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I'm installing a rebuilt automatic transmission in my 1992 Chevy Silverado 1500 extended cab two wheel drive. What all should I buy at the parts store besides transmission fluid , pan gasket and new filter? Also changing out the torque converter.

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  • Welcome to Motor Vehicle Maintenance & Repair! May 19 at 13:15
  • Great answers everyone ! Thanks
    – Jaime T
    May 21 at 0:23

3 Answers 3

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If this is a newly rebuilt transmission which comes with a warranty, you won't need to replace the pan gasket and filter. These should be brand new and already be installed. Obviously you'll need the fluid. Your best bet with fluid is to use DEXRON VI, which is a fully synthetic fluid used in GM transmissions. It is fully backwards compatible and replaces DEXRON III. Use DEXRON VI unless you are specifically told not to by the transmission refurbisher.

If this is newly rebuilt but has miles on it since the rebuild, you'll want to replace the input and output seals to ensure those are fresh. Lube the seals with transmission fluid so they aren't dry or the installation of torque converter and slip yoke might damage them. You'd also want to replace the filter and gasket as you originally suggested (not absolutely needed, but I'd do it just to be on the safe side ... you never know). Consider getting a new seal for the dipstick tube, as replacing this before you put the transmission in is a lot easier then when it's in the vehicle.

As far as things to look out for ...

  • As GdD stated, the exhaust is a big thing. Look out for rusted nuts/bolts at the exhaust joints. These can not only stall your progress, if they are rusted enough, you might have to replace exhaust parts to get it back on the road. If you hit these fasteners with PB Blaster several different times (on different days) prior to doing the work, it will help tremendously.
  • Check your u-joints before pulling the driveshaft. Any movement other than allowing it to go around is bad. Tape the caps on the u-joint when you pull it down so they won't fall off. This will save you a LOT of headaches. EDIT: What I mean by "movement" is, while the driveshaft is still attached, grab ahold of it and shake it in several different directions to see if it will move. I'm mainly talking about vertically and horizontally perpendicular to the driveshaft. Do this at both ends of the driveshaft (transmission and differential).
  • Check the yoke's slip joint surface where it enters the transmission to ensure it is smooth. If there's a valley dug into it, it won't seal very good and you can lose transmission fluid out the back end.
  • Transmission lines can be a PITB. Tube wrenches can come in handy to help you separate them. Be careful not to cross thread them during reinstallation or you'll never get them to seal.
  • Ensure you put transmission fluid in the torque converter (TC) prior to installation. If you put it in the transmission dry, you will destroy it on startup. A quart should give you enough without it all pouring out as you're installing it into the transmission.
  • When installing the TC into the transmission, you should feel three separate "thunks" as you turn the TC to fully engage the transmission. If you do not feel three distinct thunks, you probably do not have it fully engaged. If it isn't fully engaged, you will destroy the transmission pump on startup which is located at the front of the transmission. When the TC is fully engaged, it should be well behind the mounting face of the transmission bell housing.
  • Before installing the transmission, you need to clean the cooler lines. Purge them of all old fluid and flush them out. Most transmission rebuilders require this with their transmissions or you void the warranty.
  • As GdD stated, check the transmission mount. There should only be one of them at the tail of the transmission. If it is cracked in any way (which is common) you'll want to replace it.
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  • Rear engine seal.
    – Jupiter
    May 19 at 13:02
  • @Jupiter - Possibly. Though, it's one of those things ... if it ain't broke, don't fix it. If the rear-main isn't leaking and you replace it and don't do a good job of it, you could be introducing a leak which wasn't there in the first place. May 19 at 13:14
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    This is a great reply - might want to specify what you mean by "Any movement other than allowing it to go around is bad". It took me a couple tries to understand it and I believe that's only because I know what you're talking about. May 19 at 16:03
  • @iDriveSidewayz - Edit has been inserted. Let me know if this is clearer or if I need to update further. May 19 at 17:26
  • @Paulster2 I respectfully disagree. This is a 1992. The seal is old and inexpensive. It is expected to install correctly. It could start leaking at any time. If done now the tranny will not have to be removed to replace it in the future.
    – Jupiter
    May 20 at 12:26
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Much of this depends on the condition of certain items and whether you can re-use them. Basically, if you have to take it off to replace the transmission make sure you have what you need to put it and everything else back on. I'd look closely at these before you start:

  • Transmission mounts: if they are worn or cracked then you'll want to replace them
  • Badly rusted bolts
  • Driveshaft hardware: as your driveshaft has to come off it's a great time to replace worn bushings, mounts, etc.
  • Exhaust gaskets/parts: if you have to take off your exhaust to drop the transmission
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Do the rear main seal on the engine while you're in there. 100% do this. Also inspect flywheel for cracks, missing teeth and warpage.

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