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sorry for this stupid question

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J

jimd

Senior Member
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Hello Everyone,

Sorry for this one but it is driving (pun intended) me nuts...

When I bought the 69 mgb the seller said that the overdrive selector lever on the steering column should be pushed forward to engage the overdrive and pulled aft to disengage it. I left it aft, drove the car home and have been working on it (the car) since.

After alot of routine maintenance - some of which I've discussed here and gotten help with, thank you - I had the car out yesterday on the highway and I pushed the selector lever forward. The car engine rpm increased and the performance seemed "rougher". So, I pulled the lever back and the engine rpm dropped and the car performance seemed smoother. So that has me thinking that either the seller was confused at the time (wouldn't surprise me as far as the (*&^ I've had to deal with so far) or perhaps I misunderstood him.

By the way, I have reversed the car a few times backing out of the driveway, etc - not a good thing from what I've read about the overdrive.

First, can anyone tell me how their overdrive is engaged/disengaged. And, most importantly, is there a simple elect. test I can do? I was thinking that if I go from the overdrive solenoid wire feed to ground with a voltmeter, if I have 12volts with the ignition on then that would show me that the selector switch lever is disengaged. Moving the selector lever to the opposite position should then show no volts since there is no potential difference and that would indicate an engaged overdrive. Does that make sense (or are there other switches in the circuit via the shift or otherwise that would prevent this test from working)?

Thanks,
Jim Delaney
Sparta, NJ
 
Pulling the selector toward you ingages the overdrive. Pushing it away from you disengages it.
 
Hello Jim,
the solenoid is energised to engage the Overdrive,
i.e. you will have 12 volts at the solenoid connection. I presume it works on third and fourth gear?, and there is an inhibitor switch so it can only be selected when in those gears.

With the car stationary, ignition on and engine off, 4th gear selected, you should be able to hear the solenoid engaging when you operate the switch. There is a distinct click as it engages.
Leave the switch on and put the gear lever to neutral and back to 4th, you should hear it click in and out. This proves the inhibitor switch is still in circuit. This is important because, as you are rightly aware, reversing with the overdrive engaged will damage it.

P.S. don't run with it engaged at less than forty miles per hour in 4th.

Alec
thirsty.gif


[ 02-17-2004: Message edited by: piman ]</p>
 
It sounds to me like your OD is working fine. The above responses are right on and the "roughness" you seem to perceive when the OD is disengaged (forward or away from the steering wheel) at a cruising speed with little load, the increase in RPMs with sound a little rougher running...I know mine does

Bruce
cheers.gif
 
Thanks for the info. I did check out the system last night in my garage. Pulling the lever aft does engage the od - I should have known this as I think this (pulling the lever aft) engages/energizes circuits on my other cars. Hopefully I didn't screw anything up in the meantime...
 
No,
you have ruined the OD. I am feeling generous, and I'll take it off you hand for the cost of shipping. Heck, I'll even give you one of my working non-overdrive trannys out of the goodness of my heart.....
wink.gif


Ed
 
<blockquote><font size="1" face="Verdana, Arial">quote:</font><hr>Originally posted by Ed Wynne:
No,
you have ruined the OD. I am feeling generous, and I'll take it off you hand for the cost of shipping. Heck, I'll even give you one of my working non-overdrive trannys out of the goodness of my heart.....
wink.gif


Ed<hr></blockquote>

Whata guy, I'il even take the one out of my car and even trade. Of course, I wont mention the bad synchro in third or the general high mileage looseness and vibrations.
 
Jim,
I was kidding of course. You will find if you continue to frequent this and other MG boards, that overdrive transmissions are very highly prized, and it is not at all uncommon for people to buy otherwise junk cars, if they have an OD.

Ed
 
Yes, I would love to have an OD transmission. I will have to do something with mine in the near future but with no income it is hard to justify stuff like that.

Of course, I was just kidding too. Without OD these cars really sing at highway speeds. Jim, take yours out on the interstate and don't put in the OD and that is what a non-OD car is like.
Bob

[ 02-25-2004: Message edited by: mrbassman ]</p>
 
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