Gmc sonoma transmission

SOURCE: transmission

Transmission model is 4L60E,and the symptoms you are describing is a common failure on these transmissions all the way back to it's predecesor,the 700 R 4 model.The reverse input shell,splines into the low/reverse planetary sun gear.The reverse input shell has a collar with splines made into it,and these splines are prone to stripping,and sometimes the collar itself will break free from the shell.Without the shell functioning,no reverse,and this is likely what you are hearing.Aftermarket companies sell heavy duty,and standard duty,replacements.Eventually,you will lose the forward gears also.Good luck.

Marvin

• 85242 Answers
• Posted on Nov 02, 2008

SOURCE: 97 gmc pickup with automatic transmission trouble

1st thing to do is test the system for codes, the problem is most likely a failed or stuck shift solenoid indside the trans, have you ever serviced the trans, sometimes a fluid and filter cahnge will cure these kinds of issues.

SOURCE: transmission - no reverse

i had to put a new trans in my 2000 jimmy about a year ago there is something inside called a "reverse hub" its made from aluminum and not very hard to break..when mine broke i was stuck trying to move in reverse and it heard a pop then a winding down noise and sure enough its the reverse hub to fix it i just had the trans rebuilt

SOURCE: Rebuilt the Trans.(4L60E) in my

did you do the rebuild or did a shop do it? it sounds like the clutches werernt done properly. if the reverse is out the other gears will go out too if driven too far in that condition,

SOURCE: no reverse after rebuild on 4L60E Transmission from 1995 GMC Sono

There isn't a modulator on this trans as it is electronic

You can have first gear going forwrd but no reverse. It is possible. The low/ reverse clutch isn't needed to go forward.