Questions about Marathon with seatbelt installation in an Odyssey

[HIU8]

We have a 2006 Odyssey. We had to reconfigure our seats as my neice is staying with us for 5 days this week. Stats:

DS 3.5 yrs old and 33 lbs, rides FF in a Marathon
DN 2 yrs old and just about 33 lbs, rides FF in a Marathon
DD 11 months on Friday, 23 lbs, rides in a Safeseat

We have the two Marathons outboard in the third row. The one on the right installed pretty tight using the seatbelt. The one on the left is giving us issues. It took over 30 minutes to install that one and we still have a ton of movement at the front of the base (near the seat edge). No matter what we do, we cannot get the Marathon on the left to install as tightly as the one on the right. Plus, the one on the left always leans. Is a seatbelt installation a bit looser than LATCH? (DS's seat was installed in the 2nd row captains chair using LATCH, but we took the chair out to be able to get to the third row easier). Also, when I strap DS in and pull to tighten the harness, the entire seat moves forward and then retracts a little. Is this normal? Both Marathons are also top tethered to the tether on the seatback. What can we do to make the install tighter? I'm just not comfortable with the install as I am used to LATCH and how rock solid I can get it. Can two Marathons be installed next to one another, one with seatbelt and one with LATCH?

Thanks:wavey:

[Joolsplus2]

What usually helps is reclining the vehicle seatback, then installing (get weight in the seat, pull UP HARD on the shoulderbelt on the buckle side to get the lapbelt tight, then lock the shoulderbelt in the lockoff), do NOT switch the retractor, just use the shoulderbelt lockoff, and then pull the seatback upright again to really lock that seat in tight. Then top tether and tighten.
If you did that then...uh...er...um... I'll have a friend with a newer Ody chime in :)

[HIU8]

Julie,

We have the seatback reclined already b/c otherwise the base of the MA was way to forward. I didn't put the seatback upright again though. I will have to try the install doing that. Are you saying not to retract the shoulderbelt at all, just use the lockoff?