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5 speed autobox for X300
Posted: Wed Mar 01, 2017 11:29 am
by Uli
Hi
does anybody know whether there was also a 5 speed autogearbox installed in late X300, 3.2 L?
It concerns SAJ JFALG4BP811511, VIN 811511 where the owner noted, that when changing the selector from 3 to D, that the gearbox still changes gears twice???
Many thanks in advance for some clarifications.
Best regards
Uli
Re: 5 speed autobox for X300
Posted: Wed Mar 01, 2017 4:28 pm
by poprivet
The 4 speed auto XJ40s had a lock up torque converter that feels like a fifth gear, it catches around 55mph. Could it be that?
Re: 5 speed autobox for X300
Posted: Wed Mar 01, 2017 10:26 pm
by davidr
Many people who don't understand how that gearbox works get fooled into thinking that it's 5 speed and I think Pop is absolutely right.
It is 4 speed with a separate clutch that locks up the torque converter at around 53-55mph. This feels just likes its changing gear as the clutch engages and the revs drop but it's really the torque converter being locked up. This is an economy measure to give a straight through drive and saves torque converter losses at cruising speeds.
The only 5 speed gearbox on an X300 was the (rare) manual box.
No 5 speed auto box until the X308 and the AJ-V8 engine.
Hope that helps
David
Re: 5 speed autobox for X300
Posted: Thu Mar 02, 2017 8:46 am
by Uli
Many thanks for your prompt replies. I think this clearly explains my friends impression, that he's driving a 5 speed autogearbox.
Best regards from Switzerland
Uli
Re: 5 speed autobox for X300
Posted: Thu Mar 02, 2017 10:22 am
by pimgmx
ALL XJ40/X300 auto gearboxes (V12s and supercharged excepted) were ZF 4HPxx boxes.
As the '4' prefix suggests these are four speeds with - as poprivet mentioned already - convertor lockup at appr 85kmh/55mph.
If the lockup 'clunk' is noticeable rather prominently it may be time for fresh gearbox fluid and a new filter...