Question Tether Anchor Kit

U

Unregistered

Guest
I have a 98 Buick Century and the seat belt buckle position requires a rear tether strap to be safely installed using belts as there is no LATCH system. Our local police department child seat inspector confirmed we would be okay with a rear tether. We've confirmed with the dealer that the discontinued Buick anchor kit is not in stock anywhere in the country. They will install a generic anchor through.

So I am trying to determine what anchor to purchase to ensure proper safety. I have a Graco My Size 70. I found a website that says E-Z-On Products, Snug Seat and Safety Angel all have tether anchors - I'm about to check each of these out as well.

Thank you!
 
ADS

aeormsby

New member
How old/big is the child? Can you use the Myride rear-facing until you get the tether situation figured out? (or if you're just moving from an infant seat to the Myride keeping the child RF until at least age 2-3 is the safest anyway).

I would trust the EZ-On tether, those products are recommend here on occasion (the harnesses). It needs to be installed correctly in the same way the Buick tether would have been.
 

Pixels

New member
You should be aware that any tether anchor you could procure would not be approved by Buick or Graco. You would be going against the manufacturer's recommendations.
 

murphydog77

Admin - CPST Instructor
Staff member
I read through the '98 Century manual and didn't see anything anywhere where it's required that a top tether be used. Carseats are tested with a lap-only seat belt and are not required to have a top tether. We do recommend that tethers be attached whenever possible because they greatly reduce head excursion and the possibility that a child will come into contact with the interior of a vehicle during a crash, but it's not mandatory in the US.

Since tether use is mandatory in Canada, you may have more luck finding a tether kit from a Canadian dealership, but I wouldn't get my hopes up. At this point, an E-Z-On tether kit installed professionally by someone who has installed them before may be your best bet.
 

Dillipop

Well-known member
You should be aware that any tether anchor you could procure would not be approved by Buick or Graco. You would be going against the manufacturer's recommendations.

Even if her Buick dealership has agreed to install the aftermarket tether as above?

This is something that is going to come up a bit now. It's been Lin enough that factory made parts are no no her available and famines will need to make the decision to use other anchors. Before retrofits were available, there were generic anchors and I can't imagine that they would work any differently than car specific ones.
 

Pixels

New member
The dealer has agreed to add something to the vehicle at the owner's request. That does not mean it has been approved by Buick corporate.

It's kind of like paying the dealer to install an aftermarket stereo. Buick corp has not said that stereo is approved for the vehicle. If the vehicle was still in warranty, the aftermarket stereo could void the warranty on the electrical system.

The difference is we are talking about a safety device, not a stereo.
 

TechnoGranola

Forum Ambassador
Maybe I'm coming from a different point of view because tethering had been mandatory here for a long time...but back when my oldest was little, my cars didn't come standard with top tethers ('89, '91, and '02). The anchor locations existed but there was no anchor. Child seats came with the anchor. And you could buy anchors at Canadian Tire and Walmart. Those anchors didn't specify a specific torque or have a specific bolt thread for your vehicle either.

You may have been able to order an anchor from your manufacturer, but no one did as why would you when the child's seat came WITH an anchor for you to use? I don't recall there ever being a warning about not using the included anchors or if you were off by a foot pound that something was going to explode, or kids dying left, right and centre because of tether anchors snapping and becoming projectiles or increased head excursion.

Once vehicle started having tether anchors from factory, child seats stopped coming with them.

If there are a few companies out there that make tether anchors they've done some testing with, and the vehicle had a designated spot for an anchor already (and a vehicle of that year should, right?), I'd think that anchor screwed in as per directions and using it has to be better than no top tether.
 

Pixels

New member
Since it is going against the directions of the manufacturers (Buick, Graco, and E-Z On, if that's the anchor selected), that is a decision that must be made by the care giver. I can not make that decision for anyone else.
 

TechnoGranola

Forum Ambassador
Since it is going against the directions of the manufacturers (Buick, Graco, and E-Z On, if that's the anchor selected), that is a decision that must be made by the care giver. I can not make that decision for anyone else.

I guess I don't get what you're saying. You think it's safer for the OP to use no tether anchor than to add one on? I'm not agreeing or disagreeing, I'm just trying to figure out what your suggestion is. Or were you just providing info but no solutions?

And sorry, why is this against EZ on instructions? I thought they made heavy duty tether anchors for this purpose. Or they don't do that anymore and only make them explicitly for their vests?
 

Pixels

New member
Providing information only. :)

E-Z On only allows their heavy dirty tether anchors to be used with their products, not with those made by any other manufacturer.
 

Kecia

Admin - CPST Instructor
Since the vehicle-specific anchor isn't available anymore you can definitely use a generic tether anchor BUT you need to find one that fits the pre-drilled tether anchor holes in your vehicle. The problem with using Britax or Dorel generic anchors (and I don't think they are available anymore anyway so it's probably not even an option) is that there are the wrong bolt size - they are 5/16 inch bolts. Most likely you need a 8mm metric bolt.

If you can track down a generic tether anchor with an 8mm bolt then you'll be golden. The heavy duty bolts sold by Snug Seat and EZ-On are too big to fit in the factory installed pre-drilled holes because they are 7/16 inch bolts.

http://www.saferidenews.com/srndnn/LinkClick.aspx?fileticket=ifRDwrcdGns=&tabid=173 Page 6

Correct bolt size for a weld-nut

It is very important to have the correct size bolt for a tether anchor point with a pre-drilled hole and weld nut. Threading the wrong size bolt into a weld nut can ruin the tether anchor point! Bolt and nut sizes are typically either 8 mm or 5/16 inch. Bolts in many generic kits are 5/16 inch while nearly all weld nuts in vehicles are 8 mm. A bolt marked “8.8” is compatible with an 8-mm nut.

Good luck!
 

Keeanh

Well-known member
Kecia, you're amazing!! Wow, that's a great PDF. :D Would it be a good guess that Volvo also used an 8mm bolt? Friends of ours have a '92 sedan with only one anchor kit, but 3 weld-nuts.

I'm pretty sure an anchor kit with a 5/16 bolt could be used if you swapped out the bolt with an 8mm bolt from the hardware store.

Since it is going against the directions of the manufacturers (Buick, Graco, and E-Z On, if that's the anchor selected), that is a decision that must be made by the care giver. I can not make that decision for anyone else.

Actually, it's not against the car seat manual, as I'm reading it, and that's the one that matters. The manual doesn't specify using an approved or official tether anchor. All the manual will say is to attach the tether to "the anchor hardware", or something to that effect. So it doesn't really matter what Buick or EZ-on say about their anchors. The car seats are okay with a DIY tether. I'm also from the generation that had 80's - early '90s cars and DIY with the tether bolt that came with your car seat was all we had.
 

Kecia

Admin - CPST Instructor
Would it be a good guess that Volvo also used an 8mm bolt? Friends of ours have a '92 sedan with only one anchor kit, but 3 weld-nuts.

I'm pretty sure an anchor kit with a 5/16 bolt could be used if you swapped out the bolt with an 8mm bolt from the hardware store.

Thanks! I can't comment on swapping out the bolt because I have no idea if that's a good idea or even possible.

As for the Volvo retrofit parts - they vary by model and year. Some being 5/16 and others being 8mm. Hopefully Volvo isn't out of retrofit anchors too because owners really need to order the specific hardware for their specific Volvo model and model year. HTH!
 

ketchupqueen

CPST and ketchup snob
Staff member
EZ on does include instructions for drilling out and sealing the hole if making it larger is necessary, as I recall.

I'd expect other HDTA makers do too.
 

AustinMusic

Active member
It is very important to have the correct size bolt for a tether anchor point with a pre-drilled hole and weld nut. Threading the wrong size bolt into a weld nut can ruin the tether anchor point! Bolt and nut sizes are typically either 8 mm or 5/16 inch. Bolts in many generic kits are 5/16 inch while nearly all weld nuts in vehicles are 8 mm.

First, as Kecia has correctly made clear, to ensure safety using the correct bolt is critical. While I do not mean to complicate matters (nor write anything overly technical) I feel I should highlight some important aspects of selecting and fitting a tether anchor, particularly when modifications maybe involved. I myself only discovered such when installing the E-Z-On Heavy Duty Tether Anchors in our family vehicle.

(Please note - I can’t comment on issues regarding the approved compatibility of parts and vehicles – I will leave this to the far more knowledgeable members and CPSTs on the forum!)

To find the correct bolt to be used, the following must be addressed:

1) Diameter

This has been mentioned above. Simply put, the diameter of the bolt must match the diameter of the nut. This choice will nearly always be between imperial (inches) and metric (mm) sizes. Where car seat tether anchors are concerned, the most common sizes are 5/16 inch and 8mm sizes, respectively.

2) TPI (Threads Per Inch) / or “Pitch”

All bolts have a TPI measurement. In simple terms this informs of the fineness or coarseness of the thread. A high TPI means a finer thread, a lower a more coarse thread:

ThreadTPI_zps218fe27c.png


Importantly, the TPI of a bolt is not related to the diameter of a bolt. Any bolt can have any TPI. The TPI of the bolt must match the TPI of the nut. If it does not, and the bolt is tightened, the thread could be stripped. Without a thread, the bolt will not be secure. In the event of a crash, this could mean the bolt slips out of the nut resulting in the tether strap becoming detached from the vehicle.

3) Grade

In basic terms the grade is the quality of the bolt (and nut). The higher the grade, the better quality and thus, inherent strength of the bolt. The grade of a bolt is identified by markings on the bolt head (usually 4.6, 8.8 or 12.9 for metric bolts and a series of markings for imperial bolts – see this chart).

This is very important and relates directly to a couple of points already mentioned in some previous messages in this thread.

First, while I do not doubt the LATCH Manual supplement, I am surprised at the following comment as written in the pdf referenced in post #12:

"A bolt marked “8.8” is compatible with an 8-mm nut."

While a bolt marked “8.8” maybe compatible with an 8mm nut, these two aspects are not related for “8.8” relates to the grade of the bolt, not the size. Personally, I would disregard this comment – not because it is necessarily incorrect, but because it is somewhat misleading.

I'm pretty sure an anchor kit with a 5/16 bolt could be used if you swapped out the bolt with an 8mm bolt from the hardware store.

Second, for bolts which are to be used to secure tether anchors, I do not recommend purchasing bolts from hardware stores. Such bolts are often of a lower grade intended for use in applications far less demanding than a vehicle tether anchor. While they maybe strong enough, there is no way of telling unless they are marked. I would only recommend using bolts with the correct markings from a reputable supplier of vehicle parts or vehicle safety restraints.

4) Tightness

All critical bolts in vehicles, are tightened to a certain degree depending on their application. If a bolt is under-tightened it could work loose, if it is over-tightened it could shear or split. It is critical to tighten the bolt to the correct tightness to ensure performance of the bolt and thus, safety. Most manufacturers will specify this measurement and a torque wrench should be used to make sure the bolt is tightened correctly.


In short, choosing the correct bolt for the correct application is far more complicated than it may first appear! Most of the above are decided by the manufacturers (of the vehicle and/or the restraint) and the consumer rarely has a decision to make. However, in light of the original post, such factors may need to be researched and I would recommend these factors are considered with the utmost care – or the task given to a professional mechanic or company who can install the tether anchor to the correct specification.

I apologise if this has made matters too complicated, this was certainly not my intention, however I feel I should mention such aspects as they are critical to occupant safety.

If needed, I’d be happy to answer any questions regarding the above.:)
 

Brigala

CPST Instructor
I have no experience with Buick, but I will mention that before EZ-On changed their stance for the 2013 LATCH manual (they used to be OK with using their anchor as a generic retrofit) I installed one in an older Honda Accord and didn't have to make any modifications at all. It went right into the hole that was available for a factory retrofit. We chose to use the EZ-On for two reasons: One, it was cheaper, and Two, Honda at that time had a weight limit on all their anchors of 40 lbs child weight and the child it was intended for was over 40 lbs.

Although EZ-On has changed their stance, I have not gone back to that family member and told her to take out the anchor (it's no longer in use anyway since the child has since graduated to a booster, but regardless I still don't find it necessary to undo something that was done at a time when it was considered OK to do). I am confident that it is perfectly safe and, in fact, an improvement over the approved Honda anchor. It's really too bad that this option was removed and I can no longer recommend it. I actually asked EZ-On about it once, and they said the reason they changed it was "probably because people were using it for other car seats and not just our vests." Yeah, that was a clear answer, huh?

Snugseat is the only manufacturer (as of the 2013 LATCH manual) which still makes an aftermarket tether approved for generic use. But I don't know of anybody besides NMEDA installers who have access to order the part.
 

Car-Seat.Org Facebook Group

Forum statistics

Threads
219,656
Messages
2,196,896
Members
13,530
Latest member
onehitko860

You must read your carseat and vehicle owner’s manual and understand any relevant state laws. These are the rules you must follow to restrain your children safely. All opinions at Car-Seat.Org are those of the individual author for informational purposes only, and do not necessarily reflect any policy or position of Carseat Media LLC. Car-Seat.Org makes no representations as to accuracy, completeness, currentness, suitability, or validity of any information on this site and will not be liable for any errors, omissions, or delays in this information or any losses, injuries, or damages arising from its display or use. All information is provided on an as-is basis. If you are unsure about information provided to you, please visit a local certified technician. Before posting or using our website you must read and agree to our TERMS.

Graco is a Proud Sponsor of Car-Seat.Org! Britax is a Proud Sponsor of Car-Seat.Org! Nuna Baby is a Proud Sponsor of Car-Seat.Org!

Please  Support Car-Seat.Org  with your purchases of infant, convertible, combination and boosters seats from our premier sponsors above.
Shop travel systems, strollers and baby gear from Britax, Chicco, Clek, Combi, Evenflo, First Years, Graco, Maxi-Cosi, Nuna, Safety 1st, Diono & more! ©2001-2022 Carseat Media LLC

Top