ATF Fluid question!

[Tyler99s]

I have a 1999 Chevy Silverado 1500 5.3L 4x4 truck. My trans clutches burnt up like 2 weeks ago. I’m buying a used 4L60E today. He said it came out of a wrecked Tahoe with 150k miles. I’m going to swap the transmissions this week and I’m trying to figure out how I go about the fluid types. I know I need the Dexron III but do I need synthetic? Would it be better to run synthetic? Also should I change the transmission filter while I’m at it? I know nothing about transmissions. I did recently  swap to a blend on my motor oil. Truck has 300k miles so I figured it might help it out and she seems to run better to me. Any inputs would be fantastic! Thank y’all 

[sefiroxx]

Dextron VI is synthetic. It is backwards compatible with III and IV. Most quality rebuilders will require its use due to its improved characteristics.

Yes. Replace the filter. Ok, the filter is not that important, but the process is. What you really want is:
- check the pan to see if anything like metal or clutch material is in it.
- put on a new pan gasket.
- might as well change input/output seals
- flush the system

Also, to consider:
- upgraded valve body and valves (plenty of upgraded rebuilt options)
- torque convertor

[Tyler99s]

33 minutes ago, sefiroxx said:

Dextron VI is synthetic. It is backwards compatible with III and IV. Most quality rebuilders will require its use due to its improved characteristics.

Yes. Replace the filter. Ok, the filter is not that important, but the process is. What you really want is:
- check the pan to see if anything like metal or clutch material is in it.
- put on a new pan gasket.
- might as well change input/output seals
- flush the system

Also, to consider:
- upgraded valve body and valves (plenty of upgraded rebuilt options)
- torque convertor

Okay so run the Dexron VI synthetic, new pan gasket, and seals? Might as well do the filter since I’m there. Anything else?

I don’t know what ya mean by flush the system but I can YouTube it.
 

The trans I’m getting is coming with a torque converter but I don’t know if it’s a new one or the one that was already on the truck. Should I go ahead and get a new one if it’s a old one?

Im kinda taking a chance on getting this one. So I’m not trying to put more money in than I have to for the time being. Just until I know it works properly and there’s no problems.

[Tyler99s]

Just now, Tyler99s said:

Okay so run the Dexron VI synthetic, new pan gasket, and seals? Might as well do the filter since I’m there. Anything else?

I don’t know what ya mean by flush the system but I can YouTube it.
 

The trans I’m getting is coming with a torque converter but I don’t know if it’s a new one or the one that was already on the truck. Should I go ahead and get a new one if it’s a old one?

Im kinda taking a chance on getting this one. So I’m not trying to put more money in than I have to for the time being. Just until I know it works properly and there’s no problems.

Also, check the pan on the one I’m buying?
(For shaving and clutch material)

[sefiroxx]

The seller has probably drained the tranny, but old fluid can be found in nooks and crannies, and especially in the convertor.

Pull pan, inspect pan, and the wire harness. Replace filter, gasket, seals.

Install, add new fluid. Disconnect upper radiator tranny cooling line. Connect tranny hose via vinyl hose to 5g bucket. Start truck and the tranny pump will pump new fluid through system into bucket.

Shut off when bucket is half full (majority fluid pumped out). Add equivalent new back in. Reconnect tranny cooler line. Restart truck, level ground, warm up, shift through forward/reverse gears with brake on, recheck level and adjust accordingly.

[Black02Silverado]

A good idea to change out the front and rear seals.  You will have to pull the torque converter to get to the front seal. Dump as much fluid out of the converter as you can and then fill it back up with fresh dexron VI fluid when you put it back on the transmission.

 

Blow out the transmission lines on your truck with compressed air before you hook it up.