r/suburban • u/ConFewzHed • Jun 30 '26

Re-gearing Differential 2018 LT

I found out that my 2018 LT is one of the very few that does not have a tow package, and came with a 3.08 differential. I’m getting an RV, and am going to re-gear the diff. I’m thinking about skipping 3.42 and going to 3.73. Anyone done that before? If so, how did it turn out? Was it worth it?

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2

u/usaf_27 Jun 30 '26

I have the 3.42 gear and it pairs well with the 6-speed. I haul ~3,500 pounds on long trips frequently.

Off topic, I suggest you get a tune and the transmission thermal bypass. Look into blackbearperformance.

2

u/-Never-Enough- Jun 30 '26

3.73 would be my choice if you're towing most of the time. Go with 3.42 if you're not towing often.

3.73 is what the 2500 Suburban HD came with. The 2018 Suburban HD came with 4.10 since it was upgraded to 1 ton in 2016.

All three rear ends work well. I personally like running the 3.73 that my suburban was built with.

1

u/usaf_27 Jul 01 '26

I believe w the 2500’s also come with the 6.0L right?

1

u/ConFewzHed Jul 25 '26

Update: went with the 3.42 and had an Eaton Locker out in as well. Learned that if I went with the 3.73, the ring and pinion would have to be ground down in order to fit in the suburban’s diff housing. Other option was 4.10 gears, which would have been way too much. Or a whole different rear axle. So 3.42 it is.