2000 xj8 ...SO today out of the blue i got in my car to go to the gas station at work and i was having trouble moving my gear shift lever from park to drive it was almost getting jammed like in reverse...then when i got it into drive it would not fully engage until i played with the gas pedal it shifted up finally...I had the transmission completely rebuilt 45k ago so im skeptical it is that because i have no message indicating transmission failure like last time ...only gear box fault and this performance crap...anyway i babied it on the way home from work it ran like **** felt like something was pushing from behind the gas pedal almost felt like a stage 4 clutch pressure and wouldnt run above 70mph...i got home shut it off turned it back on and it ran fine around the block i came back home played with the gear shift lever again and it started to stick ...im totally lost on where to start besides the gear box...helpp!!!!

 

Something may have come adrift at the selector, it could be time to have a look...

You'll need to remove the 'ski slope' to get a look in there.

 

i cant find anything in there that would jam the selector...its not all the time if i let it warm up a half hour put it in drive then back to park shut it off then back on it works fine...when it not working it feels like im starting in 4th gear...it doesnt feel like its the trans i just had it rebuilt 45k ago i no how it feels when it goes and its not slipping or shifting hard at all...temperature has dropped significantly since it started happening two days ago randomly...im feeling like it may be electrical or worst case the actual gear box malfunction...any info?

 

It has to be one of the following 3 things:

1) The selector lever mechanism at the gearlever

2) The connecting Selector Cable binding between the gearlever & the gearbox

3) A fault in the valve block inside the gearbox causing stiff movement


To track the fault down, you'd need to disconnect the selector cable at the gearbox end after noting it's position & the alignment of any clamps there. Then see how stiff the actual selector lever is on the gearbox itself. The selector lever on the actual gearbox operates an internal valve inside the gearbox-it's inside the valve block body.

To access the valve block body you'd need to have the gearbox fluid drained & the sump pan removed-then the valve block removed to check the operation of the selector valve.

Your fault doesn't sound like a complete gearbox failure & probably won't require removing the transmission. You can get away with just dropping the sump pan & removing the valve block with the gearbox still in the car. It sounds like the selector valve is binding inside the valve body-so it makes the gearlever feel very stiff at times...

I have an old BMW with a 5-speed ZF gearbox that does this-when the gearbox is fully warmed up the selector lever is very stiff to move & it's not at the gearlever end-it's in the gearbox valve block body that's causing the fault.