whats wrong with my 86 4+3??
Thread Starter
Heel & Toe
Joined: Aug 2000
Posts: 19
Likes: 0
From: seattle,wa,USA
whats wrong with my 86 4+3??
It shifts in and out of low and high range in all gears including first gear. Seems to happen more when its cold and when I get on it. I bought the O/D switch that mounts under the gear shift but I understand there is another O/D switch and an O/D solenoid. How can I tell which component might be the source of the problem? :cry
Team Owner
Joined: Mar 2001
Posts: 54,124
Likes: 30
From: Cincinnati, Oh USA
Re: whats wrong with my 86 4+3?? (flyinv55)
Once you press the OD switch and the engine is up to temp and you are over 35 mph, the OD will shift and stay in OD until you go below about 2 mph and then it will shift out. If your OD is shifting out of OD without any switch input, then you have an intermittent short in your OD switch installation, or more serious problems with the OD internals.
Burning Brakes
Joined: Oct 2001
Posts: 1,033
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From: Tracy California
St. Jude Donor '05
Re: whats wrong with my 86 4+3?? (flyinv55)
How does it drive with the OD off? I think you're desrcibing an O/D issue, but it's hard to say based off your description. My other thought was that it's an electrical switch perhaps.
KM
KM
Team Owner
Joined: Mar 2000
Posts: 83,383
Likes: 87
From: Boston, MA
There is an overdrive relay near the brake booster in the engine compartment. The wires on the wiring harness are quite short and over time expose the wires allowing them to short each other out when you hit bumps and such. This can cause it to shift in and out of OD at will. Is the light on the dash changing as the tranny does? If so this may be worth looking into. I had to rewrap the wires on mine.
Thread Starter
Heel & Toe
Joined: Aug 2000
Posts: 19
Likes: 0
From: seattle,wa,USA
Re: whats wrong with my 86 4+3?? (flyinv55)
well I'm sure its an electrical issue....the same time this all started happening was when the dash cluster fried and I lost the cluster, fuel level sending unit and this O/D problem. All happened at once, I have since replaced the cluster and bought the O/D switch that mounts under the shifter but havent installed it yet, I changed the fluid and filter in the O/D unit about 2 years ago and have only put about 15k miles on since. Thanx for the help, I'll check the suggestions.
Melting Slicks
Joined: Aug 2001
Posts: 2,516
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From: Lockport NY
Re: whats wrong with my 86 4+3?? (flyinv55)
Back when I still had my button in the ****, I adjusted it down so I could rest my hand on top...It was like a hair-trigger; the slightest nudge would set it off...I finally set it back up, but I wasn't happy with that...
So, is your T-rod adjusted too low? If so, raise it up a bit...
I also had a broken/grounded blue wire at the bottom of the trans side cover (don't know what it was for) that kept the OD from working at all...But the indicator light still worked... :lol:
So, is your T-rod adjusted too low? If so, raise it up a bit...
I also had a broken/grounded blue wire at the bottom of the trans side cover (don't know what it was for) that kept the OD from working at all...But the indicator light still worked... :lol:
Team Owner
Joined: Mar 2000
Posts: 83,383
Likes: 87
From: Boston, MA
Back when I still had my button in the ****, I adjusted it down so I could rest my hand on top...It was like a hair-trigger; the slightest nudge would set it off...I finally set it back up, but I wasn't happy with that...
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Re: whats wrong with my 86 4+3?? (flyinv55)
Scorp is right :yesnod:
My OD light would go on and be ok for a few minutes/miles and then it would flicker on and off, making the OD jump in and out of 'gear'. The connector for my OD relay under the hood on the firewall was loose.
Your wires might have pulled the connector right out of the relay too - there's 2 relays on the firewall. If I remember correctly, it's the one closer to the brake.
If you need a new OD relay, I've heard it's a $10 part - fortunately, mine just needed the plug pushed in until it clicked into place.
Hope yours is this easy!
My OD light would go on and be ok for a few minutes/miles and then it would flicker on and off, making the OD jump in and out of 'gear'. The connector for my OD relay under the hood on the firewall was loose.
Your wires might have pulled the connector right out of the relay too - there's 2 relays on the firewall. If I remember correctly, it's the one closer to the brake.
If you need a new OD relay, I've heard it's a $10 part - fortunately, mine just needed the plug pushed in until it clicked into place.
Hope yours is this easy!