Justin93

My 1991 Camaro RS 305 TBI (stock, rebuilt TBI) equipped with the automatic 700r4 transmission just recently started slipping in and out of gear(s). Daily drove it just fine 111-139k mostly city traffic with no experience of slipping before in any gears.

About the Camaro:
140,0xx Miles
Original Motor/Trans
Bone stock drivetrain
Diagnosis so far:
- TPS voltage swept across within spec with no drop spots.
- TBI and Vacuum lines also seemed fine just rebuilt it about 1-2 months before this problem began.
- New Distributor, spark plugs & wires, 02 sensors, EGR, IAC, TPS etc,.

Experience:

I have to reverse out my driveway and most of the time it works fine but it will occasionally stall out the car completely if insufficient fuel is added or the vehicle isn’t warm enough (stalling might be separate issue from slipping). This than requires me to put back in park and restart the vehicle, sometimes the vehicle will not start unless fuel is added - This is an intermittent but frequent problem, especially in the mornings.

When I shift into 1st it inconsistently catches gear - It feels like I am pressing onto the gas pedal and the motor is winding up the RPMS but nothing is going through the driveline to the wheels - it will eventually catch gear and the driveline feels like its operating fine again until it slips in and out of each gear, repeating the process.

I drove it longer on the freeway and found that it skipped in all gears (even when in/out of OD). I drove in 4th gear and in OD cruising down the freeway with consistent pressure applied on the gas pedal and all of a sudden I’ll feel the force/intertia from the vehicle’s driveline intermittently loosing power (energy) from the engine as the RPM’s continue to whind up. It’s similar to the feeling when engine braking in a manual vehicle. I got stuck in traffic and my vehicle relied on the downward hill for momentum as the car would catch and release the gears leaving me unable to move in traffic.


Suggestions from local Transmission shops:

I spoke to a few shops that HAVEN’T seen the car — as I don’t want to drive it and get stuck on the road.
Most of the shops claim it to be the Torque converter and the ‘fins’ going out within the TCC..
I’ve been advised to dump the fluid, check for particles (with a magnet) and if no metal/debris is found to install a new TCC.

Is what the shops saying true? I feel there may be potential damage to the internals of the transmission.. Is there any other diagnosis I can/should do prior to this? Maybe by testing the VSS itself or Speedo cable and if so, how do I test.

I’m more than capable of R/R’ing any external transmission components or removing the trans all together, but I’m not confident rebuilding the internals of the 700r4 so am seeking some transmission guru’s advice!


Here’s my catch: I don’t want to toss a ton of money at parts trying to shotgun fix the problem — I am saving my money for a t56 that I plan on installing with an LS motor I built a while back.

I am trying to confirm the problem hopefully with your guys help so I can determine if its cost effective to just non-op the camaro until I can afford the new transmission (insurance $$) OR if it’s something I can diagnose and ultimately fix myself with the tools I have accessible on a weekend.


About a week before the problem began I had built a Moser 9” w/ Eaton LSD, 3.54 gears, 31 spline moser axles, daytona pinion support with Baer’s 4 piston brakes etc,. and haven’t found the motivation to install it and address what else may be needed until I get this slipping issue fixed.

Thanks for reading this novel in the first place and I hope to hear back from some folks as this has been killing me - appreciate your guys time and help in advance.

RBob

iTrader: (1)

Check the transmission line pressure first. There may be a pump/boost issue causing the clutches to slip. Can also drop the trans pan and see what is lying in the bottom of it.

If that all checks out OK I'd go with the TC.

RBob.