Went from 35's to 37's, feels like it wants to go offroad on its own over bumps?

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area51-s4

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Forgive my ignorance on jeep things and diagnosing, im still kinda new to jeeps and jeep upgrading.

I live near some really shitty paved streets and a highway or two that has stretches of bumps and more shitty paving. Currently have an AEV 2.5in lift and last wednesday I went from 35s to 37s (37x13.50, nitto ridge grappler), keeping my fuel wheels (20x10). This friday I drop the jeep off to get a big brake kit, new balljoints, regearing (i think im gonna go with 4:88), and a suspension check (i got the AEV kit last september).

Anyway, so when I had 35s, going over bumps on local roads and highways was pretty rough before I got the AEV kit. Getting a fox steering stabilizer when I got the AEV kit last september helped a bit with general highway driving but going over even small bumps was a pain as the weather got colder (feels like the same ride before the AEV kit now - because of the cold i was told). I ended up airing down from 37 to 30psi, not much difference.

So now that I put 37s on last wednesday, bumps arent just painful, it feels like the steering wants to get away from me as if the tires would rather follow the contours of the bumps, pulling left and right going over them. At 30mph+ and highway speeds, this does not feel fun. I have to have both hands on the wheel kung fu grip style when im going over any series of bumps at 30+mph. When I had the 35s this was an issue but now its WAY more an issue.

What are some thing I need to investigate / diagnose / switch / replace / buy / hit my head over regarding this specific issue?

Thanks in advance!
 
BLACKJKU said:
Is that using the chalk test to figure out that pressure?
Click to expand...

No, actually it was what the truck shop filled it to when i put on the 37s.

After I posted this thread I did some more research and found that others with the same tires have had the same issues. Also being a hybrid mud its gonna ride rougher than the all season 35s I had. In other news I ended up dropping the psi to 28, and its a noticeable difference in a good way. When I go over bumps my jeep makes all sorts of interior noises where i think the damn thing is falling apart, and i just chalk it up to it being old (10 yrs) and very used (160k miles). When I had the 37s at 34psi the car really felt like it was about to split in half. Now at 28psi not so much. In fact, the handling is better, and bumps are more manageable when it comes to steering.

I read somewhere the chalk test doesnt account for load or something. Is that have anything to do with frequency of passengers or the weight of them or what?
 
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area51-s4 said:
No, actually it was what the truck shop filled it to when i put on the 37s.

After I posted this thread I did some more research and found that others with the same tires have had the same issues. Also being a hybrid mud its gonna ride rougher than the all season 35s I had. In other news I ended up dropping the psi to 28, and its a noticeable difference in a good way. When I go over bumps my jeep makes all sorts of interior noises where i think the damn thing is falling apart, and i just chalk it up to it being old (10 yrs) and very used (160k miles). When I had the 37s at 34psi the car really felt like it was about to split in half. Now at 28psi not so much. In fact, the handling is better, and bumps are more manageable when it comes to steering.

I read somewhere the chalk test doesnt account for load or something. Is that have anything to do with frequency of passengers or the weight of them or what?
Click to expand...


No the chalk test is for the load that's on it when you do it.
 
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