Overdrive ?

[kirstythorne]

Does anyone know what would indicate a faulty overdrive ? I've just had a new clutch put in cos I thought it was that causing slippage with the gears. But it still does not engage in 1,2,3 and 4th gears, (without overgrive engaged) when demanding high revs from the car. ..any ideas gratefully recieved!

[v8mg]

Kirsty
I dont understand your problem. The overdrive should only engage in 3rd and 4th. There is a clutch in the overdrive that can cause slipping.
Mick

[smifffy]

Does the overdrive drop out at all when you're in 3,4 gears?

[kirstythorne]

Thanks for reply. Sorry was not explicit enough...yes overdrive only works with 3 and 4 gears, , but generally I'm finding that when putting in gear and taking out clutch fully and wanting to accelerate quickly (e.g. uphill, away from traffic lights, overtaking), then revs go up but car takes a short while to respond and almost sounds like gear is not engaged. This can occur in any gear, generally not whilst in overdrive, although it did 'slip' once the other day whilst in overdrive.

[kirstythorne]

Thanks for reply. Sorry was not explicit enough...yes overdrive only works with 3 and 4 gears, , but generally I'm finding that when putting in gear and taking out clutch fully and wanting to accelerate quickly (e.g. uphill, away from traffic lights, overtaking), then revs go up but car takes a short while to respond and almost sounds like gear is not engaged. This can occur in any gear, generally not whilst in overdrive, although it did 'slip' once the other day whilst in overdrive.

And no, overdrive does not drop out. It just when I engage the gears and pull out clutch for fast pull away

[colin m]

I remember a story once where the flexi hose in the clutch circuit had perished. This wouldn't allow the clutch fluid to flow as normal (due to a partial blockage) and would effect the operation of the clutch.
If you try bleeding the clutch hydraulic circuit and you get tiny pieces of black rubber in the expelled fluid, the hose has had it!

Colin M.......

[Buffalo]

First thing - check fluids in gearbox/overdrive. If in doubt change.

Sluggish overdirve is often caused by low oil level. Mine got better after oil change and continual use...

[smifffy]

Agreed.

In my old overdrive unit a drop in oil level meant the resultant drop in pressure operated an otter switch causing the electric overdrive to drop out, returning you to the gear.

[andy_clap]

I read somewhere years ago that putting friction reducers (Slick 50, etc) in an overdrive gearbox would cause something like this and was to be avoided. Haven't got a friction reducing oil in there have you?

(P.S.Hello from a newbie!!).

[fore_deck]

Doesn't sound like O/D to me...

Generally I find ('79 B) that O/D takes about 1/2 sec to engage from when I flick the switch, anything much longer than that indicates it's time for a gearbox oil-change.

What you describe is not O/D as it applies in all gears. I should investigate gearbox oil level/state & get that changed.

You could also (assuming you're an MGOC member) call their technical advice line (available from www.mgcars.org.uk). This will connect you to one of their workshop guys & they're pretty good normally.

Last alternative is to call up an MGOC recommended garage (again listed on the website) and get their opinion. I can supply details of good garages in Soton/Winchester and Staines areas if required.