I have two different brands of car seats and I have the same problem. Sometimes when I pull the strap to tighten the harness only one side tightens really well.

One side will be very tight, probably too tight (in the shoulder area) and I can fit my hand under the other shoulder. If I pull the strap tighter it just tightens the side that is already tight. It doesn't happen all the time but when it does it's very frustrating. I find it happens more with Cameron's seat (he's rear facing) than it does with Matthew's seat.

I don't understand why it only happens sometimes.

By Trina~moderator on Wednesday, October 18, 2006 - 11:50 am:

Check to be sure the harness is threaded correctly and is not caught on something. I've had it happen also, but it's usually not hard to fix. Sometimes there may be a fold or kink in a strap that makes it not adjust smoothly and/or evenly. Try loosening the harness by pulling on both shoulder straps at the same time and then try to tighten again. What car seats are they?

By Heaventree on Wednesday, October 18, 2006 - 12:36 pm:

The one I'm currently using is the Britax Marathon, it's brand new, not sure of the model number. It could be that DH just reinstalled it on the weekend, I'll get him to check it when he gets home. The other car seat was the Alpha Omega Eddie Bauer seat, had the same problem but it was so bad I bought two new Britax seats.

I do try to loosen and tighten again, it doesn't always work, don't why I have such bad luck with car seats. I will try checking the straps next time.

Thanks Trina!