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used reverse with OD switch on

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nevets

nevets

Jedi Knight
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I backed out of my garage with the OD switched on. Had just a bit of trouble getting into reverse and heard a few clicks. I drove off and realizing what I had done, I flipped the toggle to Normal while still in 2nd gear. I drove a bit but not far or fast enough to try the OD. My question is, how likely is it that I caused any damage? Thanks
 
Hi Nev, If the little switch on your transmission shift lever is hooked up and working correctly you probably didn't do any damage. The little switch only allows the OD to be engaged when the trans is in 3rd or 4th gear. So the electricity never got to the OD solenoid. Donald thought about your posibility way back when, remember who they were trying to sell these things to back in the '50s & '60s. Dave.
 
"Hi Nev, If the little switch on your transmission shift lever is hooked up and working correctly you probably didn't do any damage. "

I agree with that--Keoke-:encouragement:
 
Even if your OD was actually on in reverse, you'd have to go quite some distance to build up enough pressure to get the OD clutch fully engaged. Andy.
 
For your own piece of mind, first chance you have, check the od wiring to see if it is installed properly. You will probably do this again.

Marv
 
I agree with vette and Keoke. Those clicks you heard may have been the OD relay. When my OD would stick on, I had to put it in reverse momentarily to get it to come out until I could get it fixed.
 
You mean solenoid getting stuck? If all is hooked up properly and the "relay" sticks, it should not matter, as long as you are not in 3rd or 4th.
 
57_BN4 said:
Even if your OD was actually on in reverse, you'd have to go quite some distance to build up enough pressure to get the OD clutch fully engaged. Andy.
Click to expand...
I've only seen the OD left ON once, but when the car was put in reverse the solenoid might have been stuck but it made a heck of a noise. It had no pressure from driving but there's something inside that doesn't like reverse pressure or no pressure.
 
healeyblue said:
You mean solenoid getting stuck? If all is hooked up properly and the "relay" sticks, it should not matter, as long as you are not in 3rd or 4th.
Click to expand...
I wasn't clear. My OD would stick for mechanical reasons. Even though the solenoid would release as it should the OD wouldn't release. My point was that it didn't hurt being in reverse for a bit.
 
Thanks for the comments. I'm still kicking myself over this. Hopefully no harm was done. The reason why the switch was in the OD position was because several weeks ago I was doing some OD electrical troubleshooting, trying to discover why the OD was not engaging, and I hadn't touched the car since.
 
I've had the OD switch on while reversing dozens of times. The gear shift switch protects against engaging the OD unless the shift lever is to the right (3rd/4th). You can check if your gear shift switch is working if the OD does not engage while in second gear with the dash switch on.
 
If the overdrive wasn't protected by the top-gear switch mentioned above by others, the car would not have moved, only free-wheeled. There is a thing inside the overdrive called a "sprag" or one-way clutch" that prevents drive in reverse. I too recommend checking that the top-gear switch is functional.
 
The sprag is the bit that grenades when reversing in OD. It over-runs when driving in overdrive since the annulus (output) is spinning faster than the planets (input) because the OD clutch has locked the sun stationary. If the sun is still locked stationary in reverse then the power tries to feed through the planetary gears at 1:0.7 ratio at the same time as through the sprag which is now trying to turn in its locking direction at 1:1. This difference of ratios applies a massive overload to the sprag from only mild torque input.

The earlier Borg Warner ODs suffered from exploded sprags a lot more often because they have no clutch, only a peg that drops into a slot to engage OD. If the peg sticks in the slot- as they often do- then kerbang in reverse. The Laycock design requires the clutch to be pushed firmly into the engaged position which is far less likely when backing out of the garage as there is no hydraulic pressure. If the clutch is firmly stuck in OD due to mechanical problems then it will quite likely grenade and the gear lever switch will not prevent this.

Andy.
 
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