I've got a 94' s-10 blazer with some tranny problems.

when i've been driving it hard for a while and the tranny gets hot, it starts slipping and the speedometer goes wild... its struggeling with deciding witch gear to put itself in and sometimes goes into protection mode..

as soon as the tranny gets cooled down again after giving it a little break, it starts gearing normally again...

any advices or tips?

sorry for my english,,, im from norway

 

well,shift points etc has sometime to do to with the speedometer. id try replacing it first. if its still no fix,test/replace the throttle position sensor. If trans is bad,sadly ONLY a 93 and 94 year trans will work. Dont buy anything but those 2 years if u have to replace trans. 92 is when 700r4 type existed,and 95 is a 1 year on its on. 96+ is a different computer type.

 

Sounds like what my truck trans did on me for a while its the same year .I cha ged the fluid and filter and flushed it.Put in fresh fluid annd bottle of lucus.Walla still going this was 3 years ago.So try that.

 

chris015;
Ive got the digital speedometer and have newly replaced it to a rebuilt one,, had the same problems with my old speedo so dont think thats the problem. Ive thought about replacing the speedsensor on the gearbox, but its so expencive!

where is the throttle position sensor located?

1sttimejimmyowner; ive newly changed the oil, but not flushed the system tho,, do you mear flushing the cooling system, or just pouring oil into the trans-fill hole while the trans-pan is open and kinda flush the system with new oil that way?

Thanks to you both for reply!

 

The throttle position sensor is on the throttle body on top of the engine.

I would like to second 1sttimejimmyowner's suggestion to get the transmission flushed. You can do it yourself if you know what you're doing but I would recommend that you take it to a shop where they can properly pump all of the old fluid out of the transmission and pump new fluid in.

You may also check the vehicle speed sensor. I believe that's another part of the system for determining how the transmission shifts.

 

change the speed sensor, the speedo runs off it and so goes the trans. If it goes the speedo and the trans will go WTF!?!?!? and trans will go into limp mode (2nd gear). The TPS tells the trans to downshift when you give it throttle, if this fails it will just shift early and not kickdown (it will downshift normally). TPS is not your problem.

 

but is it normal that the speedsensor fails when the tranny gets hot?

 

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