Hot & Bothered Gears and Starter

[Peter27]

1963 3.8 FHC. Two unrelated issues except they both only happen when the car is thoroughly hot. Firstly, it can be impossible to select reverse without a nasty grating noise - like the clutch is dragging. Selecting another gear first or taking things really slowly makes no difference. No problem with forward gears (it seems) and no problems when car is cold. I have bled the clutch but still get the problem.

The other problem is the starter and normally only happens when the car has been sitting for a few minutes after a long run. It is a high-torque starter which is only a couple of years old, but when trying to start it just clicks as if it is stuck (ammeter showing power is flowing). Repeated trying normally results in success (after a 'sweaty' wait), or leaving it for 30 minutes or so, also yields success. Does not always happen when the car is hot but sufficiently frequently to raise the spectre of a journey home on the back of a low-loader. Any help gratefully received. Thanks.

[mgcjag]

Have you adjusted the clutch pushrod as per the service manual......contacts in high torque starter motor...they are quite crude in some starters...Steve

[Peter27]

Hi Steve. I have checked clutch pushrod and all seems correct. Also if it was this, I am not sure why I would only be getting the problem when the car is hot. Baffling...

[Philk]

It can be impossible to select reverse without a nasty grating noise - like the clutch is dragging. Selecting another gear first or taking things really slowly makes no difference. No problem with forward gears (it seems) and no problems when car is cold. I have bled the clutch but still get the problem.

Noting you have a 3.8 (and therefore, presumably, the Moss Box with no synchro on first and reverse), what you're describing could be down to the viscosity of the gearbox oil when hot. When we first got our 3.8 back on the road, it changed gear perfectly at the beginning of journeys but then got increasingly cantankerous when attempting to select 1st gear (and reverse) when hot. Switching to "Redline MTL" 75W80 GL4 oil made a considerable difference (plenty of posts on the forum on this). This oil is slightly thinner at start-up but maintains its viscosity when hot thereby providing a more even gearbox performance across the temperature range.

[mgcjag]

Hi Peter its either gearbox or clutch.....so easy things first......re check the pushrod adjustment and bleed the slave again.....ist a really common problem and usually solved by the above.....bleeding the slave can be very difficult to get all the air out...when bleeding on the last stroke of the pedal hold it down (wedge with a piece of timber) then push in the slave pushrod fully(typically you will see more air come out) and hold it in......then tighted the bleed nipple.........Why could it only happen when hot...parts expand and tolorences.............so re adjust pushrod and measure free play.......Steve

[Peter27]

Thanks Steve & Phil. Good advice thanks. I will do the oil change and bleed system again and see (hear) what happens.

[christopher storey]

(wedge with a piece of timber) then push in the slave pushrod fully(typically you will see more air come out) and hold it in...Steve

I wedge it with a device called a wife. However, it's a very expensive piece of kit !

[rossbraithwaite]

Having had a similar starter problem albeit on a 4.2 and from cold the only solution turned out to be an extra spacer between starter and bellhousing. The pinion couldn't go far enough forward for the motor to engage. Not sure if the hi torque motor works the same way.

[chrisfell]

When my car graunched when selecting reverse I thought it was air in the hydraulic line (it wasn’t). I thought it was out of adjustment (it wasn’t). I thought it was a poor slave cylinder (it wasn’t). I thought it was the wrong length push rod (it wasn’t). I thought it was the master cylinder (yup, it wasn’t that either). It was the release bearing. It had shattered into several pieces and the bearing material was so worn that the bearing carrier was engaging with the clutch metal to metal.

Being a worn release bearing meant engine and gearbox out. As I was working at the time and needed the car for an imminent continental tour, I paid someone else to do the job.

OUCH doesn’t quite cover it.