Crazy 4L60e
 

Hi friends, I've been mad trying to understand the strange behaviour of my gearbox last week.

This is wath it hapend:

-First, doing off road on sand dunes, I cut al the wire harness of my transfer, so I went only 4x2
-I re-made the harness with a 94 diagram that I found here (mine its a 93 full size)
-Everything works great for one hour, I was driving by the highway, and afther 75 kilometers working well, 3rd gear didnt work anymore...
I was running at 100kmh (65 mph) and I just press a bit the gas for an extra punch, but the tachometer goes to 5000 rpm, like the tranny went in to Neutral...
Stop at the side, shift OD, press the gas, first and second was ok, but when it was time to shift 3rd, nothing hapend, again it was like being in neutral...

As I was going to an off road trip, I just made the day in 2nd, and then back by the highway (10 kilometers) at 40 kmh.

But now, I shift OD, push the gas and the truck runs but it didnt shift any other gear... If a release a bit the gas, it shift the gear...

But the strangest thing is that if I shift 2nd, and I push the gas strong, It make a shift at 3000 rpm...

I know its complicated, but imagine how I feel now... Its so stressful to drive my blazer couse you have to guess how transmission will react!!!

Please friends, HELP ME!!!

Thanks

If you tore one wiring harness, I would look over all the rest with a fine toothed comb. You likely damaged something else.

I had a similar problem with my '83 Firebird, which I believe has the same tranny, can't remember right now. Either way it turned out that the one of the governor's arms was broken so it wasn't building pressure and releasing properly.

I believe that would have been the TH700R4, a non-electronic predecessor of the 4L60E.

check the wires going the vehicle speed sensor. probably around the tailhousing of the transfercase. i have similar issues on my 93 cause i dont have mine hooked up does your speedo work?

Speedo its working, but ABS signal came on afther one day using the truck with tranny problems.
I remove the brake fuse, and the tranny didnt make any shift, so I put it back, but the signal keeps on.

Did anybody know where can I buy a Transfer case wire harness???

And, wich R&P comes on my blazer???
Its a 10 bolt GM axle, with a "gmk17" grabbed on it.

Thanks again

actually i have a used one that i never installed on my truck because someone told me that something was wrong with my tranny because when i put the truck in 4hi i doesnt engage and when i put it in low it jumps, jerks and skips while i drive, so i never used it

You're right, the Firebird had the 700R4, my bad :icon_google: