Car won't go into reverse (automatic transmission)

My car, a 2000 (2001?) Chevy Blazer won’t go into reverse as of 2am last night. I went into reverse, but when I hit the gas, I heard a loud pop and a whine that died out over about 4 seconds. Then, no more reverse.

The car also started making a whirring sound while driving in forward, which is slightly alarming. I drove it into the parking lot of my nearest auto repair shop (choosing a place that is on a slight upward incline in case I need to back out in neutral).

It’s Sunday and I was hoping someone could give me an idea of what I should expect to hear when I talk to the mechanics tomorrow. Please tell me I don’t need to replace the whole transmission. Please. If I wish hard enough, will it be true?

Well, I would answer…but you said not to tell you.

Don’t have a general purpose auto shop evaluate it - you need a reputable local transmission specialist - i.e. not a national chain transmission operation.

erg. Thanks for such a quick answer though. Are there any other issues that could have caused this that wouldn’t entail a complete transmission replacement?

And who needs to go into reverse anyway? I’m a forward-thinking kind of person.

A loud pop in this particular transmission with no reverse following usually means a broken sun shell. To be exactly sure drive it in forward. If the trans wont shift into 2nd or 4th gears also it is definite that the sun shell has broken. This is a very common problem with these transmissions. The onl fix is removal and disassembly of the transmission.


Hi transman - thanks for the note. I just tested it out, and, while reverse still doesn’t work, I tried shifting into 2nd and 3rd gears while driving forward, and it seemed to work fine (no change from having it in drive - should there be a change? in rpms or something else?).

Does this rule out a sun shell issue?

Also, can I drive the car to a trans specialist (do I need a tow truck?), or am I going to be risking messing it up further?

Addendum: I don’t think I have a 4th gear on this car, though I don’t know a thing about cars so I may be missing something obvious. There’s a 1, 2, and 3 on the dashboard, along with D N R P, but no 4.

Thanks transman and cigroller for your help on this!

After looking online a bit, could it be the “reverse input clutches” (whatever that means)?

You do have an overdrive (4th gear) Dont manually shift it, just place the gear selector in “D” and count how many times the transmission shifts itself. It should upshift by itself 3 times (from 1-2, then 2-3 then 3-4) Tell me if it does this or not.

As far as the reverse input clutches go… Your transmission has two sets of clutches which operate in reverse. One, the reverse input clutches which are housed in the reverse input drum in the front of the transmission, and second, the low/reverse or what we call them, the L/R clutches which ar housed in the back of the case. When troubleshooting a reverse issue you can rule out the L/R’s by placing the gear selector in “D”, driving the vehicle to about 15mph then while coasting at 15mph drop the gear selector all the way down to the “1” position. When you do this you should feel the transmission drop down into 1st gear and you should feel engine braking. If no engine braking is found, the L/R’s are bad. If you do feel the engine braking the reverse input clutches are probably bad. Thats only if the transmission properly upshifts from 1st through 4th by itself.

Let me know what you find out.


Thank you for the instructions - I didn’t know this was what I should do (though thinking about it now it seems obvious - “automatic” transmission meaning what it does).

So, no, the car wouldn’t even pop into 2nd.

Looks like I’m calling the transmission guys in Seattle in the morning.

Thanks for all your help, and for taking the time to explain all that to me - I appreciate it!

well, one more question - any idea or rough estimate of the cost I’m looking at? From what I can see online, it looks like the price varies from $1000-2000, but that seems like a rather wide range.

So I get in the car today to take it in to the transmission shop, but the engine won’t turn over - just keeps clicking. The red low battery light is tittering, like a light bulb with a bad connection. After I jump the car, I notice the battery indicator is already at 14 volts, and I’m like, whoa that’s odd. But every indicator light is going bonkers - emergency brake (though it’s released already), ABS, service engine, etc., just turning on for a bit, then going out, then back on, and I’m like, whoa, that’s even more odd.

I drive it around the corner to let the engine idle a bit longer in a legal parking space, and when I shift the car into park, the engine just dies.

Does this tend to happen when the sun shell is broken, is something else wrong now, or does my car just hate me?

Ok, so it wont hit 2nd by itself. You’re sun shell is broken. Stop, dont drive it anymore. Have it towed to a trans shop because since the sun shell has separated from the sun gear the shell is turning and tearing up the inside of the transmission case. Dont take it to a chain type shop. Find a smaller shop, preferrably one that builds heavy duty versions of the 4L60E because your transmission had many issues from the factory and will need certain upgrades. Remember, you get what you pay for here. You’ll probably smoke one of those Auto Zone $900 cheapies so stay away from any auto part store specials. Have it built with some basic upgrades. My BASIC rebuild on one of these is a heavy duty sun shell, upgraded 3-4 stack up (3-4 clutches) valve body upgrades for the TCC regulator valve, and some pump upgrades along with new electronics (EPC, shift solenoids). As far as your electrical issue, you might want to have the trans shop do a basic charging system check on it, they should be able to handle that. Find a good trans shop and get it towed. Let us know what happens.


You have or did have a 4th gear.