LAZY GEARBOX

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tinyloughlin
Posts:17
Joined:Fri Apr 18, 2008 6:34 pm
Location:Hertfordshire
LAZY GEARBOX

Postby tinyloughlin » Thu Aug 21, 2008 4:22 pm

i recently took my v12 sov for a quick spin after it had been standing for a couple of weeks, and although everything was fine at first and the gm400 gearbox shifted through the gears as it should.... after i gave it a bit of gas in order to achieve kickdown (of which it did quite happilly) the gearbox will no longer shift out of 1st. can any of you fine people and enthusiasts for these "Thatcher Cabs" give me any pointers?

many thanks

tinyloughlin
1988 soverign v12

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almcl

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Location:Shropshire

Postby almcl » Fri Aug 22, 2008 8:13 am

Not in any sense an expert on the GM400, but check fluid level and then the pipe to the vacuum modulator.

There is a check for a permanently energised detent solenoid but you really need the manual for that, and beyond there, there are lots of oil pressure checks but again the manual is required.
Al McL
'93 XJS 4.0 - '20 XF 2.0 Sportbrake

tinyloughlin
Posts:17
Joined:Fri Apr 18, 2008 6:34 pm
Location:Hertfordshire

Postby tinyloughlin » Fri Aug 22, 2008 3:42 pm

hi al

thanks very much for your advise, i'll let you know how i get on.

cheers

joe
1988 soverign v12

tinyloughlin
Posts:17
Joined:Fri Apr 18, 2008 6:34 pm
Location:Hertfordshire

Postby tinyloughlin » Mon Aug 25, 2008 12:37 pm

solved it!

please excuse my laymans terms but the reason for the gearbox's reluctance to shift up was to do with the kickdown switch. its the one that is connected to the throttle pedestal and that is activated by the throttle cable when the peddle is fully depressed. it seems that the switch was slightly deformed due to a sudden and rather violent depression of the gas peddle which locked the swich in the closed possition and therefore keeping the box in constant kickdown mode. all i have done is fiddle with the swich to make function correctly and now the box shifts up and kicks down as it should. panic over

Al thanks again for your advise
1988 soverign v12

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almcl

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Posts:775
Joined:Sun Jan 15, 2006 7:56 pm
Location:Shropshire

Postby almcl » Tue Aug 26, 2008 9:36 am

Well done for solving it, glad it wasn't expensive!
Al McL
'93 XJS 4.0 - '20 XF 2.0 Sportbrake


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