Author Topic: Truck sometimes won't engage when put into Drive  (Read 498 times)

Offline juancano

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Truck sometimes won't engage when put into Drive
« on: December 20, 2021, 03:48:54 PM »
Howdy; have an 1986 C10 2WD with automatic transmission, think it's a 700r4 transmission. The last two times I've driven it, I move the shifter to "D" (overdrive D) and it doesn't engage. I put back to P or N then go back and it engages. Minor pain of course, but want to know if this is a precursor to a bigger issue?

Been pretty cold those two times, 30 degrees. Could be a factor? Or not at all.
Have yet to check the transmission fluid, but I don't think that helps with the engaging right? It shifts just fine when driving.

Thanks!

Offline JohnnyPopper

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Re: Truck sometimes won't engage when put into Drive
« Reply #1 on: December 20, 2021, 03:59:57 PM »
Probably sluggish oil pressure. Can indicate that the filter is plugging up.

When my TH350 starts doing that, I draw out the fluid through filler tube using a extractor.

Refill with clean fluid, and she purrs.

Sound like you need to service it, filter and fluid
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Offline frotosride

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Re: Truck sometimes won't engage when put into Drive
« Reply #2 on: December 20, 2021, 10:14:44 PM »
Howdy; have an 1986 C10 2WD with automatic transmission, think it's a 700r4 transmission. The last two times I've driven it, I move the shifter to "D" (overdrive D) and it doesn't engage. I put back to P or N then go back and it engages. Minor pain of course, but want to know if this is a precursor to a bigger issue?

Been pretty cold those two times, 30 degrees. Could be a factor? Or not at all.
Have yet to check the transmission fluid, but I don't think that helps with the engaging right? It shifts just fine when driving.

Thanks!
As Johnny said, check the level for sure. If you've ever rebuilt an auto trans or ever decide to don't be surprised as to how much fluid it takes just to get it in first gear let alone the next 2+4 gears. 4l60e is almost 12qrts
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Offline juancano

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Re: Truck sometimes won't engage when put into Drive
« Reply #3 on: December 21, 2021, 08:36:02 AM »
Thanks for the tips! Will check the fluid and the filter.

Offline MIKE S

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Re: Truck sometimes won't engage when put into Drive
« Reply #4 on: December 21, 2021, 10:35:38 AM »
If this happens after sitting a few days, it could be converter drain back. Usually caused by a worn converter hub and or converter pump bushing. Check fluid level after it sits for a few days BEFORE you start truck. If it is overfull, you have drainback