Join Date: Sep 2011
Location: Los Angeles, CA
Another 'losing reverse' thread -- but with details!!!
Hi, I know this problem has been asked before, but it seems like everyone else’s problem is slightly different enough to make me ask the question again.
The car: 1995 Impala SS, 145,000 miles; original everything, no rebuilds on anything. Tranny fluid was last replaced around 100,000.
The problem: losing reverse - still backs up on a level road, but with a intermittent chatter. If I’m going slightly uphill and have to push on the gas — nothing. If I REALLY step on the gas, it ‘catches’, takes off really quick.
All the other gears work fine (I think: I hear it shifting around 15, 25, and 35); the engine ‘brakes’ in manual 1st; the fluid looks old, but I don’t think it smells burnt
The “4L60E common failures” page tells me...
“…“lo-reverse” clutches are worn out, fluid leak in the reverse apply circuit, or broken sunshell. It is possible to help a fluid problem by removing the checkball from its cage in the case in the rear of the trans may help (must remove valvebody), or adding a high-viscosity additive such as Lucas Transmission additive or other seal restorer product. May also have worn boost valve (can replace this by removing the pan).”
A Trans shop told me that it’s the “trans pump” is out, as is the converter, and that I’ll need a full rebuild; he said that line pressure dropped when the car was warm, and no codes showed up (unfortunately, I don’t think I trust him)
Here’s my overly-optimistic thinking: since I’ve still got all the forward gears, my “reverse” problem is a pressure one. Since I don’t have trans pressure gauge or scanner, I’m going to 1) drain the transmission, 2) drop the pan, 3) look for it for clutch material/clean, 4) remove the checkball behind the valvebody, 5) look at the boost valve/replace if necessary, 6) put it back together, 7) add some seal restorer, and 8) drive it and hope it made some difference.
Where do I find this checkball? What does a valvebody and boost valve look like and where can I find them? Does a “worn boost valve” look “worn”? Since they’re only $17, should I just replace it while I’m there?
Can anyone offer advice on this plan of attack? Can anyone recommend a good trans guy in LA?
Thanks in advance.
Culver City, CA -- 1995 Impala SS; 150K miles; stock everything