Hi all, I'm a brand new user and have found this site extremely helpful so thought I would share my experience along with another issue I am having.

Now, I have a 2007 X-Type 2.5 AWD Auto which has done 127000 miles, I have had both the transfer case and gearbox fail in the last 18 months but still the old girl lives on.
The issue I am having now is still drive train related but I think it is either the rear diff or a bearing somewhere back there.
First of all there is a whirring noise coming from the rear passenger side (left) of the car which I suspect is the bearing so I am prepared to get a new hub assembly, that's not really the issue. The main problem is sometimes when accelerating or shifting into reverse there is a thump, in addition to this when the car shifts from 4th to 5th there is a slight grind/hesitation coming from the rear.
Now before everybody has a sharp intake of breath and very apologetically tells me the transmission is doomed, it was literally rebuilt last month and as I say the noises are confined to the rear middle/Left so I am pretty confident it's not the gearbox.
Sorry for the essay and any help would be appreciated.

 

Hi Motas88,
Approx. half way along the transmission shaft is a sealed bearing.
Have you inspected/checked that for lubrication, loose housing and alignment?

 

Thanks for quick reply. Em I guess I need to do this anyway as I still have that whine that people talk about but the issue is coming from the centre of the very back of the car, which is what leads me to suspect the diff or at least a bearing inside. Do you know if the diff itself is serviceable or is it a sealed unit?

 

motas, you can have the rear end re-built. From what you describe, you may have a bad pinion bearing in your car, leading to the noises you are hearing. If your transfer case bit the dust and it shifted the rear driveshaft around, it may have hurt the pinion bearing. Once this starts to go, it can cause all sorts of weird noises and whatnot. If you crawl under the car, you can grab on to the drive shaft and if you can move it front to back, then your pinion bearing is toast.

 

Thanks Thermo. I suspect you may be right, will have a look tomorrow and check. The transfer case did chew itself up on the inside while I was doing 70, causing it to seize then release with a fairly loud bang a number of times before I managed to pull over. Do you reckon a rebuild is the way forward or can you replace this individual bearing and do you reckon a diy mechanic could attempt this?

 

Motas, this is something that you can possibly do yourself. The big thing, do you have a torque wrench that will go into the neighborhood of about 200 NM? That is going to be key with this sort of job. There is a crush collar that you have to torque a very specific way. To tight and too much pressure is applied to the bearing and it will eat itself. Too little and the pinion bounces around and the ring and pinion eats itself. It is a one time torque item. If you mess up, you have to get a new collar and start all over. Not trying to scare you, but that is the reality of this type of job.

Do not forget that once you start messing with the pinion bearing, you will also need a new seal for the front of the differential (pinion seal). That is also a one time use item.

 

So I crawled under the back of the car today had a good root around but none of the 3 shafts have any play in them what so ever. There is a badly degraded rubber bush on the right shock but apart from some surface rust it looks pretty clean. Any ideas anyone? Diff internals maybe?

 

Motas, I would say to get yourself a magnet on the end of a string and drop it down into the rear diff and then pull it back up. Do you have any metal shavings on the magnet? If so, then you are just buying time before you have major issues as once you get metal shavings there, the bearings are going to eat themselves fairly quickly.

If the oil looks good, then I would say to top of the rear diff (till fluid starts to come out the fill hole) and then take the car for a drive. Is the noise still there. If you are low on fluid, it can cause strange noises and whatnot. If the noise is gone, I would simply keep an eye on things and see what happens.

If the noise is still there, grease the carrier bearing (the bearing in the middle of the rear driveshaft). This has been known to make noises and drive people nuts trying to find it. If your noise diminishes/goes away after greasing this bearing, at some point in the future you will be replacing this bearing. Mine was making some minor noises, but a greasing and 4 years later, all is good.

Much beyond that, you are looking at having the rear diff pulled and then an overhaul done at that point. Not sure if it would really be worth it unless the noise is that bad.

 

Hi everyone, ok I'm revisiting an old post, I've an 02 X-type 2.5 automatic and finally running decent except there is a rather loud noise coming from the rear. I can't pinpoint exactly where the noise is coming from and well I've been reading through some of the threads on this. I jacked up the rear and put as much grease as the differential as it could take it would take before dripping out. no luck, then I looked at the center carrier bearing, and really didn't see any grease holes on the rear.

I just saw the post on how to check the rear wheel bearings and will to that next.to see if I can find anything there. Any other suggestions ?

 

Grease in the rear differential?

 

Yes there must have grease in there I topped it off with about 3/8 of a quart before it overflowed. I’ll wait till it warms up before checking rear wheel bearings. Note, I’ve swerved left and right and couldn’t notice much noise difference. Also curious if the center carrier bearing could be the cause of the noise coming from the rear?

 

The issue is linguistic: grease is a semi-solid lubricant, and that is not what is in the differential (or the transfer case). The differential takes a synthetic high pressure oil-like lubricant (75w140), as does the transfer case.

 

ok yes I meant rear end gear oil, oh I used synthetic75W-90, hope that's ok ?

 

Nope

Some folks may think 90 versus 140 is more viscosity when it really is an indicator of REMAINING AT THE SAME VISCOSITY at higher temperatures. The 75 is starting point for both, the W stands for winter (not weight).

So simply put the higher the temperature created by moving parts (friction) the viscosity remains consistant at higher temperatures on the 140.

 

Oiy, ok then. I’ll look for a flexible syringe type hose to suck out the fluid and replace with the 75W140!
thanks