TC Gearbox Jumping Out of Second Gear

[MJansen]

Hello Forum,

I would like to know the most common causes of why a TC gear box slips out of second gear. While driving in second when I release the throttle pedal the gear box shifts to neutral. If I hold the shift knob in second by hand, it remains in second (although there is some force wanting to shift it to neutral). If you could point me to some documentation that has been written on the causes and resolutions I would certainly appreciate it too. I have the gear box removed in order to repair the rear seal leak and to also replace the clutch, and thought this would be a good time to fix the second gear issues.

Cheers,

Mike Jansen
TC 1357
USA

[Ray White]

I expect there are some worn parts and the gearbox probably needs an overhaul. You might find this link - by our own Rick Storms - helpful.

http://www.mg-tabc.org/library/gearbox/ ... earbox.htm

[MJansen]

Thank you for the article. I suspect the issues is with the Spring and Ball sets of the sliding hubs. I'll follow the instruction in the article and perform some inspections and see just where this goes! Thanks!

[Ray White]

Thank you for the article. I suspect the issues is with the Spring and Ball sets of the sliding hubs. I'll follow the instruction in the article and perform some inspections and see just where this goes! Thanks!

I can take no credit as all the appreciation must go to Rick Storms. As it happens, I couldn't have achieved what I have on my TC without his help.

[ROGER FURNEAUX]

When I first did mine, many years ago, because it was jumping out of gear, the main wear was in the front layshaft thrust bearing. The layshaft constantly rotates, and because of the teeth direction, it is pushed to the front. These simple little thrust washers are quite expensive, and only available as "standard", but the clearance should only be 4-thou, so a thicker one might be required. I have long thought about making some, but never got around to it...the late Gerry Brown used to stock various thicknesses for the gearboxes he rebuilt. While it is apart, simply replace the two main bearings, and leave everything else alone. The problem was cured, but of course years later I had to do it all again (and only took 3 hours!)
BTW we have made 1st. motion shaft nuts (#64 in Moss, who don't have them) because they are often mangled by POs who did not realise they are LH...

Roger

[Kenmgtc]

Hi Mike, before you begin pulling the motor and gearbox, check the large nut on the gearbox prop shaft output flange. If it’s loose everything in the box will shift forward and you lose 2nd gear first. Years ago I had this exact same symptom and that’s all it was. Fingers crossed!
Ken