Need advice diagnosing 4L60E shift issues
July 29th, 2020, 4:18 AM
#1
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Need advice diagnosing 4L60E shift issues
Hi everybody!
I hope that this thread is the right place for asking about transmission issues on old suburbans. Anyway, I just bought a 1998 suburban with 214k miles that has a weird issue shifting.
The problem is that the transmission will not use 2nd gear. It doesn't slip into and out of 2nd gear, it simply skips over it. I have reverse, first, third, and fourth (OD). All those gears shift in and out without any trouble. I've tried accelerating from a stop several times to get a feel for it and from 0-20mph the suburban stays in 1st gear. Between 20-25mph I momentarily back off on the throttle and the vehicle shifts into 3rd. I can then carefully accelerate all the way to highway speed if I want.
I've also tried locking the suburban down into 1st, 2nd, and 3rd. With the shifter on 3rd, I get both 1st and 3rd gear. With the shifter on 2nd, I only get 1st gear. I ended up talking the seller down from $2500 to $1900 so that I've got some cash to dig into this problem. Besides, I figured worst case I have to drop $2500 putting a refurbished transmission in it and I'll have an SUV that lasts another 100-150k. Engine and everything else appears to be very clean and well kept.
In searching threads and forums about this topic, people have given about 50 different possible causes. Everything from a clogged filter to the TPS sensor to solenoids to a complete tear-down and rebuild of the tranny. Because I have 4th gear and there's no slipping, clunking, jerking, or other audible/felt issues with the tranny I would guess that the issue is electrical, not mechanical.
I'm looking to build a checklist of things I should look out for when I open up the pan. Alternatively, if someone just happens to know what the problem most likely is I'd be happy to hear it and check it out on my next day off work.
Any help people can give would be greatly appreciated. Thank you for your time!
--James Willmus
I hope that this thread is the right place for asking about transmission issues on old suburbans. Anyway, I just bought a 1998 suburban with 214k miles that has a weird issue shifting.
The problem is that the transmission will not use 2nd gear. It doesn't slip into and out of 2nd gear, it simply skips over it. I have reverse, first, third, and fourth (OD). All those gears shift in and out without any trouble. I've tried accelerating from a stop several times to get a feel for it and from 0-20mph the suburban stays in 1st gear. Between 20-25mph I momentarily back off on the throttle and the vehicle shifts into 3rd. I can then carefully accelerate all the way to highway speed if I want.
I've also tried locking the suburban down into 1st, 2nd, and 3rd. With the shifter on 3rd, I get both 1st and 3rd gear. With the shifter on 2nd, I only get 1st gear. I ended up talking the seller down from $2500 to $1900 so that I've got some cash to dig into this problem. Besides, I figured worst case I have to drop $2500 putting a refurbished transmission in it and I'll have an SUV that lasts another 100-150k. Engine and everything else appears to be very clean and well kept.
In searching threads and forums about this topic, people have given about 50 different possible causes. Everything from a clogged filter to the TPS sensor to solenoids to a complete tear-down and rebuild of the tranny. Because I have 4th gear and there's no slipping, clunking, jerking, or other audible/felt issues with the tranny I would guess that the issue is electrical, not mechanical.
I'm looking to build a checklist of things I should look out for when I open up the pan. Alternatively, if someone just happens to know what the problem most likely is I'd be happy to hear it and check it out on my next day off work.
Any help people can give would be greatly appreciated. Thank you for your time!
--James Willmus
August 1st, 2020, 10:22 AM
#2
There are a lot of people who know the 4l60e inside out. I’m not one of them but have been into mine on my 93 a few times to fix various things.
There are shift solenoids inside which you can google to see what combination of active/not active result in what gear. See if one of them bad or stuck in a position would results in the gear behavior you see. This is where the experts would be able to tell which one exactly is likely your problem.
you might get more eyes on the question if you post questions like this which are common between suburban and trucks on the GMT400 forum
There are shift solenoids inside which you can google to see what combination of active/not active result in what gear. See if one of them bad or stuck in a position would results in the gear behavior you see. This is where the experts would be able to tell which one exactly is likely your problem.
you might get more eyes on the question if you post questions like this which are common between suburban and trucks on the GMT400 forum
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