Transmission Trouble, Slipping?? (Series I SC)

Even if we accept the 4T60 tranny wasn't the most stout of units, four WOT runs to 100 mph shouldn't cause a complete failure, especially at such low miles. There are just too many of them out there holding up fine receiving similar levels of spirited driving. Something else had to have gone wrong here.

I don't care what kind of car it is, if the transmission can't survive more than a dozen hard launches to 100 mph in its lifetime, I call the car "junk". I don't think '96 Rivieras were junk, so would call this failure a fluke before I blame it on user abuse.

well im going to drop the transmission pan tomorrow and see if theres any shrapnel layin around....Ill keep ya's updated

Take photos, please, if you see anything. I didn't get the chance when mine died.

AA wrote:

Take photos, please, if you see anything. I didn't get the chance when mine died.

will do man

so new trannys in, cars faster now, I think my gears were all slipping lol, and sorry guys, didnt get pics I didnt have a camera on me at the time and i was heading to the states next day so couldnt take em

When you say new tranny is in, do you mean you had yours rebuilt or you swapped for a good used or bought a high performance trans for it.?

Rickw wrote:

When you say new tranny is in, do you mean you had yours rebuilt or you swapped for a good used or bought a high performance trans for it.?

its a good used one, only has 50xxx miles on it

TheNewEra95 wrote:

so new trannys in, cars faster now, I think my gears were all slipping lol, and sorry guys, didnt get pics I didnt have a camera on me at the time and i was heading to the states next day so couldnt take em

What was in the pan of the trans you removed?

albertj wrote:

TheNewEra95 wrote:

so new trannys in, cars faster now, I think my gears were all slipping lol, and sorry guys, didnt get pics I didnt have a camera on me at the time and i was heading to the states next day so couldnt take em

What was in the pan of the trans you removed?

nothing, no shavings or anything...so its strange

the next thing to do would be to pull off the valve body and inspect. It's moot now though.

Albertj

So i was driving down the expressway about 65 mph then my car shifted out of overdrive. the display still said that it's in overdrive but i went from 1800 rpm to 2600 rpm. what up with that? The car still shifts fine from a dead start and i dont notice any slippage from the tranny. So is this a vacuum leak or is my tranny starting to go bad? should i just change the fluid and hope for the best ? the car has about 120000 miles on it with a rebuilt motor.

95rivy wrote:

So i was driving down the expressway about 65 mph then my car shifted out of overdrive. the display still said that it's in overdrive but i went from 1800 rpm to 2600 rpm. what up with that? The car still shifts fine from a dead start and i dont notice any slippage from the tranny. So is this a vacuum leak or is my tranny starting to go bad? should i just change the fluid and hope for the best ? the car has about 120000 miles on it with a rebuilt motor.

Might be a stupid question....but were you going uphill?

It sounds like you lost 4th gear. This can happen as a result of the car going into 'limp home' mode. The PCM throws it into 3rd and maxes trans pressure to 96 psi. If this is the case, next time it happens, try shifting into 3rd manually to see if anything changes.

If shifting into 3rd causes a change, your TCC is not locking up, meaning you have 4th with no TC lock-up. You should see a SES lamp for that.

Did this happen after a long drive? I think heat can cause the trans to go into limp mode, but not sure in your case.

AA wrote:

It sounds like you lost 4th gear. This can happen as a result of the car going into 'limp home' mode. The PCM throws it into 3rd and maxes trans pressure to 96 psi. If this is the case, next time it happens, try shifting into 3rd manually to see if anything changes.

If shifting into 3rd causes a change, your TCC is not locking up, meaning you have 4th with no TC lock-up. You should see a SES lamp for that.

Did this happen after a long drive? I think heat can cause the trans to go into limp mode, but not sure in your case.

could be a ssimple as a flaky trans temp sensor?!? Check the connectors. Car this age, may be a marginal crimp on a lead finally bit the big one.

Albertj

Well lets see if i can answer all your qeustions. No i was not going up hill, the road was really flat. I did try to shift the into 3rd gear and no rpm change, nothing happend at all. I was only on the road for maybe 10/15 mins, so not a long drive at all. Later in the day i took the car out again and it ran fine, i did have 4th gear.im not really sure what going on.

Update today i took the car out on the expressway again no overdrive.. drove the for 15 mins stopped shut it off for 10mins. started it back up to come home and now have 4th gear again. I dont get it

Whens the last time you serviced your tranny filter and fluid?

well i i have not done one yet. thats next on my list. hopefully next weekend. ive ony had this car on the road for about 5 months. im tring to work all the bugs out and man theres a lot of them.

Do a transmission fluid change and filter change.
Also, go to Advance Auto, Autozone or any of the auto parts stores and get a can of TransX and add the appropriate amount to your trans after the fluid drop and with the new fluid..
Your problem sounds like a sticky valve and the TransX will help with that and I have never had a bad reaction using TransX for many years. It may fix your problem but won't cause any more problems. That's been my experience with the product.
If after the fluid and filter change it does not solve the issue then you are going to have to look into getting that particular solenoid/ switch replaced for 4th gear.
I don't know enough about it to speak about it, but if the trans is operating good in every other driving mode but only giving you trouble in the 4th gear engagement, I wouldn't let anyone talk me into an overhaul unless it's covered under a warranty or you have the money and the car has high mileage.
Also, when I mentioned a fluid and filter change, I assumed you would be doing this your self and not bringing to a shop. Is this correct.?
If you plan on having a shop do it then don't go to the quikie lube with a discount for a Trans FLUSH. You Do Not want to get it flushed this late in it's life if you have no idea of when it was changed last.
Find a regular service shop that will drop the pan and replace the filter, install new gasket if necessary (GM installs a very nice rubber and metal gasket that is re-usable up to a point, NAPA also carry's that gasket but have to ask for the metal/rubber, as they also sell a paper/cork gasket) and add the TransX and the correct amount of fluid. On my car it is around 12 quart's to re-fill, IIRC. Verify for your year and model trans.
I don't know what yours takes. Maybe someone with a 95 can chime in.
One last suggestion: If you are planning on keeping the car and you plan on doing the Trans Fluid changes yourself, buy the universal drain plug made by Dorman or one of the other manufacturers to install in the corner of the pan. This will make all future fluid and filter changes painless. Right now there is no drain plug if it's stock so you end up making a mess trying to drain the pan into a container in your driveway or garage. With the drain plug costing from $3.00 at Advanced Auto to $9.00 at NAPA it is well worth the investment and time to install. Heck, even if you plan on paying someone to do the job they will be more than happy to install the drain plug so the next time they can just pull the plug for drainage.
Good Luck

The trans may hold 12 quarts capacity, but should only take 6-7 to change. The rest stays in the trans and torque converter.

AA, do you change your own trans fluid and if so how much do you have to install.??
I could swear that I had to install 12 or more quarts after dropping the pan.
But as usual, I could be wrong as I forget very easily now a days.
All I know was that I recently bought another 14 quarts in preparation of doing just a fluid drop later this fall on my car.
So, it will be a couple of more months before I KNOW again. I should be writing this stuff down as I know my memory is all out of shape lately.
I did the fluid and filter change along with adding the drain plug in June and figured I would change just the fluid this fall and then do another change with filter in the spring.
I also bought the same trans fluid cooler with thermo0stat you did. I want to add the cooler and I need to replace my OEM hoses as both are seeping near the swedged joints.
I am putting 3/8" compression fittings on the original steel lines after I cut out the OEM rubber and run new rubber (Jegs) hoses onto barbed fitting. The 3/8" fittings were ordered from the company that supplied the cooler and thermostat. They are similar if not identicle to the Earls fittings in that they compress on the existing steel tubing and have a barbed fitting on the end to accept the hose and clamp. They were about $5.00 per fitting and should do the job nicely. I measured the OD of both steel lines coming from the trans and they both measured 3/8". I mention the size because after reading through the complete thread I have seen where someone needed 5/16" and 3/8" to accommodate their lines. I hope I end up with the right fitting for the radiator. Because as I said, I only measured the 2 lines as they come from the trans in an easy to get to spot. I do not plan on removing any tubing fittings from the radiator at all. I am just going to cut the lines with a tubing cutter and install the swedged type fittings.
Have everything I need to get that job done except the high pressure Fuel line band clamps that I intend on using instead of worm clamps.
Thanks for documenting the install with part numbers, it really helped me when it came time to order the parts.

cool thanks for the help guys. Can i just say i love this website. never seen anything like it before.

Except for one time, I've changed my own fluid every 25k miles. I'm pretty certain it took 6- 7 quarts for the change. I use Dexron VI, which is $8/quart, so helps to know how much to use. Fluid change write-up is here:

https://rivperformance.editboard.com/care-maintenance-f8/write-up-transmission-fluid-filter-change-t3692.htm#78551

ok so i got an update on my car. Did the fluid change and filter, also changed the vaccum control module. Still have trouble with overdrive, but here is the funny part i just found out.. if i drive at highway speed at first no OD but if i pull off the road and shut the car off for a few seconds and then get back up to speed i have OD again with no problems..any ideas could it be the tranny range sensor or what that piece that sits on top of the tranny.

Any engine light? The shutting down and restarting fixing it sounds like it is hitting limp home mode.
That *should* be trowing a service engine light. If you don't see one, the light may be burned out. Scan the car.

Based on what you describe I'm willing to bet you are getting a Torque Converter Clutch failure code.