Rear seat back noise knocking over bumps

C-Mack · Aug 22, 2024

Trying to track down an intermittent heavy sounding knocking noise in rear area of my Grenadier when going over sharp bumps I noticed the hinge point at the bottom of split fold down rear seats has extra play in it. With the seats upright and locked you can hit the smaller of the two seat backs near the top where they split and you can hear the heavy knocking. Seems to be the hinge point between the two seat backs has extra play on the smaller seat back side. The larger split down seat back seems nice and solid but not the smaller. It’s as if there is extra play at the pivot mount and you can feel the pin knock inside the pivot bushing. I don’t see an easy way to tighten or fix this as it appears to be all internal to the hinge. Anyone else had this issue?

CRH · Aug 22, 2024

C-Mack said:
Trying to track down an intermittent heavy sounding knocking noise in rear area of my Grenadier when going over sharp bumps I noticed the hinge point at the bottom of split fold down rear seats has extra play in it. With the seats upright and locked you can hit the smaller of the two seat backs near the top where they split and you can hear the heavy knocking. Seems to be the hinge point between the two seat backs has extra play on the smaller seat back side. The larger split down seat back seems nice and solid but not the smaller. It’s as if there is extra play at the pivot mount and you can feel the pin knock inside the pivot bushing. I don’t see an easy way to tighten or fix this as it appears to be all internal to the hinge. Anyone else had this issue?

Try pulling at top of large rear door with smaller open, mine wasn't catching on the latch and would make loud knocking noise. Improved after adjusting

C-Mack · Aug 22, 2024

Thanks, I’ve checked the rear doors all is solid with no movement. I’m talking about the upper part of the rear seats where they are hinged at the bottom of the cargo floor and fold forward. There is a big metal bracket between where the seats splits that contains the pivot points for the the left hand and right hand seat backs. The wider seat back pivot point is solid when the seat is up and locked. However, the pivot point for the small seat back going into the bracket has extra play and you can hear solid metal on metal contact. When the smaller seat back is up and locked and you thump your hand on the back of it to simulate road vibration you can hear the pin inside the bracket make solid contact. Sounds like hitting the floor of the cargo area with a ball peen hammer a solid knock noise. If someone is sitting in the seat no noise but when the seat is unoccupied the seat back bounces slightly as you are going down the road and on sharp bumps it makes the knocking ball peen hammer noise. This is a brand new vehicle with less than 200 miles on it so it’s a bit frustrating.

C-Mack · Aug 22, 2024

Here is the sound it is making.

AJH · Aug 23, 2024

C-Mack said:
Trying to track down an intermittent heavy sounding knocking noise in rear area of my Grenadier when going over sharp bumps I noticed the hinge point at the bottom of split fold down rear seats has extra play in it. With the seats upright and locked you can hit the smaller of the two seat backs near the top where they split and you can hear the heavy knocking. Seems to be the hinge point between the two seat backs has extra play on the smaller seat back side. The larger split down seat back seems nice and solid but not the smaller. It’s as if there is extra play at the pivot mount and you can feel the pin knock inside the pivot bushing. I don’t see an easy way to tighten or fix this as it appears to be all internal to the hinge. Anyone else had this issue?

I had same issue. Dealer replaced seat. Sorted. I had to send a video of problem to Ineos/dealer with sound.

grnamin · Aug 23, 2024

If not yet 100% confirmed, I'd fold down the seat backs and drive around rough roads to see if sound persists. I have a similar issue and will test.

C-Mack · Aug 23, 2024

I think I’ve found the issue. There are two small white plastic bushings on the smaller seat back pivots points. One of them (the one in located between the two seat backs was broken. Brand new vehicle with just a couple hundred miles on it so I can only assume an assembly issue? Now the real challenge begins how to find replacements??? Included a few shots of both pivot points of the smaller seat back. Kinda shocked at how fragile these parts are and most likely will fail at some point in the future for folks folding their seats up and down regularly.

anand · Aug 23, 2024

C-Mack said:
Now the real challenge begins how to find replacements???

This is the easiest answer.... Have it replaced under warranty

Tom109 · Aug 23, 2024

grnamin said:
If not yet 100% confirmed, I'd fold down the seat backs and drive around rough roads to see if sound persists. I have a similar issue and will test.

Me too. I though it was the spare tire cover, but it was still there after I removed it.

Tom109 · Aug 25, 2024

I adjusted a little play in my larger rear door catch, broke one of the tabs on the cover in the process

I rotated the tires, so I left the wheel cover off too. We’ll see if there is any change.

C-Mack · Sep 10, 2024

Update on my rattling rear seat back. I was never able to get a replacement plastic bushing from the dealer, rather disappointed in their lack of follow up on the issue after showing them the defective part. I ended up making a new plastic sleeve out of Delrin plastic bushing material. I carefully turned it down to dimensions (required a bit of measuring and test fitting) that fit over the seat back pivot pin and inside the seat back itself. It turned out perfect and took all the play and knocking noise away.

Seat folds up and down with no resistance just like before. My guess is either the seat base/frame that contains the pivot point was made undersized or the hole in the seat back where the OEM bushing is supposed to fit was drilled out slightly oversized during manufacturing allowing excessive slop between the assemblies. Either way, it’s fixed now and the bushing I made is wider and offers more support at the seat pivot pin for the seat back and is rock solid.

parb · Sep 10, 2024

Put the dimensions to the diy part of the forum. This sounds like something we should be able to 3d print easily

NotHerDecision · Sep 10, 2024

C-Mack said:
Update on my rattling rear seat back. I was never able to get a replacement plastic bushing from the dealer, rather disappointed in their lack of follow up on the issue after showing them the defective part. I ended up making a new plastic sleeve out of Delrin plastic bushing material. I carefully turned it down to dimensions (required a bit of measuring and test fitting) that fit over the seat back pivot pin and inside the seat back itself. It turned out perfect and took all the play and knocking noise away.

Seat folds up and down with no resistance just like before. My guess is either the seat base/frame that contains the pivot point was made undersized or the hole in the seat back where the OEM bushing is supposed to fit was drilled out slightly oversized during manufacturing allowing excessive slop between the assemblies. Either way, it’s fixed now and the bushing I made is wider and offers more support at the seat pivot pin for the seat back and is rock solid.

I need the same. Would you sell me the parts?

anand · Sep 10, 2024

C-Mack said:
Update on my rattling rear seat back. I was never able to get a replacement plastic bushing from the dealer, rather disappointed in their lack of follow up on the issue after showing them the defective part.

So you took the vehicle to the dealer and they refused to fix it, or you were looking for them to send you a part?

C-Mack · Sep 11, 2024

anand said:
So you took the vehicle to the dealer and they refused to fix it, or you were looking for them to send you a part?

It’s a 200 mile round trip to the dealer and I wanted them to send me the part as I already had the rear seat apart and it would literally have taken 20 minutes to install. Also, my concern was there still would have been a tolerance issue with the replacement part and I wanted the whole assembly to fit together without an slop (knocking sound) so the only way to do that was make my own.

C-Mack · Sep 11, 2024

parb said:
Put the dimensions to the diy part of the forum. This sounds like something we should be able to 3d print easily

Rough dimensions on the sleeve I made were about 22mm OD and 20.5mm ID and about 15mm in width. It will vary from vehicle to vehicle depending on how the seat back components were manufactured. It’s sort of a test fit and retest fit scenario so you get the tolerance just right. Once done you should have no vertical movement between pivot pin and hole in the seat back where the pin is inserted. It’s a fiddly job but much better result than fitting the OEM bushing which would not have taken up the tolerance in the parts completely and leave me with the seat back knocking over bumps again.

Here is the Delrin tubing/bushing stock I used:

McMaster-Carr

McMaster-Carr is the complete source for your plant with over 595,000 products. 98% of products ordered ship from stock and deliver same or next day.

www.mcmaster.com

I believe I stared with the 7/8” OD 3/4” ID stock and machined it from there to get tight fitment I needed.

C-Mack · Sep 11, 2024

Here is a couple of pictures of what you are trying to make, just a basic plastic sleeve to fit over the pivot pin and inside the seat back to take up the tolerance. Delrin is very smooth and friction free so it’s perfect for a bushing like this.

The other two pictures are the pivot pin located between the two seat backs which your new sleeve will fit over and the hole in the seat back where your new bushing will fit in. Measure your parts then machine the sleeve to fit with zero free-play. I light interference fit is all that is needed. (Ignore the broken OEM bushing in the last two photos as this is the part you’ll be doing away with.

The pin/bushing on door side of the seat should be fine and has a torx screw holding the bushing in and the seat back from moving laterally. If you are having problems with that bushing you can make another sleeve for it but it will need to be considerably narrower maybe around 5mm wide. Mine was fine so I reused OEM one as it was only the pin between the two seat backs that had the loose knocking noise.

grenadierboy · Sep 14, 2024

Since I took delivery exactly 1 year ago - I have been putting up with what I thought was a persistent knock type rattle from my camp table when driving over potholes in the road.

I tried everything - inserting felt & foam into every metal surface on the table.

Today I completely removed it - and - still this bloody rattle.

So I test every other surface in the rear cargo area by trying to find something slightly loose.

I found that I can move the bottom left side of the smaller split rear seat back & forth 2-3mm on the mounting pin - and it makes exactly "the" knocking/rattle sound I have put up with since I took delivery - exactly as C-Mack mentions above. The larger rear seat has no movement at all.

I could potentially fix it myself but I will call the agent.

Has anyone in Australia had similar problem and how was it fixed?

C-Mack · Sep 16, 2024

grenadierboy said:
Since I took delivery exactly 1 year ago - I have been putting up with what I thought was a persistent knock type rattle from my camp table when driving over potholes in the road.

I tried everything - inserting felt & foam into every metal surface on the table.

Today I completely removed it - and - still this bloody rattle.

So I test every other surface in the rear cargo area by trying to find something slightly loose.

I found that I can move the bottom left side of the smaller split rear seat back & forth 2-3mm on the mounting pin - and it makes exactly "the" knocking/rattle sound I have put up with since I took delivery - exactly as C-Mack mentions above. The larger rear seat has no movement at all.

I could potentially fix it myself but I will call the agent.

Has anyone in Australia had similar problem and how was it fixed?

Yup, that was exactly the symptoms I had and only discovered it once I realized the noise disappeared when someone sat in the right rear seat and had their weight and back pushing up against the smaller seat back. If I was running with no rear passengers then it rattled/knocked again. Making my own sleeve to take out the extra tolerance at the pivot pin was an easy fix. I doubt a new OEM plastic bushing would have solved the issue and I didn’t fancy 200 mile round trips to the dealer to have them potentially miss-diagnose it requiring multiple trips back. It’s still rattle free as I type this not a knock or rattle from it now.

Most likely if the dealer was to fix it they would replace the entire lower seat frame which includes the pivot pin as it’s all one assembly. Not a big job but it would require taking out the entire rear seat and transferring over the lower seat squabs and seat backs. If the problem was with the smaller seat back itself and the hole that rests on the pivot was loose then most likely they’d replace the entire rear seat as a whole. The only concern with that would be if there is no part number change or updated part to specifically address the pivot pin tolerance issue then the noise has the potential to come back I would assume.

grenadierboy · Sep 17, 2024

C-Mack said:
Yup, that was exactly the symptoms I had and only discovered it once I realized the noise disappeared when someone sat in the right rear seat and had their weight and back pushing up against the smaller seat back. If I was running with no rear passengers then it rattled/knocked again. Making my own sleeve to take out the extra tolerance at the pivot pin was an easy fix. I doubt a new OEM plastic bushing would have solved the issue and I didn’t fancy 200 mile round trips to the dealer to have them potentially miss-diagnose it requiring multiple trips back. It’s still rattle free as I type this not a knock or rattle from it now.

Most likely if the dealer was to fix it they would replace the entire lower seat frame which includes the pivot pin as it’s all one assembly. Not a big job but it would require taking out the entire rear seat and transferring over the lower seat squabs and seat backs. If the problem was with the smaller seat back itself and the hole that rests on the pivot was loose then most likely they’d replace the entire rear seat as a whole. The only concern with that would be if there is no part number change or updated part to specifically address the pivot pin tolerance issue then the noise has the potential to come back I would assume.

Thanks for the expalination C-Mack.

Are you saying that the bushing you made & inserted has less tolerance (i.e. a tighter fit) around the pivot arm than the OEM bushing?

I called my agent yesterday (only 10km away) and explained the problem.

They asked me to bring the car in today for their service manager to assess problem and assess what parts are needed to fix under warranty.

Let's see what they do.

cheers

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