found a guy in Liverpool who did it for me some years ago. I think I paid £25.
D MULLEN

This thread was discussed between 06/02/2017 and 10/02/2017

MG MG Y Type index

This thread is from the archives. Join the live MG MG Y Type BBS now