4r55e Transmission removal question (Torque Converter)

[Abbondanza]

My 4r55e failed completely (previous owner killed it towing without knowing how), so now I am replacing it with a salvage trans that came with a torque converter.

I was wondering if someone could tell me why it's emphasized so much not to let the torque converter come out of the transmission when it is removed (outside of the obvious damage that could occur on ground impact)

Is the issue alignment also when reinstalling?

As I said, I have a used transmission that I got from a yard to swap out with my completely failed trans, but the torque converter for the used unit I got was already separate from the transmission body when I picked it up. Will this be a problem for me when I install the two of them? (with regards to possible 'lining up' problems).

Thanks in advance to anyone who can shed some light for me.

 

[SoHK_alumni]

Easy!

The torque converter sits on a three shaft input to the transmission, and has an oil seal at the very front of the transmission case.

If the torque converter is not properly seated on all three shafts, you can easily crush the internals of the transmission as you tighten the transmission bell housing to the block. Seriously not good!

So, the chance of damaging the oil seal, or mis-aligning the converter on it's shafts is eliminated if you never remove the converter from the transmission int he first place.

It's NOT that you cannot, or even should not remove the torque converter, its just that you MUST be very careful with the installation and alignment.

 

[Abbondanza]

Thank you for the answer...so should I put the TC that came with the replacement transmission back into the bell housing (onto the shafts) before I bring it up to the engine for mounting, or put in the TC in first and secure it to the flywheel and then bring the trans to the block? Is there a way to know the TC is properly seated in the transmission before trying to mount it to the engine? I thought I read something about hearing 'clicks' as it get gets into position?

Thanks again!

 

[SoHK_alumni]

Hands down, install the torque converter onto the transmission first.

Spin the torque converter repeatedly until it slides into the transmission farther than it'll sit when bolted to the block. Take some careful measurements of the flex plate to block so you'll know how far the torque converter needs to sit.

You should be able to feel all three of the shafts align as the torque converter slips further and further into the transmission.

As a suggestion, ensure you rotate the engine to where you have visual access to the holes in the flex plate for the torque converter bolts, and then as close as you can, pre-align the torque converter to the same orientation. Makes it much easier to get the torque properly/fully lined up on the flex plate if you're as close as possible before you start the "cinch down" of the transmission to the engine and torque converter to the flex plate.

 

[Abbondanza]

Awesome info, thanks much.

 

[Grego50]

Just make sure when you reinstall the torque converter, that you have it completely seated in the transmission, before bolting up to the flywheel.

 

[amigodana]

Just make sure when you reinstall the torque converter, that you have it completely seated in the transmission, before bolting up to the flywheel.

Second that!!!

 

[BrooklynBay]

Don't reuse an old torque converter. It will have internal wear plus dirty fluid.

 

[imp]

When you bring the transmission into place on the locating dowels, it should easily slide forward up against the engine for a snug fit. If you find you are "fighting" to get the two together, it is likely the converter is not fully seated in the oil pump. There are "flats on the back converter hub which engage in the pump, to drive it. These must be correctly aligned.

It is the last 3/8 inch or so which is critical. Zillions of guys thinking the dowel pins are binding up, have installed the bolts, squeezed the trans up against the engine with the TC not engaged properly in the pump, with dire consequences. imp

 

[Abbondanza]

Don't reuse an old torque converter. It will have internal wear plus dirty fluid.

Unfortunately, don't have the budget at this time to get a remanufactured one.

Hoping that the one that came with the used transmission (which the yard says was tested ok before removing from previous vehicle).

Just need a vehicle that is functional again. If I am successful at this swap and get her moving properly again, anything over one year of use would be a bonus to me at this point.

 

[Abbondanza]

Thank you for all the advice and guidance, I appreciate it.

 

[Abbondanza]

Don't reuse an old torque converter. It will have internal wear plus dirty fluid.

I will pour out the dirty fluid in the the replacement torque converter and pour in new fluid before I mount it with the trans, though.

 

[BrooklynBay]

The old torque converter has a lot of internal crevices with dirt, band or clutch material. This could create issues in the transmission it's installed into. It's very difficulty to completely clean an old torque converter without cutting it open to rebuild it.

 

[transman304]

Don't put a remanufactured converter in a used transmission. Just use the converter that came with the transmission. Make sure it is seated fully in the pump on installation. Make sure you flush out the cooler lines before hooking them back up.

 

[Abbondanza]

Don't put a remanufactured converter in a used transmission. Just use the converter that came with the transmission. Make sure it is seated fully in the pump on installation. Make sure you flush out the cooler lines before hooking them back up.

What method do I use to flush the cooler lines? Compressed air?

 

[BrooklynBay]

Use a can of cooler cleaner chemical spray.

 

[transman304]

Kooler clean works great but you can use brake kleen also. Get a container to collect old fluid out of lines. Take one line and put compressed air through it while the other line in the container,apply air slow cause it can get messy very quick. Once all old fluid is removed.Spray some in each line and follow with compressed air. make sure air flows the same in both directions. You can tell by a change in sound. Hope this helps.