snowmass2dr

My brother and I just picked up a 1995 Tahoe, the issue, reverse doesn't work. It shifts into reverse and you can rev the engine without hearing any grinding, screeching, etc, there is just no power. All other gears work fine and the truck drives forward great, lots of power, shifts smoothly. Not sure if it's electrical, (the brake lights don't seem to work) a linkage issue, or something greater in the tranny. Any help would be great, my brother and I have decent mechanical ability and are willing to tackle just about anything, hence buying (cheaply) a vehicle that only goes one direction. Thanks in advance.

SabrToothSqrl

I'd guess it's the tranny, but that's a guess.

in PA you need reverse to pass inspection (who knew!?)

LARIDERS

I know alot of times the reverse shell goes out in the 4l60e trans.

cooter26

<TABLE class=product_table id=product_table width="96%" border=0><TBODY><TR><TD>Problem

</TD><TD>

</TD><TD>Symptoms

</TD><TD> </TD><TD>Possible repair

</TD></TR><TR><TD width="35%">Slow, slipping or no reverse</TD><TD width="1%"> </TD><TD width="31%">“lo-reverse” clutches are worn out, fluid leak in the reverse apply circuit, or broken sunshell.. May also have worn boost valve.</TD><TD width="2%"> </TD><TD width="31%">It is possible to remedy a fluid problem by removing the checkball from its cage in the case in the rear of the Transmission may help (must remove valvebody), or adding a high-viscosity additive such as Lucas Transmissionmission additive or other seal restorer product.</TD></TR><TR><TD>1-2 shift does not happen at WOT until you let off the gas</TD><TD> </TD><TD>Middle case leak in the 2nd gear apply circuit (servo assembly or 1-2 accumulator). Doublecheck by using the pressure gauge and watch for a big drop when the PCM commands 2nd gear. Worst case poor line pressure rise (see below).</TD><TD> </TD><TD>Try replacing the ThrottlePosition Sensor ThrottlePosition Sensor (TPS).</TD></TR><TR><TD>1-2 Shift shudder at WOT delayed or abnormal 1-2 shift There's a problem only on the 1-2 shift</TD><TD> </TD><TD>1-2 accumulator piston cracked or stuck cocked in the bore. </TD><TD> </TD><TD>Check the yellow spring inside the accum housing for breakage. Also, if the accumulator housing walls are scored, the housing must be replaced. Easy fix in the pan.</TD></TR><TR><TD>1-2 shift is delayed and harsh, may not shift into Over Drive</TD><TD> </TD><TD>CheckThrottlePosition Sensor (TPS).for smooth and linear electrical response over the entire range of motion.</TD><TD> </TD><TD>If not, replace.</TD></TR><TR><TD>Transmission does not upshift out of first, speedometer reads zero at all times Speed Sensor (VSS) failure.</TD><TD> </TD><TD>
Cross member must come out to access Speed Sensor (VSS).</TD><TD> </TD><TD>Easy fix on rear of Transmissionmission,</TD></TR><TR><TD>Will not work in 3rd or 4th gear</TD><TD> </TD><TD>
“3-4” clutches are worn out. The car is safe to drive (in 2nd) until you can get it fixed.</TD><TD> </TD><TD>Remove & replace or rebuild </TD></TR><TR><TD>Sudden grinding noise with no prior warning primarily in 2nd gear, behavior in reverse may be abnormal</TD><TD> </TD><TD>sunshell is fractured. Try not to run or drive the car or further damage could result.</TD><TD> </TD><TD>Remove & replace or rebuild</TD></TR><TR><TD>1st and 3rd only, will not work in 2nd ,4th or Reverse</TD><TD> </TD><TD>sunshell is fractured or splines are sheared off. Try not to run or drive the car or further damage could result.</TD><TD> </TD><TD>R&R</TD></TR><TR><TD>Will not work in 2nd or 4th gear</TD><TD> </TD><TD>2-4 band is slipping. Servo seals may be damaged (can be fixed without removing Transmission. Otherwise, 2-4 band is worn out. </TD><TD> </TD><TD>Remove & replace or rebuild</TD></TR><TR><TD>Shifts into gear harshly, car feels sluggish off the line, No 1st, 4th or Torque Converter Control (TCC) lockup available, Manual 2nd, 3rd and Reverse are only available gears, CEL is on</TD><TD> </TD><TD>
Transmissionmision is either in limp-home mode or has lost electrical power. If there are lots of error codes in the PCM, check the underhood fuse that powers the Transmissionmission, and if it pops again, look for a short in that circuit like an O2 sensor harness touching exhaust. Otherwise, check PCM codes for a particular fault in the Transmissionmission causing the PCM to put it in limp-home mode.</TD><TD> </TD><TD>check the underhood fuse that powers the Transmissionmission</TD></TR><TR><TD>
Will not work in 1st or 4th available Transmission shifts 2nd to 3rd by itself in Drive or Over Drive and locks the converter </TD><TD> </TD><TD>ShiftA solenoid failed. Or a wiring problem from PCM to Transmission.. or PCM.</TD><TD> </TD><TD>Easy fix in the pan.</TD></TR><TR><TD>Transmissionmission goes into gear but feels very sluggish like the brakes are on, but it will roll easily (starts out in 4th gear), you manually shift to 2 to get it moving, once it's moving you put it back in OD and the car shifts 3rd to 4th on its own and locks the converter at the appropriate time</TD><TD> </TD><TD>Shift B solenoid failed. Or a wiring problem from PCM to Transmission.. or PCM.</TD><TD> </TD><TD>Easy fix in the pan</TD></TR><TR><TD>No Torque Converter Control (TCC) lockup</TD><TD> </TD><TD>
Brake pedal switches improperly adjusted (always on), Torque Converter Control (TCC) solenoid failed (easy fix in the pan), Torque Converter Control (TCC) clutch worn out</TD><TD> </TD><TD>(must remove Transmission and replace TC).</TD></TR><TR><TD>Torque Converter Control (TCC) always locked</TD><TD> </TD><TD>Torque Converter Control (TCC) apply solenoid circuit shorted to ground, Torque Converter Control (TCC) solenoid blockage.</TD><TD> </TD><TD>Easy fix by removing the pan. or Torque Converter is damaged (must remove Transmission and replace TC).</TD></TR><TR><TD>Loud noise in 4th gear and feels like the brakes are on </TD><TD> </TD><TD>overrun clutches are applying due to a cracked or leaking forward piston. Overrun clutches will be worn out after 30 seconds of this behavior. Car can be safely driven in D.</TD><TD> </TD><TD>Remove & replace or rebuild</TD></TR><TR><TD>Soft shifting, gradual performance degradation </TD><TD> </TD><TD>
Poor line pressure rise due to leaking boost valve, clogged Electronic Pressure Control (EPC filter screen, failing Electronic Pressure Control (EPC solenoid, or worst case leaky seals throughout. Transgo HD2-C kit fixes first two without removing Transmission. Seal restorer may fix last problem.</TD><TD> </TD><TD>Also try a Transmissionmission flush with BG brand products if problem continues, probably R&R</TD></TR><TR><TD>No forward movement in OD or D, but L2, L1 and R work</TD><TD> </TD><TD>
Forward sprag is broken. </TD><TD> </TD><TD>Remove & replace or rebuild Try not to run or drive the car or further damage could result.</TD></TR><TR><TD>Extremely harsh shifts from P or N, normal shifts at WOT </TD><TD> </TD><TD>
Electronic Pressure Control (EPC (Electronic Pressure Control) solenoid failed.</TD><TD> </TD><TD>Easy fix in pan. Fix as soon as possible or hard parts will eventually break.</TD></TR><TR><TD>Loud bang, grinding sound, loss of all gears, and a binding driveshaft </TD><TD> </TD><TD>snapped output shaft. Try to wiggle driveshaft - if more than 0.020" play, that's the sign.</TD><TD> </TD><TD>Remove & replace or rebuild</TD></TR><TR><TD>Transmission seems noisy when moving in 1st and Reverse, noise goes away instantly if you shift to N or the Transmission goes into 3rd gear</TD><TD> </TD><TD>Reaction planetary is worn out due to high miles or insufficient lubrication. Not a critical failure, but not a good sign either. </TD><TD> </TD><TD>Remove & replace or rebuild sooner rather than later.</TD></TR><TR><TD>No movement in any gear</TD><TD> </TD><TD>pump failure, or total loss of fluid. If out of fluid, avoid running the engine until the Transmission is refilled to avoid pump damage. To check for pump failure, check fluid level with the engine off, then start the engine and recheck fluid level. If level does not go down when engine is running, the pump is broken.</TD><TD> </TD><TD>Remove & replace or rebuild, or refill pan and find the leak.</TD></TR><TR><TD>Transmissionmission does not shift automatically, only manually.</TD><TD> </TD><TD>Check wiring, check other sensors such as Speed Sensor (VSS) andThrottlePosition Sensor (TPS)..</TD><TD> </TD><TD>Swap in a known-good PCM, </TD></TR><TR><TD>3rd gear starts, can manually shift through all gears. When car has been turned off for a bit, then back on it will run normally.</TD><TD> </TD><TD>Speed Sensor (VSS) dropoff w/ Hi-stall converter. The rpms are too high, but Speed Sensor (VSS) is showing no movement. Happens after a tire burning take-off. Doesn't store a code, will not throw a CEL. </TD><TD> </TD><TD>Reprogram PCM for Speed Sensor (VSS) dropoff</TD></TR><TR><TD>Fluid leak out of the front of Transmission where the converter connects partial or full loss of movement</TD><TD> </TD><TD>Front pump bushing walked out.May have to replace converter also if hub is scored. Note that a leaking front seal usually means the bushing is walking out</TD><TD> </TD><TD>Remove & replace or rebuild </TD></TR><TR><TD>Torque converter shudder in 4th while lockup is engaged</TD><TD> </TD><TD>problem goes away when the brake pedal is pressed slightly to unlock converter. Have a shop verify line pressure, and provided no valves in the Torque Converter Control (TCC) hydraulic circuit are worn, replace the torque converter. </TD><TD> </TD><TD>Lubegard Shudder Fix will at least fix this for awhile. Or try a Transmissionmission flush by a shop that uses BG brand products.</TD></TR><TR><TD>Shifting suddenly become very hard. When going from park to either reverse or drive it slams into gear. 1-2 and 2-3 shifts are also harsh. All gears seems to work. May be intermittent</TD><TD> </TD><TD>CheckThrottlePosition Sensor (TPS).for smooth electrical response. If the response is jumpy or erratic at all.</TD><TD> </TD><TD>replaceThrottlePosition Sensor (TPS)..</TD></TR><TR><TD>Fluid pumped out through the vent tube</TD><TD> </TD><TD>Plugged cooler line. </TD><TD> </TD><TD>Flush the Transmissionmission cooler and cooler lines. Also could be overfiled Transmissionmission.</TD></TR><TR><TD>Transmissionmission acts like it's in Over Drive in neutral, car is locked stationary in Reverse, engine feels loaded in ark,, all four forward positions work fine</TD><TD> </TD><TD>Internal crossleak feeding the forward clutches all the time. Most likely a cracked input housing, or cracked forward piston means forward clutches are fused together. Car can safely be driven gently in forward gears until the repair.</TD><TD> </TD><TD>Remove & replace or rebuild</TD></TR><TR><TD>Needle bearings in the pan, first gear and/or reverse may be noisy </TD><TD> </TD><TD>Either a torrington bearing or a planetary bearing is on its way out. Transmission will eventually die a loud, catastrophic death. Cheaper to rebuild now (saves further damage to hard parts). It is drivable until it breaks.</TD><TD> </TD><TD>Remove & replace or rebuild</TD></TR><TR><TD>1-2 or 2-3 shift is slow/soft above part throttle</TD><TD> </TD><TD>Transmissionmission is failing.</TD><TD> </TD><TD>Remove & replace or rebuild </TD></TR></TBODY></TABLE><TABLE class=product_table id=product_table width=584 border=0><TBODY><TR><TD></TD><TD> </TD><TD>Problem</TD><TD> </TD><TD></TD><TD>Problem</TD></TR><TR><TD width="8%"></TD><TD width="3%"> </TD><TD width="37%">TPS circuit</TD><TD width="3%"> </TD><TD width="8%"></TD><TD width="41%">3-2 Control solenoid circuit fault </TD></TR><TR><TD></TD><TD> </TD><TD>TPS out of adjustment</TD><TD> </TD><TD></TD><TD>Torque Converter Control (TCC) solenoid circuit </TD></TR><TR><TD></TD><TD> </TD><TD>Transmissionmission range pressure switch </TD><TD> </TD><TD></TD><TD>Torque Converter Control (TCC) stuck on </TD></TR><TR><TD></TD><TD> </TD><TD>park/neutral switch </TD><TD> </TD><TD></TD><TD>Speed Sensor (VSS) circuit loss Transmissionmission output signal </TD></TR><TR><TD></TD><TD> </TD><TD>Transmissionaxle shift control (3.8L)</TD><TD> </TD><TD></TD><TD>Transmission pressure control solenoid</TD></TR><TR><TD></TD><TD> </TD><TD>brake switch(4L60-E Transmission)</TD><TD> </TD><TD></TD><TD>Transmissionmission fluid temp high</TD></TR><TR><TD></TD><TD> </TD><TD>Torque Converter Control (TCC) knock sensor shorted(4.3L)</TD><TD> </TD><TD></TD><TD>Transmissionmission 2-3 error </TD></TR><TR><TD></TD><TD> </TD><TD>Transmission code-TTS temp high </TD><TD> </TD><TD></TD><TD>Transmissionmission 1-2 error </TD></TR><TR><TD></TD><TD> </TD><TD>Transmission code-TTS temp low </TD><TD> </TD><TD></TD><TD>Torque Converter Control (TCC) solenoid circuit fault </TD></TR></TBODY></TABLE>

<TABLE style="WIDTH: 34%" width="96%" border=0><TBODY><TR><TD width="37%">A - Ground</TD><TD width="10%"> </TD><TD width="53%">F - Torque Converter Control (TCC)</TD></TR><TR><TD>B - Test Terminal</TD><TD> </TD><TD>G - Fuel Pump</TD></TR><TR><TD>C - Air Injection</TD><TD> </TD><TD>H - Brake Sense Speed Input</TD></TR><TR><TD>E - Serial Data</TD><TD> </TD><TD>M - Serial Data</TD></TR></TBODY></TABLE>

snowmass2dr

Thanks, I'll start with checking the pressure and see what that shows me.

snowmass2dr

Update - So my brother says with enough throttle it will creep in reverse - does this sound more like a pressure/pump issue? If the sun shell is gone would it still be able to move slightly? Thanks - still trying to find some pressure testing equip.

WUG

my 95 GMC Suburban did the exact same thing at 140k = complete trans rebuild

gsferraro

Hello,
Im gary, i have a trans shop in new york. Your shell is not the problem, if the shell strips or breaks you would have no 2nd,4th or reverse. If it drives ok foward then the shell is ok, also your pump is good because it works foward ok, More than likely your low/reverse clutches are bad if you only have no reverse. Gary