Hello,my 91 jaguar xjs v12 convertible has been running great till yesterday, when i found it would not shift out of 1st. gear in drive . I tried putting it in 1st and shift to 2nd manually still the same. I replaced the modulator a month ago so that's new, I am now thinking it's a governor gear problem. The problem is the convertible has no access to the governor from inside the car, I think the conv. has floor stiffners to stop body flex, so no access door. Can I drop the rear Transmission mount to reach the governor or do I have to remove the Trannie? Looking forward to hearing any advice on my problem Regards, Graham

 

Did you use a genuine part for the modulator? I remember replacing one years ago with an aftermarket adjustable unit in one of those beasts and it didn't shift right. We obtained a genuine modulator and it shifted fine. Just a thought. I think that is still the TH400 trans in that year so you might want to troll some forums regarding that trans for help as well.

 

Are you sure the vacuum hose to the modulator is OK?


Cheers
DD

 

As already stated, plus.

I do remember doing one of mine, and I took the trans mount spring fiasco off, trans duly supported of course, and replaced the governor. That was before I knew the Coupes had a hole, but no matter as the "cotton reel" mount was buggered, and the rubber spring seat insulator none existant.

If you are going to replace that vac hose, use the old hose to "pull thru" the new hose, as it travels behind that heat shield board, and that is the easiest way of getting a new one thru.

 

Thank you all for suggestions. I did remove the governor after disconnecting trans. spring support and drive shaft, did not find any problem, the vacuum hose is good I'm pulling 16in. hg vacuum at the modulator. I decided to replace trans mount spool and cushion and the modulator again I cannot find any other reason other than a transmission tear down,the modulator was cheaper wish me luck , I should have the part's in a few days , then I will let you know the out come. Regards, Graham

 

The valve in the governer moves OK?
Is the kickdown switch stuck?

 

Thank you everyone for your help. Well it was not the modulator or vacuum leaks or even the governor. It was the kickdown switch staying on even after adjustment, a big thank you to Doug Leithauser for mentioning this as I would never of dreamed a switch could stop a transmission Gota love Jaguar enginering. Regards Graham

 

Graham, don't be too hard on Jaguar engineering. I learned about this transmission when I was working as a mechanic at a GM dealer, it is the same unit that was used in pickup trucks.

 

Doug, my mention of Jaguar engineering was realy in reference to the fragile micoswitches they used. Thank's again for the direction you sent me. My cat runs great now. Graham Clarkston, Michigan. 91 XJS v12 convertible, oyster.