Thread: Is there an auto trans specialist in the house?

I'm no expert but personally I would have not gone to the effort and expense of removing the trans, paying for a new upgraded TC and not putting in a rebuilt transmission. It's false economy. But I do hope you get some joy with your legal efforts!

Mike, whats broken/failed exactly in the transmission?

I'm not sure, forward drive failed, reverse was OK so I suspect a band or something like that. I am rather ignorant to more modern transmissions, give me a Borg Warner 35 any day.

Transmission fluid was dirty??????? And that was about 16 weeks after fitting.

And yes, if I had known I was going to pay as much as for a recond tranny I would have gone that way but I was having to borrow off a friend anyway!

Regards

Mike

At that I would suspect it's certainly got nothing to do with the TC with only a few thousand clicks on it. Sounds more like the forward sun gears gone, or possibly with the black discoloration, the friction plates are burnt, thus pressure is not being transferred to valves through the valve body,,,, did the oil smell burnt, can you tell if there's any metal in there?
Valve body faults are generally due to a couple of things,, o rings, (laminated or damaged) or sticking valves, which can be from being worn or chipped/damaged or just general sludge type crud. This crud can also effect the solenoids which get the little filters blocked, thus stopping the valves from transferring.
We had a few trannies where the TC was the problem, but it took basically 100K + to become an issue enough to halt the operation of the trans, and it was an internal part.

Without disassembling the transmission, its hard to know exactly what the route cause is.

citing the blindingly obvious mismatchign the torque converter to the auto or fitting a faulty/damaged torque converter will kill the front end of an auto very quickly.


assuming the shape of the TC is correct and only the internals that handle the fluid and the lock up have been changed somewhat briefly

Fitting a torque converter that is set up to provide a bigger torque multiplication will burn out the first set clutch pack in short order. (the biggest torque mulitplication typically occurs when your first moving off with the wheels stationary and the engine RPMS rising sharply)

fitting one with insufficient lock up clutch pressure will contaminate the fluid (as the lockup clutch spalls out) and not provide sufficient drive causing gear hunting around lockup killing the clutches (not usually first)

fitting one with a too agressive lock up clutch or too much lock up pressure (which means it may not release correctly) will over stress the initial drive gear of any gear engeged when the lock up occurs as well as any holding sprags relevent to those gears

fitting one with an agressive raised RPM stall will rip the transmission to pieces (think along the lines of a drag car launch on every gear change.)

adding in a chipped up engine and not remapping the auto pattern and the torque convert to suit the power application can destroy the box for a combination of the same reasons above.

adding in a torque converter with a lower Stall RPM will over work the clutches and may cause fluid areation, eventually boiling as the torque converter is over driven until lock up (if it occurs) occurs


so yeah, easy, even excluding a mechanically incorrectly sized TC a sufficiently wrong TC can fry up a transmission in fairly short order.

A poor installation of a TC to the transmission can also do very unkind things to autos.

picking the wrong model TC for a specific gearbox from another similar gearbox is a not uncommon cause of issues for autos, From memory there is something like 7 or 8 different TCs that fit the ZF in a disco but vary from box suffix and engine all of them look very similar to the tune of just a couple of mm.


IMHO. knowing of the company that did your TC... I suspect that (assuming they were given accurate information about the auto the TC was to go into, the engine and vehicle configuration that the auto and TC were to be fitted to) its highly unlikely you would have been provided a TC that was sufficiently horrendously inappropriate as to destroy a reasonable condition auto in such a short time frame. Were it me.. I would be having the TC pulled and inspected for condition and then part matched by the providing company (torque convertor tech in melb) off of their catalogs. If the part numbers match up as being the correct unit for the box and there is no obvious manufacturing defects then the TC is not to blame.

That said...

16 weeks is just long enough to be outside of the 90 day warranty that most second hand non reconditioned car parts carry ( and in some cases its as little as 7 days)

Without having seen the items in question (and stripping them down) I cant provide more help.

take heart in you dont have to have a dedicated auto specialist to go 1:1 with a workshop. If you have enough qualified/licensed mechanics with the appropriate codes for transmission work then you can make the case on weight of numbers.

Dont forget the ZF is very picky about its oil... what oil did they put in it?

and yeah, if I get my hands on your parts/fluids and can get verification of some bits of info I'm more than happy to put my honest opinion on paper for you to help support your case. I might even know an engineer who'll back me on it if I can prove the numbers game to him.

Good info Dave, I didn't even give an incorrect TC a thought. If it has been "up graded" as Simon says, it could well be along those lines.

This happened over 18 months ago so any evidence is gone now.

The TC siezed into the crankshaft extension, it was misfitted, showing binding on one side of the spigot and nothing on the other.

They had to cut through the bolts holding the extension to the C/S to get the TC free.

TCT managed to pull the extension off to show the reason why and had to replace the front of the TC because of the mechanical damage done by a porta power. Don't ask.

Thanks for your input so far.

Mike

If it's had a miss alignment issue, then it's more than likely damaged the input shaft as well as the pump gears, and it would have taken out the oil sealing ring as well probably. This would create a major concern with fragments of metal getting directly into the valve body.

To me this would be the responsibility of the mechanic who fitted it all up.

As an aside, it can be very easily missed if the person fitting the TC to the trans doesn't understand exactly how they lock into the pump.