Torque converter test/check

[supra87]

Hi guys as you may have seen I've had issues with a rattle on me na jap spec auto. we've narrowed it down to the torque converter. ive recently purchased a replacement on here from another member. now before I swap them over is there a way off checking it's working correctly some kind of test ect?

[Chris Wilson]

TC's usually work or they don't, and being full of oil are highly unlikely to rattle. I would suspect the flex plate is cracked or loose on the crank, or the TC bolts are not tight. Be sure whoever removes the gearbox understands the TC *MUST MUST MUST* come out on the gearbox, and unbolted from the flex plate. I have seen people think it should be left bolted to the flex plate....

[supra87]

Thanks Chris the engine and box was removed a couple of weeks ago all tc bolts were removed the gearbox was split but the tc stayed on the engine should this not of happend?

[Swampy442]

No, you risk damage to the TC and the oil pump on the gearbox. Always leave the TC with the gearbox, and vice versa when fitting the TC should be fully seated on the gearbox splines before fitting

[supra87]

The tc stayed on the engine even tho all bolts were removed the tc was locked onto the engine and would not pull off some spline inside the tc had to be turned to release the tc from the engine. Maybe this could be my issue somehow??

[Chris Wilson]

There's every chance the oil pump in the front cover of the gearbox is now damaged, every chance the oil pump seal is knackered, and a good chance the flex plate is now bent or cracked. The TC *ALWAYS* has to be unbolted from the flex plate, via the rubber covered access aperture, then pushed fully into the gearbox before trying to unbolt and remove the box itself. You may even have damaged the TC internally.

[and1c]

Is this the same work done by the company who replaced the main bearings? It's gearbox 101 taking the tc out with the box...

[Chris Wilson]

Given the lack of room in the transmission tunnel it was probably an epic battle getting the box out with the TC on the flex plate, and even more of one putting it back and aligning the TC splines and especially the oil pump drive dogs. I fear the worst and would replace box, TC and flex plate.

[supra87]

Let's clear a few things up maybe I wasn't clear enough.All the tc bolts were removed via the inspection plate when they were first separated nothing is bent nothing has split the gearbox changes gear perfectly nothing leaks.what I'm saying is when the engine and box were split the tc stayed on the engine this wasn't intentionally it's just what happend the box split from the engine with out and struggle both engine and box were out the car when it was split the reason both came out is we thought the rattle was the bottom end bearing so all bearings in the bottom end have been replaced car has been put bk together and is currently driving but I've still got this slight rattle that must be tc related I did a gearbox flush 4 weeks prior to this problem the oil that came out was well over due I'm thinking the new oil has loosened some debris allowing something in the tc to rattle obviously I'm just guessing at this point as I'm running out of ideas??

[and1c]

Ahh so they were out of the car when split? Not ideal but this is a good article on confirming if its torque converter or not

 

http://etereman.com/blog/transmission-care/diagnosing-torque-converter-problems-procedures-for-all-vehicles

[supra87]

Cheers I'll have a read much appreciated I'll post a sound clip up so you can have a listen it's not the best but you can hear the rattle.

Edited September 14, 2017 by supra87 (see edit history)

[supra87]

[and1c]

Sounds like bottom end to me but very hard to tell. Drop the oil out and check it with a magnet for anything untoward would be a simple thing to try first. Is the oil pressure all good? . Flex plate bolts I'm guessing are correctly tightened? This can be checked relatively easily anyway, worth it to be sure.

[supra87]

All bearings were replaced in the bottom end a few weeks ago all the tc bolts tightend to the specific torque settings.

[and1c]

Was the engine stripped and rebuilt then? Reground crank and oversized bearings? Or just replaced damaged bearings for new ones stock sized?

[supra87]

The bearings that were in the engine would have been ok to put back in but I had them replaced anyway as I'd all ready baught the new bearings before any work had even commenced the noise is I'm 100 percent coming from the gearbox as the rattle disappears when you listen under the engine sump the crank was in perfect condition with no marks at all it wasn't pulled out and measured as the builder did not feel it was necessary and I wanted to keep costs down as much as I can.

[and1c]

Hmm, sounds like it would be worth fitting new torque converter then.

[supra87]

I've got a replacement coming from another member of this group it's come off a perfect working car I just want to know if there's a away of checking it before it gets fitted it does say somthing on tsrm about standing it on its end and turning some kind of tool inside I cant work it out hence the start of this thread

[and1c]

Cant see how you can test a torque converter without stripping it down to inspect. It lives its life rotating with the engine and is full of hydraulic fluid. Recreating those conditions would take a proper test rig IMO

[Chris Wilson]

With good used auto boxes, torque converters and flex plates freely available at low cost we are not yet at the stage where a rebuilt TC or box is sensible save for somneone doing a cost no object restoration. The auto box is costly to rebuild, as is the TC, but both can be rebuilt should anyone so wish. In the case of the original poster I would just swap in good used items even if visually all seems well, although a flex plate is easily crack tested and able to be checked easily for any deformation.

[supra87]

My replacement tc should be here next week I'm Gona get my mechanic to run the engine while the box is off to rule that out I've attached a screenshot of the tc test shown on the tsrm app