Help 1991 burb shift issues

[rjohn]

Bought 91 burb 5.7 tbi 4x4, the lady I bought from had it sitting for 12 yrs so i scored it for 500 Canadian dollars which is like 12bucks American. She said she had head gaskets done and new vortec heads but she started havin trainy issues so she parked it never looked into it, left it to rot. I saved it brought back home started lubing hinges ect.. cleaned it out and new batt and gas fired right up ran really good no hiccups . Long story short I topped atf up 2quarts drove truck drives ok doesnt shift over second just revs up wondering if tv cable was messed with during repairs to 350 I've watched adjustment vids but they all had a button to release cable to adjust mine theres no button I've attached some photos

You must be registered for see images attach

 

[austinado16]

You'll need to have it rebuilt, and the rebuilder needs to pay attention to the check balls inside the case. Mine did the same thing at about 235K (original transmission). I had it rebuilt by a local GM tech who had a great reputation for rebuilding them. I read up on all the upgrade parts that are available, and purchase all of it, including a torque converter. It failed the same way about 30,000mi later and this time the guy paid attention to the check balls.....D'oh. It's been fine since, and most of what I do is either towing in the steep mountains, or (at least back when all this was going on) transporting 9 all over southern and central California, to and from high school cross-country and track meets.

Spend up, replace the TV cable, and make sure that cable is precisely adjusted or you'll burn up the new transmission fairly quickly. If you'll be in the heat, consider the much deeper aluminum B&M pan, a mechanical temp gauge bunged into the pan, and the big 11"x11" B&M (Tru-Cool) stacked plate trans cooler installed AFTER the heat exchanger in the right radiator tank.


This is my set up...

You must be registered for see images attach

 

[SirRobyn0]

There is a button on the TV cable, but you can't see it from that angle as it's behind the bracket. However with that said the TV cable is not your problem. Like Austinado16 said the tranny needs to be rebuilt. I assume what you are saying is that it stays in second, never getting into third. But not going into a neutral like state either. Yea, that's a problem in the valve body more than likely, because like Austinado16 I've had to many problems with builders not doing a good job with valve bodies I now insist on a new valve body with a rebuild, even if I'm having them modify the valve body I still want them to do it on a new one.

 

[austinado16]

Both times that mine failed in this exact way, once it shifted out of 2nd, it was as if it was in neutral. So I drove it home by taking back roads, winding it up in 2nd, shifting to neutral anyway, letting it coast back down to a speed where I could shift back into 2nd, and then repeating the process.

I like the recommendation of using a new valve body. Parts for these are so inexpensive, that yes, that should definitely be done. And IMO, build (or have built) it like you're gonna tow 10,000lbs and run 500hp through it. That way you have a trans that will hold up to anything you ever wind up doing. Once built, keep an eye on you trans temps so you can avoid cooking the thing again. There are some charts online that show transmission life span vs. temperatures that it gets run at. It's amazing how heat quickly kills them.

As set up, mine will run 160*F(ish) locally, and anywhere along the CA coastal freeways. Over in the valley, in near/or at, triple digit temps, it will sit at 180*F. If I'm towing the 2,200lb tent trailer, climbing the 30mi long grade into the Sierra's in those temps, it will get to 190-200*F for the last few miles, and sometimes 205*F in the final few minutes.

 

[Matt69olds]

If you accelerate hard enough, can you get it to skip 3rd gear and go into overdrive? If so, most likely the 3-4 clutches are smoked. What does the fluid look like? Is the 1-2 shift at the expected speed?

 

[Matt69olds]

I think I need to clarify. If you accelerate in 2nd gear, then let off the throttle, will it go into 3rd or 4th? If the trans just hangs in 2nd gear, you may be able to get it going with some valve body work.

 

[rjohn]

Thanks for the help I gotta tinker with her some more but worse case rebuild it like the rest of the truck. Haven't had time to work on the burb had to replace wife's diff in a murano what a **** show and iam restoring a small tin boat so burb is sitting