tranny question

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bigbull338

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ok ive got a tranny q for yall.1st background on the truck.its a 96 chevy 1500 z71 4x4 auto tranny truck with prolly 200,000 on it maybe more.maintaince has been avidly kept up on it.an it has been greased.just had the rear end worked on an serviced.now the tranny will not shift into drive.but itll go in reverse an low 1 2 3 gears.do you think the tranny needs replacing.going to take it to the tranny shop.an have it looked at.
 
I'll assume its a 4L80 trans, could be something simple like the bands getting wore out or could be the clutch plates got smoked in D, towed something heavy and didn't kick out the overdrive? Round here the quickest fix is a Jasper trans, but if your local shop is good they can likely do a rebuild and shift kit update for less than $1500. While you're at it, and if it hasn't been done, it might be worth a new torque converter as well.
 
the truck has never pulled anything heavy.but those are goodthings to have the shop look at thanks.was thinking it needed a new tranny put in.
 
bigbull338":t1a5yh23 said:
the truck has never pulled anything heavy.but those are goodthings to have the shop look at thanks.was thinking it needed a new tranny put in.
Actually being a 1500 it is probably a 4L60 and it probably needs replace I quit using anything but GM rebuilds about 8 yrs ago and if you are replacing or rebuilding it you have to change the torgue converter or all of the rebuilders I know will not warranty the tranny
if you are going to have yours rebuilt better make sure the shop is good because alot of them can't rebuild them and make them live
 
will have to wait an see what the shop says when they look at it.all the shop does is work on trannies.an the shop done some work on the truch a month or so ago.so they may know what the prob is.
 
my bad, I read 2500 not 1500, should have double checked that, 4L60 would be right. It was fresh in my mind because I've rebuilt two 4L80's in the past couple of weeks, one had wore out the brake band and couldn't get reverse, the other had smoked the plates for overdrive.
 
200K miles on a 4L60 is really pushing it. More than likely you have a pump problem or possibly the forward clutch pack is gone. In reverse you have a pressure boost circuit from the pump which is probably why you get reverse but not forward. But the forward control unit could also cause the problem. (really, there are several things that could cause this problem)

Either way, the tranny will probably need rebuilding. Like I said above even if you are able to talk the shop into fixing JUST what's wrong with it they won't gaurantee the job because the next control unit (with 200K) will go out, and so on.

Replacing the torque converter is not an option. The converter is full of little dirt catching vanes that can't be cleaned without opening the converter up. All that contamination will flow right back through the valve body and pump and cause premature failure. The torque converter MUST be replaced. (again, most shops won't gaurantee their work without a new or rebuilt TC)

I'm not a big fan of putting in a bench job rebuilt tranny. One, it hasn't been road tested, two, at least you know what your tranny has and has not done for you over the years (history) and three, you won't have to worry about a porous case or sticking valves, etc (see two). But I know folks who have chosen to stick in a bench job and the transmission, most of the time, holds up just fine. Then there are those who get ........(be nice).
 
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