Grinding ,scraping noise

[jonywishbone]

My 97 XK8 is giving off a substantial grinding/grating noise at between 40-50 in 5th gear (doesn't do it locked in 4th) noise comes on and off at around 2 second intervals then around 50MPH disappears. If I floor it it goes away and I never hear it. Only occurs under gentle acceleration on an incline car appears to slow when grinding noise on. Could it be one of the solenoid valves or is there an overdrive unit on the gearbox or is there a history of gearbox problems on this car. The ASC has also started coming on for no reason for the 1st minute in the morning (turn traction control switch to off and goes) could this be related. I had the brake discs thoroughly checked at 60K service. Appreciate any feedback from members who have had similar problems
Jony

[Phil Hopkins]

Jony,

I've not heard of any well known problems relating to the gearbox.


(and that is the extent of my knowledge re your question.... oh to be a technical person! )

[melhook]

Without stating the obivous, has you checked oil levels, in Engine, Gearbox, and Diff. Engine you can do your self, the other two are quite tricky, and it would probably be best to get your local dealer to do it for you.

Edited by melhook on Tuesday 5th September 23:52

[jonywishbone]

I haven't checked the levels but I thought the gearbox was sealed for life and I don't understand why it only does it at a specific speed and is also gear specific, if the levels were low surely it would grate all the time

[P700DEE]

Get it checked. Sealed for life LOL If you beleive that are you also happy to buy a new one when it's "life" is over ?

[Jonywishbone]

I think its a bearing issue since it only comes on at specific revs in a specific gear but was open to suggestions is LOL a lubricant?

[Trooper2]

Hi Jony, your 97 XK8 will have the ZF 5HP 24 transmission in it. If it was low on fluid your car would be stalling at every stop as the torque converter cluth is hydraulically released.

You mentioned that when you have the noise symptoms that it is at light throttle and the car seems to slow, sounds like a classic case of a slipping holding member to me, a band or a clutch pack on its way out.

This is just an educated guess on my part as it could be many, many things. Best to get it in for a service.

[melhook]

having serviced these cars and gearboxes for a while, they will not always stall when low on oil. they will however make noises and do funny things..... trust me, get the level checked first, sealed for life means, sealed for the life of the warranty. these cars are not as complicated as like to make out. hope this helps

[GavinPearson]

The 5HP24 engages a different primary clutch pack for 5th than 1 to 4, but you also have a slip control torque converter clutch.

I really doubt it to be the oil level - if you had a very low oil level the car would not move, and if it was lowish it would lose drive on a gradient. You don't have either.

If the torque converter engagement is causing resonance then you could potentially change that alone.

This is going to mean a trip to a dealer to diagnose the issue.

[jonywishbone]

Thanks to the last 3 posts which make sense. Since it is specific to the 5th gear (so much so that if I slip the gear lever left (select4th) as soon as the noise starts it immediately ends), I assume torque convertors are replaceable items without a new gear box but clutch packs look to be part of the box so is this a replacement required for this, I will get the car in next week.

Edited by jonywishbone on Tuesday 12th September 06:15

Edited by jonywishbone on Tuesday 12th September 06:16

Edited by jonywishbone on Tuesday 12th September 06:16

[jonywishbone]

As a further note to this post the gearbox and vehicle was tested thoroughly and no codes showed and no problems could be found I have now posted another thread since I believe the Stability Control is the issue.

[james s]

Clutch pack is replacable. A company called VMTP in Hayes did mine a few months ago