Overdrive

[CosworthCabrioLee]

Just been out in my mk1 and the overdrive is not working what are the usual things that stop it working There is power to it.

[Dane_Rescueman]

Re: Overdrive

Does the solenoid click when you select overdrive?

[CosworthCabrioLee]

Re: Overdrive

Yes there is a click not been underneath the car yet only drove it for the first time ever tonight

[Tnick]

Re: Overdrive

Lee

Canley Classics have a useful page giving fault finding guidance http://www.canleyclassics.com/infodatabase.asp?article=overdrivesdtype

Hope this helps

[greyV8pete]

Re: Overdrive

Hi Lee. When you say not working do you mean not engaging at all or engaging but "slipping"? Peter.

[b_caswell]

Re: Overdrive

First thing is to check the oil level in the box second is to take out the filter and clean it.

[CosworthCabrioLee]

Re: Overdrive


ben where is the filter ? changing the oil tomorrow on the box, did i tell you it goes like hell in all gears and well impressed with the handling.










d

[CosworthCabrioLee]

Re: Overdrive


ben where is the filter ? changing the oil tomorrow on the box, did i tell you it goes like hell in all gears and well impressed with the handling.










d

[neilryland]

Re: Overdrive

"Pound to a penny" it's a "J" type & the solenoid is gummed up. These are reknown for this problem. I had the same issue on my roadster which has a Dolomite box with J Type O/D. I just took the solenoid plunger apart, cleaned it out and fitted new "O" rings - a very fiddly job for someone with good eyesight.

I also had the same problem on my Truimph Stag, again with a "J" Type O/D - same solution fixed that one as well.

For info, the filter on a J Type is located under the flat sump plate with 6 fixing bolts. It's easy to remove, you will get gear oil everywhere even after you have drained the box first - so beware. Wash it out thoroughly with petrol.

[neilryland]

Re: Overdrive

Forgot to mention, James Paddock Ltd - http://www.jamespaddock.co.uk do an exchange solenoid for £45.

[greyV8pete]

Re: Overdrive

When O/D switch is on check if the setting hole in the lever is lined up with the hole in the casing using the correct size drill blank. If not 1) the clamp may have come loose. To reset, slacken clamp, use setting pin through hole, switch O/D switch on, do up clamp bolt. If not 2) the solenoid if stuck will probably have cooked the windings.

From my experience with O/D on both a TR3A and Sunbeam Talbot there are two coils wired in parallel, one with thick wire to activate the solenoid which pulls a lot of current, the other with thin wire is a "holding coil" just enough to hold the thing in the activated position. If travel is set correctly there is a switch in the top of the solenoid which "opens" at full travel and disconnects just the heavy winding and leaves the holding coil in circuit to do its job. If it sticks the switch doesn’t open and you soon cook the solenoid. The other fault is if the holding coil is faulty. In this case you hear a rapid rattling sound as the solenoid closes and opens again. Same principle as a buzzer works! My O/D solenoids were mounted vertically with gravity return when disengaged. What returns yours as it is mounted horizontally? Peter.

[neilryland]

Re: Overdrive

Peter,

Thats for an "A" Type O/D. As you say, it's easy to check if the lever is moving to the correct position.

It would be nice to know which type of O/D Lee has - it's marked on the Ident Plate.

[CosworthCabrioLee]

Re: Overdrive

Thanks for the advise everyone I am going to look at it this weekend been waiting to get on the 4 post lift at my fathers will let you all know

[b_caswell]

Re: Overdrive

Thanks Neil Sorry Lee not been on line. PS dont keep booting it too hard or you will break the transmission.