Transmission/Engine surges around 50mph
04-21-2017, 04:12 PM
#31
Registered User
Problem fixed
I had this problem and read posts on fixing grounds. The bottom line is that all positive and negative wires need to be looked at. Also, always check both ends of the wires.
Don't forget the connections in the relay/fuse box under the hood.
I changed the battery terminals with compression fittings. They compress the wires into the end of the terminals. The original molded battery terminals looked like they were getting loose.
Battery shops carry these types of terminals.
Bad connections seem to send spikes to the PCM and confuse it.
Everything is shifting smooth.
Don't forget the connections in the relay/fuse box under the hood.
I changed the battery terminals with compression fittings. They compress the wires into the end of the terminals. The original molded battery terminals looked like they were getting loose.
Battery shops carry these types of terminals.
Bad connections seem to send spikes to the PCM and confuse it.
Everything is shifting smooth.
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Mark Nichols (11-16-2020)
10-13-2017, 02:18 AM
#32
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Join Date: Oct 2017
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Fix for Tranny shifting in and out of overdrive
Here is what my 47RE transmission has started to do....it's a little hard to describe. I honestly can't tell if it's trying to come out of overdrive and then drops back in. Or, maybe it's the torque converter acting up.
It gets worse when I'm pulling my 5000 llb trailer. Tranny works fine at speeds above 55 in overdrive. Also works fine below 45 in 3rd gear. The problem is when I'm cruising and the speed drops to about 48 to 53. Around there the engine surges, RPM increase about 300 RPM just for fraction of second then drops back. It feels like it's trying to downshift, but won't complete the shift. It will keep repeating until I do something to make it stop.
It does not do this as much when I'm not towing anything.
I can stop it by: (1) Turning overdrive off. (2) Accelerating to about 60mph. This involves forcing a shift out of overdrive with throttle. Then letting it drop back into OD at the higher speed. (3) Going downhill, so there is less load on engine/transmission.
It gets worse when I'm pulling my 5000 llb trailer. Tranny works fine at speeds above 55 in overdrive. Also works fine below 45 in 3rd gear. The problem is when I'm cruising and the speed drops to about 48 to 53. Around there the engine surges, RPM increase about 300 RPM just for fraction of second then drops back. It feels like it's trying to downshift, but won't complete the shift. It will keep repeating until I do something to make it stop.
It does not do this as much when I'm not towing anything.
I can stop it by: (1) Turning overdrive off. (2) Accelerating to about 60mph. This involves forcing a shift out of overdrive with throttle. Then letting it drop back into OD at the higher speed. (3) Going downhill, so there is less load on engine/transmission.
Good luck
05-11-2022, 12:18 PM
#33
Issues
I lived with this problem for 4 years and numerous unnecessary repairs by the dealer while the truck was still under warranty. when the warranty ended I decided to tackle the problem myself and I was able to permanently repair it for under a dime. I can provide you the info to do the repair if you will contact me at miked49@charter.net.
Mike
Mike
good afternoon Mike I tried to email you at your email address above but it says it was unable to go through. Apparently since I got the bright idea of washing the underside of my truck and washing under the engine trying to get all the excess grease and oil off I caused this problem with my truck now it's a 98 12 valve with a 47re I don't know it's got to have something to do with the torque converter lockup switch it's weird how it will almost put you through the windshield when you're slowing down going down a hill when you let off the gas and sometimes it does it when you hit the brake I don't know how to describe it. But any help anybody has with this please send it my way and if you don't mind send me that right up you were talking about you had thank you you all have a wonderful and blessed day. Remember Jesus Christ personally loves you guys and you guys are awesome. Thank you
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