Can you solve this Tranny Problem?
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Can you solve this Tranny Problem?
This may be an easy problem to solve for all you brilliant Gear Heads out there.
Our truck is a 1987 F-250, with a fuel saving 460.
Automatic transmisson, 4x2, extended cab. Did I miss anything? It does have a tranny cooler, does it work?? We tow a 2003, 28 ft fifth wheel. About 8,500 lbs loaded with driver and passengers.
Here's my problems:
While towing at highway speeds, it seemed to drop a gear and then normal again, that process took about 3 seconds, happened 2xs in about a 150 mile journey. Then after we were unloaded, we took truck out, when we would slow down, you could feel some soft jerks. It stopped when we were completely stopped, and would do the soft jerky thing almost every time we stopped. Now it doesn't do it. We don't seem to have the downshifting thing happen when not loaded.
Is it a matter of the tranny getting too hot? Maybe the tranny cooler isn't working properly? On the way home from our trip, it was raining and cooler and there didn't seem to be any issues. Should we just travel in the rain?
Our truck is a 1987 F-250, with a fuel saving 460.
Automatic transmisson, 4x2, extended cab. Did I miss anything? It does have a tranny cooler, does it work?? We tow a 2003, 28 ft fifth wheel. About 8,500 lbs loaded with driver and passengers.Here's my problems:
While towing at highway speeds, it seemed to drop a gear and then normal again, that process took about 3 seconds, happened 2xs in about a 150 mile journey. Then after we were unloaded, we took truck out, when we would slow down, you could feel some soft jerks. It stopped when we were completely stopped, and would do the soft jerky thing almost every time we stopped. Now it doesn't do it. We don't seem to have the downshifting thing happen when not loaded.
Is it a matter of the tranny getting too hot? Maybe the tranny cooler isn't working properly? On the way home from our trip, it was raining and cooler and there didn't seem to be any issues. Should we just travel in the rain?
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Joined: Apr 2004
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Possibly:
Torque converter locking and unlocking. Under load (towing) it would not be unusual for the converter to lock and unlock as you go through dips and curves etc.
&/or
Hunting between 3rd and 4th, a common problem with OD trans.
The description of your problem doesn't seem to match this perfectly, but it's a possible.
Perhaps a routine tranny service is in order? Modulators, linkage adjust, whatever else they can do?
There are outfits that sell controls for transmissions to electronically "lock" them in OD or torque converter locked etc. Can't recall names etc, but I think I saw someone post a link here in the last few days.
If I have time later and find it, I'll post if over here.
Or, the better minds will pick up on your post and post it along with perhaps better theories or fixes.
Stay tuned.
Torque converter locking and unlocking. Under load (towing) it would not be unusual for the converter to lock and unlock as you go through dips and curves etc.
&/or
Hunting between 3rd and 4th, a common problem with OD trans.
The description of your problem doesn't seem to match this perfectly, but it's a possible.
Perhaps a routine tranny service is in order? Modulators, linkage adjust, whatever else they can do?
There are outfits that sell controls for transmissions to electronically "lock" them in OD or torque converter locked etc. Can't recall names etc, but I think I saw someone post a link here in the last few days.
If I have time later and find it, I'll post if over here.
Or, the better minds will pick up on your post and post it along with perhaps better theories or fixes.
Stay tuned.
Last edited by 85e150; Aug 26, 2004 at 11:19 AM.
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Joined: Apr 2004
Posts: 34,499
Likes: 2,811
If no OD (you sure? No button on the end of the shifter? No 0 with D in it? Just P R N D 2 1 on the shifter?
If it's just a 3 gear, then it probably has no lockup torque converter either.
In which case, back to tranny service and adjustments, make sure filter is good and cooler is working.
If it's just a 3 gear, then it probably has no lockup torque converter either.
In which case, back to tranny service and adjustments, make sure filter is good and cooler is working.
