Transmission Problem!

C_More

Registered User
I have an 89 SC auto!When my car is cold it shifts smooth but as soon as the car warms up the tranny starts to slip,and making a constant high pitch whissel!I have never had a tranny go out so this is all new to me.I was considering doing a tranny rebuild but want to rule out any other possibilities first!

Could it be a torque converter?
Could a tranny flush and filter change fix the problem or does it sound more serious?

Chris
 
Last edited:
C_More said:
I have an 89 SC auto!When my car is cold it shifts smooth but as soon as the car warms up the tranny starts to slip,and making a constant high pitch whissel!I have never had a tranny go out so this is all new to me.I was considering doing a tranny rebuild but want to rule out any other possibilities first!

Could it be a torque converter?
Could a tranny flush and filter change fix the problem or does it sound more serious?

Chris
No it is not the converter. Aod converters are pretty trouble free excluding the early 80's ones with a cast iron direct drive damper.
 
Try the flush and fill...

It's not all that difficult a job, but it can get really messy. Raise the front, either on jackstands or ramps, and drop the pan (unbolt three sides and then loosen the bolts on the remaining side, that will allow the most of the fluid to drain out on the opposite side). Once the pan is empty, remove the flap/cover from the bottom front of the case, rotate the crank until the drain plug on the torque converter is visible through the opening. Remove the plug to drain the TC. Once everything is empty, replace the TC plug, install a new pick-up screen/filter onto the valvebody, and re-install the pan with a new gasket (be sure to remove all the old gasket material or it will leak). Put the car back on the ground (if you're on ramps, have someone in the car as you roll it back with the engine off). Pour in about 4-5 qts of ATF before you crank the engine. Fire the engine, let it come up to temp and check the dipstick. Keep adding ATF slowly intil you have about 8 qts in it. Put the car in reverse with the brake applied and give it some gas until you feel the tranny engage. This is loading the TC. Check the fluid level again and keep adding until it hits the full mark. Total capacity is between 12 and 13 qts (if you drained the TC). Don't worry if it doesn't move when you first put it in gear, the pump has to "charge" the TC before it will engage.
A couple of hours and less than $50.00 in fluid, filter, and gaskets could fix it right up. If not, at least you will know how to service the new/rebuilt AOD...
 
C_More said:
Who thinks a tranny flush would fix my problem?
I think your chances are less than 50/50 that it will fix anything. I had a problem where the tranny wouldn't shift out of 1st gear. Decided to drop the pan and take a look and changed the fluid while I was at it. I couldn't find anything wrong and the problem went away, but I can't explain why. I have a theory, but no evidence to back it up. The theory is that my fluid got contaminated by water which entered the case through the breather cap on the top while I was driving over a long stretch of standing water. Changing the fluid got rid of most of the water.
 
C_More said:
Who thinks a tranny flush would fix my problem?

..what do you have to lose...I flushed mine and got an extra year out of the tranny before it died,could possibly save yourself some money now.
z
 
Try Some LUCAS STOPS LEAK

C_More said:
I have an 89 SC auto!When my car is cold it shifts smooth but as soon as the car warms up the tranny starts to slip,and making a constant high pitch whissel!I have never had a tranny go out so this is all new to me.I was considering doing a tranny rebuild but want to rule out any other possibilities first!

Could it be a torque converter?
Could a tranny flush and filter change fix the problem or does it sound more serious?

Chris

First, check the tranny fluid level. Second, look at the fluid to see if it is nice and red like it is suppose to be or brown like it is old. Third, smell the fluid on the end of the dip stick. If it smells burnt, then it is probably the clutches are gone and you need to rebuild. But, before I do that I would get a couple of bottles of LUCAS STOPS SLIP tranny fix (www.lucasoil.com) and try that. $20 is better then a grand or more.

Ed Springer


90 Black XR7 5-speed: 70mm TB, Fresh Air Intake, '94 Supercharger, 5% SC Pulley, Raised SC Top, I/C Fan, UD Pulleys, 190 l/h Fuel Pump, 36# Injectors, Headers, Magnaflow Muffler (no cats) with stock resonators, 3:27 Gears, Ripper Shifter, 73mm CL MAF (Blue Tube), Magnacore Wires, NGK Iridium Plugs, Royal Purple Lubricants and Rear Spring Air Bags.

94 Red SC Auto: 70mm TB, Fresh Air Intake, Stock 90 SC Pulley, Raised SC Top, I/C Fan, 190 l/h Fuel Pump, 38# Injectors, Headers, Raven Muffler (no cats) with stock resonators, 3:73 Gears, 76mm CL MAF (Gold Tube), Magnacore Wires, NGK Iridium Plugs, Royal Purple Lubricants, TRANSGO Shift Kit, Pro-Torque 2500 Stall TC, Haydon Auxiliary Transmission Cooler, Tokico Struts & Shocks, American Racing 17” Sniper Wheels, Michelin Pilot Sport A/S Tires and 235 RWHP with 315 LB-FT Torque.
 
I think it needs repaired or rebuilt. If you wait until you have problems to service the transmission you waited too long. I would expect to find damaged forward clutches, worn pump seals and or stator support. Possibly a clogged filter or bad/missing filter gasket. Anything is possible however.
Alan
 
Thanks for all the help looks like a tranny rebuild is in the near future.I always check my fluid levels and it has been good but when it started slipping I check the level still good but seems to be turning maroon,this leads me to believe bad forward clutches!I have drove it 5 times since I posted this thread and it seems to be burning the ATF now so it is a pretty easy answer now!

Where would I get a rebuild kit for a good price?SCPerformance has them for $260 but I find their prices to be a little high most of the time!I would like to buy straight from the manufacture if possible.
 
Try this site...

Company name is Makco Distributing http://www.bulkpart.com/ They seem to have about everything, even transmission tools. There are also a lot of rebuild kits for AOD's on ebay. That will give you an idea of the "market price" for rebuild kits. You will want to do some research to make sure the kit you buy has everything you need. Not all kits are "created equal". I still think a fluid flush-n-fill is worth a try. If it has been a long time since it was done (if ever) the pick-up screen/filter is probably clogged up. Dropping the pan will tell you a lot about what is going on in the tranny. If the clutchpacks are shot, you'll have a bunch of mud, sludge, and debris in the bottom of the pan.
 
hey dude, i think i know what ur problem is... yes ur tranny is old and tired but yes it can still be a good daily driver... do the flush and fill thingy and add 2 bottles of LUCAS TRANSMISSION FIX, will help u out big time.. also... i think ur car is overheating... make sure ur lines are open... also... do u have an aftermarket transmission cooler? if so... did u bypass the radiator? if u did then thats ur problem.. ur transmission fluid is overheating and it is staying too thin to work properly... when the transmission fluid is cold it is nice and thick... when it is hot it thins up... if it thins up too much then ur having cooling problems....
 
C_More said:
How do I know if I have a stamped drum or cast iron?

Stock AOD drums are cast iron. Yes your clutch's are burnt as indicated by your fluid condition. Been there done that and have the T shirt. :)
 
Back
Top