surging wile in overdrive

[David]

i have a 01 blazer and i keep getting surging wile going down the hwy at 55-60, the rpm jump about 500+ from 1500 in overdrive, any tips?

Topic

[Roy French]

It sounds like your lock up torque converter is slipping. You can test for this. Drive at a steady highway speed on a flat section of road. While maintaining your speed and foot pressure on the gas, hit the brakes just enough to turn on the brake light for a second. This will drop you out of converter lock up. You should see your rpms go up. If it’s the same increase as when you are surging you will know what the problem is.
Unfortunately, there is no easy fix. The problem could be in the tranny or the torque converter itself.

[Shaun_300]

Agree with the comment above about the TCC slipping. Have seen this a few times with the 4L60E transmissions. Like stated it could be the clutch itself or sticking valves in the valve body. Could also be the TPS but from your symptoms it doesn’t sound that simple.

If you can find a stretch of road that is flat and then has an incline, staying at a steady speed, if it starts doing it a lot more on the incline as it puts more load on the TCC then it’s almost certain it’s in the torque converter itself.

[David]

the test confirmed there is a problem with the tcc. Now what do i need to replace the tc or what

[Roy French]

It looks like that is what needs to happen. Make sure you put in a new front tranny seal while you have it out.

[David]

I do not have the cash to replace the TC right now.am I endanger of having the blazer leaving me on the side of the road?

[Shaun_300]

If that’s all that’s wrong with the transmission it will not leave you stranded, the only thing you won’t have is the lock up the TCC provides, so the only sacrifice you have is fuel economy which the Blazer/Jimmy lacks of even with the TCC operating lol.

[EricTheCarGuy]

It may not be the torque converter at all. It may just be the seals on the input shaft. It’s a common failure BTW.

[Author]

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