Gearbox and Torque Converter

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awillemsen

Active Member
Posts
210
Location
Llandrindod Wells, Powys
My father-in-law has an 05 plate L322 TDV6 with something over 80k on the clock. I guess he may have gearbox problems at some point if he's not one of the fortunate ones? And is the best preventative measure to replace the torque converter? Is this a permanent fix, or something that needs to be done at intervals?

Many thanks (on his behalf)!
 
TDV6 not fitted to the L322 in 2005 or ever IIRC.

The 2005 model will still have the GM box, and unfortunatly just replacing the TQC isn't enough to prevent failure.

The cause of the failure lies with the Valve Block on the GM model. The original valve block was made from a very soft poor quality aluminium and with the operation of the valves, particularly the constant pressure modulation of the TQC Lock Up Clutch valve, caused premature wear of the valve bores allowing hydraulic pressure to be reduced that hold the TQC LUC in place to limit the total TQC slippage to around 3% until it fully locks up above 56(?)mph....

As the valve bore wears, the system tries harder to modulate the hydraulic pressure to holf the LUC in, but this wear in the bore stops this from happening, and the TQC LUC starts to slip more and more, dumping copious amounts of friction material into the oil, this then acts like a cutting paste and exponetially increase the wear on the LUC friction material further and also all the other components it comes into contact with.

This additional debris starts to clog the filter which means the poor pump struggles harder to pull the oil through and this in turn starts to also reduce available hydraulic pressure, exasperating the problem until the TQC lUC friction plates are worn to the base metal, and then that ends the box completly...

The only true fix is to replace the TQC and also the Valve Block which is available from a company that begins with S (Sonnex, Sonax, Solex - or something liek that) which is made from better quality aluminium.

If you are lucky and catch the box early enough, you can get away with just a total fluid change, new TQC and a new Valve Block.....if it is getting bad, you will have to strip the box and check for wear in the Clutch pack friction plates as the 'Cutting Paste' oil will contaminate these surfaces too.....

L322TransmissionsH.jpg
 
Sorry about the "V" - slipped in there. So used to writing V8... :eek:

Father-in-law has asked two questions: What are the symptoms that something is starting to go wrong? And how can he check if the work has already been done?

Thanks!
 
Hi, Before my gearbox expired there would be no forward drive for a couple of seconds in the morning and occasional harsh vibration through the car at a steady 45-50mph when you put your foot down before the box changes down. Other than that the gear changes were lovely, until the dreaded TRANS PROG FAIL message displayed and all drive lost after a dash down the M5. Had the box reconditioned at a transmission specialist in Solihull (£1300) and been brilliant ever since. Get the oil changed and it will probably be ok. Cheers
 
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