Gearbox bad to worse
Discussion
Hhmm I hope its not time to part company with my jag
Gearbox has been running a littel less than smoth for a month or so - holding low gears and occasonally clunking into first at junctions. Got some transmission fluid but havn't put it in yet.
Last nmight I picked the car up from the airport parking guys and things were a lot worse. In drive it wouldn't take up - just a big bang as the revs build and then the gearbox fault light came on. This is amber however so I tried it in reverse and its fine. Managed to get it going it 4 ,but not drive oddly and limped home. All seems fine except on take off when progress is slow and feels fragile. All changes smooth once on the go however.
Any thoughts on what it might be and whether I should be driving or recovering to the local specialist
cheers
j
Gearbox has been running a littel less than smoth for a month or so - holding low gears and occasonally clunking into first at junctions. Got some transmission fluid but havn't put it in yet.
Last nmight I picked the car up from the airport parking guys and things were a lot worse. In drive it wouldn't take up - just a big bang as the revs build and then the gearbox fault light came on. This is amber however so I tried it in reverse and its fine. Managed to get it going it 4 ,but not drive oddly and limped home. All seems fine except on take off when progress is slow and feels fragile. All changes smooth once on the go however.
Any thoughts on what it might be and whether I should be driving or recovering to the local specialist
cheers
j
I had the gearbox fail completely on my XJR (not sure if they are the same 'box). The symptoms were pretty much the same as yours and it completely failed within 30 miles of me first noticing it.
Get it to the dealer/specialist quick smart. I've heard that changing the fluid can sometimes resolve the issue - even though it's supposed to be a 'sealed for life' unit.
Good luck.
Get it to the dealer/specialist quick smart. I've heard that changing the fluid can sometimes resolve the issue - even though it's supposed to be a 'sealed for life' unit.
Good luck.
Which model of car have you got? I Believe 6-cylinder X300's had a 4-speed ZF auto which could be topped up, whereas V8 X300's had sealed 5-speed ZF autos and the V8 XJR had a heavy-duty Merc 5-speed auto.
Many years ago I had a Ford Granada auto that would lose drive when cold, unless you revved the engine whereupon the box engaged with a 'bang' and heavy jolt.
Turned out to be a leaking transmission oil cooler pipe and the autobox had lost enough fluid so as not to engage 'drive' when cold unless the engine was revved to increase the speed of the autobox fluid pump to a level that would engage the gears with an almighty 'thunk'
Not long after the box failed completely.
Have you noticed any fluid leaks under the car? Is the fault worse when cold or hot?
The engine drives the autobox fluid pump to generate fluid pressure, which is then controlled on the switchable electronic boxes by solenoid valves in the autobox which 'channel' the fluid to the appropriate multi-plate clutches to select the right gear.
Sadly very little the DIY owner can do apart from check the fluid level, and that's becoming a thing of the past with modern sealed-for-life autoboxes.
Faults can be anything from low fluid level to blocked filter through to worn out multi-plate cluthces, sticking solenoid valves, even faulty gearbox ECU.
Can only suggest checking and topping up fluid level if this is possible on your model, otherwise it's down to the autobox specialist I'm afraid for a proper diagnosis.
Sometimes lack of use can cause odd problems with valves gumming-up slightly.
Fingers crossed it's just something simple.
Many years ago I had a Ford Granada auto that would lose drive when cold, unless you revved the engine whereupon the box engaged with a 'bang' and heavy jolt.
Turned out to be a leaking transmission oil cooler pipe and the autobox had lost enough fluid so as not to engage 'drive' when cold unless the engine was revved to increase the speed of the autobox fluid pump to a level that would engage the gears with an almighty 'thunk'
Not long after the box failed completely.
Have you noticed any fluid leaks under the car? Is the fault worse when cold or hot?
The engine drives the autobox fluid pump to generate fluid pressure, which is then controlled on the switchable electronic boxes by solenoid valves in the autobox which 'channel' the fluid to the appropriate multi-plate clutches to select the right gear.
Sadly very little the DIY owner can do apart from check the fluid level, and that's becoming a thing of the past with modern sealed-for-life autoboxes.
Faults can be anything from low fluid level to blocked filter through to worn out multi-plate cluthces, sticking solenoid valves, even faulty gearbox ECU.
Can only suggest checking and topping up fluid level if this is possible on your model, otherwise it's down to the autobox specialist I'm afraid for a proper diagnosis.
Sometimes lack of use can cause odd problems with valves gumming-up slightly.
Fingers crossed it's just something simple.
Though things may seem very pessimistic at first, the diagnostic kit the Jaguar dealer has is actually very good. That can tell them if there is a clutch issue or just a problem getting oil to it (a solenoid issue). That in turn says whether you need a full rebuild or a valve body swap.
I would make a visit to a fanchised dealer and get them to diagnose the problem and then walk you through the diagnosis. That requires you to be an examiner for a subject you don't teach, but it really is down to following ther logic set out by Jaguar. If you do this then whatever repair you pay for you will at least know it was done for the right reason. A lot of dealers fit a new 'one' - generically anything on the car - if they aren't 100% sure of the diagnosis. That gets expensive for engines and transmissions.
Ask me offline if you have questions.
I would make a visit to a fanchised dealer and get them to diagnose the problem and then walk you through the diagnosis. That requires you to be an examiner for a subject you don't teach, but it really is down to following ther logic set out by Jaguar. If you do this then whatever repair you pay for you will at least know it was done for the right reason. A lot of dealers fit a new 'one' - generically anything on the car - if they aren't 100% sure of the diagnosis. That gets expensive for engines and transmissions.
Ask me offline if you have questions.
Know its a much older type so apples and oranges, but my old GM400 used to "fail to engage" or hunt up and down ... this was caused by slow leaking of oil, the box relies on a certain level of oil / pressure to engage stuff (no technical wizz here) once the oil was topped up, box was happy ... but it progressively leaked more and more oil everywhere ...
in my case, stuck a replacement in from a breakers ...
in my case, stuck a replacement in from a breakers ...
Thank guys
I know this sounds a bit odd but I can't find the place to fill up the gearbox.
The guy who looks after the car describes a dipstick tube under the plastic panel which covers the wiper motor. I just cant find anything that fits that description in that place.
The nearest I can gind is a sealed plastic lid arround an inch in diameter with deep groves in the side with the code lnc151 5aa pa 66- gf 33 printed on it.
It does have a couple of flexible pipes coming off it leading to the area of the gearbox - Is this the place to top it up
thanks James
I know this sounds a bit odd but I can't find the place to fill up the gearbox.
The guy who looks after the car describes a dipstick tube under the plastic panel which covers the wiper motor. I just cant find anything that fits that description in that place.
The nearest I can gind is a sealed plastic lid arround an inch in diameter with deep groves in the side with the code lnc151 5aa pa 66- gf 33 printed on it.
It does have a couple of flexible pipes coming off it leading to the area of the gearbox - Is this the place to top it up
thanks James
First of all, what model of Jag have you got exactly, and what year is it? Need to know this to establish if it is possible to top up the autobox onesself.
Don't just add fluid willy-nilly to an autobox-find out if it's leaking gearbox fluid first. Too much fluid can cause 'frothing' and gear selection problems.
Most, if not all, modern 5-speed autos are not designed for the owner to check & top up fluid levels, as it's not a simple 'pull the gearbox dipstick out-check the fluid level-top up as necessary' procedure like topping up engine oil.
Autoboxes have a different procedure for fluid level checking which is a bit more fiddly, even if you can do it in the first place.
Auto gearboxes as a rule don't just 'break' totally-it's always a certain part inside the box that's failed, just like engine faults.
Problem is autoboxes are a black art/source of fear to most people, and most garages prefer to simply fit a new box rather than trace the actual component inside the box that's failed. Only problem is the labour charges for gearbox removel/strip-down and fault finding can come close to the cost of a new autobox on older cheaper autos.
With modern autos costing anything from £1k to £5k reconditoned/new, it may actually be more cost effective to have an old box rebuilt for hundreds rather than shell out thousands on a brand new unit.
Best thing is to take yours to either a Jag dealer or autobox specialist for a proper diagnosis, and ask them what they think the specific fault is inside the autobox-if you don't like the diagnosis then just walk away and go somewhere else.
Not a good idea to leave it too long though in case slight preventable faults become more serious.
Good luck!
Don't just add fluid willy-nilly to an autobox-find out if it's leaking gearbox fluid first. Too much fluid can cause 'frothing' and gear selection problems.
Most, if not all, modern 5-speed autos are not designed for the owner to check & top up fluid levels, as it's not a simple 'pull the gearbox dipstick out-check the fluid level-top up as necessary' procedure like topping up engine oil.
Autoboxes have a different procedure for fluid level checking which is a bit more fiddly, even if you can do it in the first place.
Auto gearboxes as a rule don't just 'break' totally-it's always a certain part inside the box that's failed, just like engine faults.
Problem is autoboxes are a black art/source of fear to most people, and most garages prefer to simply fit a new box rather than trace the actual component inside the box that's failed. Only problem is the labour charges for gearbox removel/strip-down and fault finding can come close to the cost of a new autobox on older cheaper autos.
With modern autos costing anything from £1k to £5k reconditoned/new, it may actually be more cost effective to have an old box rebuilt for hundreds rather than shell out thousands on a brand new unit.
Best thing is to take yours to either a Jag dealer or autobox specialist for a proper diagnosis, and ask them what they think the specific fault is inside the autobox-if you don't like the diagnosis then just walk away and go somewhere else.
Not a good idea to leave it too long though in case slight preventable faults become more serious.
Good luck!
james s said:
Thank guys
I know this sounds a bit odd but I can't find the place to fill up the gearbox.
The guy who looks after the car describes a dipstick tube under the plastic panel which covers the wiper motor. I just cant find anything that fits that description in that place.
The nearest I can gind is a sealed plastic lid arround an inch in diameter with deep groves in the side with the code lnc151 5aa pa 66- gf 33 printed on it.
It does have a couple of flexible pipes coming off it leading to the area of the gearbox - Is this the place to top it up
thanks James
The filler plug is on the back right hand side adjacent to the extension housing on the main case just above the sump.
You need to find somebody who is very familiar with these transmissions - use a high volume Jaguar dealer. To not do so really risks overrepairing the problem.
Gassing Station | Jaguar | Top of Page | What's New | My Stuff