Mystery vibration/growl driving straight and turning right

[YRob]

I have a 2012 LWB Transit Connect "Trend"

I recently replaced the clutch myself, and afterwards noted a growling noise when turning right. At the time the front toe was out and the tyres needed replacing, so I did that and corrected the toe (+10' to -30'). After that the growl was noticeable driving straight as well, but still louder going right and quieter turning left.

The noise is road speed related, and is a very quiet repeated scrape or rub at under 20kph, becoming a vibration/growl at louder speeds.

So far I think I've eliminated:

Brakes - no change in sound while braking

Bearings - lifted front and back of van and there is no play in the bearings when rocking the wheels by hand at 12&6 or 3&9 o' clock, the wheels turn freely, except the rear left, which has a sticky drum brake and a bit of cyclic resistance (I feel like it's unlikely to be the cause, from the feel of it). I've also noticed there is uneven outer tread wear on the rear right tyre, not sure if that is a clue or not.

Suspension - no appreciable play or knocking in any of the joints or bushings with the wheels off the ground

Driveshafts - no knocking/clacking sounds driving at full lock, no knocks felt when gripping shaft or cups and turning wheels when off the ground, the intermediate shaft support bearing on the right shaft feels fine as well.

I really thought it was a driveshaft joint, since I had them out for the clurch and could have made a mistake refitting. I even spun the wheels with the engine when off the ground and locked the steering each way. There was of course ESP/ABS noise, but when applying the footbrake lightly this went away and I couldn't hear anything else. One thing I noticed when doing this is that the driveshafts both wobble a bit whilst turning - not in that there is any play in the joints, but the shafts do not rotate around an exactly fixed axis. Is that normal?

Any other ideas what the mystery growl might be? I think it's getting louder...

Help much appreciated!

[metalworker0]

The only thing i can think of is the gearbox bearings ...you've disturbed these by doing the clutch ..how hard was it to get the drive shafts out or back in ,..did you hammer on them
Right slap bang in the middle between the two drive shafts in the gearbox is the differential.This slows down and speeds up the drive shafts according to which way you are turning , and is supported by the two bearings that the drive shafts enter....i mention this because your problems come when turning.
Could be that you van has a hell of a mileage ..and just disturbing these bearings caused the problem.

They also have lock rings on the shafts ..these can get damaged during installation. There is a video on YouTube were the guy had a hell of a job getting the shaft out ..and undid the universal coupling and left the shaft in place before he dropped the box out..later he explained ..that he should have knocked the shaft out with a bar from the other side.

So if you struggled and hammered ..you may have damaged these bearings, or you have a high millage and disturbing the bearings was all that was needed to finish them.

RIGHT about 1995 - 2008 some cars gearboxes were fitted with inferior bearings that had plastic races in them ..don't know if the transit connect gearboxes had these ..they suffer when the oil degrades the plastic after so many years. the plastic becomes brittle and breaks ..shocks to them (as in installing drive shafts) would also break them when they have become brittle.

But it could be another problem ..let others answer before you make your mind up.

all the best.mark

[metalworker0]

Just looked up the gearbox its an mtx75 and they look like they are built like a brick outhouse inside, taper roller bearings throughout ..and according to the net good for 250,000

[YRob]

Thanks for that Mark. It's a possibility I'll think about.

The van has 133k km (83k miles). Don't ask me why I've ended up replacing the clutch so early... In fact the previous owner did it once already at 100k km!

I did have a little difficulty getting the left driveshaft out, but managed it after a while using a lever between the cup and gearbox housing as suggested by Haynes. Getting it back in again was also a bit difficult, and I tried tapping it lightly, but in the end it went in and locked. I can't quite remember but I think it went with a bit of "shugging" the joint into the cup.

I forgot to say in my original post that I took the left driveshaft out of the wheel again to investigate, as I noticed a bit of play (maybe 1-2mm) between the cup and gearbox and thought this might somehow cause noise in the joints if the shaft is sliding in and out of the bearing slightly and altering the distances during steering. I had the thought that the retaining circlip at the gearbox end might have broken and was causing problems (I think I've seen the same video you mention, which made me aware of it). However the shaft was firmly locked in into the bearing. Seeing that, I didn't want to take it out again and have to deal with losing oil and topping it up.

I may take it to a mechanic to get it checked, but I suspect they will just replace each of the things I'm trying to rule out until the sound goes away - a valid yet expensive approach, especially here in Norway.

Might also try fixing that sticking rear left drum, and trying the spare on the rear right which has what I think is called "cupping"... But it really sounds like the sound is coming from in front of me (left hand drive).

Cheers

[YRob]

I've just had a feel around where the left driveshaft enters the gearbox bearings. Before I noticed there was some in and out movement, but heard that a little of that is normal. Now after rattling the driveshaft around a lot I think there's a bit of movement side to side where it enters the bearing - normal or not? I can also get a little rattle in the inner driveshaft joint - not when I rotate it, but if I jiggle side to side. I can feel that on the right side too, but maybe not as much.

I'm thinking I'll investigate further... Maybe take it out and try to feel the bearing?

[metalworker0]

Take it back to the tyre depot ..and see if they will balance your wheels again

[YRob]

I really don't think it's a wheel balancing issue. As I said before the droning was the same before and after replacing the front tyres, but was there with slightly less right steering angle after decreasing the toe.

After more jiggling of the left driveshaft I think it's either the inner CV joint or movement between the driveshaft and gearbox bearing. I can feel side to side play in both of those interfaces when the wheels are steered right and the shaft is pulled outwards by the wheel, but that movement is not there with the wheels facing left. I presume the driveshaft is then pressed inwards and the amount of play is reduced, and the noise goes away.

Couple of questions:

is some side to side play normal where the driveshaft enters the gearbox? If so I will go ahead and replace the CV joint. If not I need to decide if it's a gearbox bearing problem.

Is there usually a little gap between the CV joint cup and the gearbox? I'm pretty sure it was tight and not moving when I took it off - now it's secure but jiggles back and forth a bit.

Also, can I get away with driving for a while if it's a gearbox bearing problem?

Thanks in advance!

[metalworker0]

Fore and aft play yes ..it will pull out a little and push in a little ..as much as 1/4 inch until the lock ring stops it. in the gearbox.

Never had a CV joint go like you say ...they usually knock whilst performing tight turns ........you still have the genuine ford ones ...at that low mileage . (85,000)
The ones you are going to replace them with, because fords price will probably be nuts , will not be genuine ford and could have covered a lot of miles, with the conditioner just re-placing the hub end with Chinese junk and not the inner joint and then fitting cheap and nasty perishable rubber gators ..and giving them a splash of paint .
Unless you go Delphi, then you'll get a proper drive shaft...last time i bought two of them they were £150 per side exchange with Delphi ...16 years ago.

all the best..mark

[metalworker0]

just realised after a post just made that there is a carrier bearing on the drivers side ..it could well be this that is causing problems ..sorry new to transits ..did not even know it had one ..my info was based on other cars that did not have one of these .

it's a £20 part

all the best.mark

[YRob]

Thanks Mark.

Yes, I know about the carrier bearing but don't think it's that.

I now have a slight clunk in the steering which could be either associated wear or the actual problem becoming clearer. I'll check the inner tie rods with front jacked up, then with outer ball joints detached from hub if still not clear... But maybe the clunk is where the steering column enters the rack - what is actually there? (Doesn't seem like it's the universal joint you can see from the footwell - I had my head and hand in there while turning the wheel).

[YRob]

just realised after a post just made that there is a carrier bearing on the drivers side ..it could well be this that is causing problems ..sorry new to transits ..did not even know it had one ..my info was based on other cars that did not have one of these .

it's a £20 part

all the best.mark

Oh yes, that would be on the driver's side, but not in my case as it's left hand drive. Nonetheless the source of the noise could be deceptive!

[metalworker0]

Thanks Mark.

Yes, I know about the carrier bearing but don't think it's that.

I now have a slight clunk in the steering which could be either associated wear or the actual problem becoming clearer. Will check the inner tie rods first.

Do you know if you can replace the inner tie rods without removing the control arm, or would you need one of those special tools?

Tie rods ..just done mine . very easy job ..but you need a 12 inch stiltsen ..which is the only tool suitable for the job, use any other tool and it becomes a hard job - control arms and rest stay in place.

but ..cant think why you are blaming these, as you said it was road speed related ..therefor it is a rotating part that is to blame.
..unless the noise you are hearing is coming from the power steering pump ?!?

Another thing that can happen depending how gentle or hard you were when pulling it all apart and assembling the various parts when you did the clutch.

This can result in "brinelling" of the bearings ...hammering , WALLOPING when you took it apart or assembled..can cause the balls in the ball bearings to impact the races...causing depressions...that accelerate wear .

https://www.linearmotiontips.com/how-be ... rinelling/

They would have no play at the beginning ..but there will be noise ......and it will steadily get worse until you do get play then bearing failure

[YRob]

but ..cant think why you are blaming these, as you said it was road speed related ..therefor it is a rotating part that is to blame.

I thought maybe any slight imbalance in the wheels could generate a roadspeed related knock in the inner ball-joint - whichever one has less force holding it in place while turning right. With the wheels on the ground at a standstill, I can push the steering left and release with no sound, but it clunks when I release it after pushing right. I'm thinking that could be the left ball-joint reseating after being pushed out. All highly theoretical.

Re: "brinelling"... What's to be done if this is gearbox bearing damage? Replace gearbox?

[metalworker0]

I'm confused now ..first you said it was a growl, now a knock.

if it's a knock .....its the a CV joint

Unlikely that gerarbox bearings are brinelled as they are taper roller bearings.

There again, i don't know how much walloping you've given them or how hard

[YRob]

It's a growl/drone at speed, but a regular thud (not quite the right word, but something like a helicopter noise) at slower speeds before it's not discernable below 20 or 30 kph.

I think I was pretty gentle putting the driveshafts back in, compared to what I've seen on YouTube anyway.

Just had the front up, rocking the wheels etc with an assistant on the steering wheel. Seems like the clunk I mentioned is in the middle of the steering rack, not the track rods. You mentioned the power steering pump?

I am just about ready to throw in the towel and take it to a mechanic - the noise is concerning... or else I just start replacing things in order of likelihood. Thanks for all the ideas... maybe I'm just not experienced enough to detect the fault.