Transmission not working properly

JWR2009

MEMBER
1998 CHEVROLET BLAZER
4.3L
V6
4WD
AUTOMATIC
187,000 MILES

The vehicle listed above with a 4.3 vortex 4x4, just bought this for scrap price trying to see if I can fix it. When first started car goes into gear no problems when going into reverse back out of a spot put in drive it seems like it has no forward gears. If you shut the car off and restart after few minutes, it will go into drive and pick up speed and shifts until 40MPH then acts like it went into neutral. No codes that show. Will not move until shut down for a minute and restarted then will do the same thing over. Transmission fluid is full it is dark red and seems to have black specs of something in it. My guess is burned the clutch plates in it and is it hard to remove the transmission and replace with a used one. Also is it a 4l60e that is in this vehicle and if so, anything I should look out for?

Sunday, November 7th, 2021 AT 10:31 PM

3 Replies

KASEKENNY

MECHANIC
18,907 POSTS

This could be a clutch plate issue, but we need to start with checking the fluid level and condition. Here is a guide that will help with this:

https://www.2carpros.com/articles/how-to-check-and-add-transmission-fluid

Once we know what the fluid looks like and if it is low, fill it, we will have a better idea what next steps are.

However, I suspect we are going to have to check the pressure in the unit as this sounds like a pressure issue. When you put it in gear, and it doesn't move sounds like the torque converter is not pushing the fluid efficiently or the pump is not building the pressure correctly in order to apply the clutches.

The fact that you say there is no issue in reverse makes me lean to a pump issue.

However, I am attaching the info below on how to test the pressure so let's do this and go from there. Let me know if you have questions on this.

Thanks

Images (Click to make bigger)

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Monday, November 8th, 2021 AT 4:08 PM

JWR2009

MEMBER
45 POSTS

It does it in reverse and in drive. If I shut it off for a minute, it is like it resets and allows you to put in gear one time and accelerates to 40 then nothing again. I will make it to the vehicle probably tomorrow I will hook my scan tool up and pull codes again and see what it shows. And go from there.

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Monday, November 8th, 2021 AT 4:37 PM

KASEKENNY

MECHANIC
18,907 POSTS

Okay. Sounds good. Yeah, I assume there would be codes but if not then that points even more to a converter or pump issue. However, shutting it off and getting it to "reset" seems like a control issue so I would expect codes with that issue.

Keep us posted with what you find, and I am sure we can figure this out. Just make sure you check the fluid as well. Thanks

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Monday, November 8th, 2021 AT 5:53 PM