Hello!

I know this has been asked many times before, but I will explain my situation:

I'm an '04 MC LS. My transmission blew at 38,000 miles over 10 years ago. The following were fixed under warranty:

• TRANS KIT
• HOUSING
• PISTON, IN
• PARTS CLE MX FAC
• VALVE SOL
• SEAL

The transmission has been fine since it was fixed under warranty. I'm now at 135,000 miles (around 90,000 miles on the fixed transmission since warranty).

At 130,000 miles, I knew it was time to change the fluid in my transmission, and I talked to a buddy of mine who works for a car dismantler shop as to whether I should do a fluid change or a flush. He told me that my transmission (4t65e) works better as a closed pan system, and that I should only do a fluid change, and not drop the pan without risking damage to the transmission. He said not to worry about the filter, either.

So, I followed his advice, and got my transmission fluid changed at 130,000 miles. I run as smooth as butter now. However, sometimes I notice a jolt when shifting between gears (this also happened before the fluid change). It happens rarely. I haven't been able to link it to anything specific yet that might be causing it.


Is this an indicator of my transmission fluid filter getting clogged? Or an indicator that my solenoids need to be replaced? Should I bite the bullet by dropping the pan, changing the filter, and adding fluid back in? I know I just recently changed my transmission fluid, but I'm willing to do whatever to keep this transmission going!

Is my buddy's advice about the transmission wrong? Should I be dropping the pan and changing the filter?

Thanks!

All the best,
Bessie

 

For what it is worth here is my $.02.
If you don't change all of the fluid and flush the system your wasting your money. The old fluid that is still in the transmission will just contaminate the new fluid and you have not done much. A half change like you did is still better than not changing it at all, but if your going to do it, do it right.
Where I work we used to drive Ford Crown Victorias. We found that at about 40,000 miles the transmission would start to shudder, so we started changing the fluid and flushing the system every 35000 miles. Once I started getting the shutter so I took it in for a flush. The new shop I went to only dropped the pan and changed that fluid, they did not flush the cooler or torque converter. The shudder went away for about 3000 miles, then came back. I took it to another shop for a full flush and the shudder went away for about 30,000 miles. So, for what it is worth leaving the fluid in the cooler and the converter contaminated the new fluid and was a waste of money.
I am not a chevy guy, but I used to be a mechanic, mainly a Ford guy, but I don't see how dropping the pan and letting the oil out would hurt the transmission. Without a clean filter your not going to gain much, if the filter is clogged with the old fluid it will still be clogged with a new filter.
Now for another personal opinion that I have. I never recommend flushing or changing fluid in a high mile vehicle. You said you only have 90,000 on the transmission, so I wouldn't be too afraid of that but that is about the limit. I have seen more than once when someone with over 150,000 miles changes fluid the transmission goes bad within a few hundred miles. If fluid has been changed every 40000 miles or so it is fine. My theory on that is adding the new fluid and new filter changes the oil pressure in the transmission and causes worn parts to fail. Again this is just a theory of mine, but I have talked to a few mechanics and transmission guys that agree. Yours is not high mile so it should work fine. I would go ahead and do a full flush of the fluid and change the filter if it were my car. Make sure you or the shop flushes the torque converter and the oil cooler, get all of the old fluid out. I am not sure about these transmissions, but for a Ford C4 transmission the torque converter can hold 2 quarts of fluid for the smaller converters. The cooler will hold another 2 quarts between the cooler and the lines. If you change the engine oil would you replace it with 3 quarts of new oil and 2 quarts of the old oil? So to leave the old fluid in these area will not do much good. Changing fluid from everywhere except the transmission pan will leave more old fluid in it than that between what is in the pan and what is up in the valve body and pump.
If this were my car I would drop the pan and do a full flush with a new filter.
Hope this helps. I am sure someone that has a little more knowledge on these transmission will add to it, and I may learn that I am wrong so take it for what it is worth.

 

So if I were to drop the pan, change the fluid, and change the filter right now, would I be able to do it again in another 40,000 miles without damaging the transmission? Or would I be better just doing fluid changes after this full trans service?

 

What I have found with older cars is if the transmission is serviced regularly, keep doing it and it will be fine. The ones I have seen that have trouble changing fluid at high miles are the ones that have not changed the fluid in 150,000 miles then decide to do it. If you change it now then yes change it again in 30 or 40 thousand.

 

Thanks for your response. Hoping I can get more opinions so I can have a solid answer to work with from the MCF.

 

Are there any guides about Monte Carlos for doing a full transmission flush, both pan, filter, transmission cooler, and torque converter?

 

Update:

Ok, I found how to drain the transmission cooler lines, drop the pan, and the filter, but not finding much about draining the torque converter:

 

To drain the converter you need to hook it up to a flush machine. I find that just routine pan drops and fluid/filter changes are the best for these cars.

You could also do a pan drop change fluid, run the car for 100 miles, do another pan drop. But there's no good way to drain the converter at home.

 

I'm interested in keeping my Monte for 1 million miles and getting as much as I can out of my transmission.

For someone like me who wants to keep this car as long as possible, is it necessary to flush the torque converter and transmission cooler?

I know you mentioned just dropping the pan and changing the filter will do me good, but I just want to double check for my case.

Thanks again!

-Bessie

 

Yeah, I truly believe that if you drop the pan and do a fluid/filter change every 30-40,000 miles you should be fine. Outside of that, the failures that would arise would be hard parts failing because they did, and not because of lack of routine maintenance done.

On my DD Camaro, I actually change the trans and differential fluid every spring, just because it's so darn easy!