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4L80E - No 4th gear - please help!

Mort

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Mort Enthusiast

Mort

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I need some help. I flushed out my trans and while it was a messy time consuming job it seemed to go alright. When I test drove the truck it was a little low on fluid because I flushed too much out. Anyway it was slipping in 4th so I put it in second and it seemed to work fine. I got some more fluid and filled it up but it is still slipping in 4th. In fact I don't think that I have forth gear at all but the rest seem to be working fine if I put it in third. It required quite a bit of a tug to get the pan out and a good solid push to put it back in. Do you think that I damaged something?

1. Does anyone know what I should be looking for when I open the trans up again?

2. If I undo the exhaust at the manifold will it let the exhaust drop enough to get the pan out without further damage? Does the heat shield on the passengers side of the trans need to be removed as well? Will the exhaust seal back up again when I tighten it back up or will I need new gaskets or something?

 

Thanks guys I could sure us some help. :thumbs::lol:

concours Enthusiast

concours

Posted
Posted

I got the heat sheild off with lots of cursing the punk engineer :lol::thumbs: who designed it, the shifter cable bracket that are both in the way and the recessed drain plug that leaves 2 quarts of fluid behind. All these could have designed for eaisier servicability. I understand the wedging it in and out routine... did you drive it long while it was slipping?

Mort Enthusiast

Mort

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I did not drive too far with it slipping. I felt it right away and gave it a little tap and it revved up to about three grand. I immediately pulled it down to second gear and it seemed to drive fine. It does not feel like it is engaging fourth gear at all. I took it home and filled it up with about 3 litres of ATF and tried it again with the same result. When it shifts into fourth under easy throttle you can fell it slip. If I pull it down into third it seems to go fine.

 

Thanks

99Silver6.0 Senior Enthusiast

99Silver6.0

Posted
Posted

You may have run into the same problem my friend did. His truck wouldnt go into overdrive after a flush. It ended up beng a little solenoid that went bad. Not sure the exact designation of the noid. He replaced it and all was well. If you take the y-pipe loose at the manifolds it wll drop enough for you to get the pan off. Thats how I do it. Does your fluid smell burnt at all?

Scott02Z71 Enthusiast

Scott02Z71

Posted
Posted

Look also at the shift solenoid connection. When I changed mine I accidentally unpluged it a bit removing the shift linkage. Mine slipped and was a "piece" until i repluged that back in. I think i may have broken the lil plastic lock piece as it seems to pop out a bit on occasion, but i just have to crawl under and fix it quick.

 

Hope this helps you out!

 

Scott

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