Constant rumbling and chattering driving me insane

[Rhi327]

I have two boys, we got T (he's about 10-11 months now) in February from a pet store, and A(they said he was 1-2 years old then) in March from a shelter.

I did the meeting outside the cage for hours with a ton of hay before putting them in the cage. I've taken them on car rides together, I've given them baths together, there's 2-3 of everything in the cage, their cage is 2x5 (I even tried 2x6 and no change)with two hay lofts, and they have a ton of toys that they won't even chew on, they just poop on them. They've been together for almost 9 months now and still acting like this.

T is constantly rumbling, chattering, and peeing on(?) A. Then A will chase T and mount him, T will squeal and run, but then go right back to rumbling, and repeat all day long. I have even got a cage divider and split the cage for a while and T would pee on A through the wires, and rumble and chatter from the other side.

It's driving me absolutely insane. I've done so much research on how to care for them, and things to try to help them bond, but nothing works. I wake up to T's rumbling all the time, and I already have insomnia (The only space for them is in my room.) I know T is in his teen phase, and I'm hoping he'll stop it when he's older.

But is there anything else I should try? because at this point, I can't stand them together. Alone they are great piggies and I love them. I don't want to just separate them because them being herd animals, and I don't have room for 2 more for each of them to bond with.

Please help me regain my sanity

 

[Piggies&buns]

A few points to pick up on.

Chew toys - most piggies will not use them. The only thing they need to chew is hay.

The behaviour.
This is normal boar behaviour and how they maintain their relationship. It’s something which goes on throughout the whole of their lives. It will lessen as they age - one of my pairs are about to turn 6 years old and I hadn’t heard them rumble for a few months now.
If they are not fighting, one is submitting and nobody is losing weight through actual bullying, then there may not be an issue between them at all.
Spraying pee is a strongly worded ‘stay away from me’ though.
A high pitched squeak is usually submission.

Taking them on car rides, bathing or separating them will not stop it if they are actually happy together.
Separating them if they have a happy bond will actually make things worse as they then reestablish their relationship every time you put them back together - more dominance.
The same with bathing - it temporarily changes their smells and can cause more issues. Bathing is not recommended unless there is a medical need to do so

However, it is also important to work out whether it goes beyond normal dominance (which is normal and nothing you can nor should you do anything about) or whether their relationship is actually dysfunctional.

If you separate them permanently because you’ve determined they don’t actually like each other and their bond is not working; then you are still likely to see the behaviours between the bars at least for a while, as that is also how they will patrol and mark their own territories. They will still continue to interact with each other through the bars at all times.
In the case of separation, you don’t need to bond them with more piggies, they just need to be side by side with each other to interact between the bars. You would need to increase the cage size though so each piggy had a minimum of a 2x3 cage but ideally a 2x4 each.
(You can’t split a 2x5 as each half is too small and doesn’t meet minimum requirements)

Bonds In Trouble
A Comprehensive Guide to Guinea Pig Boars
Boars: Teenage, Bullying, Fighting, Fall-outs And What Next?
Dominance Behaviours In Guinea Pigs
A - Z of Guinea Pig Behaviours