I have to apologise because I read that you have a 1989 Deville. Just clarify what you mention 4.8 engine size and I don't know what engine that is, probably a 4.5. Any way the TH440 was used in a number of GM vehicles so this one from a Pontiac, I assume a Bonneville, should work. Looks like you will have to pull the transmission anyway so when it is out you will be able to do a good compatibiltly check.

 

Katz, the Chevy Silverado Z-71 came with the 4.8 L engine .. nice upgrade for this '89 Cadi, dont you think? I sure like to see how they achieved that setup.

If the trany shifts, the gears ARE ENGAGING .. sounds odd to me ..
I agree with carnut on the shifting thing, maybe they forgot to hook up the transmission when they installed that 4.9 Chev engine?

forget wasting your money on the Haynes .. buy a FSM instead.


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I made a mistake, the engine is a 4.5 not a 4.8. That would be cool if someone did that swap. I plan on pulling the tranny soon. Thanks for all the suggestions. FSM ? Is that a service manual ?

 

Factory Service Manual ...

 

I finally got some time to work with this tranny problem. I put the car on jackstands, and pulled the tranny pan, and replaced the filter. I filled it with new tranny fluid, and I figured what the heck so I turned her on and put it in drive. It started to actually move the axles and the rotors spun. Is that possible just because it is in the air ? I put the wheels back on took it off the jackstands and it wont budge in any gear just like before. I figured a ditry filter wont cause the tranny not to work, but I guess it was worth a try. I guess my next step is pull it out. Any particular thing I should look out for ? Thanks

 

did you recheck the fluid when it was hot to see if you needed to add more? if you change the filter out it will need 6 or 7 quarts. other wise is the check engine or service vehicle light on if so try to get codes. if the service vehicle is on that can be triggered by transmision problems.

 

you ran the trans without the pan ?

what did you find in the filter when you pulled it? that is a great place to see what is going wrong, by the materials found.

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Daddylac,
I did recheck the fluid, and it was in the HOT operating range after running for about 15 minutes. It took 6 quarts. I did not notice any check engine lights but I will look again for service light and check engine. Thanks

Stomper,
I pulled the tranny pan, and pulled the filter, and replaced the filter, gasket, and pan. No I did not run it without the pan. The fluid was really clean and looked new in the pan and the filter. There was a slight amount of metal shavings on the magnet that is located in the pan. Thanks

 

You bought a car with a trans problem to start with. The owner most likely had car checked out prior to selling, which may be why lack of debris. Trans not electric shift - computer doesn't control shifting other than TCC. In a "nutshell" trans needs to come out to be repaired or replaced. V6 trans should bolt up there are 2 different final drives (speedo) also TCC can be an issue. Your best bet is to find a the correct trans - use the info on the tag on your transmission to find the correct one. Make sure to flush trans cooler before running next trans so debris possible in it won't cause failure. Check to be sure modulator has strong vacuum - carbon build up in T-body can lead to weak signal effecting line pressure causing failure. Possible causes of initial problem : torque converter, pump/pressure regulator, internal leakage.

 

Them metal shavings is a bad bad sign.

I agree .. if you bought from the owner, this was likely a sale in bad faith
or
if the car was traded in and you got it from a dealer, the dealer probably never saw the problem.



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