95 4l60 no first

[nhyrum]

I rebuilt my trans about 3 months ago, put about 5000 miles on it. I've only had one small hiccup since the rebuild. Last night, the truck stopped going into first gear, and the fluid level is much higher now. No slipping ever, and the truck will start in drive, just starts in 2nd, and if I manually shift into 1st, it's still second. Fluid level only drops a little (probably about half an inch) between off and cold.

Last night when I got home I checked the fluid level, and it was reading about half a quart over the hot full line. I have a little siphon pump, so I pumped a little out. This morning I went and checked the fluid, and cold, it was reading higher than it was reading hot. Makes me think the pump is bad? I only replaced the little cork (I think) and viton seal/cushon on the pump ring.

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[1997]

any codes?
OBD1 can set codes without the check engine light coming on.

 

[nhyrum]

Only code I have is a 43, for the knock sensor. I've got the 4.3, and I'm pretty sure there's one back by the distributor, and that's the one that's bad, as I already replaced the one on the side of the block.

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[1997]

https://shop.ukrtrans.biz/wp-content/uploads/catalogs/4L60E.pdf

this helped me out when i had issues. very good trouble shooting section.

 

[jjester6000]

It sounds to me like shift solenoid A is dead.

xc_hide_links_from_guests_guests_error_hide_media

(This video should explain it)
Even though solenoid A is used for 4th gear, you can still shift into it manually.

 

[jjester6000]

Here's the 4l60e's shift logic.

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With no computer, you'll still have 3rd, and you can shift it manually into 2nd/OD.

 

[nhyrum]

It sounds to me like shift solenoid A is dead.

xc_hide_links_from_guests_guests_error_hide_media

(This video should explain it)
Even though solenoid A is used for 4th gear, you can still shift into it manually.

That really could be it. I DID check all the solenoids during the rebuild using a volt meter, and they all checked good, but they should be an easy swap.

In the atsg manual, page 18 has "2nd gear start" which only mentions the sprag being installed backwards, but that can't be the case, since I've driven it a bunch since the rebuild, and I got new, dual race sprags. Maybe a failure though?

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[Schurkey]

Fluid level increasing? Coolant leaking into the trans cooler in the radiator?